ABCMdb

ABCC7 p.Arg347Pro

Admin's notes:	Class II-III-VI (maturation defect, gating defect, reduced stability) Veit et al.
ClinVar:	c.1039C>T , p.Arg347Cys ? , not provided c.1040G>A , p.Arg347His D , Pathogenic c.1040G>T , p.Arg347Leu D , Pathogenic c.1040G>C , p.Arg347Pro D , Pathogenic
CF databases:	c.1040G>C , p.Arg347Pro D , CF-causing ; CFTR1: This mutation destroys a Hha I restriciton site and creates an NcoI site and occurred in a family diagnosed as PS. The mutation have been identified and analyzed using the SSCP technique. c.1040G>A , p.Arg347His D , CF-causing ; CFTR1: The patient is of Italian origin and carries the [delta]F508 mutation on the other chromosome. Initially we thought this was the same mutation as R347 because it destroys the same hhai site; however, R347H does not create the NcoI site. c.1040G>T , p.Arg347Leu (CFTR1) D , A nucleotide change, G->T at position 1172, was detected leading to R347L. The other chromosome carries a [delta]F508. This mutation was found on one chromosome among 150 CF chromosomes screened. c.1039C>T , p.Arg347Cys (CFTR1) ? , This mutation was identified by DGGE and direct sequencing.
Predicted by SNAP2:	A: D (95%), C: D (95%), D: D (95%), E: D (95%), F: D (95%), G: D (95%), H: D (71%), I: D (95%), K: D (95%), L: D (80%), M: D (95%), N: D (95%), P: D (75%), Q: D (95%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: N, C: D, D: D, E: N, F: D, G: D, H: N, I: D, K: N, L: N, M: N, N: N, P: N, Q: N, S: N, T: N, V: D, W: D, Y: D,

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II-III-VI (maturation defect, gating defect, reduced stability) <a href="https://www.ncbi.nlm.nih.gov/pubmed/26823392">Veit et al.</a>
admin on 2016-08-19 15:16:22

Publications
[hide] Insight in eukaryotic ABC transporter function by ... FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19. Frelet A, Klein M
Insight in eukaryotic ABC transporter function by mutation analysis.
FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19., 2006-02-13 [PMID:16442101]

Abstract [show]
With regard to structure-function relations of ATP-binding cassette (ABC) transporters several intriguing questions are in the spotlight of active research: Why do functional ABC transporters possess two ATP binding and hydrolysis domains together with two ABC signatures and to what extent are the individual nucleotide-binding domains independent or interacting? Where is the substrate-binding site and how is ATP hydrolysis functionally coupled to the transport process itself? Although much progress has been made in the elucidation of the three-dimensional structures of ABC transporters in the last years by several crystallographic studies including novel models for the nucleotide hydrolysis and translocation catalysis, site-directed mutagenesis as well as the identification of natural mutations is still a major tool to evaluate effects of individual amino acids on the overall function of ABC transporters. Apart from alterations in characteristic sequence such as Walker A, Walker B and the ABC signature other parts of ABC proteins were subject to detailed mutagenesis studies including the substrate-binding site or the regulatory domain of CFTR. In this review, we will give a detailed overview of the mutation analysis reported for selected ABC transporters of the ABCB and ABCC subfamilies, namely HsCFTR/ABCC7, HsSUR/ABCC8,9, HsMRP1/ABCC1, HsMRP2/ABCC2, ScYCF1 and P-glycoprotein (Pgp)/MDR1/ABCB1 and their effects on the function of each protein.

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398 R334W and R347P associated with mild clinical disease displayed altered single-channel properties [45]. Login to comment

[hide] Novel pharmacologic therapies for cystic fibrosis. J Clin Invest. 1999 Feb;103(4):447-52. Zeitlin PL
Novel pharmacologic therapies for cystic fibrosis.
J Clin Invest. 1999 Feb;103(4):447-52., [PMID:10021451]

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128 Class IV mutants such as R117H, G314E, R334W, and R347P are associated with normal PKA-dependent phosphorylation and ATP binding. Login to comment
131 R347P affects the rate of chloride flow, whereas R117H and P574H reduce the channel open time. Login to comment
133 Class IV mutations such as R117H, R334W, R347P, A455E, and P574H are associated with a pancreatic sufficient phenotype or late onset pancreatic insufficiency. Login to comment

[hide] Cystic fibrosis-associated mutations at arginine 3... J Biol Chem. 1999 Feb 26;274(9):5429-35. Cotten JF, Welsh MJ
Cystic fibrosis-associated mutations at arginine 347 alter the pore architecture of CFTR. Evidence for disruption of a salt bridge.
J Biol Chem. 1999 Feb 26;274(9):5429-35., 1999-02-26 [PMID:10026154]

Abstract [show]
Arginine 347 in the sixth transmembrane domain of cystic fibrosis transmembrane conductance regulator (CFTR) is a site of four cystic fibrosis-associated mutations. To better understand the function of Arg-347 and to learn how mutations at this site disrupt channel activity, we mutated Arg-347 to Asp, Cys, Glu, His, Leu, or Lys and examined single-channel function. Every Arg-347 mutation examined, except R347K, had a destabilizing effect on the pore, causing the channel to flutter between two conductance states. Chloride flow through the larger conductance state was similar to that of wild-type CFTR, suggesting that the residue at position 347 does not interact directly with permeating anions. We hypothesized that Arg-347 stabilizes the channel through an electrostatic interaction with an anionic residue in another transmembrane domain. To test this, we mutated anionic residues (Asp-924, Asp-993, and Glu-1104) to Arg in the context of either R347E or R347D mutations. Interestingly, the D924R mutation complemented R347D, yielding a channel that behaved like wild-type CFTR. These data suggest that Arg-347 plays an important structural role in CFTR, at least in part by forming a salt bridge with Asp-924; cystic fibrosis-associated mutations disrupt this interaction.

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12 At least four CF-associated mutations have been identified at position 347 in M6: R347C, R347H, R347L, and R347P, suggesting that Arg-347 is important for CFTR structure and function (13-15).2 Early studies by Sheppard et al. (7) showed that mutation of Arg-347 to proline significantly decreased single-channel conductance with little effect on CFTR trafficking to the plasma membrane. Login to comment
210 The Arg-347 residue is targeted by several CF-associated mutations, R347C, R347H, R347L, and R347P (13-15).2 Our data suggest that CF-associated as well as other mutations at residue 347 affect CFTR similarly. Login to comment

[hide] Proportion of cystic fibrosis gene mutations not d... JAMA. 1999 Jun 16;281(23):2217-24. Mak V, Zielenski J, Tsui LC, Durie P, Zini A, Martin S, Longley TB, Jarvi KA
Proportion of cystic fibrosis gene mutations not detected by routine testing in men with obstructive azoospermia.
JAMA. 1999 Jun 16;281(23):2217-24., 1999-06-16 [PMID:10376575]

Abstract [show]
CONTEXT: Infertile men with obstructive azoospermia may have mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, many of which are rare in classic cystic fibrosis and not evaluated in most routine mutation screening. OBJECTIVE: To assess how often CFTR mutations or sequence alterations undetected by routine screening are detected with more extensive screening in obstructive azoospermia. DESIGN: Routine screening for the 31 most common CFTR mutations associated with the CF phenotype in white populations, testing for the 5-thymidine variant of the polythymidine tract of intron 8 (IVS8-5T) by allele-specific oligonucleotide hybridization, and screening of all exons through multiplex heteroduplex shift analysis followed by direct DNA sequencing. SETTING: Male infertility clinic of a Canadian university-affiliated hospital. SUBJECTS: Of 198 men with obstructive (n = 149) or nonobstructive (n = 49; control group) azoospermia, 64 had congenital bilateral absence of the vas deferens (CBAVD), 10 had congenital unilateral absence of the vas deferens (CUAVD), and 75 had epididymal obstruction (56/75 were idiopathic). MAIN OUTCOME MEASURE: Frequency of mutations found by routine and nonroutine tests in men with obstructive vs nonobstructive azoospermia. RESULTS: Frequency of mutations and the IVS8-5T variant in the nonobstructive azoospermia group (controls) (2% and 5.1% allele frequency, respectively) did not differ significantly from that in the general population (2% and 5.2%, respectively). In the CBAVD group, 72 mutations were found by DNA sequencing and IVS8-5T testing (47 and 25, respectively; P<.001 and P = .002 vs controls) vs 39 by the routine panel (P<.001 vs controls). In the idiopathic epididymal obstruction group, 24 mutations were found by DNA sequencing and IVS8-5T testing (12 each; P=.01 and P=.14 vs controls) vs 5 by the routine panel (P=.33 vs controls). In the CUAVD group, 2 mutations were found by routine testing (P=.07 vs controls) vs 4 (2 each, respectively; P=.07 and P=.40 vs controls) by DNA sequencing and IVS8-5T testing. The routine panel did not identify 33 (46%) of 72, 2 (50%) of 4, and 19 (79%) of 24 detectable CFTR mutations and IVS8-5T in the CBAVD, CUAVD, and idiopathic epididymal obstruction groups, respectively. CONCLUSIONS: Routine testing for CFTR mutations may miss mild or rare gene alterations. The barrier to conception for men with obstructive infertility has been overcome by assisted reproductive technologies, thus raising the concern of iatrogenically transmitting pathogenic CFTR mutations to the progeny.

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28 Analysis for 31 of the most common CFTR mutations found within the white CF population,60 consisting of ⌬F508, W1282X, G542X, G551D, N1303K, R553X, G85E, R117H, S549N, V520F, R334W, A455E, R347P, R1162X, Y122X, S549R, 621+1G→T, ⌬I507, R560T, R347H, 3659delC, Q493X, 1898+1G→T, 711+1G→T, 3849+10C→T, 1717-1G→A, 3849+4A→G, 3905insT, 1078delT, 2183AA→G, and 2789+5G→A. Briefly, the technique involved amplification by polymerase chain reaction61 of the relevant exons, followed by digestion with appropriate restriction endonucleases and acrylamide gel electrophoresis with ethidium bromide staining. Login to comment
45 (%) Men With 2 Mutations ⌬F508/IVS8-5T 7 (11) ⌬F508/IVS8-5T 1 (10) ⌬F508/IVS8-5T 1 (1.8) ⌬F508/R117H 6 (9) W1282X/IVS8-5T 1 (1.8) ⌬F508/L206W 1 (1.6) G544S/IVS8-5T 1 (1.8) ⌬F508/M952T 1 (1.6) V754M/-741T→G 1 (1.8) ⌬F508/P67L 1 (1.6) R75Q/R258G 1 (1.8) ⌬F508/S549R 1 (1.6) R334W/R334W 1 (1.6) R117H/R117H 1 (1.6) R117H/IVS8-5T 1 (1.6) R347P/IVS8-5T 1 (1.6) N1303K/IVS8-5T 1 (1.6) 1677delTA/IVS8-5T 1 (1.6) R117L/IVS8-5T 1 (1.6) D979A/IVS8-5T 1 (1.6) IVS8-5T/IVS8-5T 1 (1.6) Men With 1 Mutation IVS8-5T/N 10 (16) ⌬F508/N 1 (10) IVS8-5T/N 9 (16) ⌬F508/N 1 (2) ⌬F508/N 6 (9) IVS8-5T/N 1 (10) ⌬F508/N 1 (1.8) G542X/N 1 (2) W1282X/N 2 (3) R75Q/N 1 (1.8) IVS8-5T/N 5 (10) L206W/N 1 (1.6) W1282X/N 1 (1.8) 4016insT/N 1 (1.6) R117H/N 1 (1.8) 2423delG/N 1 (1.8) Men With No Mutations 18 (28) 7 (70) 37 (66) 42 (86) *N indicates that no CFTR mutations or variants were detected. Login to comment
47 tion panel included W1282X (2 alleles), R334W (2 alleles), S549R (1 allele), R347P (1 allele), and N1303K (1 allele). Login to comment
58 (%) 31 Mutation panel† ⌬F508 23 (18) ⌬F508 2 (10) ⌬F508 2 (1.8) ⌬F508 1 (1) R117H 9 (7) W1282X 2 (1.8) G542X 1 (1) W1282X 2 (1.6) R117H 1 (0.9) R334W 2 (1.6) S549R 1 (0.8) R347P 1 (0.8) N1303K 1 (0.8) Extensive screen† ⌬F508 23 (18) ⌬F508 2 (10) ⌬F508 2 (1.8) ⌬F508 1Mutations included in R117H 9 (7) W1282X 2 (1.8) G542X 131 mutation panel W1282X 2 (1.6) R117H 1 (0.9) R334W 2 (1.6) S549R 1 (0.8) R347P 1 (0.8) N1303K 1 (0.8) L206W 2 (1.6)‡ R75Q 2 (1.8)‡Mutations not included in P67L 1 (0.8)‡ G544S 1 (0.9)‡31 mutation panel 1677delTA 1 (0.8)‡ 2423delG 1 (0.9)‡ R117L 1 (0.8)‡ V754M 1 (0.9)‡ 4016insT 1 (0.8)‡ -741T→G 1 (0.9)‡ D979A 1 (0.8)§ R258G 1 (0.9)§ M952T 1 (0.8)¶ IVS8-5T 25 (20)# 2 (10) 12 (11) 5 (5) Detectable mutations 72 (56)# 4 (20) 24 (21)# 7 (7) Detectable mutations missed by 31 mutation panel 33 (46) 2 (50) 19 (79) Detectable non-IVS8-5T mutations missed by 31 mutation panel 8 (17) 0 (0) 7 (58) *Percentages indicate allele frequency. Login to comment
85 These mild CFTR gene mutations are associated with pancreatic sufficiency and tend to be class 4 through 5 mutations: R117H, R334W, R347P, L206W,andP67L.Thethirdgroupcon- sists of mutations identified exclusively in some men with obstructive azoospermia; however, because these sequencealterationsareextremelyrare, it is only speculated that they contribute to this phenotype.7,10,12 These CFTR genesequencechangesincludeD979A, R258G, and M952T. Login to comment

[hide] Frequency of CFTR gene mutations in males particip... Hum Reprod. 1999 Jul;14(7):1833-4. Jakubiczka S, Bettecken T, Stumm M, Nickel I, Musebeck J, Krebs P, Fischer C, Kleinstein J, Wieacker P
Frequency of CFTR gene mutations in males participating in an ICSI programme.
Hum Reprod. 1999 Jul;14(7):1833-4., [PMID:10402399]

Abstract [show]
A higher prevalence of cystic fibrosis transmembrane regulator (CFTR) gene mutations has been suggested both in men affected by congenital aplasia of the vas deferens, and in individuals presenting with reduced sperm quality. In this case, an increased risk for offspring being affected by cystic fibrosis (CF) can be expected in couples who are planning to undergo intracytoplasmic sperm injection (ICSI), since most of the male partners suffer from infertility. In order to determine the risk for these couples more precisely, we offered them a test for the most frequent CF mutations prevalent in the German population. The frequency of mutations within the CFTR gene in the female group was in the same range as expected for the general population (six out of 150). In 10 out of 207 males tested, infertility could be explained by exogenous factors not related to CFTR. Among the remaining 197 males with idiopathic infertility, we detected 13 heterozygotes for a mutation within the CFTR gene. This slightly, but significantly (P = 0.014), elevated rate could indicate that infertile males have, compared with the general population, an increased risk of being a carrier of a CFTR gene mutation.

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13 Materials and methods CFTR screening included the most frequent CFTR mutations in the German population (R347P, ∆F508, G542X, S549I,N,R(A→C), G551D, R553X, N1303K, and 3849ϩ10kbC→T) (Do¨rk et al., 1994) as well as the mutation R117H and the analysis of the IVS8-T haplotype. Login to comment

[hide] Two buffer PAGE system-based SSCP/HD analysis: a g... Eur J Hum Genet. 1999 Jul;7(5):590-8. Liechti-Gallati S, Schneider V, Neeser D, Kraemer R
Two buffer PAGE system-based SSCP/HD analysis: a general protocol for rapid and sensitive mutation screening in cystic fibrosis and any other human genetic disease.
Eur J Hum Genet. 1999 Jul;7(5):590-8., [PMID:10439967]

Abstract [show]
The large size of many disease genes and the multiplicity of mutations complicate the design of an adequate assay for the identification of disease-causing variants. One of the most successful methods for mutation detection is the single strand conformation polymorphism (SSCP) technique. By varying temperature, gel composition, ionic strength and additives, we optimised the sensitivity of SSCP for all 27 exons of the CFTR gene. Using simultaneously SSCP and heteroduplex (HD) analysis, a total of 80 known CF mutations (28 missense, 22 frameshift, 17 nonsense, 13 splicesite) and 20 polymorphisms was analysed resulting in a detection rate of 97.5% including the 24 most common mutations worldwide. The ability of this technique to detect mutations independent of their nature, frequency, and population specificity was confirmed by the identification of five novel mutations (420del9, 1199delG, R560S, A613T, T1299I) in Swiss CF patients, as well as by the detection of 41 different mutations in 198 patients experimentally analysed. We present a three-stage screening strategy allowing analysis of seven exons within 5 hours and analysis of the entire coding region within 1 week, including sequence analysis of the variants. Additionally, our protocol represents a general model for point mutation analysis in other genetic disorders and has already been successfully established for OTC deficiency, collagene deficiency, X-linked myotubular myopathy (XLMTM), Duchenne and Becker muscular dystrophy (DMD, BMD), Wilson disease (WD), Neurofibromatosis I and II, Charcot-Marie-Tooth disease, hereditary neuropathy with liability to pressure palsies, and defects in mitochondrial DNA. No other protocol published so far presents standard SSCP/HD conditions for mutation screening in different disease genes.

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20 The distribution of analysed known mutations is similar to that of the total number of mutations in the entire CFTR gene: missense mutations account for 35% (G27E, G85E, R117H, A120T, I148T, H199Y, R334W, T338I, R347P, R347H, A455E, M718K, S5449N, S5449I, G551D, R560T, R560S, S945L, S977P, I1005R, R1066C, R1070Q, M1101K, D1152H, S1235R, R1283M, N1303K, N1303H), followed by 28% of frameshift mutations (175delC, 394delTT, 457TAT- > G, 905delG, 1078delT, I507, F508, 1609delCA, 1677delTA, 2143delT, 2176insC, 218delA, 2184insA, 2869insG, 3659delC, 3732delA, 3821delT, 3905insT, 4016insT, 4172delGC, 4382delA), 21% of nonsense mutations (Q30X, Q39X, Q220X, W401X, Q525X, G542X, Q552X, R553X, V569X, E585X, K710X, R792X, Y1092X, R1162X, S1255X, W1282X, E1371X), and 16% of splice site mutations (621 + 1G- > T, 711 + 1G- > T, 711 + 5G- > A, 1717-1G- > A, 1898 + 1G- > A, 1898 + 5G- > T, 2789 + 5G- > A, 3271 + 1G- > A, 3272-26A- > G, 3601-17T- > C, 3849 + 4A- > G, 3849 + 10kbC- > T, 4374 + 1G- > T). Login to comment
34 Intron 19, all 27 exons and their exon-intron boundaries, including the 24 most common mutations worldwide (G85E, R117H, 621 + 1G- > T, 711 + 1G- > T, 1078delT, R334W, R347P, A455E, I507, F508, 1717-1G- > A, G542X, S549N, G551D, R553X, R560T, 1898 + 1G- > A, 2184delA, 2789 + 5G- > A, R1162X, 3659delC, 3849 + 10kbC- > T, W1282X, N1303K) (Cystic Fibrosis Genetic Analysis Consortium 1994), and the 15 most common mutations in our population (I148T, 1078delT, R334W, R347P, F508, 1717-1G- > A, G542X, R553X, 2347delG, D1152H, R1162X, 3849 + 10kbC- > T, 3905insT, W1282X, N1303K), were considered in this study. Login to comment
92 The technique developed demonstrates excellent single-strand separation and non-radioactive visualisation on polyacrylamide gels, and is time-saving and directly Table 2 Known mutations identified in 198 CF patients analysed investigatively Exon (E) Number of CFTR mutations intron (I) chromosomes Patient`s nationality Highest prevalence ∆F508 E10 212 miscellaneous 3905insT E20 025 Swiss Swiss, Amish, Arcadian R553X E11 020 Swiss, German German 1717-1G->A I10 017 Swiss, Italian Italian N1303K E21 011 Swiss, French, Italian Italian W1282X E20 014 Swiss, Italian, Israelit Jewish-Askhenazi G542X E11 009 Swiss, Spanish, Italian Spanish 2347delG E13 008 Swiss R1162X E19 006 Swiss, Italian, Russian Italian 3849+10kbC->T I19 005 German, French R347P E07 004 Swiss T5 I08 004 Swiss R334W E07 003 Swiss Q525X E10 003 Swiss 3732delA E19 003 Swiss S1235R E19 003 Italian, Turkish G85E E03 002 Italian, Greek I148T E04 002 Austrian, Turkish French-Canadian 621+1G->T I04 002 French French-Canadian 1078delT E07 002 Swiss E585X E12 002 Italian 2176insC E13 002 Swiss, Italian 2789+5G->A I14b 002 Italian Spanish D1152H E18 002 Swiss, French 4016insT E21 002 Turkish Q39X E02 001 Swiss 394delTT E03 001 Swiss Nordic, Finnish R117H E04 001 Swiss A120T E04 001 Swiss G126D E04 001 Swiss 711+5G->A I05 001 Russian M348K E07 001 Italian L568F E12 001 Italian 2183AA->G E13 001 Italian Italian K710X E13 001 Swiss S945L E15 001 French 3272-26A.->G I17a 001 Swiss M1101K E17b 001 Swiss Huttite 3601-17C->T I18 001 Swiss R1158X E19 001 Swiss 4005+1G-A I20 001 Italian applicable to early diagnostic testing, carrier detection and prenatal diagnosis. Login to comment

[hide] Analysis of 31 CFTR mutations by polymerase chain ... J Med Screen. 1999;6(2):67-9. Gasparini P, Arbustini E, Restagno G, Zelante L, Stanziale P, Gatta L, Sbaiz L, Sedita AM, Banchieri N, Sapone L, Fiorucci GC, Brinson E, Shulse E, Rappaport E, Fortina P
Analysis of 31 CFTR mutations by polymerase chain reaction/oligonucleotide ligation assay in a pilot screening of 4476 newborns for cystic fibrosis.
J Med Screen. 1999;6(2):67-9., [PMID:10444722]

Abstract [show]
OBJECTIVES: Molecular biological testing for genetic diseases has grown rapidly, but speed, accuracy, specificity, sensitivity, throughput, and cost become more important as large scale screening is considered. This is a pilot study of an assay for the simultaneous detection of up to 31 cystic fibrosis mutations in a multicentre population based screening of 4476 Italian newborns. METHODS: The assay is a polymerase chain reaction, followed by an oligonucleotide ligation assay (PCR/OLA) and finally a sequence coded separation. It allows the detection of up to 31 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Guthrie spots were used as a source of template DNA. RESULTS: 144 carriers were detected during the analysis of 4476 samples, which translates into a carrier frequency of 1/31.1. Forty two carriers were detected from 1341 samples in Pavia (1/31.9), 53 from 1574 in Turin (1/29.7), and 49 from 1561 in San Giovanni Rotondo (1/31.8). Fifteen different mutations were detected, the most common being delta F508 (0.625). Other common mutations included G542X (16 of 144), which was particularly common in southern Italy (14 of 49), N1303K (8 of 144), and R117H (8 of 144), detected only in the northern centres. CONCLUSIONS: PCR/OLA is a robust, accurate, user friendly method for cystic fibrosis screening of newborns using blood spots in a semiautomated way at a low cost per mutation (0.8 Euro).

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46 Table 1 Mutations analysed in the CFTR gene using polymerase chain reaction/oligonucleotide litigation assay/sequence coded separation Mutation Location Nucleotide Result F508 Exon 10 3 bp deletion Deletion of Phe-508 I507 Exon 10 3 bp deletion Deletion of Ile-507 (or -506) Q493X Exon 10 C-1609 →→ T Gln-493 → Stop V520F Exon 10 G-1690 → T Val-520 → Phe 1717-1G → A Intron 10 G-1717-1 → A 3`-splice site mutation G542X Exon 11 G-1756 → T Gly-542 → Stop G551D Exon 11 G-1784 → A Gly-551 → Asp R553X Exon 11 C-1789 → T Arg-553 → Stop R560T Exon 11 G-1811 → C Arg-560 → Thr S549R Exon 11 T-1779 → G Ser-549 → Arg S549N Exon 11 G-1778 → A Ser-549 → Asn 3849+10 kb C → T Intron 19 C-3849+10 kb → T Splice mutation 3849+4A → G Intron 19 A-3849+4 → G Splice mutation R1162X Exon 19 C-3616 → T Arg-1162 → Stop 3659delC Exon 19 1 bp deletion Frameshift W1282X Exon 20 G-3978 → A Trp-1282 → Stop 3905insT Exon 20 1 bp insertion Frameshift N1303K Exon 21 C-4041 → G Asn-1303 → Lys G85E Exon 3 G-386 → A Gly-85 → Glu 621+1G → T Intron 4 G-621+1 → T 5`-splice site mutation R117H Exon 4 G-482 → A Arg-117 → His Y122X Exon 4 T-498 → A Tyr-122 → Stop 711+1G → T Intron 5 G-711+1 → T 5`-splice site mutation 1078delT Exon 7 1 bp deletion Frameshift R347P Exon 7 G-1172 → C Arg-347 → Pro R347H Exon 7 G-1172 → A Arg-347 → His R334W Exon 7 C-1132 → T Arg-334 → Trp A455E Exon 9 C-1496 → A Ala-455 → Glu 1898+1G → A Intron 12 G-1898+1 → A 5`-splice site mutation 2184delA Exon 13 Deletion A-2184; A-2183 → G Frameshift 2789+5G → A Intron 14B G-2789+5 → A Splice mutation Table 2 Summary of cystic fibrosis screening results No of samples analysed Normal subjects Carriers Carrier frequency Turin 1574 1521 53 1/29.7 Pavia 1341 1299 42 1/31.9 San Giovanni Rotondo 1561 1512 49 1/31.8 Total 4476 4332 144 1/31.1 Table 3 Detailed list of mutations detected in the Italian population Centre F508 G542X R347P 2183-AG N1303K 711+1GT 1717-1A R347H R117H 1898+1G 2789+5G W1282X R1162X I507 Other TO 33 2 1 1 5 1 1 2 3 2 2 - - - PV 27 - - 1 2 - 1 - 5 - 1 2 1 1 SGR 30 14 2 1 1 1 - - - - - - - - TO, Dipartimento di Patologia Clinica, Ospedale Infantile "Regina Margherita, Torino; PV, Istituto di Anatomia Patologica, Sezione di Anatomia Patologica, Università di Pavia, Pavia; SGR, Servizio di Genetica Medica and Divisione di Neonatologia, IRCCS Casa Sollievo della SoVerenza, San Giovanni Rotondo, Foggia. Login to comment

[hide] A phase I study of adenovirus-mediated transfer of... Hum Gene Ther. 1999 Dec 10;10(18):2973-85. Zuckerman JB, Robinson CB, McCoy KS, Shell R, Sferra TJ, Chirmule N, Magosin SA, Propert KJ, Brown-Parr EC, Hughes JV, Tazelaar J, Baker C, Goldman MJ, Wilson JM
A phase I study of adenovirus-mediated transfer of the human cystic fibrosis transmembrane conductance regulator gene to a lung segment of individuals with cystic fibrosis.
Hum Gene Ther. 1999 Dec 10;10(18):2973-85., 1999-12-10 [PMID:10609658]

Abstract [show]
A third-generation adenoviral vector containing recombinant human cystic fibrosis transmembrane conductance regulator (CFTR) gene was delivered by bronchoscope in escalating doses to the conducting airway of 11 volunteers with cystic fibrosis. Assessments of dose-limiting toxicity (DLT), efficiency of gene transfer, and cell-mediated and humoral immune responses to vector administration were performed. DLT, manifest by flulike symptoms and transient radiographic infiltrates, was seen at 2.1 x 10(11) total viral particles. A highly specific assay for gene transfer was developed using in situ hybridization with an oligoprobe against unique vector sequence. Detectable gene transfer was observed in harvested bronchial epithelial cells (<1%) 4 days after vector instillation, which diminished to undetectable levels by day 43. Adenovirus-specific cell-mediated T cells were induced in most subjects, although only mild increases in systemic humoral immune response were observed. These results demonstrate that gene transfer to epithelium of the lower respiratory tract can be achieved in humans with adenoviral vectors but that efficiency is low and of short duration in the native CF airway.

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87 STU DY DESIGN A ND DO SE OF ADEN OVIRA L VECTOR H5.001CBCFTRa Baseline FEV1 Subject Dose (particles) a Region dosed Age/sex Genotype (% Pred) 1 2.1 3 109 Left lower lobe 20/M D F508/unknown 85 2 2.1 3 109 Right lower lobe 21/M D F508/G542X 67 3 7.0 3 109 Left lower lobe 23/F D F508/unknown 71 4 7.0 3 109 Left lower lobe 25/F D F508/R347P 48 5 2.1 3 1010 Left lower lobe 20/F D F508/unknown 89 6 2.1 3 1010 Right lower lobe 26/M D F508/unknown 95 7 7.0 3 1010 Right lower lobe 19/M D F508/unknown 108 8 7.0 3 1010 Left lower lobe 25/F D F508/D I507 70 9 2.1 3 1011 Left lower lobe 47/M D F508/unknown 90 10 2.1 3 1011 Right lower lobe 35/M D F508/R117H 61 11 2.1 3 1011 Right lower lobe 24/F D F508/unknown 107 a The dose is reported in total viral particles in a 7-ml suspension. Login to comment

[hide] Pharmacologic restoration of delta F508 CFTR-media... Kidney Int. 2000 Mar;57(3):832-7. Zeitlin PL
Pharmacologic restoration of delta F508 CFTR-mediated chloride current.
Kidney Int. 2000 Mar;57(3):832-7., [PMID:10720936]

Abstract [show]
Cystic fibrosis (CF) is an autosomal inherited disorder caused by over 800 different mutations in the CFTR gene. The most common mutation, delta F508, causes a trafficking arrest in the endoplasmic reticulum and the CFTR protein is degraded. Restoration of CFTR trafficking in vitro restores cAMP-mediated chloride transport at the cell surface. The hypothesis of this discussion is that the short chain fatty acids, butyrate and 4-phenylbutyrate, up-regulate mature CFTR at the plasma membrane. Evidence that these compounds regulate CFTR production and maturation in part through effects on molecular chaperones in CF cells in culture is discussed. The oral drug, 4-phenylbutyrate, was tested in a Phase I clinical trial in CF subjects and further trials are underway. Other new therapeutic approaches directed at different classes of mutations in CFTR are also discussed. Chemical and pharmacologic agents that regulate endogenous gene expression at different steps in the biosynthetic processing pathway of a membrane glycoprotein will be needed to comprehensively treat a complex inherited disorder like cystic fibrosis.

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102 Restoration of ⌬F508 CFTR trafficking will R347P are associated with normal trafficking, proteinbe necessary for the flavonoids to be effective (abstract; kinase A (PKA)-dependent response to phosphoryla-Gondor et al, Pediatr Pulmon S17:253, 1998). Login to comment
106 R347P affects the rate of chloride flow, Chemical and pharmacologic mediators of protein whereas R117H and P574H reduce the channel open trafficking are needed in CF and other diseases caused time. Login to comment

[hide] Partial CFTR genotyping and characterisation of cy... Clin Genet. 2000 Jan;57(1):56-60. Zebrak J, Skuza B, Pogorzelski A, Ligarska R, Kopytko E, Pawlik J, Rutkiewicz E, Witt M
Partial CFTR genotyping and characterisation of cystic fibrosis patients with myocardial fibrosis and necrosis.
Clin Genet. 2000 Jan;57(1):56-60., [PMID:10733236]

Abstract [show]
Myocardial necrosis and fibrosis is a rare complication of cystic fibrosis (CF) causing sudden and unexpected death in infancy due to cardiac arrest. Characteristic morphological lesions are recognisable postmortem. The 18 CF patients with this complication had varied clinical features including mild pulmonary involvement, early onset severe pancreatic insufficiency, and profound electrocardiogram (ECG) changes. In this group of patients, 5 were deltaF508 homozygotes, 1 was deltaF508/ N1303K and 1 was a deltaF508/M compound heterozygote. A pair of affected siblings (deltaF508 homozygotes) were fully concordant for myocardial involvement and for the general course of the disease. The co-existence of a genetic predisposition to myocardial lesions resulting most probably from severe cystic fibrosis transmembrane (CFTR) genotypes (such as deltaF508/deltaF508, deltaF508/N1303K) and deficiency of certain trophic factors necessary for metabolism of the myocardium, are postulated to cause myocardial complications in CF leading to circulatory failure and early death.

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78 No correlation of myocardial complications with CFTR mutations has been performed so far and, in the literature, only one case was recognised as a DF508/M compound heterozygote, negative for R347P, G551D, R553X and N1303K as a second mutation (9). Login to comment

[hide] The two halves of CFTR form a dual-pore ion channe... J Biol Chem. 2000 Apr 7;275(14):10030-4. Yue H, Devidas S, Guggino WB
The two halves of CFTR form a dual-pore ion channel.
J Biol Chem. 2000 Apr 7;275(14):10030-4., 2000-04-07 [PMID:10744680]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) exhibits two conductance states, 9 picosiemens (pS) and 3 pS. To investigate the origin of these two distinct conductance states, we measured the single-channel activity of three truncated forms of CFTR. These include: TNR, which contains the first transmembrane domain, the first nucleotide binding domain, and the R domain; RT2N2, which contains the R domain, the second transmembrane domain, and the second nucleotide-binding domain; and T2N2, which contains only the second transmembrane domain and the second nucleotide-binding domain. The results show that TNR exhibits only the large conductance of 9.2 pS, whereas RT2N2 and T2N2 exhibit only the small conductance (3.8-4.0 pS). Co-expression of TNR with T2N2 resulted in a mixed pattern of two conductance states, which is similar to that observed in wild-type CFTR. In further studies, a "dual-R mutant," R334W and R347P in the transmembrane segment 6 of the first half of CFTR, severely impaired the large conductance channel without affecting the small conductance channel. The ion selectivity and gating behavior of the two conductance channels are different regardless of whether they are measured in wild-type CFTR or in truncated CFTRs. The ion selectivity of the large conductance channel is Br(-) > Cl(-) > I(-), whereas the ion selectivity of the small conductance channel is Br(-) = Cl(-) = I(-). The open probability (P(o)) of the large conductance is about 4-fold higher than that of the small conductance. Transition from closed to open states of the small conductance is not dependent upon the open or closed states of the large conductance. The independent behaviors of the two conductances in CFTR strongly suggest that CFTR may have two distinct pores. Thus, like ClC0, CFTR is likely to be a double-barreled ion channel, with the first half of CFTR forming the large conductance and the second half forming the small conductance.

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5 In further studies, a "dual-R mutant," R334W and R347P in the transmembrane segment 6 of the first half of CFTR, severely impaired the large conductance channel without affecting the small conductance channel. Login to comment
76 We also tested the Cl- conduction mutations, R334W and R347P. Login to comment
79 As expected the "dual-arginine" mutants, R334W/R347P, in full-length CFTR severely reduced whole cell Cl- currents in airways cells transiently transfected with this mutant. Login to comment
122 Dual arginine mutants R334W and R347P in the transmembrane segment six of TMD1 eliminate the large conductance but retain the small conductance of CFTR. Login to comment

[hide] CFTR gene mutations and male infertility. Andrologia. 2000 Mar;32(2):71-83. Stuhrmann M, Dork T
CFTR gene mutations and male infertility.
Andrologia. 2000 Mar;32(2):71-83., [PMID:10755189]

Abstract [show]
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are a relatively frequent cause of male infertility. Depending on their molecular consequences, CFTR mutations may either result in typical cystic fibrosis (CF), one of the most common autosomal recessive disorders, which is characterized by chronic lung disease, pancreatic exocrine insufficiency, an increase in the concentration of sweat electrolytes and male infertility, due to obstructive azoospermia, or in atypical (often monosymptomatic) forms of CF such as congenital absence of the vas deferens (bi- or unilateral), bilateral ejaculatory duct obstruction or bilateral obstructions within the epididymides. All males with idiopathic obstructive azoospermia bear an increased risk for CF offspring. Couples requesting microsurgical epididymal sperm aspiration and in vitro fertilization, e.g. intracytoplasmic sperm injection, should be offered genetic counselling and molecular genetic analysis of the CFTR gene, if male infertility due to obstructive azoospermia is the underlying cause.

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95 Most patients are of German origin CFTR genotype (mutation class in brackets) Patients with typical CF (%) Patients with CBAVD (%) DF508 (2)/DF508 (2) 247 (59.4) 0 DF508 (2)/N1303K (2) 17 (4.1) 0 DF508 (2)/R347P (4) 13 (3.1) 0 DF508 (2)/R553X (1) 11 (2.6) 0 DF508 (2)/G542X (1) 11 (2.6) 0 DF508 (2)/G551D (3) 11 (2.6) 0 DF508 (2)/R1162X (1) 10 (2.4) 0 DF508 (2)/3849+10 KbC T (5) 9 (2.2) 0 DF508 (2)/2789+5G A (5) 9 (2.2) 0 DF508 (2)/3272-26 A G (5) 7 (1.7) 2 (2.6) DF508 (2)/1717-1G A (1) 6 (1.4) 0 DF508 (2)/CFTRdel21Kb (1) 5 (1.2) 0 DF508 (2)/R117H (4) 3 (0.7) 21 (26.9)* DF508 (2)/IVS8-5T (5) 2 (0.5) 9 (11.5)* DF508 (2)/other 33 (7.9) 20 (25.6) Other/other 22 (5.3) 26 (33.3) *Including one CUAVD patient each. Login to comment
116 men with BEDO were compound heterozygous Probably the largest molecular genetic study on for DF508 and R117H, two were heterozygous for the etiology of CUAVD was conducted by Mickle DF508, and two were heterozygous for R553X or et al. (1995) who investigated 21 CUAVD males, R347P, respectively. Login to comment

[hide] Genotype and phenotype in cystic fibrosis. Respiration. 2000;67(2):117-33. Zielenski J
Genotype and phenotype in cystic fibrosis.
Respiration. 2000;67(2):117-33., [PMID:10773783]

Abstract [show]
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene which encodes a protein expressed in the apical membrane of exocrine epithelial cells. CFTR functions principally as a cAMP-induced chloride channel and appears capable of regulating other ion channels. Besides the most common mutation, DeltaF508, accounting for about 70% of CF chromosomes worldwide, more than 850 mutant alleles have been reported to the CF Genetic Analysis Consortium. These mutations affect CFTR through a variety of molecular mechanisms which can produce little or no functional CFTR at the apical membrane. This genotypic variation provides a rationale for phenotypic effects of the specific mutations. The extent to which various CFTR alleles contribute to clinical variation in CF is evaluated by genotype-phenotype studies. These demonstrated that the degree of correlation between CFTR genotype and CF phenotype varies between its clinical components and is highest for the pancreatic status and lowest for pulmonary disease. The poor correlation between CFTR genotype and severity of lung disease strongly suggests an influence of environmental and secondary genetic factors (CF modifiers). Several candidate genes related to innate and adaptive immune response have been implicated as pulmonary CF modifiers. In addition, the presence of a genetic CF modifier for meconium ileus has been demonstrated on human chromosome 19q13.2. The phenotypic spectrum associated with mutations in the CFTR gene extends beyond the classically defined CF. Besides patients with atypical CF, there are large numbers of so-called monosymptomatic diseases such as various forms of obstructive azoospermia, idiopathic pancreatitis or disseminated bronchiectasis associated with CFTR mutations uncharacteristic for CF. The composition, frequency and type of CFTR mutations/variants parallel the spectrum of CFTR-associated phenotypes, from classic CF to mild monosymptomatic presentations. Expansion of the spectrum of disease associated with the CFTR mutant genes creates a need for revision of the diagnostic criteria for CF and a dilemma for setting nosologic boundaries between CF and other diseases with CFTR etiology.

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90 Several mutations (R117H, R334W, R347P) were shown to affect the properties of CFTR single-channel conductance [23]. Login to comment

[hide] Characterization of a novel 21-kb deletion, CFTRde... Hum Genet. 2000 Mar;106(3):259-68. Dork T, Macek M Jr, Mekus F, Tummler B, Tzountzouris J, Casals T, Krebsova A, Koudova M, Sakmaryova I, Macek M Sr, Vavrova V, Zemkova D, Ginter E, Petrova NV, Ivaschenko T, Baranov V, Witt M, Pogorzelski A, Bal J, Zekanowsky C, Wagner K, Stuhrmann M, Bauer I, Seydewitz HH, Neumann T, Jakubiczka S
Characterization of a novel 21-kb deletion, CFTRdele2,3(21 kb), in the CFTR gene: a cystic fibrosis mutation of Slavic origin common in Central and East Europe.
Hum Genet. 2000 Mar;106(3):259-68., [PMID:10798353]

Abstract [show]
We report a large genomic deletion of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, viz., a deletion that is frequently observed in Central and Eastern Europe. The mutation, termed CFTRdele2,3(21 kb), deletes 21,080 bp spanning introns 1-3 of the CFTR gene. Transcript analyses have revealed that this deletion results in the loss of exons 2 and 3 in epithelial CFTR mRNA, thereby producing a premature termination signal within exon 4. In order to develop a simple polymerase chain reaction assay for this allele, we defined the end-points of the deletion at the DNA sequence level. We next screened for this mutation in a representative set of European and European-derived populations. Some 197 CF patients, including seven homozygotes, bearing this mutation have been identified during the course of our study. Clinical evaluation of CFTRdele2,3(21 kb) homozygotes and a comparison of compound heterozygotes for deltaF508/CFTRdele2,3(21 kb) with pairwise-matched deltaF508 homozygotes indicate that this deletion represents a severe mutation associated with pancreatic insufficiency and early age at diagnosis. Current data show that the mutation is particularly common in Czech (6.4% of all CF chromosomes), Russian (5.2%), Belorussian (3.3%), Austrian (2.6%), German (1.5%), Polish (1.5%), Slovenian (1.5%), Ukrainian (1.2%), and Slovak patients (1.1%). It has also been found in Lithuania, Latvia, Macedonia and Greece and has sporadically been observed in Canada, USA, France, Spain, Turkey, and UK, but not in CF patients from Bulgaria, Croatia, Romania or Serbia. Haplotype analysis has identified the same extragenic CF-haplotype XV-2c/KM. 19 "A" and the same infrequent intragenic microsatellite haplotype 16-33-13 (IVS8CA-IVS 17bTA-IVS 17bCA) in all examined CFTRdele2,3(21 kb) chromosomes, suggesting a common origin for this deletion. We conclude that the 21-kb deletion is a frequent and severe CF mutation in populations of Eastern- and Western-Slavic descent.

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57 At a later stage of the study, the same pattern was observed in nasal epithelial samples from two further patients who were compound heterozygous for the deletion allele and the R347P or ∆F508 mutations, respectively. Login to comment
109 A few compound heterozygous patients carrying mild CF mutations (e.g., I336 K, R347P, 3849+10kbC→T) in trans exhibited less severe pulmonary symptoms and were pancreatic sufficient as predicted from the well-documented dominance of milder CF alleles (Kristidis et al. 1993). Login to comment

[hide] Permeation through the CFTR chloride channel. J Exp Biol. 2000 Jul;203(Pt 13):1947-62. McCarty NA
Permeation through the CFTR chloride channel.
J Exp Biol. 2000 Jul;203(Pt 13):1947-62., [PMID:10851114]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) protein forms a Cl(-) channel found in the plasma membranes of many epithelial cells, including those of the kidney, gut and conducting airways. Mutation of the gene encoding CFTR is the primary defect in cystic fibrosis, a disease that affects approximately 30 000 individuals in the United States alone. Alteration of CFTR function also plays an important role in the pathophysiology of secretory diarrhea and polycystic kidney disease. The basic mechanisms of permeation in this channel are not well understood. It is not known which portions of the protein contribute to forming the pore or which amino acid residues in those domains are involved in the biophysical processes of ion permeation. In this review, I will discuss (i) the present understanding of ion transport processes in the wild-type CFTR channel, (ii) the experimental approaches currently being applied to investigate the pore, and (iii) a proposed structure that takes into account the present data on mechanisms of ion selectivity in the CFTR channel and on blockade of the pore by open-channel blockers.

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276 Here, it is believed that K335 and R347 influence selectivity and Cl-conductance (Tabcharani et al., 1997): R347 confers anomalous mole-fraction effects and protocol-dependent block by I- (Tabcharani et al., 1997); cysteine substitutions for several residues interact with SH-modifying reagents as if they face the pore (Cheung and Akabas, 1996); T338 and T339 together control the permeability of the channel to polyatomic anions as if they contribute to a narrow region (Linsdell et al., 1997b, 1998); disease-associated mutations (R334W and R347P) alter the kinetics and conductance of single channels (Sheppard et al., 1993); and the anion/cation selectivity filter is formed by T351, R352 and Q353 (Cheung and Akabas, 1997; Guinamard and Akabas, 1999). Login to comment

[hide] Future pharmacological treatment of cystic fibrosi... Respiration. 2000;67(4):351-7. Zeitlin PL
Future pharmacological treatment of cystic fibrosis.
Respiration. 2000;67(4):351-7., [PMID:10940786]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disorder that is caused by over 850 different mutations in the CF gene. It is useful to group these mutations according to the defect that results in the CFTR mRNA or protein. New pharmacological treatments targeted towards specific mutations that are relatively common are being developed. Class I mutations do not produce CFTR protein because of a premature stop signal in the CFTR DNA. These null mutations can be corrected by certain aminoglycosides which cause the aberrant stop signal to be skipped. Mutations leading to a CFTR protein that attains an unstable structure shortly after translation in the endoplasmic reticulum form class II. Class II mutations can be restored to the protein trafficking pathway by manipulation of chaperone protein/CFTR interactions with chemical chaperones or drugs that affect gene regulation such as the butyrates. Production of a CFTR with reduced Cl(-) transport on the basis of abnormal regulation of the chloride channel is the basis of class III. Genistein can overcome this block in regulation. Mutations that partially reduce chloride conductance through CFTR (class IV) can be stimulated with milrinone, which is a phosphodiesterase inhibitor. Finally, mutations that lead to a severe reduction in normal CFTR protein form class V. Increased levels of CFTR could be generated with the butyrates or supplemented with gene therapy. Although most of the reported mutations in CFTR are rare and unclassified, it may be possible to use genotype-phenotype correlations to determine the best approach.

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22 Examples of CFTR mutations organized by classification of the defect in CFTR biosynthesis Type Genotype Phenotype Defect Cell diagram Drugs that may improve phenotype G542X 621+1 G → T 3905insT W1282X R553X 1717-1 G → A PI no CFTR protein no cell surface chloride transport gentamicin G418 Class II [64] 'F508 N1303K (P574H)a (A455E)a PI defective CFTR processing defective CFTR trafficking no cell surface chloride transport chemical chaperones CPX phenylbutyrate deoxyspergualin Class III [64] G551D G551S PI defective chloride channel regulation reduced or absent cell surface chloride transport genistein pyrophosphate Class IV [64, 66] R117H R334W G314E R347P ('F508)a P574H PS reduced chloride conductance reduced levels of cell surface chloride transport genistein milrinone phenylbutyrate Class V [64] 3849+10 kb C → T 2789+5 G → A 3272-26 A → G A455E 3120+1 G → A 1811+1.6 kb A → G 5Tb PS normal CFTR channels reduced numbers of normal CFTR reduced cell surface chloride transport genistein milrinone phenylbutyrate a Some mutants have features of more than one class of defect. Login to comment
115 R117H, R334W, and R347P are class IV mutants with reduced single-channel conductances [66]. Login to comment

[hide] Mutations of the cystic fibrosis gene, but not cat... Am J Gastroenterol. 2000 Aug;95(8):2061-7. Ockenga J, Stuhrmann M, Ballmann M, Teich N, Keim V, Dork T, Manns MP
Mutations of the cystic fibrosis gene, but not cationic trypsinogen gene, are associated with recurrent or chronic idiopathic pancreatitis.
Am J Gastroenterol. 2000 Aug;95(8):2061-7., [PMID:10950058]

Abstract [show]
OBJECTIVE: We investigated whether mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and cationic trypsinogen gene are associated with recurrent acute, or chronic idiopathic pancreatitis. METHODS: Twenty patients with idiopathic pancreatitis (11 women, nine men; mean age, 30 yr) were studied for the presence of a CFTR mutation by screening the genomic DNA for more than 30 mutations and variants in the CFTR gene. Selected mutations of the cationic trypsinogen gene were screened by Afl III restriction digestion or by a mutation-specific polymerase chain reaction (PCR). In each patient exons 1, 2, and 3 of the cationic trypsinogen gene were sequenced. Patients with a CFTR mutation underwent evaluation of further functional electrophysiological test (intestinal current measurement). RESULTS: No mutation of the cationic trypsinogen gene was detected. A CFTR mutation was detected in 6/20 (30.0%) patients. Three patients (15.0%) had a cystic fibrosis (CF) mutation on one chromosome (deltaF508, I336K, Y1092X), which is known to cause phenotypical severe cystic fibrosis. One patient was heterozygous for the 5T allele. In addition, two possibly predisposing CFTR variants (R75Q, 1716G-->A) were detected on four patients, one of these being a compound heterozygous for the missense mutation I336K and R75Q. No other family member (maternal I336K; paternal R75Q; sister I1336K) developed pancreatitis. An intestinal current measurement in rectum samples of patients with a CFTR mutation revealed no CF-typical constellations. CONCLUSIONS: CFTR mutations are associated with recurrent acute, or chronic idiopathic pancreatitis, whereas mutations of the cationic trypsinogen mutation do not appear to be a frequent pathogenetic factor.

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53 Using the ARMS technology (elucigene CF20, Zeneca Diagnostics, Oxfordshire, UK) all samples were tested additionally for the mutations E60X, R347P, A455E, 1078delT, 2183AA3G, G542X, G551D, N1303K, W1282X, 1717-1G3A, R553X, 621ϩ1G3T, R117H, R1162X, 3849ϩ10kbC3T, R334W, S1251N, and 3659delC. Login to comment

[hide] Effect of genistein on native epithelial tissue fr... Br J Pharmacol. 2000 Aug;130(8):1884-92. Mall M, Wissner A, Seydewitz HH, Hubner M, Kuehr J, Brandis M, Greger R, Kunzelmann K
Effect of genistein on native epithelial tissue from normal individuals and CF patients and on ion channels expressed in Xenopus oocytes.
Br J Pharmacol. 2000 Aug;130(8):1884-92., [PMID:10952679]

Abstract [show]
The flavonoid genistein has been shown to activate a Cl(-) conductance in various cell types expressing CFTR. We examined if similar effects can be observed when genistein is applied to native ex vivo tissues from human respiratory tract and rectum. We further compared the effects when genistein was applied to oocytes of Xenopus laevis expressing CFTR. In oocytes, both wtCFTR and DeltaF508-CFTR were activated by genistein while both cyclic AMP (K(v)LQT1) and Ca(2+) (SK4) activated K(+) channels were inhibited at high concentrations of genistein. Biopsies from nasal polyps and rectal mucosa were obtained from normal individuals (non-CF) and CF patients and in the presence of amiloride (10 micromol l(-1); mucosal side) the effects of genistein were assessed using a perfused Ussing chamber. In non-CF airway epithelia, genistein (50 micromol l(-1); mucosal side) increased lumen negative I(sc) but had no additional effects on tissues pre-stimulated with IBMX and forskolin (100 micromol l(-1) and 1 micromol l(-1); both sides). In non-CF rectal biopsies, in the presence of amiloride (10 micromol l(-1); mucosal side) and indomethacin (10 micromol l(-1); basolateral side), genistein increased lumen negative I(sc) and enabled cholinergic (carbachol; CCH, 100 micromol l(-1); basolateral side) stimulation of Cl(-) secretion indicating activation of luminal CFTR Cl(-) channels. However, after stimulation with IBMX/forskolin, genistein induced opposite effects and significantly inhibited CCH activated I(sc). In CF airway and intestinal tissues genistein failed to induce Cl(-) secretion. Thus, genistein is able to activate luminal CFTR Cl(-) conductance in non-CF tissues and mutant CFTR in oocytes. However, additional inhibitory effects on basolateral K(+) conductance and missing effects in native CF tissues do not support the use for pharmacological intervention in CF.

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26 Eight CF patients presenting with nasal polyps were tested for six common mutations: DF508, R553X, N1303K, G542X, G551D and R347P. Login to comment
30 In all CF patients from whom rectal biopsies were studied DNA analysis was carried out for the following CFTR mutations: DF508; R117H and S108F in exon 4; R347P, R347H, I336K and T338I in exon 7; S549N, G551D, R553X, G542X, Q552X, 1717-1 G?A in exon 11; W1282X and 3905insT in exon 20; N1303K in exon 21 and 3849+10kB C?T in intron 19. Login to comment

[hide] Prenatal detection by real-time quantitative PCR a... Clin Chem. 2000 Sep;46(9):1417-20. Costes B, Girodon E, Vidaud D, Flori E, Ardalan A, Conteville P, Fanen P, Niel F, Vidaud M, Goossens M
Prenatal detection by real-time quantitative PCR and characterization of a new CFTR deletion, 3600+15kbdel5.3kb (or CFTRdele19).
Clin Chem. 2000 Sep;46(9):1417-20., [PMID:10973878]

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51 The mutations tested were S549N, S549R, R553X, G551D, V520F, ⌬I507, ⌬F508, Q493X, 1717-1G3A, G542X, R560T, R347P, R347H, 3849ϩ4A3G, W1282X, R334W, 1078delT, 3849ϩ10kbC3T, R1162X, N1303K, 3659delC, 3905insT, A455E, R117H, Y122X, 2183AA3G, 2789ϩ5G3A, 1898ϩ1G3A, 621ϩ1G3T, 711ϩ1G3T, and G85E. Login to comment

[hide] Increased frequency of CFTR gene mutations in sarc... Eur J Hum Genet. 2000 Sep;8(9):717-20. Bombieri C, Luisetti M, Belpinati F, Zuliani E, Beretta A, Baccheschi J, Casali L, Pignatti PF
Increased frequency of CFTR gene mutations in sarcoidosis: a case/control association study.
Eur J Hum Genet. 2000 Sep;8(9):717-20., [PMID:10980579]

Abstract [show]
A complete screening of the CFTR gene by DGGE and DNA sequencing was performed in patients with sarcoidosis. In 8/26 cases, missense and splicing CFTR gene mutations were found, a significant difference over controls (9/89) from the same population (P = 0.014). The odds ratio for a person with a CFTR gene mutation to develop the disease is 3.95 (1.18 < OR < 13.26). Seven different CFTR gene mutations were observed: R75Q, R347P, 621 + 3 A/G, 1898 + 3 A/G, L997F, G1069R, and a novel mutation which was detected in this study, I991V. R75Q mutation was present in 3/26 patients, a significant increase (P = 0. 01) in cases over controls, indicating its preferential association with sarcoidosis. A trend towards disease progression was observed in patients with CFTR gene mutations compared to patients without mutations. These data suggest that CFTR gene mutations predispose to the development of sarcoidosis.

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3 Seven different CFTR gene mutations were observed: R75Q, R347P, 621 + 3 A/G, 1898 + 3 A/G, L997F, G1069R, and a novel mutation which was detected in this study, I991V. R75Q mutation was present in 3/26 patients, a significant increase (P = 0.01) in cases over controls, indicating its preferential association with sarcoidosis. Login to comment
33 Seven different missense or splicing mutations were found in the eight patients: R75Q, R347P, 1898 + 3 A/G, 621 + 3 A/G, L997F, G1069R, I991V. R75Q was present in three patients (nos. 15, 21, 27). Login to comment
37 R347P is known to cause CF.18 1898 + 3 A/G has been found in 1/225 genes from an Italian CF birth cohort we have previously described.19 The mutation 1898 + 3 A/G abolishes the donor splice site (program cited in methods), with the possible consequence of exon 12 skipping from mature mRNA. 621 + 3 A/G, L997F, and G1069R have been described in rare CF cases (Cystic Fibrosis Genetic Analysis Consortium website: http:/ /www.genet.sickkids.on.ca). Login to comment
45 With the exception of two novel mutations, E826K7 and I991V (this study), all the mutations present in the 34 patients with sarcoidosis (R75Q, 621 + 3 A/G, R347P, DF508, 1898 + 3 A/G, V754M, L997F, G1069R, 4382 del A) have also been observed in CF and CF-related diseases. Login to comment
52 Sarcoidosis is a complex disease in which genetic and environmental factors may play Table 2 CFTR genotypes of sarcoidosis patients (n = 26) Missense and Same sense and ID splicing mutations intronic mutations TGm-Tn M470V 11 G1069R 11-7/12-7 V/V 13 R347P 4404 C/T 10-7/11-7 M/V 15 R75Q, 1898+3A/G 186-13 C/G 11-7/11-7 V/V 20 621+3 A/G 10-7/10-7 M/M 21 R75Q 11-7/11-7 V/V 27 R75Q 1716 G/A 10-7/11-7 M/V 31 I991V 11-7/10-9 M/V 32 L997F 4002 A/G, 3041-71 G/C 10-9/11-9 M/V 10 4404 C/T 11-7/11-7 V/V 18 4002 A/G 11-7/12-7 M/V 24 3417 A/T 11-7/11-7 V/V 28 4002 A/G 11-7/11-7 M/V 34 4002 A/G 11-7/11-7 M/V 26 12-5/11-7 V/V 16 12-5/11-7 V/V 9 11-7/11-7 V/V 12 12-7/10-9 M/M 14 11-7/10-9 M/V 17 11-7/11-7 V/V 19 11-7/10-9 M/V 22 10-7/11-7 M/V 23 10-7/11-7 M/V 25 10-7/11-7 M/V 29 11-7/11-9 M/V 30 11-7/11-7 V/V 33 11-7/12-7 V/V The phase of the mutations is not known, as no segregation analysis was possible. Login to comment

[hide] Mutation in the gene responsible for cystic fibros... JAMA. 2000 Oct 11;284(14):1814-9. Wang X, Moylan B, Leopold DA, Kim J, Rubenstein RC, Togias A, Proud D, Zeitlin PL, Cutting GR
Mutation in the gene responsible for cystic fibrosis and predisposition to chronic rhinosinusitis in the general population.
JAMA. 2000 Oct 11;284(14):1814-9., 2000-10-11 [PMID:11025834]

Abstract [show]
CONTEXT: Chronic rhinosinusitis (CRS) is a common condition in the US general population, yet little is known about its underlying molecular cause. Chronic rhinosinusitis is a consistent feature of the autosomal recessive disorder cystic fibrosis (CF). OBJECTIVE: To determine whether mutations in the cystic fibrosis transmembrane regulator (CFTR) gene, which is responsible for CF, predispose to CRS. DESIGN: Case-control study conducted from 1996 to 1999 in which the DNA of CRS patients and controls was typed for 16 mutations that account for 85% of CF alleles in the general population. Chronic rhinosinusitis patients with 1 CF mutation were evaluated for a CF diagnosis by sweat chloride testing, nasal potential difference measurement, and DNA analysis for additional mutations. SETTING: Otolaryngology-head and neck clinic of a US teaching hospital. PARTICIPANTS: One hundred forty-seven consecutive adult white patients who met stringent diagnostic criteria for CRS and 123 CRS-free white control volunteers of similar age range, geographic region, and socioeconomic status. MAIN OUTCOME MEASURES: Presence of CF mutations by DNA analysis among CRS patients vs controls. RESULTS: Eleven CRS patients were found to have a CF mutation (DeltaF508, n = 9; G542X, n = 1; and N1303K, n = 1). Diagnostic testing excluded CF in 10 of these patients and led to CF diagnosis in 1. Excluding this patient from the analyses, the proportion of CRS patients who were found to have a CF mutation (7%) was significantly higher than in the control group (n = 2 [2%]; P =.04, both having DeltaF508 mutations). Furthermore, 9 of the 10 CF carriers had the polymorphism M470V, and M470V homozygotes were overrepresented in the remaining 136 CRS patients (P =.03). CONCLUSION: These data indicate that mutations in the gene responsible for CF may be associated with the development of CRS in the general population. JAMA. 2000;284:1814-1819.

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30 Analysis of CFTR Genes Genomic DNA samples extracted from the blood of participants were screened for 16 mutations (R117H, 621+1G→T, R334W, R347P, A455E, ⌬I507, ⌬F508, 1717-1 G→A, G542X, S549N, G551D, R553X, R560T, 3849+10 Kb C→T, W1282X, and N1303K) that account for 85% of CF alleles in the white population using the multiplex reverse dot hybridization system (Roche Molecular Systems, Alameda, Calif).16,17 This test also identified the 5T, 7T, and 9T variants of the splice acceptor site in intron 8 and F508C, I507V, and I506V (exon 10) polymorphisms of the CFTR gene. Login to comment

[hide] Cystic fibrosis in infertility: screening before a... Hum Reprod. 2000 Nov;15(11):2415-7. Lewis-Jones DI, Gazvani MR, Mountford R
Cystic fibrosis in infertility: screening before assisted reproduction: opinion.
Hum Reprod. 2000 Nov;15(11):2415-7., [PMID:11056144]

Abstract [show]
Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians. In 97-98% of men with CF, bilateral congenital absence of the vas deferens (CBAVD) blocks the transport of spermatozoa resulting in azoospermia. Abnormalities in sperm parameters have also been identified in males with CF. To date, over 800 disease-causing mutations of the CF transmembrane conductance regulator (CFTR) gene have been identified (also called ABCC7). Current legislation suggests that prior to intracytoplasmic sperm injection (ICSI) treatment, men with CBAVD or unexplained oligozoospermia should be considered for screening. If the male is negative with routine screening then the female partner is not screened. This is fundamentally wrong because if the female is screened and is found to be CF positive on routine testing, her partner would then need the fullest possible investigation of the CFTR gene. It is ideal to screen both partners in cases of oligozoospermia. However, if the resources are stretched, then only the female needs to be routinely screened because if she is negative, then the couple's residual risk of having a CF or CBAVD child will be reduced to 1:960. Only when the female is found to be a carrier does the male partner need routine screening followed by full testing for known mutations.

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73 R347P G1123R Dreyfus, D.H., Bethel, R. and Gelfand, E.W. (1996) Cystic fibrosis 1525-1G→A W1098R 3849ϩ10kBC→T mutation associated with severe pulmonary disease and V52OF 3495∆A male infertility. Login to comment

[hide] Type I, II, III, IV, and V cystic fibrosis transme... Curr Opin Pulm Med. 2000 Nov;6(6):521-9. Choo-Kang LR, Zeitlin PL
Type I, II, III, IV, and V cystic fibrosis transmembrane conductance regulator defects and opportunities for therapy.
Curr Opin Pulm Med. 2000 Nov;6(6):521-9., [PMID:11100963]

Abstract [show]
Recent advances in cellular and molecular biology have furthered the understanding of several genetic diseases, including cystic fibrosis. Mutations that cause cystic fibrosis are now understood in terms of the specific molecular consequences to the cystic fibrosis transmembrane conductance regulator (CFTR) protein expression and function. This knowledge has spawned interest in the development of therapies aimed directly at correcting the defective CFTR itself. In this article, we review the molecular defect underlying each recognized class of CFTR mutation and the potential therapies currently under investigation. Opportunities for protein-repair therapy appear to be vast and range from naturally occurring compounds, such as isoflavonoids, to pharmaceuticals already in clinical use, including aminoglycoside antibiotics, butyrate analogues, phosphodiesterase inhibitors, and adenosine nucleotides. Future therapies may resemble designer compounds like benzo[c]quinoliziniums or take the form of small peptide replacements. Given the heterogeneity and progressive nature of cystic fibrosis, however, optimal benefit from protein-repair therapy will most likely require the initiation of combined therapies early in the course of disease to avoid irreparable organ damage.

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106 These CFTR mutants including R117H, G314E, R334W, and R347P demonstrate a reduction in their chloride conductance or abnormal channel gating (see Fig. 2). Login to comment
108 R347P affects the rate of chloride flow, whereas R117H and P574H reduce the channel open time. Login to comment

[hide] Two mild cystic fibrosis-associated mutations resu... J Biol Chem. 2001 Mar 23;276(12):9045-9. Epub 2000 Dec 15. Clain J, Fritsch J, Lehmann-Che J, Bali M, Arous N, Goossens M, Edelman A, Fanen P
Two mild cystic fibrosis-associated mutations result in severe cystic fibrosis when combined in cis and reveal a residue important for cystic fibrosis transmembrane conductance regulator processing and function.
J Biol Chem. 2001 Mar 23;276(12):9045-9. Epub 2000 Dec 15., 2001-03-23 [PMID:11118444]

Abstract [show]
The number of complex cystic fibrosis transmembrane conductance regulator (CFTR) genotypes identified as having double-mutant alleles with two mutations inherited in cis has been growing. We investigated the structure-function relationships of a severe cystic fibrosis (CF)-associated double mutant (R347H-D979A) to evaluate the contribution of each mild mutation to the phenotype. CFTR mutants expressed in HeLa cells were analyzed for protein biosynthesis and Cl(-) channel activity. Our data show that R347H is associated with mild defective Cl(-) channel activity and that the D979A defect leads to misprocessing. The mutant R347H-D979A combines both defects for a dramatic decrease in Cl(-) current. To decipher the molecular mechanism of this phenotype, single and double mutants with different charge combinations at residues 347 and 979 were constructed as charged residues were involved in this complex genotype. These studies revealed that residue 979, located in the third cytoplasmic loop, is critical for CFTR processing and Cl(-) channel activity highlighting the role of charged residues. These results have also important implications for CF, as they show that two mutations in cis can act in concert to alter dramatically CFTR function contributing to the wide phenotypic variability of CF disease.

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14 At least four CF-associated mutations have been identified in isolation at position 347 (R347C, R347H, R347L, and R347P) and two at position 979 (D979A and D979V), suggesting that Arg-347 and Asp-979 are important for CFTR structure and/or function. Login to comment

[hide] Genetic, andrological and clinical characteristics... Int J Androl. 2001 Apr;24(2):73-9. Attardo T, Vicari E, Mollica F, Grazioso C, Burrello N, Garofalo MR, Lizzio MN, Garigali G, Cannizzaro M, Ruvolo G, D'Agata R, Calogero AE
Genetic, andrological and clinical characteristics of patients with congenital bilateral absence of the vas deferens.
Int J Androl. 2001 Apr;24(2):73-9., [PMID:11298840]

Abstract [show]
The possibility of retrieving spermatozoa from the epididymis allows patients with congenital bilateral absence of the vas deferens (CBAVD) to father a child by means of assisted reproduction techniques. This has, however, increased the chance of transmitting a mutated allele of the cystic fibrosis transmembrane conductance regulator (CFTR) gene which increases the risk of generating offspring with cystic fibrosis (CF). Because of the increased heterogeneity of the CFTR locus, the study of a discrete number of mutations, as usually carried out in a diagnostic work-up, is unable to ascertain the presence of a mutation in a relatively high proportion of the patients screened. In an attempt to increase the chance of detecting the presence of CFTR gene abnormalities, 37 patients with CBAVD and one patient with congenital unilateral agenesis of the vas deferens (CUAVD) underwent an enlarged diagnostic protocol, which included screening for the most expected mutations of the CFTR gene in our population, evaluation of the five thymidine (5T) allelic variant, sweat test, respiratory function tests, evaluation of steatocrit, and an accurate evaluation of the history of the patient to search for symptoms commonly found in patients with CF. A single CFTR gene mutation was found in 18 patients (48.6%) with CBAVD and in the patient with CUAVD. The most frequent mutation observed was the Delta F508. Eleven patients (45.8%) had the 5T variant and in five of them it was not associated with any detectable mutation of the CFTR gene. Two female partners were found to be carriers of a mutation, whereas 5 (18.5%) had the 5T variant. As many as 71% of CBVAD patients had the simultaneous presence of at least two signs and/or symptoms suggestive of CF, albeit they were of mild intensity and the patients felt fit and healthy. In conclusion, these results suggested that some patients with CBAVD without CFTR gene mutation or 5T variant, even when their sweat test is negative, may show clinical suspicion of carrying a CFTR gene mutation and therefore are at risk of generating children affected by CF if the partner carries a mutation as well. The screening for mutations and a careful clinical examination may contribute to better identification of patients with CFTR-related CBAVD.

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49 We investigated the following 11 CFTR mutations: DF508, G542X, R553X, N1303K, W1282X, R347P, L1077P, 2183AA ® G, 1717±1G > A, R1162X, and R117H. Login to comment
61 The other mutations found were: W1282X in four patients, G542X in two patients, R347P in one patient and R553X in one patient. Login to comment
87 38) with CUAVD Patient Age (years) Mutation/ 5T allele Sweat test Steatocrit FEV1 Other clinical features 1 38 R347P/ND Normal ND ND ND 2 29 DF508/ND ND ND ND ND 3 37 ±/ND ND ND ND ND 4 38 ±/ND ND ND ND ND 5 29 DF508/ND Normal ND = ND 6 40 ±/ND Normal ND = ND 7 32 DF508/ND Borderline ND = ND 8 29 DF508/ND ND ND ND ND 9 41 ±/ND Borderline ND ¯ ND 10 32 DF508/± Normal = = RB 11 35 R553X/± Borderline - = RB 12 29 ±/ND Borderline - = Diarrhoea 13 37 ±/ND Abnormal = = Sinusitis 14 36 W1282X/± Normal - = Recurrent bronchitis 15 35 G542X/± Abnormal = ¯ ± 16 34 W1282X/5T Abnormal = = Diarrhoea 17 31 ±/5T Abnormal = = ± 18 22 ±/± Borderline - = Diarrhoea 19 27 G542X/± Abnormal = = Recurrent bronchitis 20 35 ±/± Abnormal - = Recurrent bronchitis 21 33 W1282X/± Abnormal = ND Sinusitis, diarrhoea 22 30 DF508/5T Abnormal - = ± 23 20 ±/± Abnormal = = Sinusitis, diarrhoea 24 39 ±/± Normal = ¯ Asthma, collapse 25 35 ±/5T Normal - ¯ Sinusitis, diarrhoea 26 26 W1282X/5T Abnormal - = ± 27 35 ±/± Normal - = ± 28 30 DF508/5T Normal - = ± 29 29 DF508/ND ND ND ND Collapse 30 35 ±/5T Normal = ¯ ± 31 36 DF508/5T Borderline = ¯ Sinusitis, asthma, collapse, polyps 32 41 ±/5T Normal - ¯ Recurrent respiratory infection 33 39 ±/5T Normal = ¯ Sinusitis 34 27 DF508/5T Borderline - = ± 35 39 ±/± Normal ND ¯ Diarrhoea 36 37 ±/± Normal - = Polyps 37 40 ±/± Abnormal - ¯ Asthma, recurrent respiratory infection 38 29 G542X/5T Borderline - ¯ Diarrhoea ND: Not determined; ±: absence of mutations or clinical features; =: unchanged; -: increased; ¯: decreased. Login to comment

[hide] Ion channels-related diseases. Acta Biochim Pol. 2000;47(3):685-703. Dworakowska B, Dolowy K
Ion channels-related diseases.
Acta Biochim Pol. 2000;47(3):685-703., [PMID:11310970]

Abstract [show]
There are many diseases related to ion channels. Mutations in muscle voltage-gated sodium, potassium, calcium and chloride channels, and acetylcholine-gated channel may lead to such physiological disorders as hyper- and hypokalemic periodic paralysis, myotonias, long QT syndrome, Brugada syndrome, malignant hyperthermia and myasthenia. Neuronal disorders, e.g., epilepsy, episodic ataxia, familial hemiplegic migraine, Lambert-Eaton myasthenic syndrome, Alzheimer's disease, Parkinson's disease, schizophrenia, hyperekplexia may result from dysfunction of voltage-gated sodium, potassium and calcium channels, or acetylcholine- and glycine-gated channels. Some kidney disorders, e.g., Bartter's syndrome, policystic kidney disease and Dent's disease, secretion disorders, e.g., hyperinsulinemic hypoglycemia of infancy and cystic fibrosis, vision disorders, e.g., congenital stationary night blindness and total colour-blindness may also be linked to mutations in ion channels.

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311 Milder forms of the disease result from such mutations as Arg117His, Glu193Lys, Arg334Trp and Arg347Pro which produce channels that are less likely to open or have reduced amplitude (Sheppard et al., 1993; Seibert et al., 1997). Login to comment

[hide] ATP hydrolysis-coupled gating of CFTR chloride cha... Biochemistry. 2001 May 15;40(19):5579-86. Zou X, Hwang TC
ATP hydrolysis-coupled gating of CFTR chloride channels: structure and function.
Biochemistry. 2001 May 15;40(19):5579-86., 2001-05-15 [PMID:11341822]

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57 Neutralizing a positively charged residue (R334W or R347P) diminishes the channel conductance (18). Login to comment

[hide] Gastrointestinal, liver, and pancreatic involvemen... Pancreas. 2001 May;22(4):395-9. Modolell I, Alvarez A, Guarner L, De Gracia J, Malagelada JR
Gastrointestinal, liver, and pancreatic involvement in adult patients with cystic fibrosis.
Pancreas. 2001 May;22(4):395-9., [PMID:11345141]

Abstract [show]
BACKGROUND: The clinical prevalence of cystic fibrosis (CF) in adults continues to rise, with a consequent impact on adult gastroenterology practice. AIM: To characterize the gastrointestinal manifestations of CF in adult patients. PATIENTS AND METHODS: The clinical records of 89 adult CF patients treated at our institution from 1992 to 1999 were reviewed. Patients were distributed into two groups: group A (39 patients), which consisted of patients who were diagnosed with CF at when they were younger than 14 years old and who survived into adulthood; and group B (50 patients), who were diagnosed with CF at the age of 14 years or older. Data on CF genetic mutations, nutritional state, evidence of pulmonary, gastrointestinal, liver, or pancreatic involvement were collected for each patient. RESULTS: The most prevalent genetic mutation in our series was deltaF508, present in 50 patients (56.2%), 29 of whom belonged to group A and 21 who belonged to group B. In group A, the deltaF508 mutation was associated with exocrine pancreatic insufficiency (PI) in 26 of 29 patients (89.6%), whereas in group B it was associated with PI in only four patients (19%). Overall, PI was present in 33 of 39 patients (84.6%) in group A and in eight of 50 patients (16%) in group B. Four patients in group B had experienced previous episodes of acute pancreatitis; two of them had associated PI. Of the 89 patients, 12 (10 in group A) were malnourished. Malnutrition was invariably associated with PI. Hepatic and biliary tree abnormalities were particularly prevalent in patients in group A and was usually associated with PI. Intestinal manifestations were uncommon. CONCLUSIONS: Diagnosis of CF before the age of 14 years is associated with greater gastrointestinal compromise than diagnosis at an older age, particularly with regard to PI. CF carriers of the deltaF508 mutation have an increased risk of developing gastrointestinal manifestations.

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64 Other genotypes present in our series ⌬F508/711+1G>T 2A 5T/5T 1B ⌬F508/5T 2B ⌬1507/- 1A ⌬F508/R117H 2B R1162X/1898+1G>A 1A ⌬F508/R1162X 1A 2183A/- 1A ⌬F508/N1303K 1A 1609-CA/1811+1.6kbA>G 1A ⌬F508/3272-26A>G 1B 1609-CA/R347P 1A ⌬F508/D836Y 1B Q890X/- 1A ⌬F508/1717-1G>A 1A R334W/- 1B G542X/W1282X 1A N1303K/2789+5G>A 1B G542X/2789+5G>A 1B 3659-C/- 1B G542X/P205S 1B G85E/- 1B G542X/D1270N 1B Negative 1A, 20B L206W/- 1B Unknown 2A creatic insufficiency was highly prevalent, affecting 33 patients (84.6%). Login to comment

[hide] Analysis of the entire coding region of the cystic... Hum Mutat. 2001 Aug;18(2):166. Castellani C, Gomez Lira M, Frulloni L, Delmarco A, Marzari M, Bonizzato A, Cavallini G, Pignatti P, Mastella G
Analysis of the entire coding region of the cystic fibrosis transmembrane regulator gene in idiopathic pancreatitis.
Hum Mutat. 2001 Aug;18(2):166., [PMID:11462247]

Abstract [show]
Many Cystic Fibrosis (CF) carriers have been detected testing some subjects with chronic pancreatitis for a limited number of mutations. The aim of this study was to find out if some subjects with pancreatitis and a CFTR mutation actually carry another, undetected mutation. We screened for 18 CFTR mutations plus the CFTR intron 8 poly(T) tract length a population of 67 patients suffering from idiopathic either acute, or recurrent acute, or chronic pancreatitis. Three of them were diagnosed as affected by CF. Among the others, a subset of 14 (8 CFTR mutation carriers, 4 5T carriers, and 2 sweat chloride borderliners) was selected and analyzed by denaturing gradient gel electrophoresis. Six possibly CF-related mutations were detected: L997F and 3878delG were found in two of the subjects already carrying another mutation, S1235R and L997F in one patient carrying the 5T, and L997F and D614G in the two patients with borderline sweat chloride. Among the 14 selected cases a total of 11 patients carried at least one mutation, and three of them were compound heterozygotes. Though it is debatable whether these three individuals can be considered affected by CF, their pancreatitis is possibly a clinical manifestation of some CFTR-related disease. Hum Mutat 18:166, 2001.

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41 Genetic analysis Phase 1 - Patients were tested for the following mutations: F508del, I507del, R117H, R1162X, 2183AA>G, N1303K, 3849+10KbC>T, G542X, 1717-1G>A, R347P, R352Q, R553X, Q552X, G85E, 711+5G>A, W1282X, 3132delTG and 2789+5G>A, plus the CFTR intron 8 poly(T) tract length. Login to comment
43 The same genetic screening, with the exception of the R347P, R352Q, R117H mutations and of the poly(T) variant, was performed in the control population. Login to comment

[hide] Salt-independent abnormality of antimicrobial acti... Am J Respir Cell Mol Biol. 2001 Jul;25(1):21-5. Bals R, Weiner DJ, Meegalla RL, Accurso F, Wilson JM
Salt-independent abnormality of antimicrobial activity in cystic fibrosis airway surface fluid.
Am J Respir Cell Mol Biol. 2001 Jul;25(1):21-5., [PMID:11472971]

Abstract [show]
The link between the genetic defect in cystic fibrosis (CF) and the recently described breach in pulmonary host defense has focused on the role of salt and water metabolism in the airways. Using a human bronchial xenograft model we demonstrate a salt-independent abnormality in bacterial killing in CF airway surface fluid (ASF). Biochemical characterization implicates the absence or dysfunction of a molecule critical to the constitution of normal bacterial killing. Our study suggests that CF transmembrane conductance regulator (CFTR) deficiency causes a primary abnormality in the composition of ASF that leads to a salt-independent defect in host defense. Importantly, this defect is corrected by adenovirus-mediated gene transfer of CFTR.

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35 R347P, and one ⌬F508/unknown; plus one G542X/unknown, one 621 ϩ 1G Ͼ T/W1282X, and four unknown) and their bacteriology (three Staphylococcus aureus positive, three Pseudomonas aeruginosa positive, and four other positive results). Login to comment

[hide] High morbidity and mortality in cystic fibrosis pa... Eur Respir J. 2001 Jun;17(6):1181-6. Schibler A, Bolt I, Gallati S, Schoni MH, Kraemer R
High morbidity and mortality in cystic fibrosis patients compound heterozygous for 3905insT and deltaF508.
Eur Respir J. 2001 Jun;17(6):1181-6., [PMID:11491162]

Abstract [show]
Genotype-phenotype association in cystic fibrosis (CF) is difficult because of heterogeneous disease expression. The genotype-phenotype correlation for the 3905insT mutation in comparison to deltaF508 was studied here. Thirty CF patients compound heterozygous for 3905insT were compared to clinical presentation of matched patients homozygous for deltaF508 (1960-1997). Sweat tests, age at diagnosis, at death and at onset of Pseudomonas aeruginosa colonization were analysed. Chrispin-Norman scores and pulmonary function forced expiratory volume in one second (FEV1) determined severity of lung disease. Twenty-five of the patients with 3905insT had deltaF508 as a second mutation and five had another rare mutation. At the age of 15 yrs, 60% of patients with 3905insT had an FEV1 < 60% predicted in comparison to 25% of patients with deltaF508 (p<0.05). Age at death and cumulative survival rate was significantly lower (p<0.05) in the 3905insT than in the deltaF508 group (20.3 and 24.0 yrs, respectively). Age at onset of P. aeruginosa colonization was not different in the study groups. Sweat chloride concentrations were lower in patients homozygous for deltaF508 (105.63+/-15.3 mmol L(-1)) than in patients with 3905insT (119.9+/-22.1 mmol x L(-1)) (p<0.05). Patients compound heterozygous for 3905insT have similar high morbidity and mortality to patients homozygous for deltaF508.

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28 Twenty-five of these patients showed compound heterozygosity for DF508 and 3905insT, two patients heterozygosity for R553X and 3905insT, one patient for 1717-GRA and 3905insT, one patient for R347P and 3905insT and one patient with an unknown mutation and 3905insT. Login to comment
46 R553X and K710X are nonsense mutations in exon 11 and 13, respectively, whereas R347P is a missense mutation in exon 7. Login to comment
138 One patient compound heterozygous for 3905insT/R347P showed normal lung function tests at the age of 37 yrs, no P. aeruginosa colonization, normal body weight and a normal chest radiograph. Login to comment
140 In comparison to compound heterozygosity for 3905insT and DF508, the R347P mutation, together with 3905insT, seems to play a dominant role leading to a less severe clinical course. Login to comment

[hide] Intron-8 polythymidine sequence in Australasian in... Eur Respir J. 2001 Jun;17(6):1195-200. Massie RJ, Poplawski N, Wilcken B, Goldblatt J, Byrnes C, Robertson C
Intron-8 polythymidine sequence in Australasian individuals with CF mutations R117H and R117C.
Eur Respir J. 2001 Jun;17(6):1195-200., [PMID:11491164]

Abstract [show]
Compound heterozygotes for a severe cystic fibrosis transmembrane conductance regulator (CFTR) mutation and the R117H or R117C mutation (R117H/C) have clinical presentations that vary from classic cystic fibrosis (CF) to an incidental genetic finding. The aim of this study was to assess the influence of the intron-8 polythvmidine sequence (IVS8) on the relationship between genotype and phenotype of individuals with R117H/C. All individuals with R117H/C known to CF clinics in Australia and New Zealand were retrospectively studied by collecting information on genotype, age, pancreatic status, sweat electrolytes, sputum microbiology and pulmonary function. Forty-one individuals (39 with R117H and two with R117C), 16 on an IVS8-5T background and 25 on an IVS8-7T background were identified. Twelve individuals presented clinically, four were siblings of known R117H/C compound heterozygotes and 25 were detected by newborn screening. Eleven of 14 of the IVS8-5T group (78%) with sweat chloride results available had sweat CI > 60 mmol x L(-1) compared to 5 (20%) of the R117H/7T group (Chi-squared=10.4, p=0.001). Two were pancreatic insufficient, both IVS8-5T. Two IVS8-5T individuals have recently died (aged 43 and 19) and of the 14 surviving IVS8-5T group, 11 (79%) are symptomatic compared to eight (32%) of the IVS8-7T individuals (Chi-squared=6.1, p=0.01). In conclusion, most individuals with R117H/C on a IVS8-5T background have an elevated sweat chloride and clinical cystic fibrosis, which in some cases is severe. Most individuals with R117H/C on an IVS8-7T background do not have clinical cystic fibrosis but should be followed for the development of clinical disease.

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41 Infants with a positive (w60 mmol?L-1 ) or borderline (40 - 60 mmol?L-1 ) sweat chloride and in whom there is an unidentified mutation are referred for an extended mutation analysis which includes: DF508, R117H, G551D, A455E, G542X, N1303K, W1282X, 1717-1, R560T, R347P, R334W, R1162X, S549N, 621z1, 3849z10CwT, and the IVS8 polythymidine sequence. Login to comment

[hide] A combined analysis of the cystic fibrosis transme... Mol Biol Evol. 2001 Sep;18(9):1771-88. Chen JM, Cutler C, Jacques C, Boeuf G, Denamur E, Lecointre G, Mercier B, Cramb G, Ferec C
A combined analysis of the cystic fibrosis transmembrane conductance regulator: implications for structure and disease models.
Mol Biol Evol. 2001 Sep;18(9):1771-88., [PMID:11504857]

Abstract [show]
Over the past decade, nearly 1,000 variants have been identified in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in classic and atypical cystic fibrosis (CF) patients worldwide, and an enormous wealth of information concerning the structure and function of the protein has also been accumulated. These data, if evaluated together in a sequence comparison of all currently available CFTR homologs, are likely to refine the global structure-function relationship of the protein, which will, in turn, facilitate interpretation of the identified mutations in the gene. Based on such a combined analysis, we had recently defined a "functional R domain" of the CFTR protein. First, presenting two full-length cDNA sequences (termed sCFTR-I and sCFTR-II) from the Atlantic salmon (Salmo salar) and an additional partial coding sequence from the eastern gray kangaroo (Macropus giganteus), this study went further to refine the boundaries of the two nucleotide-binding domains (NBDs) and the COOH-terminal tail (C-tail), wherein NBD1 was defined as going from P439 to G646, NBD2 as going from A1225 to E1417, and the C-tail as going from E1418 to L1480. This approach also provided further insights into the differential roles of the two halves of CFTR and highlighted several well-conserved motifs that may be involved in inter- or intramolecular interactions. Moreover, a serious concern that a certain fraction of missense mutations identified in the CFTR gene may not have functional consequences was raised. Finally, phylogenetic analysis of all the full-length CFTR amino acid sequences and an extended set of exon 13--coding nucleotide sequences reinforced the idea that the rabbit may represent a better CF model than the mouse and strengthened the assertion that a long-branch attraction artifact separates the murine rodents from the rabbit and the guinea pig, the other Glires.

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100 Moreover, all of the 11 most common missense mutations or single-amino-acid deletions (i.e., F508del, G551D, N1303K, R117H, R347P, I507del, G85E, R560T, A455E, R334W, and S549N) identified in classic and atypical CF patients worldwide (http://www.genet.sickkids.on.ca/cftr) occur in stringently conserved residues across the 15 CFTR sequences. Login to comment

[hide] Mutations of the cystic fibrosis gene in patients ... Am J Gastroenterol. 2001 Sep;96(9):2657-61. Truninger K, Malik N, Ammann RW, Muellhaupt B, Seifert B, Muller HJ, Blum HE
Mutations of the cystic fibrosis gene in patients with chronic pancreatitis.
Am J Gastroenterol. 2001 Sep;96(9):2657-61., [PMID:11569691]

Abstract [show]
OBJECTIVE: Several studies have reported an increased frequency of cystic fibrosis gene mutations in idiopathic but not in alcoholic chronic pancreatitis. The impact of cystic fibrosis gene mutations on the long-term course of chronic pancreatitis has not been analyzed. The aim of our study was to determine the frequency of cystic fibrosis gene mutations in patients with chronic pancreatitis with long-term follow-up and to see whether patients with mutations have a clinically different natural course compared to those without mutations. METHODS: Eighty two patients with chronic pancreatitis and 11 patients with recurrent acute pancreatitis of our well defined pancreatitis cohort were screened for the 31 most common cystic fibrosis gene mutations. The impact of cystic fibrosis gene mutations on the long-term course of chronic pancreatitis was assessed. RESULTS: A cystic fibrosis gene mutation was detected in five of 49 patients with alcoholic chronic pancreatitis (10.2%; 2.3 times the expected frequency) and in three of 14 patients with idiopathic-juvenile chronic pancreatitis (21.4%; 4.8 times the expected frequency). No mutations were found in the remaining patients with chronic pancreatitis of rare causes, hereditary pancreatitis, and recurrent acute pancreatitis. The frequency of pancreatic calcifications was significantly higher in patients with alcoholic chronic pancreatitis without mutations. This result was not confirmed in patients with idiopathic-juvenile chronic pancreatitis. The duration of pain and the frequency of exocrine and endocrine insufficiency was comparable in both subgroups irrespective of the mutation status. CONCLUSION: Our data indicate a significantly increased frequency of cystic fibrosis gene mutations both in patients with alcoholic and idiopathic-juvenile chronic pancreatitis. The natural course was similar in patients with mutations compared to those without mutations.

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56 Using multiplex PCR, 15 genomic fragments were amplified which contain the following mutations: ⌬F508, ⌬I507, Q493X, V520F, 1717-1G3A, G542X, G551D, R553X, R560T, S549R, S549N, 3849 ϩ 10kbC3T, 3849 ϩ 4A3G, R1162X, 3659delC, W1282X, 3905insT, N1303K, G85E, 621 ϩ 1G3T, R117H, Y122X, 711 ϩ 1G3T; 1078delT, R347P, R347H, R334W, A455E, 1898 ϩ 1G3A, 2183AA3G, 2789 ϩ 5G3A. Login to comment

[hide] Cystic fibrosis phenotype evaluation and paternity... Hum Reprod. 2001 Oct;16(10):2093-7. Josserand RN, Bey-Omar F, Rollet J, Lejeune H, Boggio D, Durand DV, Durieu I
Cystic fibrosis phenotype evaluation and paternity outcome in 50 males with congenital bilateral absence of vas deferens.
Hum Reprod. 2001 Oct;16(10):2093-7., [PMID:11574497]

Abstract [show]
BACKGROUND: Most infertile males with congenital bilateral absence of vas deferens (CBAVD) carry mutations on the cystic fibrosis transmembrane conductance regulator gene and may express mild cystic fibrosis (CF) symptoms. Barriers to paternity for these men can now be overcome by assisted reproduction. Our aims were to investigate the CF-related phenotype and clinical outcome for 50 patients with CBAVD seen at a CF adult centre between 1992 and 1999. METHODS AND RESULTS: The investigation of the patients included screening for 22 CF mutations and identification of the poly-T variant of intron 8, sweat testing, clinical investigation for CF-related extra-genital manifestations, and genetic counselling. CFTR mutations were detected on 56 alleles of the 50 patients. A total of 15 (30%) was compound heterozygote and 26 (52%) heterozygote. In all, 38% of the patients had a positive sweat test. Four patients were diagnosed with typical CF not detected previously. Twenty-one patients became fathers following ICSI (eight cases), artificial insemination by donor or IVF with sperm donor (seven cases) or through adoption (six cases). A mail survey allowed the identification of CF-related clinical symptoms. Information on the occurrence of CF-related symptoms was obtained for 58.5% of patients: in the absence of initial symptoms, no new clinical signs were reported. CONCLUSION: Patients diagnosed with CBAVD need genetic counselling before assisted reproduction. Even when no wish for paternity is expressed, CF gene screening should be associated with at least a sweat test and clinical evaluation because of possible mild forms of CF disease. Medical follow-up did not reveal any new symptoms.

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30 Leukocytes samples were analysed for a series of 22 CF mutations including the five most frequently encountered in our region (The CF Genotype Consortium, 1994): ∆F508, G542X, N1303K, 1717-G-A, 885E; and 17 others: R117H, R334W, R347H, R347P, 556delA, S549N, S549I, S549R, G551D, R553X, R560T, G1244E, S1255X, W1282X, R1283K, 3898ins C, D1270N. Login to comment

[hide] Analysis of exocrine pancreatic function in cystic... Eur J Clin Invest. 2001 Sep;31(9):796-801. Walkowiak J, Herzig KH, Witt M, Pogorzelski A, Piotrowski R, Barra E, Sobczynska-Tomaszewska A, Trawinska-Bartnicka M, Strzykala K, Cichy W, Sands D, Rutkiewicz E, Krawczynski M
Analysis of exocrine pancreatic function in cystic fibrosis: one mild CFTR mutation does not exclude pancreatic insufficiency.
Eur J Clin Invest. 2001 Sep;31(9):796-801., [PMID:11589722]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is the most common cause of exocrine pancreatic insufficiency in childhood. The aim of the present study is to evaluate the correlation between genotype and exocrine pancreatic insufficiency in CF patients. The special emphasis was put on the analysis of mild CFTR mutations. DESIGN: The study comprised 394 CF patients and 105 healthy subjects (HS). Elastase-1 concentrations were measured in all subjects. RESULTS: Severe pancreatic insufficiency was associated with the presence of two CFTR gene mutations (DeltaF508, N1303K, CFTR dele 2,3 (21kb), G542X, 1717-1G-A, R533X, W1282X, 621GT, 2183AAG, R560T, 2184insA and DeltaI507, G551D, 895T) and mild insufficiency with the presence of at least one mutation (R117H, 3171insC, A155P2, 138insL, 296 + 1G-A, E92GK, E217G, 2789 + 5G-A. 3849 + 1kbC-T/3849 + 1kbC-T) genotype resulted in high elastase-1-values. However, in case of patients with genotype DeltaF508/3849 + 10kbC-T, 1717-1GA/3849 + 10kbC-T as well as with DeltaF508/R334W, both high and low elastase-1 concentrations were found. Low E1 values were found in a patient with DeltaF508/R347P genotype. CONCLUSION: Patients who carry two 'severe' mutations develop pancreatic insufficiency, whereas those who carry at least one 'mild' usually remain pancreatic sufficient. However, the presence of one mild mutation does not exclude pancreatic insufficiency.

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8 Low E1 values were found in a patient with DF508/R347P genotype. Login to comment
51 Results Among 394 genotyped CF patients, the following mutations on alleles were found (n): DF508 (464), 3849 1 10kbC-T (30), CFTR dele2,3(21 kB) (21), N1303K (15), G542X (12), 1717±1G-A (9), R533X (6), W1282X (6), 621 1 G-T (3), R117H (2), 3171insC (2), A155P2 (2), 2183AAG (2), R334W (2), 895T (2), 296 1 1G-A (2), E92GK (2), 138insL (1), E217G (1), 2789 1 5G-A (1), R347P (1), R560T (1), 2184insA (1), I507 (1), G551D (1). Login to comment
61 Low E1 concentrations were found in a patient with DF508/R347P genotype. Login to comment
81 500 DF508/3849 1 10kbC-T (17) 1 4 1 6 5 DF508/CFTR dele2,3(21kb) (15) 9 4 2 DF508/N1303K (10) 7 3 DF508/1717±1G-A (7) 5 2 DF508/G542X (7) 4 2 1 DF508/W1282X (5) 4 1 DF508/R553X (3) 3 DF508/R334W (2) 1 1 DF508/2183AAG (2) 2 DF508/R117H (1) 1 DF508/621GT (1) 1 DF508/R347P (1) 1 DF508/2184insA (1) 1 DF508/DI507 (1) 1 3849 1 10kbC-T/3849 1 10kbC-T (3) 3 N1303K/CFTR dele2,3(21kb) (2) 1 1 1717±1G-A/3849 1 10kbC-T (2) 1 1 3171insC/A155P2 (2) 1 1 296 1 1G-A/E92GK (2) 2 R117H/138insL (1) 1 W1282X/3849 1 10kbC-T (1) 1 N1303K/3849 1 10kbC-T (1) 1 CFTR dele2,3(21kb)/3849 1 10kbC-T (1) 1 R553X/G542X (1) 1 621 1 1G-T/621 1 1G-T (1) 1 G542X/M (4) 2 2 CFTR dele 2,3(21kb)/M (1) 1 2 3849 1 10kbC-T/M (2) 1 1 R533X/M (2) 2 N1303K/M (2) 2 895T/M (2) 1 1 E217G/M (1) 1 G551D/M (1) 1 R560T/M (1) 1 2789 1 5G-A/M (1) 1 Total (109) 44 21 10 4 12 18 M, unidentified mutation. Login to comment
93 In contrast to the results of the above mentioned studies [8,10,11], our patients with the mutations for 3849 1 10kbC-T (class V), R334W and R347P (class IV) combined with DF508 or 1717±1G-A presented also as pancreatic insufficient. Login to comment

[hide] A phase I study of aerosolized administration of t... Hum Gene Ther. 2001 Oct 10;12(15):1907-16. Aitken ML, Moss RB, Waltz DA, Dovey ME, Tonelli MR, McNamara SC, Gibson RL, Ramsey BW, Carter BJ, Reynolds TC
A phase I study of aerosolized administration of tgAAVCF to cystic fibrosis subjects with mild lung disease.
Hum Gene Ther. 2001 Oct 10;12(15):1907-16., 2001-10-10 [PMID:11589832]

Abstract [show]
Cystic fibrosis (CF) is one of the most common autosomal recessive disorders in North America, leading to significant morbidity and early mortality. The defect in the cystic fibrosis transmembrane conductance regulator protein (CFTR) function can be corrected in vitro by gene replacement with a wild-type gene. A Phase I, single administration, dose escalation trial was designed and executed to assess safety and delivery of tgAAVCF, an adeno-associated virus (AAV) vector encoding the human CFTR cDNA, by nebulization to the lungs of CF subjects. Four cohorts of three subjects each were administered increasing doses of the study agent, beginning with 10(10) DNase-resistant particles (DRP) and escalating in log increments up to 10(13) DRP. Sequential bronchoscopies were performed to gather analytical samples throughout the study. All 12 subjects completed the study. There were a total of 242 adverse events (AEs), six of which were defined as serious and three of which were defined as possibly being related to the study drug. A clear dose-response relationship was observed in vector gene transfer. A maximum of 0.6 and 0.1 vector copies per brushed cell were observed 14 days and 30 days, respectively, following nebulization of 10(13) DRP tgAAVCF, and this declined to nearly undetectable levels by day 90. Vector gene transfer was evenly distributed throughout the fourth airway generation following single-dose administration. RNA-specific PCR did not detect vector-derived mRNA. This Phase I trial shows that aerosolized tgAAVCF is safe and widely delivered to the proximal airways of CF subjects by nebulization.

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156 SUBJECT DEMOGRAPHICS Age Day (214) tgAAVCF Subject Gender (years) CF mutation FEV1% dose 101 M 29 F508/F508 71 1010 102 F 40 F508/unknown 90 1010 103 F 34 F508/unknown 79 1010 301 M 37 F508/F508 63 1011 104 F 28 F508/unknown 104 1011 105 F 38 F508/F508 79 1011 201 F 29 F508/unknown 99 1012 302 M 24 F508/R347P 65 1012 106 F 28 F508/R334W 69 1012 203 M 41 G551D/G551D 64 1013 303 M 19 F508/F508 82 1013 107 F 26 F508/unknown 75 1013 TABLE 2. Login to comment

[hide] ATB(0)/SLC1A5 gene. Fine localisation and exclusio... Eur J Hum Genet. 2001 Nov;9(11):860-6. Larriba S, Sumoy L, Ramos MD, Gimenez J, Estivill X, Casals T, Nunes V
ATB(0)/SLC1A5 gene. Fine localisation and exclusion of association with the intestinal phenotype of cystic fibrosis.
Eur J Hum Genet. 2001 Nov;9(11):860-6., [PMID:11781704]

Abstract [show]
The Na+-dependent amino acid transporter named ATB(0) was previously found to be located in 19q13.3 by fluorescence in situ hybridisation. Genetic heterogeneity in the 19q13.2-13.4 region, syntenic to the Cystic Fibrosis Modulator Locus 1 (CFM1) in mouse, seemed to be associated to the intestinal phenotypic variation of cystic fibrosis (CF). We performed fine chromosomal mapping of ATB(0) on radiation hybrid (RH) panels G3 and TNG. Based on the most accurate location results from TNG-RH panel, mapping analysis evidenced that ATB(0) is localised between STS SHGC-13875 (D19S995) and STS SHGC-6138 in 19q13.3, that corresponds with the immediately telomeric/distal segment of the strongest linkage region within the human CFM1 (hCFM1) syntenic region. Regarding to the genomic structure and exon organisation, our results show that the ATB(0) gene is organised into eight exons. The knowledge of the genomic structure allowed us to perform an exhaustive mutational analysis of the gene. Evaluation of the possible implication of ATB(0) in the intestinal phenotype of CF was performed on the basis of the functional characteristics of the encoded protein, its apparent relevance to meconium ileus (MI) and position in relation to the hCFM1 syntenic region. We have analysed this gene in samples from CF patients with and without MI. Several sequence variations in the ATB(0) gene were identified, although none of them seemed to be related to the intestinal phenotype of CF. Even though no particular allele or haplotype in ATB(0) appears to be associated to CF-MI disease, new SNPs identified should be useful in segregation and linkage disequilibrium analyses in families affected by other disorders caused by the impairment of neutral amino acid transport.

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151 Statistical analysis showed that the higher incidence for P17A and the lower incidence for V512L observed in the general population Table 3 CFTR mutations of the CF patients under study with and without meconium ileus (MI) CF-non MI CF-MI CFTR mutations n CFTR mutations n F508del/R117H 2 F508del/F508del 7 F508del/R334W 3 F508del/L365P 1 F508del/R347P 1 F508del/G542X 1 F508del/621+1G4Ta 1 F508del/621+IG4Ta 1 F508del/M1101K 1 F508del/R1066C 1 F508del/1609delCAa 1 F508del/W1089X 1 F508del/2789+5G4Aa 3 F508del/R1162X 1 F508del/3849+10kbC4T 1 F508del/1609delCAa 1 G542X/G85E 1 F508del/Q1281X 1 G542X/V232D 1 F508del/1811+1.6kbA4G 1 G542X/1811+1.6kb A4Ga 1 F508del/2789+5G4Aa 1 G542X/2789+5G4A 1 F508del/2869insG 1 Q890X/L206W 1 F508del/unknown 1 1811+1.6kbA4G/P205S 1 I507del/I507del 1 R1162X/3272-26A4G 1 G542X/1078delT 1 N1303K/R347H 1 G542X/1811+1.6kbA4Ga 1 N1303K/A1006E+5T 1 S549R/CFTR50kbdel 1 2789+5G4A/405+1G4A 1 R1066C/R1066C 1 W1282X/712-1G4T 1 a CF patient with a sibling presenting identical CFTR genotype and discordance of intestinal phenotype. Login to comment

[hide] Cystic fibrosis mutation testing in Italy. Genet Test. 2001 Fall;5(3):229-33. Bombieri C, Pignatti PF
Cystic fibrosis mutation testing in Italy.
Genet Test. 2001 Fall;5(3):229-33., [PMID:11788089]

Abstract [show]
In Italy, Cystic fibrosis (CF) mutation frequency differences have been observed in different regions. In the northeastern Veneto and Trentino Alto Adige regions, a complete cystic fibrosis transmembrane conductance regulator (CFTR) gene screening in CF patients detected through a newborn screening program has identified about 90% of the mutations. In these two regions, the current detection rate using a CF screening panel containing the 16 most common mutations is 86.6%. CF mutations in some other Italian regions have not been so thoroughly analysed. Available data indicate that a more general national screening panel comprising 31 mutations may detect about 75% of all CF mutations in Italy.

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24 Three of the 7 mutations found only once in the 225 alleles tested were included, because they were present in the mutation detection kits available: R347P, G541D, and 3849110KbC R T. Login to comment
35 CF MUTATIONS IDENTIFIED IN TWO ITALIAN REGIONS (VENETO AND TRENTINO ALTO ADIGE) Number of alleles Frequency Cumulative Mutation with mutation (%) frequency (%) DF508 107 47.6 47.56 R1162X 22 9.8 57.33 2183 AA ® G 21 9.3 66.67 N1303K 9 4.0 70.67 G542X 6 2.7 73.33 711 1 5 G ® A 6 2.7 76.00 1717-1 G ® A 5 2.2 78.22 G85E 3 1.3 79.56 R553X 3 1.3 80.89 2789 1 5 G ® A 3 1.3 82.22 Q552X 3 1.3 83.56 621 1 1 G ® T 2 0.9 84.44 W1282X 2 0.9 85.33 R347P 1 0.4 85.77 G551D 1 0.4 86.21 3849 1 10 Kb C ® T 1 0.4 86.67a 3132 del TG 2 0.9 87.54 2790-2 A ® G 2 0.9 88.43 457 TAT ® G 1 0.4 88.87 1717-8 G ® A 1 0.4 89.31 R709X 1 0.4 89.75 1898 1 3 A ® G 1 0.4 90.22 Total 203 90.22 Numbers refer to CFTR gene alleles carrying the specified mutation, over total tested alleles (n 5 225) from the affected subjects CF cohort, as indicated in the text (from Bonizzato et al., 1995). Login to comment
38 CF MUTATION PANEL (VENETO AND TRENTINO ALTO ADIGE ITALIAN REGIONS) DF508 R1162X 2183 AA ® G N1303K G542X 711 1 5 G ® A 1717-1 G ® A G85E R553X 2789 1 5 G ® A Q552X 621 1 1 G ® T W1282X R347P G551D 3849 1 10 Kb C ® T Note: Contrary to what is suggested for the U.S. population (Grody et al., 2001), R117H mutation (and its reflex IVS8-5T test) is not included in the panel because it is not commonly found in the Italian CF population (Bonizzato et al., 1995; Estivill et al., 1997; Rendine et al., 1997). Login to comment
44 CF GENE MUTATIONS IN ITALY Number of alleles Frequency Cumulative Mutation screened (%) frequency (%) DF508 3442 51.07 51.07 N1303K 3056 4.84 55.91 G542X 3082 4.83 60.75 2183 AA ® G 2596 2.66 63.41 R1162X 2580 2.42 65.83 1717-1 G ® A 2892 2.11 67.94 W1282X 2600 1.23 69.17 R553X 2882 1.15 70.31 T338I 2306 0.69 71.01 R347P 2642 0.61 71.61 711 1 5 G ® A 2454 0.57 72.18 G85E 1980 0.40 72.59 621 1 1 G ® T 2594 0.39 72.97 R334W 2366 0.30 73.27 R352Q 2112 0.24 73.50 S549N 2118 0.24 73.74 R347H 2184 0.18 73.92 L1077P 1840 0.16 74.09 R1158X 1878 0.16 74.25 541del C 1884 0.16 74.40 R1066H 1918 0.16 74.56 E585X 1922 0.16 74.72 Q552X 2172 0.14 74.86 D1152H 1824 0.11 74.97 2790-2 A ® G 1862 0.11 75.07 3132 del TG 1862 0.11 75.18 3667ins 4 1876 0.11 75.29 DI507 1914 0.10 75.39 1898 1 3 A ® G 1920 0.10 75.50 G1244E 1960 0.10 75.60 1784 del G 2052 0.10 75.69 From Rendine et al. (1997). Login to comment

[hide] Activation of ion secretion via proteinase-activat... Am J Physiol Gastrointest Liver Physiol. 2002 Feb;282(2):G200-10. Mall M, Gonska T, Thomas J, Hirtz S, Schreiber R, Kunzelmann K
Activation of ion secretion via proteinase-activated receptor-2 in human colon.
Am J Physiol Gastrointest Liver Physiol. 2002 Feb;282(2):G200-10., [PMID:11804840]

Abstract [show]
Proteinase-activated receptor (PAR) type 2 (PAR-2) has been shown to mediate ion secretion in cultured epithelial cells and rat jejunum. With the use of a microUssing chamber, we demonstrate the role of PAR-2 for ion transport in native human colonic mucosa obtained from 30 normal individuals and 11 cystic fibrosis (CF) patients. Trypsin induced Cl(-) secretion when added to the basolateral but not luminal side of normal epithelia. Activation of Cl(-) secretion by trypsin was inhibited by indomethacin and was further increased by cAMP in normal tissues but was not present in CF colon, indicating the requirement of luminal CF transmembrane conductance regulator. Effects of trypsin were largely reduced by low Cl(-), by basolateral bumetanide, and in the presence of barium or clotrimazole, but not by tetrodotoxin. Furthermore, trypsin-induced secretion was inhibited by the Ca(2+)-ATPase inhibitor cyclopiazonic acid and in low-Ca(2+) buffer. The effects of trypsin were almost abolished by trypsin inhibitor. Thrombin, an activator of PAR types 1, 3, and 4, had no effects on equivalent short-circuit currents. The presence of PAR-2 in human colon epithelium was confirmed by RT-PCR and additional experiments with PAR-2-activating peptide. PAR-2-mediated intestinal electrolyte secretion by release of mast cell tryptase and potentiation of PAR-2 expression by tumor necrosis factor-alpha may contribute to the hypersecretion observed in inflammatory processes such as chronic inflammatory bowel disease.

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50 Testing of an additional panel of the 19 most prevalent CFTR mutations among the Caucasian population in Europe, including G542X, N1303K, 1717-1 GϾT, W1282X, G551D, R553X, R1162X, R334W, R117H, 621ϩ1GϾT, 3849ϩ10kbCϾT, 3659delC, 1078delT, R347P, A445E, S1251N, ⌬I507, 2183AAϾG, and E60X (ELUCIGENE CF20; AstraZeneca Diagnostics) failed to identify the second disease causing mutation in six CF patients. Login to comment

[hide] Genetic and clinical features of false-negative in... Acta Paediatr. 2002;91(1):82-7. Padoan R, Genoni S, Moretti E, Seia M, Giunta A, Corbetta C
Genetic and clinical features of false-negative infants in a neonatal screening programme for cystic fibrosis.
Acta Paediatr. 2002;91(1):82-7., [PMID:11883825]

Abstract [show]
A study was performed on the delayed diagnosis of cystic fibrosis (CF) in infants who had false-negative results in a neonatal screening programme. The genetic and clinical features of false-negative infants in this screening programme were assessed together with the efficiency of the screening procedure in the Lombardia region. In total, 774,687 newborns were screened using a two-step immunoreactive trypsinogen (IRT) (in the years 1990-1992), IRT/IRT + delF508 (1993-1998) or IRT/IRT + polymerase chain reaction (PCR) and oligonucleotide ligation assay (OLA) protocol (1998-1999). Out of 196 CF children born in the 10 y period 15 were false negative on screening (7.6%) and molecular analysis showed a high variability in the genotypes. The cystic fibrosis transmembrane regulator (CFTR) gene mutations identified were delF508, D1152H, R1066C, R334W, G542X, N1303K, F1052V, A120T, 3849 + 10kbC --> T, 2789 + 5G --> A, 5T-12TG and the novel mutation D110E. In three patients no mutation was identified after denaturing gradient gel electrophoresis of the majority of CFTR gene exons. Conclusion: The clinical phenotypes of CF children diagnosed by their symptoms at different ages were very mild. None of them presented with a severe lung disease. The majority of them did not seem to have been damaged by the delayed diagnosis. The combination of IRT assay plus genotype analysis (1998-1999) appears to be a more reliable method of detecting CF than IRT measurement alone or combined with only the delF508 mutation.

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34 It was initially performed by polyacrylamide gel electrophoretic (PAGE) analysis for the delF508 mutation, and later by polymerase chain reaction (PCR) and oligonucleotide ligation assay (OLA) (31 mutations: G85E, 621 ‡ 1G ® T, R117H, Y122X, 711 ‡ 1G ® T, 1078delT, R347P, R347H, R334W, A455E, 1898 ‡ 1G ® A, 2183-AA ® G, 2789 ‡ 5G ® A, DelF508, I507del, Q493X, V520F, 1717-1G ® A, G542X, G551D, R553X, R560T, S549R, S549N, 3849 ‡ 10kbC ® T, 3849 ‡ 4A ® G, R1162X, 3659delC, W1282X, 3905insT, N1303K) (14). Login to comment
40 Mutation Frequency (%) DelF508 54 N1303K 8 G542X 6.25 1717-1G ® A 2.50 R334W 1.75 2183AA ® G 1.50 R117H, L1077P, W1282X 1.25 D110E, R347P, E585X, 2789 ‡ 5G ® A 0.75 R352Q, R553X, R1066H, D1152H, R1158X, 1782delA, 1898 ‡ 1G ® A, 3659delC 0.50 G85E, R117L, G178R, D579G, H609R, Y1032C, V1153E, R1162X, 621 ‡ 1G ® T, 711 ‡ 1G ® T, 1845delAG o 1846delGA, 2143delT 0.25 Table2.Differencesinthethreestrategiesofneonatalscreening(audit1990-1999). Login to comment

[hide] The relationship between genotype and exercise tol... Am J Respir Crit Care Med. 2002 Mar 15;165(6):762-5. Selvadurai HC, McKay KO, Blimkie CJ, Cooper PJ, Mellis CM, Van Asperen PP
The relationship between genotype and exercise tolerance in children with cystic fibrosis.
Am J Respir Crit Care Med. 2002 Mar 15;165(6):762-5., 2002-03-15 [PMID:11897641]

Abstract [show]
The relationship between fitness and genotype in children with cystic fibrosis (CF) and at least one copy of the DeltaF508 mutation was examined. Genotype was classified according to the second CF mutation. Fitness was measured by peak aerobic capacity (using a modified Bruce protocol during treadmill exercise) and anaerobic power (using the Wingate test on a cycle ergometer). The class of cystic fibrosis transmembrane regulator proteins (CFTR) mutation was statistically related with aerobic capacity, peak anaerobic power, body mass index, lung function (forced expiratory volume in one second), and disease severity as measured by the Shwachman score. Patients with mutations causing defective CFTR production (Class I) or processing (Class II) had a significantly lower peak aerobic capacity (28.6 +/- 4.2 ml/kg/min and 31.7 +/- 5.4 ml/kg/min, respectively) than those with a mutation conferring defective regulation of CFTR (Class III) (43.9 +/- 6.4 ml/kg/min). The peak anaerobic power in subjects with mutations inducing decreased CFTR conduction (Class IV) or CFTR mRNA (Class V), were significantly higher (11.4 +/- 1.7 and 11.6 +/- 1.5 watts/kg, respectively) than children with Class I (9.7 +/- 1.4 watts/kg), Class II (9.8 +/- 1.4 watts/kg), or Class III (10.5 +/- 1.8 watts/kg) mutations. There were no statistically significant differences in the lung function of patients with the different mutations. These results indicate a relationship between CF genotype and some measures of fitness, the mechanisms of which remain to be determined.

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19 The genes R117H and R347P are examples of class IV mutations. Login to comment

[hide] DHPLC screening of cystic fibrosis gene mutations. Hum Mutat. 2002 Apr;19(4):374-83. Ravnik-Glavac M, Atkinson A, Glavac D, Dean M
DHPLC screening of cystic fibrosis gene mutations.
Hum Mutat. 2002 Apr;19(4):374-83., [PMID:11933191]

Abstract [show]
Denaturing high performance liquid chromatography (DHPLC) using ion-pairing reverse phase chromatography (IPRPC) columns is a technique for the screening of gene mutations. In order to evaluate the potential utility of this assay method in a clinical laboratory setting, we subjected the PCR products of 73 CF patients known to bear CFTR mutations to this analytic technique. We used thermal denaturation profile parameters specified by the MELT program tool, made available by Stanford University. Using this strategy, we determined an initial analytic sensitivity of 90.4% for any of 73 known CFTR mutations. Most of the mutations not detected by DHPLC under these conditions are alpha-substitutions. This information may eventually help to improve the MELT algorithm. Increasing column denaturation temperatures for one or two degrees above those recommended by the MELT program allowed 100% detection of CFTR mutations tested. By comparing DHPLC methodology used in this study with the recently reported study based on Wavemaker 3.4.4 software (Transgenomic, Omaha, NE) [Le Marechal et al., 2001) and with previous SSCP analysis of CFTR mutations [Ravnik-Glavac et al., 1994] we emphasized differences and similarities in order to refine the DHPLC system and discuss the relationship to the alternative approaches. We conclude that the DHPLC method, under optimized conditions, is highly accurate, rapid, and efficient in detecting mutations in the CFTR gene and may find high utility in screening individuals for CFTR mutations. Hum Mutat 19:374-383, 2002. Published 2002 Wiley-Liss, Inc.

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42 The following mutations have been studied: exon 3: W57G, R74W, R75Q, G85E, 394delTT, 405+ 1G>A; exon 4: E92X, P99L, 441delA, 444delA, 457TAT>G, D110H, R117C, R117H, A120T, 541delC, 544delCA, Q151X, 621+1G>T, 662- 2A>C; exon 7: 1078delT, F331L, R334W, I336K, R347C, R347P, A349V, R352Q, 1221delCT; exon 10: S492F, Q493X, 1609delCA, deltaI507, deltaF508; exon 11: G542X, S549N, G551D, R553X, A559T, R560K, R560T; exon 13: K716X, Q685X, G628R, L719X; exon 17b: H1054D, G1061R, 3320ins5, R1066H, R1066L, R1070Q, 3359delCT, L1077P, H1085R, Y1092X; exon 19: R1162X, 3659delC, 3662delA, 3667del4, 3737delA, I1234V, S1235R, 3849G>A; exon 20: 3860ins31,S1255X,3898insC,3905insT,D1270N, W1282X, Q1291R; and exon 21: N1303H, N1303K, W1316X. Login to comment

[hide] DeltaF508-CFTR causes constitutive NF-kappaB activ... Biol Chem. 2002 Feb;383(2):271-82. Knorre A, Wagner M, Schaefer HE, Colledge WH, Pahl HL
DeltaF508-CFTR causes constitutive NF-kappaB activation through an ER-overload response in cystic fibrosis lungs.
Biol Chem. 2002 Feb;383(2):271-82., [PMID:11934265]

Abstract [show]
The clinical course of Cystic Fibrosis is characterized by recurrent pulmonary infections which ultimately lead to death by respiratory failure. The most common CF causing mutation, deltaF508-CFTR, produces an incorrectly folded protein, which accumulates within the endoplasmic reticulum. However, the molecular mechanism by which the deltaF508-CFTR protein facilitates pulmonary infection and inflammation remains unclear. Here we show that the expression of deltaF508-CFTR causes a constitutive activation of the pro-inflammatory transcription factor NF-kappaB by eliciting an ER stress reaction, the ER-overload response. This endogenous NF-kappaB activation stimulates the transcription of pro-inflammatory cytokines thereby commencing an inflammatory cascade within the CF lung.

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193 Of the three CF patients examined by immunohistochemistry, two patients were homozygous for ∆F508-CFTR, one patient was heterozygous ∆F508-CFTR/R347P-CFTR. Login to comment

[hide] Towards the pharmacogenomics of cystic fibrosis. Pharmacogenomics. 2002 Jan;3(1):75-87. Sangiuolo F, D'Apice MR, Bruscia E, Lucidi V, Novelli G
Towards the pharmacogenomics of cystic fibrosis.
Pharmacogenomics. 2002 Jan;3(1):75-87., [PMID:11966405]

Abstract [show]
Cystic fibrosis (CF) is the most common lethal recessive genetic disease affecting children in Europe and the US. CF is a multiorgan disease and may present a variety of clinical symptoms, like chronic obstructive lung disease, exocrine pancreatic insufficiency (PI) and elevated sweat chloride concentration. CF mutations have also been found in other related clinical diseases such as congenital bilateral absence of the vas deferens (CBAVD), disseminated bronchiectasis and chronic pancreatitis. These clinical overlaps pose etiopathogenetic, diagnostic and therapeutic questions. Despite stunning advances in genomic technologies and drug discovery, drug therapy often improves disease symptoms but does not cure the disease. One of the main causes of this failure in CF cure may be attributable to genetic variability and to the scarce knowledge of CF biochemistry. Therefore, knowing the genotype of a patient might help improve drug efficacy, reduce toxicity and suggests innovative genomic-based therapy approaches.

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114 R117H R334W G314E R347P ∆F508 P574H PS Reduced chloride conductance Reduced levels of cell surface chloride transport Genistein Milrinone Phenylbutyrate UTP INS36217 Moli1901 Class V Mutations causing defects in CFTR channel expression levels. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Clin Exp Allergy. 2002 May;32(5):756-61. Eaton TE, Weiner Miller P, Garrett JE, Cutting GR
Cystic fibrosis transmembrane conductance regulator gene mutations: do they play a role in the aetiology of allergic bronchopulmonary aspergillosis?
Clin Exp Allergy. 2002 May;32(5):756-61., [PMID:11994102]

Abstract [show]
BACKGROUND: Previous work suggests that cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations may be implicated in the aetiology of allergic bronchopulmonary aspergilosis (ABPA). OBJECTIVE: To compare the frequency of CF gene mutations in asthmatics with ABPA of varying severity with asthmatics who were skin prick test (SPT)-positive to Aspergillus fumigatus (Af) without evidence of ABPA and asthmatics SPT-negative to Af. METHODS: Thirty-one Caucasian patients with ABPA were identified, together with asthmatics SPT positive to Af without evidence of ABPA (n = 23) and SPT negative to Af (n = 28). Genomic DNA was tested for 16 CF mutations accounting for approximately 85% of CF alleles in Caucasian New Zealanders. RESULTS: Four (12.9%) ABPA patients were found to be carriers of a CF mutation (DeltaF508 n = 3, R117H n = 1), one (4.3%) asthmatic SPT positive to Af without ABPA (DeltaF508), and one (3.6%) asthmatic SPT negative to Af (R117H). All patients with a CF mutation had normal sweat chloride (< 40 mM). There was no significant difference between the frequency of CF mutations in the ABPA patients and asthmatics without ABPA. However, the frequency of CF mutations in the ABPA patients was significantly different (P = 0.0125) to the expected carrier rate in the general population. CONCLUSION: These results lend further support to a possible link between CF mutations and ABPA.

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53 Cystic ®brosis mutation analysis Genomic DNA samples were screened for 16 CF mutations utilizing allelic-speci®c oligonucleotide (ASO) hybridization; ÁF508, ÁI507, R117H, W1282X, 621 IG3T, R334W, R347P, A455E, 1717-IG3A, G542X, 5549N, G551D, R553X, R560T, N1303K and 3849 10KC3T. Login to comment

[hide] Cystic fibrosis: a worldwide analysis of CFTR muta... Hum Mutat. 2002 Jun;19(6):575-606. Bobadilla JL, Macek M Jr, Fine JP, Farrell PM
Cystic fibrosis: a worldwide analysis of CFTR mutations--correlation with incidence data and application to screening.
Hum Mutat. 2002 Jun;19(6):575-606., [PMID:12007216]

Abstract [show]
Although there have been numerous reports from around the world of mutations in the gene of chromosome 7 known as CFTR (cystic fibrosis transmembrane conductance regulator), little attention has been given to integrating these mutant alleles into a global understanding of the population molecular genetics associated with cystic fibrosis (CF). We determined the distribution of CFTR mutations in as many regions throughout the world as possible in an effort designed to: 1) increase our understanding of ancestry-genotype relationships, 2) compare mutational arrays with disease incidence, and 3) gain insight for decisions regarding screening program enhancement through CFTR multi-mutational analyses. Information on all mutations that have been published since the identification and cloning of the CFTR gene's most common allele, DeltaF508 (or F508del), was reviewed and integrated into a centralized database. The data were then sorted and regional CFTR arrays were determined using mutations that appeared in a given region with a frequency of 0.5% or greater. Final analyses were based on 72,431 CF chromosomes, using data compiled from over 100 original papers, and over 80 regions from around the world, including all nations where CF has been studied using analytical molecular genetics. Initial results confirmed wide mutational heterogeneity throughout the world; however, characterization of the most common mutations across most populations was possible. We also examined CF incidence, DeltaF508 frequency, and regional mutational heterogeneity in a subset of populations. Data for these analyses were filtered for reliability and methodological strength before being incorporated into the final analysis. Statistical assessment of these variables revealed that there is a significant positive correlation between DeltaF508 frequency and the CF incidence levels of regional populations. Regional analyses were also performed to search for trends in the distribution of CFTR mutations across migrant and related populations; this led to clarification of ancestry-genotype patterns that can be used to design CFTR multi-mutation panels for CF screening programs. From comprehensive assessment of these data, we offer recommendations that multiple CFTR alleles should eventually be included to increase the sensitivity of newborn screening programs employing two-tier testing with trypsinogen and DNA analysis.

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109 Mutational Arrays, Detection Rates and Methods by Region* Estimated Projected detection of Number of Number of Country/ allele two CFTR mutations chromosomes Region Mutation array detectiona mutationsb includedc (max/min)d Reference Europe Albania ∆F508 (72.4%) C276X (0.7%) 74.5 55.5 4 270/146 CFGAC [1994]; Macek et al. G85E (0.7%) R1070Q (0.7%) [2002] Austria ∆F508 (62.9%) 457TAT→G (1.2%) 76.6 58.7 11 1516/580 Estiville et al. [1997]; Dörk et al. (total) G542X (3.3%) 2183AA→G (0.7%) [2000]; Macek et al. [2002] CFTRdele2,3 (2.1%) N1303K (0.6%) R1162X (1.9%) I148T (0.5%) R553X (1.7%) R117H (0.5%) G551D (1.2%) Austria ∆F508 (74.6%) 2183AA→G (2.4%) 95.3 90.8 8 126 Stuhrmann et al. [1997] (tyrol) R1162X (8.7%) G551D (1.6%) G542X (2.4%) R347P (1.6%) 2789+5G→A (2.4%) Q39X (1.6%) Belarus ∆F508 (61.2%) R553X (0.5%) 75.2 56.6 9 278/188 Dörk et al. [2000]; Macek et al. G542X (4.5%) R334W (0.5%) [2002] CFTRdele2,3 (3.3%) R347P (0.5%) N1303K (3.2%) S549N (0.5%) W1282X (1.0%) Belgium ∆F508 (75.1%) 622-1A→C (0.5%) 100.0 100.0 27 1504/522 Cuppens et al. [1993]; Mercier et G542X (3.5%) G458V (0.5%) al. [1993]; CFGAC [1994]; N1303K (2.7%) 1898+G→C (0.5%) Estivill et al.[1997] R553X (1.7%) G970R (0.5%) 1717-1G→A (1.6%) 4218insT (0.5%) E60X (1.6%) 394delTT (0.5%) W1282X (1.4%) K830X (0.5%) 2183A→G+2184delA (1.2%) E822K (0.5%) W401X (1.0%) 3272-1G→A (0.5%) A455E (1.0%) S1161R (0.5%) 3272-26A→G (1.0%) R1162X (0.5%) S1251N (1.0%) 3750delAG (0.5%) S1235R (0.8%) S1255P (0.5%) ∆I507 (0.6%) Bulgaria ∆F508 (63.6%) R75Q (1.0%) 93.0 86.5 21 948/432 Angelicheva et al. [1997]; (total) N1303K (5.6%) 2183AA→G (0.9%) Estivill et al. [1997]; Macek G542X (3.9%) G1244V+S912L (0.9%) et al. [2002] R347P (2.2%) G85E (0.9%) 1677delTA (2.1%) 2184insA (0.9%) R1070Q (1.8%) L88X+G1069R (0.8%) Q220X (1.2%) 2789+5G→A (0.8%) 3849+10KbC→T (1.1%) G1244E (0.8%) W1282X (1.0%) 1717-1G→A (0.8%) 2176insC (1.0%) Y919C (0.7%) G1069R (1.0%) WORLDWIDEANALYSISOFCFTRMUTATIONS581 Bulgaria 1) DF508 4) 1677delTA - - 6 13 Angelicheva et al. [1997] (ethnic 2) R347P 5) Q493R Turks) 3) G542X 6) L571S - - 1 30 Angelicheva et al. [1997] Bulgaria 1) DF508 (100.0%) (Gypsy) Croatia ∆F508 (64.5%) G551D (1.1%) 72.5 52.6 5 276 Macek et al. [2002] G542X (3.3%) 3849+10KbC→T (0.7%) N1303K (2.9%) Czech ∆F508 (70.0%) 1898+1G→T (2.0%) 89.6 80.3 10 2196/628 CFGAC [1994]; Estiville et al. Republic CFTRdele2,3 (5.5%) 2143delT (1.2%) [1997]; Dörk et al. [2000]; G551D (3.8%) R347P (0.8%) Macek et al. [2002] N1303K (2.9%) 3849+10KbC→T (0.6%) G542X (2.2%) W1282X (0.6%) Denmark ∆F508 (87.5%) G542X (0.7%) 92.3 85.2 6 1888/678 CFGAC [1994]; Schwartz et al. (excluding 394delTT (1.8%) 621+1G→T (0.6%) [1994]; Estiville et al. [1997] Faroe) N1303K (1.1%) 3659delC (0.6%) Estonia ∆F508 (51.7%) R117C (1.7%) 80.2 64.3 10 165/80 Estivill et al. [1997]; Klaassen et 394delTT (13.3%) E217G (1.7%) al. [1998]; Macek et al. S1235R (3.3%) R1066H (1.7%) [2002] 359insT (1.7%) 3659delC (1.7%) I1005R (1.7%) S1169X (1.7%) Finland ∆F508 (46.2%) G542X (1.9%) 78.8 62.1 4 132/52 CFGAC [1994]; Kere et al. 394delTT (28.8%) 3372delA (1.9%) [1994]; Estivill et al. [1997] France ∆F508 (67.7%) 2789+5G→T (0.79%) 79.7 63.6 12 17854/7420 Chevalier-Porst et al. [1994]; (total) G542X (2.94%) 2184delA+2183A→G (0.77%) Estivill et al. [1997]; Claustres et al. [2000]; Guilloud-Bataille N1303K (1.83%) G551D (0.74%) et al. [2000] 1717-1G→A (1.35%) 1078delT (0.63%) W1282X (0.91%) ∆I507 (0.62%) R553X (0.86%) Y122K (0.59%) France ∆F508 (75.8%) R297Q (0.8%) 98.7 97.4 18 599/365 Férec et al. [1992]; Scotet et al. (Brittany) 1078delT (4.0%) R347H (0.8%) [2000] G551D (3.6%) I1234V (0.8%) N1303K (3.0%) R553X (0.8%) R117H (1.7%) 2789+5G→A (0.8%) 3272-26A→G (1.3%) 4005+1G→A (0.7%) G542X (1.1%) 621+1G→T (0.6%) 1717-1G→A (1.0%) ∆I507 (0.6%) G1249R (0.8%) W846X (0.5%) France ∆F508 (70.0%) N1303K (0.8%) 90.4 81.7 16 250 Claustres et al. [1993] (southern) G542X (6.4%) 3737delA (0.8%) 1717-1G→A (1.6%) R1162X (0.8%) L206W (1.2%) Y1092X (0.8%) R334W (1.2%) S945L (0.8%) ∆I507 (1.2%) K710X (0.8%) 2184delA (1.2%) 1078delT (0.8%) R1158X (1.2%) Y122X (0.8%) (Continued) BOBADILLAETAL. Login to comment
110 Germany ∆F508 (71.8%) 1789+5G→A (0.9%) 87.6 76.7 17 5662/1316 Dörk et al. [1992]; Dörk et al. R553X (2.0%) 3272-26A→G (0.9%) [1994]; Tümmler et al. [1996]; N1303K (1.8%) W1282X (0.7%) Estivill et al. [1997]; Dörk et G542X (1.2%) 2143delT (0.7%) al. [2000] R347P (1.2%) 1078delT (0.6%) CFTRdele2,3 (1.2%) 2183AA→G (0.6%) 3849+10KbC→T (1.0%) 2184insA (0.6%) G551D (0.9% 3659delC (0.6%) 1717-1G→A (0.9%) Greece ∆F508 (52.9%) 3272-26A→G (0.8%) 82.2 67.6 22 2097/718 Kanavakis et al. [1995]; Estivill 621+1G→T (5.0%) R1070Q (0.8%) et al. [1997]; Tzetis et al. G542X (4.1%) W496X (0.7%) [1997]; Macek et al. [2002] N1303K (3.3%) 621+3A→G (0.7%) 2183AA→G (1.8%) ∆I507 (0.7%) 2789+5G→A (1.7%) W1282X (0.7%) E822X (1.6%) 574delA (0.7%) R117H (1.2%) 1677delTA (0.7%) R334W (1.1%) A46D (0.6%) R1158X (1.0%) 3120+1G→A (0.6%) G85E (1.0%) G551D (0.5%) Hungary ∆F508 (54.9%) W1282X (1.8%) 68.3 46.6 9 1133/976 CFGAC [1994]; Estivill et al. 1717-1G→A (1.9%) G542X (1.7%) [1997]; Macek et al. [2002] R553X (2.1%) N1303K (1.3%) Y1092X (1.8%) G551D (1.0%) S1196X (1.8%) Ireland ∆F508 (70.4%) G542X (1.0%) 82.1 67.4 7 801/509 CFGAC [1994]; Estivill et al. G551D (5.7%) 621+1G→T (0.8%) [1994] R117H (2.4%) 1717-1G→A (0.6%) R560T (1.2%) Italy ∆F508 (50.9%) ∆I507 (0.65%) 60.3 36.4 9 3524 Estivill et al. [1997] (total) G542X (3.1%) W1282X (0.62%) 1717-1G→A (1.6%) Y122K (0.59%) N1303K (1.4%) G551D (0.53%) R553X (0.94%) Italy ∆F508 (47.6%) R553X (1.3%) 87.1 75.9 15 225 Bonizzato et al. [1995] (Northeast) R1162X (9.8%) 2789+G→A (1.3%) 2183AA→G (9.3%) Q552X (1.3%) N1303K (4.0%) 621+1G→T (0.9%) G542X (2.7%) W1282X (0.9%) 711+5G→A (2.7%) 3132delTG (0.9%) 1717-1G→A (2.2%) 2790-2A→G (0.9%) G85E (1.3%) TABLE 1. Continued. Estimated Projected detection of Number of Number of Country/ allele two CFTR mutations chromosomes Region Mutation array detectiona mutationsb includedc (max/min)d Reference WORLDWIDEANALYSISOFCFTRMUTATIONS583 Italy ∆F508 (56.4%) 711+1G→T (1.3%) 85.7 73.4 13 660/396 Castaldo et al. [1996]; Castaldo (southern) N1303K (6.8%) G1244E (1.3%) et al. [1999] G542X (5.7%) R1185X (1.3%) W1282X (3.8%) L1065P (1.3%) 1717-1G→A (2.3%) R553X (1.1%) 2183AA→G (1.9%) I148T (0.7%) 4016insT (1.8%) Latvia 1) DF508 (58.3%) 4) CFTRdele2,3 (2.8%) - - 6 36 Dörk et al. [2000]; Macek et al. 2) 3849+10KbC®T (8.3%) 5) W1282X (2.8%) [2002] 3) N1303K (5.6%) 6) 394delTT (2.8%) Lithuania ∆F508 (31.0%) N1303K (2.0%) 39.0 15.2 4 94 Dörk et al. [2000]; Macek et al. R553X (4.0%) CFTRdele2,3 (2.0%) [2002] Macedonia ∆F508 (54.3%) 711+3A→G (1.0%) 69.2 47.9 12 559/226 Petreska et al. [1998]; Dörk et G542X (4.2%) 3849G→A (1.0%) al. [2000]; Macek et al. N1303K (2.0%) 2184insA (0.9%) [2002] CFTRdele2,3 (1.3%) 457TAT→G (0.7%) 621+1G→T (1.3%) V139E (0.7%) 611-1G→T (1.2%) 1811+1G→C (0.6%) Netherlands ∆F508 (74.2%) R1162X (0.9%) 86.8 75.3 9 3167/1442 Gan et al. [1995]; Estiville et al. A455E (4.7%) S1251N (0.9%) [1997]; Collee et al. [1998] G542X (1.8%) N1303K (0.9%) 1717-1G→A (1.5%) W1282X (0.7%) R553X (1.2%) Norway ∆F508 (60.2%) G551D (1.2%) 69.8 48.7 6 410/242 Schwartz et al. [1994]; Estivill 394delTT (4.2%) G542X (0.6%) et al. [1997] R117H (3.0%) N1303K (0.6%) Poland ∆F508 (57.1%) CFTRdele2,3 (1.8%) 73.5 54.0 11 4046/1726 CFGAC [1994]; Estivill et al. 3849+10Kb C→T (2.7%) R560T (1.5%) [1997]; Dörk et al [2000]; G542X (2.6%) W1282X (0.7%) Macek et al. [2002] 1717-1G→A (2.4%) ∆I507 (0.5%) R553X (1.9%) G551D (0.5%) N1303K (1.8%) Portugal ∆F508 (44.7%) R334W (0.7%) 49.7 24.7 5 739/454 CFGAC [1994]; Estivill et al. G542X (1.6%) N1303K (0.7%) [1997] R1066C (2.0%) Romania ∆F508 (36.6%) G542X (1.4%) 51.5 26.5 11 224/74 CFGAC [1994]; Estivill et al. 2043delG (2.0%) R553X (1.4%) [1997]; Popa et al. [1997]; W1282X (1.7%) G576X (1.4%) Macek et al. [2002] 1717-2A→G (1.4%) 1898+1G→A (1.4%) I148T (1.4%) 2183AA→G (1.4%) 621+1G→T (1.4%) Russia ∆F508 (54.4%) 552insA (0.9%) 70.7 50.0 12 5073/2562 CFGAC [1994]; Estivill et al. CFTRdele2,3 (5.0%) G542X (0.9%) [1997]; Dörk et al. [2000]; R553X (3.5%) R334W (0.9%) Macek et al. [2002] 2183AA→G (1.3%) 1677delTA (0.8%) W1282X (1.0%) Y122X (0.5%) 394delTT (1.0%) 1367del5 (0.5%) (Continued) BOBADILLAETAL. Login to comment
111 Slovakia ∆F508 (57.3%) CFTRdele2,3 (1.2%) 82.7 68.4 14 908/254 CFGAC [1994]; Estivill et al. G542X (6.8%) 3849+10KbC→T (1.0%) [1997]; Dörk et al. [2000]; R553X (4.0%) S42F (0.9%) Macek et al. [2002] N1303K (3.4%) R75X (0.9%) 2143delT (1.8%) G85E (0.9%) R347P (1.4%) 605insT (0.9%) W1282X (1.3%) 1898+1G→A (0.9%) Slovenia ∆F508 (57.8%) R347P (1.1%) 79.7 63.5 16 455/132 CFGAC [1994]; Dörk et al. 2789+5G→A (4.1%) S4X (0.8%) [2000]; Macek et al. [2002] R1162X (3.2%) 457TAT→G (0.8%) G542X (1.9%) D192G (0.8%) Q552X (1.5%) R553X (0.8%) Q685X (1.5%) A559T (0.8%) 3905insT (1.5%) 2907delTT (0.8%) CFTRdele2,3 (1.5%) 3667ins4 (0.8%) Spain ∆F508 (52.7%) G85E (0.8%) 80.2 64.3 21 3608/1356 Chillón et al. [1994]; Casals et G542X (8.0%) R1066C (0.8%) al. [1997]; Estivill et al. [1997] N1303K (2.5%) 2789+5G→A (0.7%) 3601-111G→C (2.0%) 2869insG (0.7%) 1811+1.6Kb A→G (1.7%) ∆I507 (0.6%) R1162X (1.6%) W1282X (0.6%) 711+1G→T (1.3%) L206W (0.5%) R334W (1.2%) R709X (0.5%) Q890X (1.0%) K710X (0.5%) 1609delCA (1.0%) 3272-26A→G (0.5%) 712-1G→T (1.0%) Sweden ∆F508 (66.6%) E60X (0.6%) 85.9 73.8 10 1357/662 Schwartz et al. [1994]; Estivill et 394delTT (7.3%) Y109C (0.6%) al. [1997]; Schaedel et al. 3659delC (5.4%) R117H (0.6%) [1999] 175insT (2.4%) R117C (0.6%) T338I (1.2%) G542X (0.6%) Switzerland ∆F508 (57.2%) K1200E (2.1%) 91.3 83.4 9 1268/1173 Estivill et al. [1997]; R553X (14.0%) N1303K (1.2%) Hergersberg et al. [1997] 3905insT (9.8%) W1282X (1.1%) 1717-1G→A (2.7%) R347P (0.6%) G542X (2.6%) Ukraine ∆F508 (65.2%) CFTRdele2,3 (1.1%) 74.6 55.7 6 1055/580 Estivill et al. [1997]; Dörk et al. R553X (3.6%) G551D (1.8%) [2000]; Macek et al. [2002] N1303K (2.4%) W1282X (0.5%) United ∆F508 (75.3%) 621+1G→T (0.93%) 81.6 66.6 5 19622/9815 Schwartz et al. [1995b]; Kingdom G551D (3.1%) 1717-1G→A (0.57%) Estivill et al. [1997] (total) G542X (1.7%) TABLE 1. Continued. Estimated Projected detection of Number of Number of Country/ allele two CFTR mutations chromosomes Region Mutation array detectiona mutationsb includedc (max/min)d Reference WORLDWIDEANALYSISOFCFTRMUTATIONS585 United ∆F508 (56.6%) 621+1G→T (1.8%) 69.1 47.7 7 456 CFGAC [1994] Kingdom G551D (3.7%) R117H (1.5%) (N. Ireland) R560T (2.6%) ∆I507 (0.9%) G542X (2.0%) United ∆F508 (19.2%) 621+2T→C (3.8%) 84.4 71.2 11 52 Malone et al. [1998] Kingdom Y569D (15.4%) 2184insA (3.8%) (Pakistani) Q98X (11.5%) R560S (1.9%) 1525-1G→A (9.6%) 1898+1G→T (1.9%) 296+12T→C (7.7%) R709X (1.9%) 1161delC (7.7%) United ∆F508 (71.3%) 1717-1G→A (1.0%) 86.4 74.6 9 1236/730 Shrimpton et al. [1991]; Kingdom G551D (5.5%) 621+1G→T (0.6%) Gilfillan et al. [1998] (Scotland) G542X (4.0%) ∆I507 (0.6%) R117H (1.4%) R560T (0.6%) P67L (1.4%) United ∆F508 (71.6%) 1717-1G→A (1.1%) 98.7 97.4 17 183 Cheadle et al. [1993] Kingdom 621+1G→T (6.6%) 3659delC (0.5%) (Wales) 1898+1G→A (5.5%) R117H (0.5%) G542X (2.2%) N1303K (0.5%) G551D (2.2%) E60X (0.5%) 1078delT (2.2%) S549N (0.5%) R1283M (1.6%) 3849+10KbC→T (0.5%) R553X (1.1%) 4016insT (0.5%) ∆I507 (1.1%) Yugoslavia ∆F508 (68.9%) 3849G→A (1.0%) 82.2 67.6 11 709/398 Dabovic et al. [1992]; Estivill et G542X (4.0%) N1303K (0.8%) al. [1997]; Macek et al. R1162C (3.0%) 525delT (0.5%) (submitted for publication) 457TAT→G (1.0%) 621+1G→T (0.5%) I148T (1.0%) G551D (0.5%) Q552X (1.0%) Middle East/Africa Algeria 1) DF508 (20.0%) 4) 1812-1G®A (5.0%) - - 5 20 Loumi et al. [1999] 2) N1303K (20.0%) 5) V754M (5.0%) 3) 711+1G®T (10.0%) Jewish W1282X (48.0%) 3849+10KbC→T (6.0%) 95.0 90.3 6 261 Kerem et al. [1995] (Ashkenazi) ∆F508 (28.0%) N1303K (3.0%) G542X (9.0%) 1717-1G→A (1.0%) Jewish 1) N1303K - - 1 6 Kerem et al. [1995] (Egypt) Jewish 1) Q359K/T360K - - 1 8 Kerem et al. [1995] (Georgia) Jewish 1) DF508 2) 405+1G®A - - 2 11 Kerem et al. [1995] (Libya) Jewish 1) DF508 (72.0%) 3) D1152H (6.0%) - - 3 33 Kerem et al. [1995] (Morocco) 2) S549R (6.0%) Jewish ∆F508 (35.0%) W1282X (2.0%) 43.0 18.5 4 51 Shoshani et al. [1992] (Sepharadim) G542X (4.0%) S549I (2.0%) (Continued) BOBADILLAETAL. Login to comment
213 Ideal Recommended CFTR Mutation Screening Panel for 2001 Neonatal Screening in the USA* Location Estimated Mutation in CFTRa percentageb Reason for inclusion DF508 Exon 10 68.6% CFF registry, >1%, Pan-European G542X Exon 11 2.4% CFF registry, >1%, Mediterranean G551D Exon 11 2.1% CFF registry, >1%, Celtic W1282X Exon 20 1.4% CFF registry, >1%, Ashkenazi Jew N1303K Exon 21 1.3% CFF registry, >1%, Mediterranean R553X Exon 11 0.9% CFF registry, >0.5%, Hispanic 621+1G®T Intron 4 0.9% CFF registry, >0.5%, multi-ethnic 1717-1G®A Intron 10 0.7% CFF registry, >0.5%, Italian 3849+10KbC®T Intron 19 0.7% CFF registry, >0.5%, Hispanic R117Hc Exon 4 0.7% CFF registry, >0.5% 1898+1G→T Intron 12 0.4% CFF registry, >0.1%, East Asian DI507 Exon 10 0.3% CFF registry, >0.1%, Hispanic 2789+5G®A Intron 14b 0.3% CFF registry, >0.1% G85E Exon 3 0.3% CFF registry, >0.1% R347P Exon 7 0.2% CFF registry, >0.1% R334W Exon 7 0.2% CFF registry, >0.1%, multi-ethnic R1162X Exon 19 0.2% CFF registry, >0.1%, multi-ethnic R560T Exon 11 0.2% CFF registry, >0.1% 3659delC Exon 19 0.2% CFF registry, >0.1% A455E Exon 9 0.2% CFF registry, >0.1% 2184delA Exon 13 0.1% CFF registry, >0.1% S549N Exon 11 0.1% CFF registry, >0.1%, multi-ethnic 711+1G®T Intron 5 0.1% CFF registry, >0.1% R75X Exon 3 0.2% Hispanic 406-1G→A Intron 3 0.2% Hispanic I148T Exon 4 0.2% Hispanic, French 2055del9→A Exon 13 0.1% Hispanic 935delA Exon 6b 0.1% Hispanic I506T Exon 10 0.1% Hispanic 3199del6 Exon 17a 0.1% Hispanic 2183AA→G Exon 13 0.1% Hispanic 3120+1G®A Intron 16 1.5% African American, Arabian 2307insA Exon 13 0.2% African American A559T Exon 11 0.2% African American ∆F311 Exon 7 0.2% African American G480C Exon 10 0.2% African American 405+3A→C Intron 3 0.2% African American S1255X Exon 20 0.2% African American L1093P Exon 17b Undetermined Native American D648V Exon 13 Undetermined Native American I1234V Exon 19 Undetermined Arabian linkage S549R Exon 11 Undetermined Arabian linkage 1898+5G→T Intron 12 Undetermined East Asian linkage CFTRdele2,3 Exons 2,3 Undetermined Eastern European linkage (Slavic) Y1092X Exon 17b Undetermined French linkage 394delTT Exon 3 Undetermined Nordic linkage Y569D Exon 12 Undetermined Pakistani linkage 3905insT Exon 20 Undetermined Swiss linkage (also: Amish, Acadian, Mennonite) 1898+1G®A Intron 12 Undetermined Welsh linkage M1101k Exon 17b Undetermined Hutterite ancestry *This table presents the top 50 mutations in the USA based on the Cystic Fibrosis Foundation CF Registry data from 1997 [Cystic Fibrosis Foundation, 1998], and data generated during our investigation. Login to comment

[hide] Development and evaluation of a PCR-based, line pr... Clin Chem. 2002 Jul;48(7):1121-3. Wang X, Myers A, Saiki RK, Cutting GR
Development and evaluation of a PCR-based, line probe assay for the detection of 58 alleles in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
Clin Chem. 2002 Jul;48(7):1121-3., [PMID:12089190]

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No. Sentence Comment
68 Amplicon Size, bp Mutations (polymorphisms) Exon 13 598 2307 insA Intron 8, exon 09 548 A455E, 5T (7/9 T polymorphism) Exon 10 482 G480C, ⌬I507, ⌬F508 (F508C, I507V, I506V polymorphisms) Intron 10, exon 11 433 1717-1G3A, G542X, G551D, R553X, A559T, R560T Exon 19 420 R1162X, 3659delC Exon 21 397 N1303K Exon 20 359 S1255X, W1282X Exon 07 328 1078delT, R334W, R347P Exon 04, intron 4 288 R117H, 621ϩ1G3T Intron 14b 248 2789ϩ5G3A Intron 19 237 3849ϩ10kbC3T Exon 03 210 G85E, 405ϩ3A3C Intron 5 166 711ϩ1G3T Intron 16 139 3120ϩ1G3A Clinical Chemistry 48, No. Login to comment
88 The genotypes of each sample are as follows: lane 1, ϩ/ϩ (ϩ is the wild type); lane 2, 5T, R117H/3659delC; lane 3, G542X/ϩ; lane 4, I506V/ϩ; lane 5, I507V/ϩ; lane 6, F508C/⌬F508; lane 7, G85E/⌬F508; lane 8, 405ϩ3A3C/3120ϩ1G3C; lane 9, R117H/ϩ; lane 10, 621ϩ1G3T/⌬F508; lane 11, 711ϩ1G3T/⌬F508; lane 12, 1078delT/ϩ; lane 13, R334W/⌬F508; lane 14, R347P/⌬F508; lane 15, A455E/ϩ; lane 16, G480C/⌬F508; lane 17, ⌬I507/ϩ; lane 18, ⌬F508/ϩ; lane 19, 1717-1G3A/ϩ; lane 20, G542X/ϩ; lane 21, G551D/⌬F508; lane 22, R553X/ϩ; lane 23, R560T/⌬F508; lane 24, G551D/A559T; lane 25, 2307insA/ϩ; lane 26, 2789ϩ5G3A/⌬F508; lane 27, 3120ϩ1G3A/⌬F508; lane 28, R1162X/R1162X; lane 29, 3659delC/⌬F508; lane 30, 3849ϩ10kbC3T/⌬F508; lane 31, S1255X/⌬F508; lane 32, W1282X/G542X; lane 33, N1303K/ϩ. Login to comment

[hide] Predicting the risk of cystic fibrosis with abnorm... Am J Med Genet. 2002 Jun 15;110(2):109-15. Muller F, Simon-Bouy B, Girodon E, Monnier N, Malinge MC, Serre JL
Predicting the risk of cystic fibrosis with abnormal ultrasound signs of fetal bowel: results of a French molecular collaborative study based on 641 prospective cases.
Am J Med Genet. 2002 Jun 15;110(2):109-15., 2002-06-15 [PMID:12116247]

Abstract [show]
Hyperechogenic fetal bowel is prenatally detected by ultrasound during the second trimester of pregnancy in 0.1-1.8% of fetuses. It has been described as a normal variant but has often been associated with severe diseases, notably cystic fibrosis (CF). The aim of our study was to determine the risk of CF in a prospective study of 641 fetuses with ultrasonographically abnormal fetal bowel and the residual risk when only one mutation is detected in the fetus. Fetal cells and/or parental blood cells were screened for CFTR mutations. Two screening steps were used, the first covering the mutations most frequently observed in French CF patients (mutation detection rate of 70-90%) and, when a CF mutation was detected, a DGGE-sequencing strategy. We observed a 3.1% risk of CF when a digestive tract anomaly was prenatally observed at routine ultrasound examination. The risk was higher when hyperechogenicity was associated with bowel dilatation (5/29; 17%) or with the absence of gall bladder (2/8; 25%). The residual risk of CF was 11% when only one CF mutation was detected by the first screening step, thereby justifying in-depth screening. Mutations associated with severe CF (DeltaF508 mutation) were more frequently observed in these ultrasonographically and prenatally detected CF cases. However, the frequency of heterozygous cases was that observed in the normal population, which demonstrates that heterozygous carriers of CF mutations are not at increased risk for hyperechogenic bowel. In conclusion, fetal bowel anomalies indicate a risk of severe cystic fibrosis and justify careful CFTR molecular analysis.

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52 T, 1078delT, R347P, R347H, R334W, A455E, 1898 þ 1G ! Login to comment

[hide] Genotype-phenotype correlation in cystic fibrosis:... Am J Med Genet. 2002 Jul 22;111(1):88-95. Salvatore F, Scudiero O, Castaldo G
Genotype-phenotype correlation in cystic fibrosis: the role of modifier genes.
Am J Med Genet. 2002 Jul 22;111(1):88-95., 2002-07-22 [PMID:12124743]

Abstract [show]
More than 1,000 mutations have been identified in the cystic fibrosis (CF) transmembrane regulator (CFTR) disease gene. The impact of these mutations on the protein and the wide spectrum of CF phenotypes prompted a series of Genotype-Phenotype correlation studies. The CFTR genotype is invariably correlated with pancreatic status-in about 85% of cases with pancreatic insufficiency and in about 15% of cases with pancreatic sufficiency. The correlations between the CFTR genotype and pulmonary, liver, and gastrointestinal expression are debatable. The heterogeneous phenotype in CF patients bearing the same genotype or homozygotes for nonsense mutations implicated environmental and/or genetic factors in the disease. However, the discordant phenotype observed in CF siblings argued against a major role of environmental factors and suggested that genes other than CFTR modulate the CF phenotype. A locus that modulates gastrointestinal expression was identified in mice and subsequently in humans. By analyzing nine CF patients discordant for meconium ileus we were able to show that this locus had a dominant effect. Moreover, in a collaborative study we found a higher rate of polymorphisms in beta-defensin genes 1 and 2 in CF patients and in controls. In another multicenter study mutations in alpha-1 antitrypsin (A1AT) and mannose binding lectin genes were found to be independent risk factors for liver disease in CF patients. The body of evidence available suggests that the variegated CF phenotype results from complex interactions between numerous gene products.

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46 A series of mutations usually associated with pancreatic sufficiency have been identified and defined as ''mild`` with reference to pancreatic status [Kerem et al., 1989c]: G85E, G91R, R117H, E193K, P205S, R334W, T338I, R347H, R347L, R347P, R352Q, A455E, S492F, S549N, P574H, D579G, 711 þ 5 G > A, C866Y, F1052V, H1054D, R1066H, R1068H, H1085R, D1152H, S1159P, S1251N, F1286S, G1349D, 2789 þ 5 G > A, and 3849 þ 10kb C > T [Dean et al., 1990; Cutting et al., 1990a; Cremonesi et al., 1992; Highsmith et al., 1994]. Login to comment

[hide] Screening for cystic fibrosis in newborn infants: ... J Med Screen. 2002;9(2):60-3. Corbetta C, Seia M, Bassotti A, Ambrosioni A, Giunta A, Padoan R
Screening for cystic fibrosis in newborn infants: results of a pilot programme based on a two tier protocol (IRT/DNA/IRT) in the Italian population.
J Med Screen. 2002;9(2):60-3., [PMID:12133923]

Abstract [show]
OBJECTIVE: To assess the performance of a two tier neonatal screening programme (IRT/DNA/IRT) for cystic fibrosis, based on immunoreactive trypsinogen (IRT) followed by direct cystic fibrosis transmembrane conductance regulator (CFTR) gene analysis (based on a panel of up to 31 mutations) in hypertrypsinaemic newborn infants and to compare it with a previous screening protocol. SETTING: The study comprised all the newborn infants in the period 1 October 1998 to 31 December 1999 in the Lombardia region, north western Italy. METHODS: The screening strategy consisted of an immunoreactive trypsinogen assay from dried blood spots, a polymerase chain reaction (PCR) followed by an oligonucleotide ligation assay (PCR-OLA), and a sequence code separation. RESULTS: 104 609 newborn infants were screened. 1457 hypertrypsinaemic infants (1.39%) were analysed with the PCR-OLA assay. 18 newborn homozygotes or compound heterozygotes for CFTR mutations were identified and referred to the cystic fibrosis (CF) centre at a mean age of 3 weeks. 125 infants presenting only one mutation were recalled for a sweat test: a diagnosis of CF was made in 13 infants, and parents of 112 neonates identified as carriers (1:13) received genetic counselling. The remaining 1314 hypertrypsinaemic newborn infants were recalled for IRT retesting and 177 were referred for a sweat test because the second IRT measurement was above the cut off value. Among this group a further two infants were diagnosed with CF (1.1%) leading to a CF prevalence of 1:3170. CONCLUSIONS: This strategy resulted in an early and accurate diagnosis of CF. The IRT/DNA/IRT protocol with an OLA assay was shown to be useful in an Italian population with a genetic heterogeneity, leading to the identification of 94% of infants with CF.

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266 Mutations identified by the assay are G85E, 621+1G→T, R117H, Y122X, 711+1G→T, 1078delT, R347P, R347H, R334W, A455E, 1898+1G→A, 2183-AA→G, 2789+5G→A, delF508, I507del, Q493X, V520F, 1717-1G→A, G542X, G551D, R553X, R560T, S549R, S549N, 3849+10kbC→T, 3849+4A→G, R1162X, 3659delC, W1282X, 3905insT, and N1303K. Login to comment

[hide] Analysis by mass spectrometry of 100 cystic fibros... Hum Reprod. 2002 Aug;17(8):2066-72. Wang Z, Milunsky J, Yamin M, Maher T, Oates R, Milunsky A
Analysis by mass spectrometry of 100 cystic fibrosis gene mutations in 92 patients with congenital bilateral absence of the vas deferens.
Hum Reprod. 2002 Aug;17(8):2066-72., [PMID:12151438]

Abstract [show]
BACKGROUND: Limited mutation analysis for congenital bilateral absence of the vas deferens (CBAVD) has revealed only a minority of men in whom two distinct mutations were detected. We aimed to determine whether a more extensive mutation analysis would be of benefit in genetic counselling and prenatal diagnosis. METHODS: We studied a cohort of 92 men with CBAVD using mass spectrometry and primer oligonucleotide base extension to analyse an approximately hierarchical set of the most common 100 CF mutations. RESULTS: Analysis of 100 CF mutations identified 33/92 (35.9%) patients with two mutations and 29/92 (31.5%) with one mutation, compound heterozygosity accounting for 94% (31/33) of those with two mutations. This panel detected 12.0% more CBAVD men with at least one mutation and identified a second mutation in >50% of those considered to be heterozygotes under the two routine 25 mutation panel analyses. CONCLUSION: Compound heterozygosity of severe/mild mutations accounted for the vast majority of the CBAVD patients with two mutations, and underscores the value of a more extensive CF mutation panel for men with CBAVD. The CF100 panel enables higher carrier detection rates especially for men with CBAVD, their partners, partners of known CF carriers, and those with 'mild' CF with rarer mutations.

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20 Given the frequency of CF mutations, especially in the Caucasian population ( in 25), and the common request by CBAVD men to sire their own offspring by using surgical Table I. The 100 most common cystic fibrosis mutations listed by exon Mutationa Exonb Frequency (%)c G85E 3 0.1 394delTT 3 Swedish E60X 3 Belgium R75X 3 405ϩ1G→A Int 3 R117H 4 0.30 Y122X 4 French 457TAT→G 4 Austria I148T 4 Canada (French Canadian) 574delA 4 444delA 4 R117L 4 621ϩ1G→T Int 4 0.72 711ϩ1G→T Int 5 Ͼ0.1 712-1G→T Int 5 711ϩ5G→A Int 5 Italy (Caucasian) L206W 6a R347P 7 0.24 1078delT 7 Ͼ0.1 R334W 7 Ͼ0.1 1154InsTC 7 T338I 7 Italy R347H 7 Turkey Q359K/T360K 7 Israel (Georgian Jews) I336K 7 R352Q 7 G330X 7 S364P 7 A455E 9 0.20 I507 10 0.21 F508 10 66.02 1609delCA 10 Spain (Caucasian) V520F 10 Q493X 10 C524X 10 G480C 10 Q493R 10 1717-1G→A Int 10 0.58 R553X 11 0.73 G551D 11 1.64 G542X 11 2.42 R560T 11 Ͼ0.1 S549N 11 Q552X 11 Italy S549I 11 Israel (Arabs) A559T 11 African American R553G 11 R560K 11 1812-1G→A Int 11 A561E 12 E585X 12 Y563D 12 Y563N 12 1898ϩ1G→A Int 12 0.22 1898ϩ1G→C Int 12 2183AA→G 13 Italian 2184delA 13 Ͻ0.1 K710X 13 2143delT 13 Moscow (Russian) 2184InsA 13 1949del84 13 Spain (Spanish) 2176InsC 13 2043delG 13 2307insA 13 2789ϩ5G→A Int 14b Ͼ0.1 2869insG 15 S945L 15 Q890X 15 3120G→A 16 2067 Table I. continued Mutationa Exonb Frequency (%)c 3120ϩ1G→A Int 16 African American 3272-26A→G Int 17a R1066C 17b Portugal (Portugese) L1077P 17b R1070Q 17b Bulgarian W1089X 17b M1101K 17b Canada (Hutterite) R1070P 17b R1162X 19 0.29 3659delC 19 Ͼ0.1 3849G→A 19 3662delA 19 3791delC 19 3821delT 19 Russian Q1238X 19 S1235R 19 France, South S1196X 19 K1177R 19 3849ϩ10kbC→T Int 19 0.24 3849ϩ4A→G Int 19 W1282X 20 1.22 S1251N 20 Dutch, Belgian 3905insT 20 Swiss, Acadian, Amish G1244E 20 R1283M 20 Welsh W1282R 20 D1270N 20 S1255X 20 African American 4005ϩ1G→A Int 20 N1303K 21 1.34 W1316X 21 aMutations were chosen according to their frequencies (Cystic Fibrosis Genetic Analysis Consortium, 1994; Zielenski and Tsui, 1995; Estivill et al., 1997). Login to comment
35 ACMG 25 mutation panel (ACMG25): The following mutations are the recommended core mutations for general population CF carrier screening by American College of Medical Genetics (ACMG) (Grody, et al 2001): ∆F508, G542X, N1303K, G551D, W1282X, 1717-1G→A, R553X, 621ϩ1G→T, R1162X, R117H, ∆I507, 1898ϩ1G→A, G85E, R347P, A455E, R560T, R334W, 3849ϩ10kbC→T, 3659delC, 1078delT, 2789ϩ5G→A, 711ϩ1G→T, 2184delA, 3120ϩ1G→A and I148T. Login to comment

[hide] Comparison of two different protocols of neonatal ... Clin Genet. 2002 Sep;62(3):245-9. Narzi L, Lucarelli M, Lelli A, Grandoni F, Lo Cicero S, Ferraro A, Matarazzo P, Delaroche I, Quattrucci S, Strom R, Antonelli M
Comparison of two different protocols of neonatal screening for cystic fibrosis.
Clin Genet. 2002 Sep;62(3):245-9., [PMID:12220442]

Abstract [show]
The results of two different protocols of neonatal cystic fibrosis (CF) screening in the Lazio region of Italy are reported. The first study, conducted from 1992 to 2000 on about 200,000 newborns, consisted of an immunoreactive trypsin (IRT) protocol without mutation analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, referred to as the IRT/IRT protocol. Approximately 5% of the newborns with a positive first IRT test were also positive at the second test; approximately 57% of the newborns with a high IRT level at the second test were subsequently found to be affected by CF. In September 1998, a second protocol that included mutation analysis (IRT/DNA/IRT protocol) was started. Comparison of the two different screening protocols in terms of sensitivity in detecting CF patients demonstrated that the IRT/DNA/IRT protocol is more effective because it is able to detect a higher number of CF patients than the IRT/IRT protocol. In the same period, in addition to the overall diagnosis performed on a screening basis, 64 other subjects were identified as being affected by CF on the basis of symptomatic findings. The overall incidence of CF (screening + symptoms) was 1 : 2982, while that for carriers was 1 : 27. The sensitivity of the screening program increased over the period from 1992 to 2000, with the enhanced sensitivity in the past 2 years being due to the introduction of the IRT/DNA/IRT protocol.

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39 Mutations known to produce variable or mild clinical manifestations (e.g. G85E, R347P, 2789π 5GtoA) were observed in newborns with pancreatic sufficiency (PS). Login to comment

[hide] Demographics of the UK cystic fibrosis population:... Eur J Hum Genet. 2002 Oct;10(10):583-90. McCormick J, Green MW, Mehta G, Culross F, Mehta A
Demographics of the UK cystic fibrosis population: implications for neonatal screening.
Eur J Hum Genet. 2002 Oct;10(10):583-90., [PMID:12357328]

Abstract [show]
The objective was to determine the composition of the Cystic Fibrosis (CF) Population attending specialist UK CF centres in terms of age, gender, age at diagnosis, genotype and ethnicity. With the planned introduction of the national CF screening programme in the UK, cystic fibrosis transmembrane regulator (CFTR) mutations were compared between different ethnic groups enabling a UK-specific frequency of mutations to be defined. Data were analysed from the patient biographies held in the UK CF Database (see www.cystic-fibrosis.org.uk). The currently registered population of 5,274 CF patients is 96.3% Caucasian with a male preponderance that significantly increases with age. The majority of the 196 non-Caucasian CF patients are from the Indian Subcontinent (ISC), of which one in 84 UK CF patients are of Pakistani origin. The commonest CFTR mutation, deltaF508, is found in 74.1% of all CF chromosomes. In the Caucasian CF population, 57.5% are deltaF508 homozygotes but the UK ISC CF population with only 24.7%, has significantly fewer deltaF508 homozygotes patients (95% confidence interval (CI) 0.2-0.4). The distribution of Caucasian patients with deltaF508/deltaF508, deltaF508/Other and Other/Other does not fit the expected distribution with a Hardy-Weinberg model unless those patients without a detected mutation are excluded (P<0.001). The UK CF Database has shown the UK CF population to have distinct characteristics separate from the North American and European CF Registries. The ISC group contains many mutations not recognised by current genetic analysis, and one in four ISC patients have no CFTR mutations identified. The CFTR analysis proposed for the screening programme would detect 96% of patients registered in the database, but is unlikely to achieve the desired >80% detection rates in the ethnic minority groups. Screen-positive, non-Caucasian infants without an identifiable CFTR mutation should be referred for a sweat test and genetic counselling when serum trypsinogen concentrations remain elevated after birth.

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83 The additional eleven are S549N, 3849+4A?G, 3905insT, 2789+5G?A, Y122X, 711+1G?T, R347P, R347H, R334W, A455E and 3281AA?G. Login to comment
103 N1303K and G542X occur at a frequency of around 5% in Italy.11 In Germany, a study of 658 CF families revealed mutation frequencies of R553X (1.8%), N1303K (1.3%), G542X (1.1%), G551D (0.8%) and R347P (0.8%).12 The frequency of CFTR mutations recorded for just over 1000 patients for the Irish CF Database include G551D in 7%, R117H in 2% and DF508 in 72% of patients.13 In the white South African population, a paper based on 192 patients found that DF508 accounts for 76% of the mutations with 3272-26A?G (4%), 394delTT (3.6%) and G542X (1.3%) the other most common mutations.14 It is suggested that the 3272-26A?G and 394delTT mutations are more common due to a founder effect in white South Africans of European descent. Login to comment

[hide] Standards and guidelines for CFTR mutation testing... Genet Med. 2002 Sep-Oct;4(5):379-91. Richards CS, Bradley LA, Amos J, Allitto B, Grody WW, Maddalena A, McGinnis MJ, Prior TW, Popovich BW, Watson MS, Palomaki GE
Standards and guidelines for CFTR mutation testing.
Genet Med. 2002 Sep-Oct;4(5):379-91., [PMID:12394352]

Abstract [show]
One mission of the ACMG Laboratory Quality Assurance (QA) Committee is to develop standards and guidelines for clinical genetics laboratories, including cytogenetics, biochemical, and molecular genetics specialties. This document was developed under the auspices of the Molecular Subcommittee of the Laboratory QA Committee by the Cystic Fibrosis (CF) Working Group. It was placed on the "fast track" to address the preanalytical, analytical, and postanalytical quality assurance practices of laboratories currently providing testing for CF. Due to the anticipated impact of the ACMG recommendation statement endorsing carrier testing of reproductive couples, it was viewed that CF testing would increase in volume and that the number of laboratories offering CF testing would also likely increase. Therefore, this document was drafted with the premise of providing useful information gained by experienced laboratory directors who have provided such testing for many years. In many instances, "tips" are given. However, these guidelines are not to be interpreted as restrictive or the only approach but to provide a helpful guide. Certainly, appropriately trained and credentialed laboratory directors have flexibility to utilize various testing platforms and design testing strategies with considerable latitude. We felt that it was essential to include technique-specific guidelines of several current technologies commonly used in laboratories providing CF testing, since three of the four technologies discussed are available commercially and are widely utilized. We take the view that these technologies will change, and thus this document will change with future review.

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307 ⌬F508 R553X R1162X 2184delA 3120ϩ1GϾA ⌬I507 G542X G551D W1282X N1303K 621ϩ1GϾT R117H 1717-1GϾA A455E R560T G85E R334W R347P 711ϩ1GϾT 1898ϩ1GϾA 1078delT 3849ϩ10kbCϾT 2789ϩ5GϾA 3659delC I148T CF 3.3.2 Inclusion of the common R117H mutation in the test panel screens for CBAVD as well as for CF: The phenotypic consequences of the R117H mutation are modulated in cis by the 5/7/9T polypyrimidine tract in intron 8 such that R117H/7T is associated with CBAVD and R117H/5T is associated with CF.34 Moreover, the 5T allele is associated as a trans mutation in CBAVD.35 It is recommended that the 5/7/9T variant be excluded from the routine carrier screen but tested as a reflex for carriers shown to be heterozygous for the R117H mutation. Login to comment

[hide] A cystic fibrosis patient with two novel mutations... Am J Med Genet. 2002 Nov 15;113(1):59-64. Wong LJ, Liang MH, Kwon H, Bai RK, Alper O, Gropman A
A cystic fibrosis patient with two novel mutations in mitochondrial DNA: mild disease led to delayed diagnosis of both disorders.
Am J Med Genet. 2002 Nov 15;113(1):59-64., 2002-11-15 [PMID:12400067]

Abstract [show]
A 21-year-old woman who has been suspected of mitochondrial cytopathy, but negative for common mitochondrial DNA (mtDNA) point mutations and deletions, was screened for unknown mutations in the entire mitochondrial genome by temporal temperature gradient gel electrophoresis (TTGE). Her asymptomatic mother's blood DNA was also analyzed and used as a reference. Two tRNA regions showing different TTGE patterns between the proband and her mother were sequenced. Two novel mutations, G15995A in tRNA(pro) and A8326G in tRNA(lys), were revealed. These mutations are present in heteroplasmic states. They both occurred at a nucleotide position that is highly conserved throughout evolution. This patient is also a compound heterozygote for the cystic fibrosis (CF) mutations, DeltaF508 and R347P. The phenotype for R347P has been associated with mild disease. Due to the mild features of the R347P mutation in the CF transmembrane conductance regulator (CFTR) gene and the heterogeneous clinical presentation of the mtDNA disease, the patient was not definitively diagnosed until age 21. This case underscores the importance of a complete mutational analysis of the entire mitochondrial genome when a patient suspected of mitochondrial disorder is negative for common mtDNA mutations.

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8 Due to the mild features of the R347P mutation in the CF transmembrane conductance regulator (CFTR) gene and the heterogeneous clinical presentation of the mtDNA disease, the patient was not definitively diagnosed until age 21. Login to comment
23 She was also screened for mutations in the cystic fibrosis transmembrane regulator (CFTR) gene and found to be heterozygous for DF508 and R347P mutations, consistent with a mild cystic fibrosis (CF) phenotype [Dean et al., 1990]. Login to comment
74 Since the finding of DF508 and R347P mutations in the CFTR gene, she has been on a pancrelipase supplement. Login to comment
99 Mutational analysis for CF revealed the presence of a compound heterozygous mutation of DF508 and R347P. Login to comment

[hide] Survey of CF mutations in the clinical laboratory. BMC Clin Pathol. 2002 Nov 19;2(1):4. Huber K, Mirkovic B, Nersesian R, Myers A, Saiki R, Bauer K
Survey of CF mutations in the clinical laboratory.
BMC Clin Pathol. 2002 Nov 19;2(1):4., 2002-11-19 [PMID:12437773]

Abstract [show]
BACKGROUND: Since it is impossible to sequence the complete CFTR gene routinely, clinical laboratories must rely on test systems that screen for a panel of the most frequent mutations causing disease in a high percentage of patients. Thus, in a cohort of 257 persons that were referred to our laboratory for analysis of CF gene mutations, reverse line probe assays for the most common CF mutations were performed. These techniques were evaluated as routine first-line analyses of the CFTR gene status. METHODS: DNA from whole blood specimens was extracted and subjected to PCR amplification of 9 exons and 6 introns of the CFTR gene. The resulting amplicons were hybridised to probes for CF mutations and polymorphisms, immobilised on membranes supplied by Roche Molecular Systems, Inc. and Innogenetics, Inc. Denaturing gradient gel electrophoresis and sequencing of suspicious fragments indicating mutations were done with CF exon and intron specific primers. RESULTS: Of the 257 persons tested over the last three years (referrals based on 1) clinical symptoms typical for/indicative of CF, 2) indication for in vitro fertilisation, and 3) gene status determination because of anticipated parenthood and partners or relatives affected by CF), the reverse line blots detected heterozygote or homozygote mutations in the CFTR gene in 68 persons (26%). Eighty-three percent of those affected were heterozygous (47 persons) or homozygous (10 persons) for the DeltaF508 allele. The only other CF-alleles that we found with these tests were the G542X allele (3 persons), the G551D allele (3 persons), the 3849+10kb C-T allele (2 persons) the R117H allele (2 persons) and the 621+1G-T allele (1 person).Of the fifteen IVS8-5T-polymorphisms detected in intron 8, seven (47%) were found in males referred to us from IVF clinics. These seven 5T-alleles were all coupled with a heterozygous DeltaF508 allele, they make up 35% of the males with fertility problems (20 men) referred to us. CONCLUSIONS: In summary, the frequency of CF chromosomes in the cohort examined with these tests was 26%, with the DeltaF508 allele affecting 83% of the CF chromosomes. It is a substantial improvement for routine CF diagnostics to have available a test system for 30 mutations plus the polypyrimidine length variants in intron 8. Our results show that this test system allows a routine first-line analyses of the CFTR gene status.

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35 All probands (or their par- Table 1: Exons and introns that are amplified with the line probe assay, and the mutations they encompass Roche assay: Amplicon Mutations exon 4 R117H,621+1G → T exon 7 R334W, R347P exon 9 A455E, 5/7/9T polymorphism exon 10 ∆1507, ∆F508. Login to comment
36 F508C, I507V, I506V polymorphism exon 11 1717-1G → A, G542X, S549N, G551D, R553X, R560T exon 20 W1282X exon 21 N1303K intron 19 3849+10kb C → T Innogenetics assay: exon 3 394delTT, G85E, E60X exon/intron 4 621+1G-T, R117H exon 7 1078delT, R347P, R334W exon 13 2143delT, 2183AA-G, 2184delA exon 19 R1162X, 3659delC intron 5 711+5G-A intron8/exon 9 A455E,, 5T,7T,9T intron 14b 2789+5G-A intron 19 3849+10kb C-T Table 2: Genotypes of patients with mutations, final results Group 1) (patients with symptoms typical for/indicative of CF) No. Login to comment

[hide] Highest heterogeneity for cystic fibrosis: 36 muta... Am J Med Genet. 2002 Dec 1;113(3):250-7. Kilinc MO, Ninis VN, Dagli E, Demirkol M, Ozkinay F, Arikan Z, Cogulu O, Huner G, Karakoc F, Tolun A
Highest heterogeneity for cystic fibrosis: 36 mutations account for 75% of all CF chromosomes in Turkish patients.
Am J Med Genet. 2002 Dec 1;113(3):250-7., 2002-12-01 [PMID:12439892]

Abstract [show]
We analyzed the CFTR locus in 83 Turkish cystic fibrosis patients to identify mutations, haplotypes, and the carrier frequency in the population. We detected 36 different mutations in 125 (75%) of the total 166 CF chromosomes. Seven novel mutations were identified: four missense (K68E, Q493P, E608G, and V1147I), two splice-site (406 -3T > C and 3849 +5G > A), and one deletion (CFTRdele17b,18). The data showed that the Turkish population has the highest genetic heterogeneity at the CFTR locus reported so far. The results of this thorough molecular analysis at the CFTR locus of a population not of European descent shows that CF is not uncommon in all such populations. The large number of mutations present, as well as the high heterogeneity in haplotypes associated with the mutations suggests that most of the mutations have persisted for a long time in the population. Consistently, the carrier frequency is assessed to be high, indicating that the disease in the population is ancient.

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80 Haplotypes Associated With the Mutations Identified in 83 Turkish CF Patients* Mutation Total number of alleles Number of alleles Number of patients Haplotypes Homo Hetero DF508 39 (23.5) 6 7 23 M 28 13 1 0 1 6 7 23 M 30 13 1 0 1 6 9 23 M 31 13 1 0 1 6 7 23 M 31 13 11 4 3 6 7 23 M 7 17 2 0 2 6 7 16 M 31 13 3 1 1 6 7 17 M 31 13 17 5 7 6 7 17 M 32 13 3 1 1 1677delTA 12 (7.2) 7 7 16 V 30 13 12 5 2 2183AA > G 7 (4.2) 7 7 16 M 30 13 1 0 1 7 9 16 M 31 13 4 2 0 7 7 16 M 32 13 2 1 0 G542X 6 (3.6) 6 7 23 M 32 13 6 3 0 F1052V 5 (3.0) 6 7 17 M 7 13 4 1 2 7 5 17 M 7 17 1 0 1 W1282X 5 (3.0) 7 7 17 M 7 17 4 1 2 7 7 17 M 7 18 1 0 1 E92K 4 (2.4) 7 7 16 V 46 13 3 1 1 7 7 17 V 46 13 1 0 1 1525 À 1G > A 4 (2.4) 7 7 17 M 7 17 4 2 0 2789 þ 5G > A 4 (2.4) 7 9 17 M 7 17 3 1 1 7 5 17 M 7 17 1 0 1 N1303K 4 (2.4) 7 7 23 M 31 13 2 0 2 6 7 22 M 30 13 1 0 1 6 7 23 M 30 13 1 0 1 A46D 3 (1.8) 6 9 23 M 31 13 1 0 1 6 7 23 M 31 13 2 1 0 2184insA 3 (1.8) 7 5 17 V 30 13 1 0 1 7 7 16 V 30 13 2 0 2 R1070Q 3 (1.8) 7 7 16 M 31 13 1 0 1 7 7 17 M 31 13 2 0 2 Q493Pa 2 (1.2) 6/7 5 16 M 46 13 2 1 0 3849 þ 5G > Aa 2 (1.2) 7 7 16 M 31 13 2 1 0 CFTRdele17b,18a 2 (1.2) 6 9 16 V - - 2 1 0 K68Ea 1 (0.6) 6 9 17 M 7 13 1 0 1 R74W 1 (0.6) 6 7 16 M 32 16 1 0 1 306delTAGA 1 (0.6) 7 7 16 M 7 17 1 0 1 D110H 1 (0.6) 7 9 16 V 30 13 1 0 1 I125T 1 (0.6) 6 7 23 V 7 16 1 0 1 406 À 3T > Ca 1 (0.6) 7 7 16 V 33 17 1 0 1 I148T 1 (0.6) 6/7 7 16/17 M 7 17/23 1 0 1 621 þ 1G > T 1 (0.6) 6 7 21 V 31 13 1 0 1 R347P 1 (0.6) 7 9 17 V 30 13 1 0 1 S466X 1 (0.6) 7 7 23 M 33 13 1 0 1 L571S 1 (0.6) 7 7 16 V 29 13 1 0 1 1717 À 1G > A 1 (0.6) 7 9 17 M 7 16 1 0 1 E608Ga 1 (0.6) 7 9 16 M/V 29/31 13 1 0 1 2043delG 1 (0.6) 7 9 17 M 7 17 1 0 1 P1013L 1 (0.6) 6 5 16 M 21 18 1 0 1 R1066L 1 (0.6) 7 7 17 M 7 13 1 0 1 3129del4 1 (0.6) 7 7 16 V 29 13 1 0 1 V1147Ia 1 (0.6) 6 7 17 M 33 17 1 0 1 S1235R 1 (0.6) 6 7 17 M 39 13 1 0 1 CFTRdele2,3 1 (0.6) 7 7 16 V 33 13 1 0 1 Total 125 (75) 125 32 61 *The order of the polymorphisms is IVS6GATT, Tn, IVS8CA, M470V, IVS17BTA and IVS17BCA. Login to comment

[hide] [National program for neonatal screening for cysti... J Gynecol Obstet Biol Reprod (Paris). 2003 Feb;32(1 Suppl):1S56-60. Navarro J, Grosskopf C, Vidailhet M, Briard ML, Farriaux JP
[National program for neonatal screening for cystic fibrosis: implementation and preliminary results].
J Gynecol Obstet Biol Reprod (Paris). 2003 Feb;32(1 Suppl):1S56-60., [PMID:12592165]

Abstract [show]
Neonatal screening for cystic fibrosis was decided by the national medical authorities after a common investigation conducted by the French association ADPHE and national health insurance fund. Based on therapeutic progress and the proposed method using determination of blood immunoreactive trypsin then study of the main CF mutations, there is strong hope of effective CF detection and clinical benefit for the patients.

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46 3 Les mutations étudiées sont : 1717-1G > A - G542X - W 1282 X - N 1303 K - DF 508 (M) - 3849 + 10kbC > T - 621+1 G > T - R553X - G 551D, R117H, R1162X - R 334W - A455E - 2183 AA > G - 3659delC-- 1078 delT - D1507 - R347P - S 1251N, E60X, 2789+5G > A - 394del T - G 85 E - 1811+1.6 - Y122X - 711+1G > T - W 846 X - Y 1092 - 3272-26A > G. Login to comment

[hide] Modulation of Ca2+-activated Cl- secretion by baso... Pediatr Res. 2003 Apr;53(4):608-18. Epub 2003 Feb 5. Mall M, Gonska T, Thomas J, Schreiber R, Seydewitz HH, Kuehr J, Brandis M, Kunzelmann K
Modulation of Ca2+-activated Cl- secretion by basolateral K+ channels in human normal and cystic fibrosis airway epithelia.
Pediatr Res. 2003 Apr;53(4):608-18. Epub 2003 Feb 5., [PMID:12612194]

Abstract [show]
Human airway epithelia express Ca2+-activated Cl- channels (CaCC) that are activated by extracellular nucleotides (ATP and UTP). CaCC is preserved and seems to be up-regulated in the airways of cystic fibrosis (CF) patients. In the present study, we examined the role of basolateral K+ channels in CaCC-mediated Cl- secretion in native nasal tissues from normal individuals and CF patients by measuring ion transport in perfused micro Ussing chambers. In the presence of amiloride, UTP-mediated peak secretory responses were increased in CF compared with normal nasal tissues. Activation of the cAMP pathway further increased CaCC-mediated secretion in CF but not in normal nasal mucosa. CaCC-dependent ion transport was inhibited by the chromanol 293B, an inhibitor of cAMP-activated hKvLQT1 K+ channels, and by clotrimazole, an inhibitor of Ca2+-activated hSK4 K+ channels. The K+ channel opener 1-ethyl-2-benzimidazolinone further increased CaCC-mediated Cl- secretion in normal and CF tissues. Expression of hSK4 as well as hCACC-2 and hCACC-3 but not hCACC-1 was demonstrated by reverse transcriptase PCR on native nasal tissues. We conclude that Ca2+-activated Cl- secretion in native human airway epithelia requires activation of Ca2+-dependent basolateral K+ channels (hSK4). Co-activation of hKvLQT1 improves CaCC-mediated Cl- secretion in native CF airway epithelia, and may have a therapeutic effect in the treatment of CF lung disease.

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32 CF patients were genotyped for the following common CFTR mutations: ⌬F508, R553X, N1303 K, G542X, G551D, and R347P. Login to comment

[hide] Cystic fibrosis mutation frequencies in an Irish p... Clin Genet. 2003 Feb;63(2):121-5. Devaney J, Glennon M, Farrell G, Ruttledge M, Smith T, Houghton JA, Maher M
Cystic fibrosis mutation frequencies in an Irish population.
Clin Genet. 2003 Feb;63(2):121-5., [PMID:12630958]

Abstract [show]
The incidence of cystic fibrosis (CF) at birth in Ireland is 1/1461. Neonate CF genetic testing is not routinely performed in Ireland. Currently, screening is only carried out where there is clinical evidence or a family history to suggest disease. Here we report the frequencies of common CF mutations occurring in an Irish population composed of samples collected from western, mid-western and southern regions of Ireland. Rarer CF mutations were also identified in a selected number of CF patients. In addition, a number of polymorphisms were identified, some of which are reported to be functionally and phenotypically important.

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18 In a selected cohort of 40 patients, six other common ABCC7 mutations were screened for, using PCR-REA: R347P, A455E, R1162X, 384910kbC> T, W1282X and N1303K. Login to comment
27 Samples (n 40) were screened using an in-house optimized protocol to screen for six additional mutations (R347P, A455E, R1162X, 3849 10kbC > T, W1282X and N1303K). Login to comment

[hide] Chronic pancreatitis and cystic fibrosis. Gut. 2003 May;52 Suppl 2:ii31-41. Witt H
Chronic pancreatitis and cystic fibrosis.
Gut. 2003 May;52 Suppl 2:ii31-41., [PMID:12651880]

Abstract [show]
Recent discoveries of trypsinogen and trypsin inhibitor mutations in patients with chronic pancreatitis (CP) support the hypothesis that an inappropriate activation of pancreatic zymogens to active enzymes within the pancreatic parenchyma starts the inflammatory process. Current data suggest that CP may be inherited dominant, recessive, or complex as a result of mutations in the above mentioned or yet unidentified genes. Evaluation of patients with CP should include genetic testing. Cystic fibrosis (CF) is an autosomal recessive inherited disorder caused by mutations in the CF transmembrane conductance regulator (CFTR) gene and is characterised by pancreatic insufficiency and chronic bronchopulmonary infection. The progression and severity of pulmonary disease differs considerably between people with identical CFTR mutations and does not seem to correlate with the type or class of the CFTR mutation. The identification of further disease modifying genetic factors will increase the pathophysiological understanding and may help to identify new therapeutic targets.

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427 Class IV mutations such R117H and R347P affect the chloride conductive function and are associated with decreased but residual CFTR function. Login to comment
430 Nucleus Class I defective protein synthesis (R553X, W1282X, 3950delT) Class II abnormal processing/trafficking (del508, N1303K) Class VI defective regulation of other ion channels (del508, G551D) Class V reduced synthesis (3849+10kbC>T) Class IV decreased conductance (R117H, R347P, D1152H) Class III defective activation (G551D) I II VI V III IV RD ATP Endoplasmic reticulum NBD NBD Golgi mutations result in a decreased amount of functional protein by abnormal splicing or reduced trafficking. Login to comment

[hide] Clinical characteristics and genotype analysis of ... Clin Otolaryngol Allied Sci. 2003 Apr;28(2):125-32. Cimmino M, Cavaliere M, Nardone M, Plantulli A, Orefice A, Esposito V, Raia V
Clinical characteristics and genotype analysis of patients with cystic fibrosis and nasal polyposis.
Clin Otolaryngol Allied Sci. 2003 Apr;28(2):125-32., [PMID:12680831]

Abstract [show]
The prevalence of nasal polyps in a group of paediatric patients with cystic fibrosis was prospectively studied in comparison with a control group with cystic fibrosis but without polyps. Clinical variables, including pulmonary function tests, skin testing and mucociliary transport, were carried out in both groups, as well as genotype analysis. Endoscopic intranasal evaluation identified polyps in 29 of 89 patients (33%). Statistical analysis revealed that patients with nasal polyposis had better pulmonary function, a higher rate of Pseudomonas aeruginosa colonization, more hospitalizations, and more prevalence of allergy to Aspergillus fumigatus than did the comparison group. We found no statistically different genotype distribution between the polyposis and the control group. However, it can be emphasized that the prevalence of the compound heterozygous genotype is higher in the nasal polyposis group than in controls. Our observations suggest that other genetic and environmental factors could play an important role in the development of nasal polyposis.

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47 Analysis of mutations in the CFTR gene as tested by the multiplex polymerase chain reaction (PCR), followed by the reverse dot-blot technique, which searches for 29 of the most frequent mutations (DF508, N1303K, G542X, W1282X, 1717±1 G-A, R553X, 2183 AA-G, DI507, G551D, R560T, 3849 10kbC > T, R1162X, 3659delC, 3905insT, G85E, 621 1GT, R117H, R347P, R334W, A455E, 2789 5GA, Q552X, S1251N, 3905insT, 394delTT, E60X, 2143delT, 2184delA, 711 5G > A), and by ASO dot-blot for the following mutations: I148T, R1158X, 4016 1T, G1244E G >A.26 Statistical analysis was performed using multivariate analysis, by forward stepwise comparison; it was done to ®nd out which of the examined characteristics could be associated (P < 0.01) to nasal polyposis. Login to comment

[hide] Analysis of cystic fibrosis transmembrane conducta... Am J Med Genet A. 2003 Jul 1;120A(1):72-6. Timmreck LS, Gray MR, Handelin B, Allito B, Rohlfs E, Davis AJ, Gidwani G, Reindollar RH
Analysis of cystic fibrosis transmembrane conductance regulator gene mutations in patients with congenital absence of the uterus and vagina.
Am J Med Genet A. 2003 Jul 1;120A(1):72-6., 2003-07-01 [PMID:12794695]

Abstract [show]
The relationship between cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations and congenital absence of the uterus and vagina (CAUV) was examined. CFTR mutations have previously been associated with congenital bilateral absence of the vas deferens (CBAVD). CBAVD is caused by a disruption in the vas deferens, a Wolffian duct derivative. Because the embryologic development of the Mullerian ducts directly depends on the prior normal development of the Wolffian ducts, the same gene products may be necessary for normal embryologic development of both ductal systems. This study evaluated the role of CFTR mutations in the development of CAUV. DNA samples from 25 patients with CAUV were tested for the presence of 33 of the most common CFTR mutations. Protein-coding DNA fragments from the CFTR gene were amplified in vitro by the polymerase chain reaction (PCR) and analyzed for mutations using allele-specific oligonucleotide (ASO) probes. Two patients were heterozygous for CFTR mutations. One was heterozygous for the W1282X mutation and the other was heterozygous for the DeltaF508 mutation. The incidence of the 33 CFTR mutations found in the patients with CAUV (8%) was twice that found in the general population (4%), but much less than the incidence of CFTR mutations in men with CBAVD (80%). This data suggests that it is unlikely for CFTR mutations to cause CAUV in females as they cause CBAVD in some males. Furthermore, the data suggest that CAUV in females may be the same disorder as CBAVD in males who do not have CFTR mutations.

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82 CFTR Gene Mutations Tested DF508 R334W Y1092X 5T variant Y122X R347H G542X S549R 3,849 þ 4 G551D 3,849 þ 10 kb 2,789 þ 5 W1282X R553X 711 þ 1 3,905 þ T 621 þ 1 1,898 þ 1 N1303K 1,717À1 R1162X R117H 1078dT A455E D1507 Q493X 218dA R347P V520F G85E R560T S549N 3659dC Wolffian duct must occur at a time when the Mu¨llerian duct is no longer dependent on the Wolffian duct for development. Login to comment

[hide] Comparison of the CFTR mutation spectrum in three ... Hum Mutat. 2003 Jul;22(1):105. Scotet V, Barton DE, Watson JB, Audrezet MP, McDevitt T, McQuaid S, Shortt C, De Braekeleer M, Ferec C, Le Marechal C
Comparison of the CFTR mutation spectrum in three cohorts of patients of Celtic origin from Brittany (France) and Ireland.
Hum Mutat. 2003 Jul;22(1):105., [PMID:12815607]

Abstract [show]
This study aims to compare the spectrum of the mutations identified in the gene responsible for cystic fibrosis in three cohorts of patients of Celtic origin from Brittany and Ireland. It included 389 patients from Brittany, 631 from Dublin and 139 from Cork. The CFTR gene analysis relied on the detection of the most common mutations, followed by a complete gene scanning using DGGE or D-HPLC. High mutation detection rates were obtained in each cohort: 99.6%, 96.8%, and 96.0% respectively. A high frequency of the c.1652_1655 del3 mutation (F508del: 74.8% to 81.3%) and of the "Celtic" mutation (c.1784G>A (G551D): 3.7% to 9.7%) was observed in each population. Apart from this, the mutation spectrums differed. In Brittany, the most common abnormalities were: c.1078delT (3.6%), c.4041C>G (N1303K: 1.4%), c.2670G>A (W846X(2): 1.0%) and c.1717-1G>A (1.0%), whereas in the cohort of Dublin, the main mutations were: c.482G>A (R117H: 3.0%), c.1811G>C (R560T: 2.4%) and c.621+1G>T (1.7%). Finally, in the Cork area, only the c.482G>A mutation (R117H) reached a frequency of 1%. Two previously-unreported mutations were identified in the Dublin cohort: c.2623-2A>G and c.3446T>G (M1105R). This collaborative study highlights the similarities of the CFTR alleles in the Breton and Irish populations, but also the disparities that exist between these populations, despite their common origin. Each population has its own history, with its mixture of founder effects and genetic drifts, which are at the origin of the current mutation distribution. The molecular study of the CFTR gene provides new tools for retracing European populations' histories.

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64 Spectrum of the CFTR Mutations Identified in the Cohorts from Brittany, Dublin Centre, and Cork Area Nucleotide Amino acid change * change Exon Number Frequency Number Frequency Number Frequency 211delG 2 1 0.1% 310G>T E60X 3 5 0.6% 4 0.3% 347C>A A72D 3 1 0.1% 368G>A W79X 3 1 0.1% 386G>A G85E 3 2 0.3% 3 0.2% 403G>A G91R 3 2 0.3% 482G>A R117H 4 4 0.5% 38 3.0% 4 1.4% 498T>A Y122X 4 1 0.1% 574delA 4 1 0.1% 577G>A G149R 4 1 0.1% 621+1G>T int 4 5 0.6% 21 1.7% 790C>T Q220X 6a 1 0.1% 875+1G>C int 6a 1 0.4% 905delG 6b 1 0.1% 1065C>G F311L 7 2 0.3% 1078delT 7 28 3.6% 1132C>T R334W 7 1 0.1% 1172G>A R347H 7 5 0.6% 1172G>T R347L 7 1 0.1% 1172G>C R347P 7 1 0.1% 1187G>A R352Q 7 3 0.2% 2 0.7% 1208A>G Q359R 7 1 0.1% 1154insTC 7 2 0.2% 1221delCT 7 2 0.3% 1248+1G>A int 7 1 0.1% 1249-27delTA int 7 1 0.4% 1334G>A W401X 8 1 0.1% 1461ins4 9 5 0.4% 1471delA 9 2 0.2% 1607C>T S492F 10 2 0.3% 1609C>T Q493X 10 1 0.1% 1648_1653delATC I507del 10 3 0.4% 10 0.8% 1 0.4% 1652_1655del 3 bp F508del 10 582 74.8% 966 76.5% 226 81.3% 1690G>T V520F 10 4 0.3% 1717-1G>A int 10 8 1.0% 9 0.7% 1756G>T G542X 11 5 0.6% 8 0.6% 1779T>G S549R 11 1 0.1% 1784G>A G551D 11 29 3.7% 82 6.5% 27 9.7% 1789C>G R553G 11 1 0.1% 1789C>T R553X 11 3 0.4% 1 0.1% 1806delA 11 1 0.1% 1811G>A R560K 11 2 0.3% 1811G>C R560T 11 30 2.4% 2 0.7% 1819T>A Y563N 12 1 0.1% 1853C>A P574H 12 1 0.1% 1898+1G>A int 12 1 0.1% 2184delA 13 1 0.1% 1 0.1% 2184insA 13 1 0.1% 2622+1G>A int 13 1 0.1% 2 0.2% 2622+1G>T int 13 1 0.1% 2623-2A>G ** int 13 1 0.1% 2670G>A W846X2 14a 8 1.0% 2752-1G>T int 14a 1 0.1% 2752-26A>G int 14a 2 0.2% 2789+5G>A int 14b 6 0.8% 2966C>T S945L 15 2 0.3% 3007delG 15 4 0.3% 3040G>C G970R 15 1 0.1% 3062C>T S977F 16 1 0.1% 3120+1G>A int 16 1 0.1% 3272-26A>G int 17a 4 0.5% 2 0.2% 2 0.7% 3320dupli(CTATG) 17b 1 0.1% 3329G>A R1066H 17b 1 0.1% 3340C>T R1070W 17b 1 0.1% 3408C>A Y1092X 17b 7 0.9% 3442G>T E1104X 17b 1 0.1% 3446T>G ** M1105R 17b 1 0.1% 3586G>C D1152H 18 1 0.1% 3601-17T>C + 1367delC int 18 + 9 1 0.1% 3616C>T R1162X 19 1 0.1% 2 0.2% 3659delC 19 2 0.2% 3832A>G I1234V 19 2 0.3% 3849+4A>G int 19 1 0.1% 3849+10kbC>T int 19 3 0.2% 3877G>A G1249R 20 1 0.1% 3884G>A S1251N 20 1 0.1% 3898insC 20 1 0.1% 3905insT 20 2 0.3% 3978G>A W1282X 20 3 0.4% 4005+1G>A int 20 6 0.8% 4016insT 21 1 0.1% 4041C>G N1303K 21 11 1.4% 5 0.4% 4136T>C L1335P 22 1 0.1% 1 0.4% 4279insA 23 1 0.1% Unidentified Unidentified - 3 0.4% 41 3.2% 11 4.0% Total 778 100.0% 1262 100.0% 278 100.0% * All nucleotide changes correspond to cDNA numbering. Login to comment

[hide] 1154insTC is not a rare CFTR mutation. Am J Med Genet A. 2003 Jul 15;120A(2):294-5. Alper OM, Wong LJ, Hostetter G, Cook J, Tenenholz B, Hsu E, Woo MS
1154insTC is not a rare CFTR mutation.
Am J Med Genet A. 2003 Jul 15;120A(2):294-5., 2003-07-15 [PMID:12833419]

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32 The frequency of this mutation was about 0.5%, higher than some of the mutations, such as DI507, R334W, R347P, and S549N that were in the routine screening panels [Cystic Fibrosis Genetic Analysis Consortium, 1994; Friedman et al., 1995]. Login to comment

[hide] Molecular consequences of cystic fibrosis transmem... Gut. 2003 Aug;52(8):1159-64. Ahmed N, Corey M, Forstner G, Zielenski J, Tsui LC, Ellis L, Tullis E, Durie P
Molecular consequences of cystic fibrosis transmembrane regulator (CFTR) gene mutations in the exocrine pancreas.
Gut. 2003 Aug;52(8):1159-64., [PMID:12865275]

Abstract [show]
BACKGROUND AND AIMS: We tested the hypothesis that the actual or predicted consequences of mutations in the cystic fibrosis transmembrane regulator gene correlate with the pancreatic phenotype and with measures of quantitative exocrine pancreatic function. METHODS: We assessed 742 patients with cystic fibrosis for whom genotype and clinical data were available. At diagnosis, 610 were pancreatic insufficient, 110 were pancreatic sufficient, and 22 pancreatic sufficient patients progressed to pancreatic insufficiency after diagnosis. RESULTS: We identified mutations on both alleles in 633 patients (85.3%), on one allele in 95 (12.8%), and on neither allele in 14 (1.9%). Seventy six different mutations were identified. The most common mutation was DeltaF508 (71.3%) followed by G551D (2.9%), G542X (2.3%), 621+1G-->T (1.2%), and W1282X (1.2%). Patients were categorized into five classes according to the predicted functional consequences of each mutation. Over 95% of patients with severe class I, II, and III mutations were pancreatic insufficient or progressed to pancreatic insufficiency. In contrast, patients with mild class IV and V mutations were consistently pancreatic sufficient. In all but four cases each genotype correlated exclusively with the pancreatic phenotype. Quantitative data of acinar and ductular secretion were available in 93 patients. Patients with mutations belonging to classes I, II, and III had greatly reduced acinar and ductular function compared with those with class IV or V mutations. CONCLUSION: The predicted or known functional consequences of specific mutant alleles correlate with the severity of pancreatic disease in cystic fibrosis.

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309 Table 2 Genotype classification according to the functional consequences of CFTR gene mutations Pancreatic status Class I Class II Class III Class IV Class V PS F1 , 875+1G→C(2) F, F (1) F, G551D (1) F, R117H (11) F,3849+10kbC→T (5) F, G85E2 (1) F, R347H (3) F,3272-26A→G (4) F, S1251N (2) F,A445E (3) F, D614G (1) F,P574H (2) F, R347P (1) F,3120G>A (1) R117H,R117H (1) F, 5T (8) F, L1335P (1) F,2789+5G→A (1) F,P67L (1) F,R347P/R347H (1) F,V232D(2) R334W, R334W(1) PS→PI F,3659delC (1) F,F (15) F,G551D (1) F, I1234V (1) F,2184insA (1) F,R560T (1) PI F, G542X (27) F,F (365) F, G551D (28) F, 621+1G→T (13) F, R560T (7) F,R553X (7) F, N1303K (9) F, R1162X (6) F,L1077P (2) F, 3659delC (5) F, I48T (1) F, 1717-1G→A (5) F,A559T (1) F, W1282X (5) F, G85E2 (2) F, 711+1G→T (5) G551D,G551D(1) F,2184delA(4) F,H199R (1) W1282X,W1282X (4) F,I1072T(1) F,Y1092X (3) F,S549 (R75Q) (1) F,556delA (3) F, Q493X (3) F,4016InsT (3) F, 3120+1G→A (2) F, G551D/R553X (2) F,Q814X(2) F,1154insTC (2) F,441delA (1) F, 4326delTC (1) F,Q552X(1) F,3007delG (1) F,2184insA (1) F, 4010del4 (1) F,3905insT (1) F,1078delT(1) F,E1104X (1) F,3876delA (1) F,4374+1G→T (1) F,E585X (1) F, E60X (1) CFTR, cystic fibrosis transmembrane regulator; PI, pancreatic insufficiency; PS, pancreatic sufficiency. Login to comment

[hide] Detection of cystic fibrosis mutations by peptide ... Clin Chem. 2003 Aug;49(8):1318-30. Malehorn DE, Telmer CA, McEwen SB, An J, Kinsey AD, Retchless AC, Mason C, Vieta WM, Jarvik JW
Detection of cystic fibrosis mutations by peptide mass signature genotyping.
Clin Chem. 2003 Aug;49(8):1318-30., [PMID:12881448]

Abstract [show]
BACKGROUND: The diversity of genetic mutations and polymorphisms calls for the development of practical detection methods capable of assessing more than one patient/one nucleotide position per analysis. METHODS: We developed a new method, based on peptide mass signature genotyping (PMSG), for the detection of DNA mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Exons of the gene were amplified, cloned, and expressed in Escherichia coli as peptide fusions, in natural as well as unnatural reading frames. Peptide analytes were purified by immobilized metal affinity chromatography and analyzed by matrix-assisted, laser desorption/ionization time-of-flight mass spectrometry. Synthetic and natural DNA samples with the 25 mutations recommended for CFTR carrier screening (Grody et al. Genet Med 2001;3:149-54) were assessed using the PMSG test for the CFTR gene. RESULTS: Peptide analytes ranged from 6278 to 17 454 Da and varied 30-fold in expression; highly expressing peptides were observed by electron microscopy to accumulate as inclusion bodies. Peptides were reliably recovered from whole-cell lysates by a simple purification method. CFTR mutations caused detectable changes in resulting mass spectrometric profiles, which were >95% reliably detected in blinded testing of replicate synthetic heterozygous DNA samples. Mutation detection was possible with both sample pooling and multiplexing. The PMSG CFTR test was used to determine compound heterozygous mutations in DNA samples from cystic fibrosis patients, which were confirmed by direct DNA sequencing. CONCLUSIONS: The PMSG test of the CFTR gene demonstrates unique capabilities for determining the sequence status of a DNA target by sensitively monitoring the mass of peptides, natural or unnatural, generated from that target.

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138 ⌬b 3 R Y 9863.78 G85E SerϾPhe 9923.90 Y 60.12 4.1 R N 7047.69 R117H AlaϾVal 7075.76 N 28.07 4.2 R Y 11161.32 lI48T AsnϾSer 11134.32 Y -27.00 621ϩ1 GϾT TyrϾTAA 6513.09 N -4648.23 5 R Y 11081.45 711ϩ1 GϾT ThrϾAsn 11094.48 Y 13.03 7.1 R N 7383.08 1078⌬T frameshift 9201.10 Y 1818.02 7 R Y 12233.9 R334W ArgϾGln 12205.87 Y -28.03 R347P ArgϾGly 12134.79 Y -99.11 9 F Y 14049.68 A455E AlaϾGlu 14107.74 Y 58.06 10.2 R Y 10525.57 ⌬I507 ⌬ Asp 10410.50 Y -115.07 ⌬F508 ⌬ Asp & LysϾAsn 10396.43 Y -129.14 11.2 F Y 11173.32 1717-1 GϾA GlyϾArg 11272.46 Y 99.14 G542X TrpϾLeu 11100.27 Y -73.05 G551D no change 11173.32 Y 0.00 R553X ThrϾMet 11203.42 Y 30.10 R560T no change 11173.32 Y 0.00 11 F N 8465.27 1717-1 GϾA no change 8465.27 N 0.00 G542X GlyϾTGA 6584.17 N -1881.10 G551D GlyϾAsp 8523.33 N 58.06 R553X ArgϾTGA 7541.18 N -924.09 R560T ArgϾThr 8410.21 N -55.06 12 F Y 10372.51 1898ϩ1 GϾA GlyϾAsp 10430.57 Y 58.06 13.2A R Y 10103.23 2184⌬A frameshift 8726.91 N -1376.32 14B R Y 9291.17 2789ϩ5 GϾA LeuϾPhe 9325.21 Y 34.04 16 F N 9398.67 3120ϩ1 GϾA ValϾIle 9412.72 N 14.05 19 F Y 17455.96 R1162X ArgϾTGA 6280.13 N -11175.83 3659⌬C frameshift 9650.06 N -7805.90 19i F Y 9699.9 3849ϩ10kB CϾT ArgϾTGA 7131.04 N -2568.86 20 F N 11125.48 W1282X TrpϾTGA 9370.40 N -1755.08 21 F Y 11183.44 N1303K AsnϾLys 11197.54 Y 14.10 a Denotes the directionality of exonic sequence when expressed as peptide. Login to comment
181 The heterozygous mutations depicted are as follows: (A), exon 3 wt/G85E; (B), exon 4.1 wt/R117H; (C), exon 4.2 wt/I148T; (D), exon 4.2 wt/621 ؉ 1G>T; (E), exon 5 wt/711 ؉ 1G>T; (F), exon 7.1 wt/1078⌬T; (G), exon 7 wt/R334W; (H), exon 7 wt/R347P; (I), exon 9 wt/A455E; (J), exon 10.2 wt/⌬I507; (K), exon 10.2 wt/⌬F508; (L), exon 11.2 wt/1717-1G>A; (M), exon 11 wt/G542X; (N), exon 11 wt/G551D; (O), exon 11 wt/R553X; (P), exon 11 wt/R560T; (Q), exon 12 wt/1898 ؉ 1G>A; (R), exon 13.2A wt/2184⌬A; (S), exon 14B wt/2789 ؉ 5G>A; (T), exon 16 wt/3120 ؉ 1G>A; (U), exon 19 wt/R1162X; (V), exon 19 wt/3659⌬C; (W), intron 19 wt/3849 ؉ 10kbC>T; (X), exon 20 wt/W1282X; (Y), exon 21 wt/N1303K. typical yield of purified protein was 1-30 ␮g/test well, depending on the analyte species. Login to comment

[hide] Mutation analysis of the cystic fibrosis transmemb... Eur J Hum Genet. 2003 Sep;11(9):687-92. Perri F, Piepoli A, Stanziale P, Merla A, Zelante L, Andriulli A
Mutation analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the cationic trypsinogen (PRSS1) gene, and the serine protease inhibitor, Kazal type 1 (SPINK1) gene in patients with alcoholic chronic pancreatitis.
Eur J Hum Genet. 2003 Sep;11(9):687-92., [PMID:12939655]

Abstract [show]
Susceptibility to alcoholic chronic pancreatitis (ACP) could be genetically determined. Mutations in cationic trypsinogen (PRSS1), cystic fibrosis transmembrane conductance regulator (CFTR), and serine protease inhibitor, Kazal type 1 (SPINK1) genes have been variably associated with both the hereditary and the idiopathic form of chronic pancreatitis (CP). Our aim was to analyze the three genes in ACP patients. Mutational screening was performed in 45 unrelated ACP patients and 34 patients with alcoholic liver disease (ALD). No mutation of PRSS1 was found in ACP and ALD patients. Three mutations of CFTR were detected in four ACP patients with a prevalence (8.9%) not significantly different from that observed (3.0%) in ALD patients and from that expected (3.2%) in our geographical area. Neither compound heterozygotes for CFTR nor trans-heterozygotes for CFTR/SPINK1 were found. One ACP patient (2.2%) was found to carry the most common mutation (N34S) of SPINK1 compared to none of the ALD patients (P=NS). In five other patients (two with ACP and three with ALD) other rare variants, including P55S, were found. In contrast with the hereditary and the idiopathic forms of CP, in which mutations of PRSS1, CFTR, and SPINK1 genes may occur, ACP is still a "gene(s)-orphan" disease. The supposed genetic susceptibility to ACP relies on other yet unknown gene(s) which could affect the alcohol metabolism or modulate the pancreatic inflammatory response to alcohol abuse.

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33 Mutation screening of the CFTR gene The 31 most frequent mutations (F508del, I507del, G551D, G542X, N1303K, 1717-1G4A, W1282X, R553X, R347P, R347H, R334W, 3849+10kb C4T, R117H, 621+1G4T, A455E, S549N, R560T, S549R, V520F, Q493X, 3849+ 4A4G, 1078delT, R1162X, 3659delC, 3905insT, Y122X, 2183delAA4G, 2789+5G4A, 1898+1G4A, 711+1G4T, and G85E) were examined with the polymerase chain reaction (PCR) followed by an oligonucleotide ligation assay (OLA, Applied Biosystems, Foster City, CA, USA) and finally a sequence-coded separation. Login to comment

[hide] The phenotypic consequences of CFTR mutations. Ann Hum Genet. 2003 Sep;67(Pt 5):471-85. Rowntree RK, Harris A
The phenotypic consequences of CFTR mutations.
Ann Hum Genet. 2003 Sep;67(Pt 5):471-85., [PMID:12940920]

Abstract [show]
Cystic fibrosis is a common autosomal recessive disorder that primarily affects the epithelial cells in the intestine, respiratory system, pancreas, gall bladder and sweat glands. Over one thousand mutations have currently been identified in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene that are associated with CF disease. There have been many studies on the correlation of the CFTR genotype and CF disease phenotype; however, this relationship is still not well understood. A connection between CFTR genotype and disease manifested in the pancreas has been well described, but pulmonary disease appears to be highly variable even between individuals with the same genotype. This review describes the current classification of CFTR mutation classes and resulting CF disease phenotypes. Complex disease alleles and modifier genes are discussed along with alternative disorders, such as disseminated bronchiectasis and pancreatitis, which are also thought to result from CFTR mutations.

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155 Mutations R117H, R334W and R347P are usually associated with less severely impaired pancreatic function (reviewed by Tsui, 1992). Login to comment

[hide] CFTR genotypes in patients with normal or borderli... Hum Mutat. 2003 Oct;22(4):340. Feldmann D, Couderc R, Audrezet MP, Ferec C, Bienvenu T, Desgeorges M, Claustres M, Mittre H, Blayau M, Bozon D, Malinge MC, Monnier N, Bonnefont JP, Iron A, Bieth E, Dumur V, Clavel C, Cazeneuve C, Girodon E
CFTR genotypes in patients with normal or borderline sweat chloride levels.
Hum Mutat. 2003 Oct;22(4):340., [PMID:12955726]

Abstract [show]
In recent years, some patients bearing "atypical" forms of cystic fibrosis (CF) with normal sweat chloride concentrations have been described. To identify the spectrum of mutant combinations causing such atypical CF, we collected the results of CFTR (ABCC7) mutation analysis from 15 laboratories. Thirty patients with one or more typical symptoms of the disease associated with normal or borderline sweat chloride levels and bearing two CFTR mutations were selected. Phenotypes and genotypes of these 30 patients are described. A total of 18 different CFTR mutations were observed in the 60 chromosomes analysed. F508del was present in 31.6 % of the mutated chromosomes and 3849+10kbC>T in 13.3 %. R117H, D1152H, L206W, 3272-26A>G, S1235R, G149R, R1070W, S945L, and the poly-T tract variation commonly called IVS8-5T were also observed. The relative frequency of CFTR mutations clearly differed from that observed in typical CF patients or in CBAVD patients with the same ethnic origin. A mild genotype with one or two mild or variable mutations was observed in all the patients. These findings improve our understanding of the distribution of CFTR alleles in CF with normal or borderline sweat chloride concentrations and will facilitate the development of more sensitive CFTR mutation screening.

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44 Table 1 : Genotypes and Phenotypes of Patients with Normal or BordIerline Sweat Tests Patient Age at diagnosis (years) CFTR GENOTYPE* Allele 1 Allele 2 SWEAT CL- MEAN (MMOL/L) PHENOTYPE 1 0.2 F508del G149R 38 P+PI, neonatal hypertrypsinemia, 2 0.3 G551D R117H-7T 31 neonatal hypertrypsinemia 3 0.4 F508del R1070W 30.5 neonatal hypertrypsinemia 4 0.4 F508del R117H-7T 52 P 5 0.6 F508del 3849+10kbC>T 48 P 6 0.11 F508del S945L 58 P+PI 7 1 F508del 5T 40 P+CBAVD 8 2 F508del L206W 53 P 9 2 W1282X 5T 42.5 P 10 5 F508del 3849+10kbC>T 55.5 P 11 5 F508del L206W 55 P 12 5 G91R 5T 47.5 P 13 6 G551D S1235R+5T 49.5 P, neonatal hypertrypsinemia 14 7 F508del 3849+10kb 50 P, nasal popyposis 15 13 F508del R117H-7T 58 P, nasal polyposis 16 18 F508del 5T 60.5 P 17 20 G542X 3849+10kbC>T 52 P+PI 18 21 I507del 3849+10kbC>T 54 P, bronchiectasis 19 30 R347P 3849+10kbC>T 43 P, Pseudomonas colonisation 20 30 I507del L206W 57.5 CBAVD, chronic cough 21 31 F508del R117H-7T 60 CBAVD 22 32 G542X 3849+10kbC>T 30 P, Pseudomonas colonisation 23 34 F508del 3272-26A>G 64 P, CBAVD 24 37 R1070Q D1152H 56 CBAVD, bronchectasis 25 46 F508del D1152H 43 P 26 55 F508del D1152H 48 P, Pseudomonas colonisation 27 56 I507del S1235R 53 P 28 >18 F508del D1152H 60 P+PI 29 >20 F508del 3849+10kbC>T 18 P, bronchiectasis 30 >20 F508del 3272-26A>G 61 P *All mutations are named in accordance with the numbering used in the CFTR Mutation Database: http://www.genet.sickkids.on.ca/cftr/. Login to comment
76 In this study, 3849+10kbC>T was observed in four adults and three children with a severe allele in trans and in one adult with R347P/3849+10kbC>T. Login to comment

[hide] Pathophysiology and management of pulmonary infect... Am J Respir Crit Care Med. 2003 Oct 15;168(8):918-51. Gibson RL, Burns JL, Ramsey BW
Pathophysiology and management of pulmonary infections in cystic fibrosis.
Am J Respir Crit Care Med. 2003 Oct 15;168(8):918-51., 2003-10-15 [PMID:14555458]

Abstract [show]
This comprehensive State of the Art review summarizes the current published knowledge base regarding the pathophysiology and microbiology of pulmonary disease in cystic fibrosis (CF). The molecular basis of CF lung disease including the impact of defective cystic fibrosis transmembrane regulator (CFTR) protein function on airway physiology, mucociliary clearance, and establishment of Pseudomonas aeruginosa infection is described. An extensive review of the microbiology of CF lung disease with particular reference to infection with P. aeruginosa is provided. Other pathogens commonly associated with CF lung disease including Staphylococcal aureus, Burkholderia cepacia, Stenotrophomonas maltophilia, Achromobacter xylosoxidans and atypical mycobacteria are also described. Clinical presentation and assessment of CF lung disease including diagnostic microbiology and other measures of pulmonary health are reviewed. Current recommendations for management of CF lung disease are provided. An extensive review of antipseudomonal therapies in the settings of treatment for early P. aeruginosa infection, maintenance for patients with chronic P. aeruginosa infection, and treatment of exacerbation in pulmonary symptoms, as well as antibiotic therapies for other CF respiratory pathogens, are included. In addition, the article discusses infection control policies, therapies to optimize airway clearance and reduce inflammation, and potential future therapies.

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80 Class 4 mutations, exemplified by R347P, reach the cell surface and the channel can be activated but have decreased chloride conductance. Login to comment

[hide] Mutations of the CFTR gene in pancreatic disease. Pancreas. 2003 Nov;27(4):332-6. Pezzilli R, Morselli-Labate AM, Mantovani V, Romboli E, Selva P, Migliori M, Corinaldesi R, Gullo L
Mutations of the CFTR gene in pancreatic disease.
Pancreas. 2003 Nov;27(4):332-6., [PMID:14576497]

Abstract [show]
INTRODUCTION: An association has been found between CFTR gene mutations and chronic pancreatitis; however, there is a lack of information about the frequency of CFTR gene mutations in acute pancreatitis and in pancreatic cancer. AIM: To prospectively evaluate the prevalence of CFTR gene mutations in acute pancreatitis, chronic pancreatitis, and pancreatic cancer. METHODOLOGY: Ninety-eight consecutive patients were studied and divided into 3 groups: 34 patients with acute pancreatitis, 46 patients with chronic pancreatitis, and 18 patients with pancreatic cancer. The mutation analysis of the CFTR gene was carried out using diagnostic commercial kits for the simultaneous detection of 29 mutations and Tn polymorphism. RESULTS: Among the 98 patients studied, 12 (12.2%) had CFTR gene mutations: 2 of the 34 patients (5.9%) with acute pancreatitis, 9 of the 46 (19.6%) with chronic pancreatitis, and 1 of the 18 (5.6%) with pancreatic cancer. All the mutations were found in heterozygosis (2 DeltaF508, 1 W1282X, and 9 T5 allele). CONCLUSION: Our prospective study adds further information about the frequency of CFTR mutations in patients with a single episode of acute pancreatitis. Furthermore, our results suggest an association of CFTR gene mutations with chronic alcoholic pancreatitis and emphasize the need for a multicenter study, possibly multinational, to conclusively establish the role of CFTR mutations as a genetic susceptibility factor for this disease.

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59 The 29 Mutations and the Tn Polymorphism Which Can Be Detected by INNO-LiPA Assays Mutation Exon/Intron (i) E60X, G85E, 394delTT 3 621 + 1G > T, R117H (i) 4, 4 711 + 5G > A (i) 5 1078delT, R347P, R334W 7 A455E, Tn (i) 8, 9 ⌬F508, ⌬I507 10 G542X, 1717-1 G > A, G551D, R553X, R560T, Q552X (i) 10, 11 2183AA > G, 2184del A, 2143delT 13 2789 + 5G > A (i) 14b R1162X, 3659delC 19 3849 + 10kbC > T (i) 19 3905insT, W1282X, S1251N 20 N1303K 21 Group 3: pancreatic cancer CFTR gene mutations were identified only in 1 of the 18 patients (5.6%) with this cancer. Login to comment

[hide] High allelic heterogeneity between Afro-Brazilians... Genet Test. 2003 Fall;7(3):213-8. Raskin S, Pereira L, Reis F, Rosario NA, Ludwig N, Valentim L, Phillips JA 3rd, Allito B, Heim RA, Sugarman EA, Probst CM, Faucz F, Culpi L
High allelic heterogeneity between Afro-Brazilians and Euro-Brazilians impacts cystic fibrosis genetic testing.
Genet Test. 2003 Fall;7(3):213-8., [PMID:14641997]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disease caused by at least 1,000 different mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). To determine the frequency of 70 common worldwide CFTR mutations in 155 Euro-Brazilian CF patients and in 38 Afro-Brazilian CF patients, we used direct PCR amplification of DNA from a total of 386 chromosomes from CF patients born in three different states of Brazil. The results show that screening for seventy mutations accounts for 81% of the CF alleles in Euro-Brazilians, but only 21% in the Afro-Brazilian group. We found 21 different mutations in Euro-Brazilians and only 7 mutations in Afro-Brazilians. The frequency of mutations and the number of different mutations detected in Euro-Brazilians are different from Northern European and North American populations, but similar to Southern European populations; in Afro-Brazilians, the mix of CF-mutations is different from those reported in Afro-American CF patients. We also found significant differences in detection rates between Euro-Brazilian (75%) and Afro-Brazilian CF patients (21%) living in the same state, Minas Gerais. These results, therefore, have implications for the use of DNA-based tests for risk assessment in heterogeneous populations like the Brazilians. Further studies are needed to identify the remaining CF mutations in the different populations and regions of Brazil.

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63 FREQUENCIES OF 70 CFTR MUTATIONS IN DIFFERENT STATES OF BRAZIL, BY CONTINENTA L GROUP CFTR mutations SC PR MG detected n n n n % n % N % DF508 53 39 54 146 47.1 8 10.5 154 39.9 G542X 6 9 8 23 7.4 1 1.3 24 6.2 R1162X 9 2 4 15 4.8 2 2.6 17 4.4 N1303K 5 5 0 10 3.2 0 0 10 2.6 R334W 5 1 4 10 3.2 0 0 10 2.6 G85E 2 2 4 8 2.6 1 1.3 9 2.3 1717-1G®A 1 3 2 6 1.9 0 0 6 1.6 W1282X 4 1 1 6 1.9 0 0 6 1.6 3849110kbC®T 1 3 1 5 1.6 0 0 5 1.3 R553X 0 2 0 2 0.7 0 0 2 0.5 1812-1G®A 0 1 3 4 1.3 1 1.3 5 1.3 2183AA®G 2 1 0 3 1.0 0 0 3 0.8 312011G®A 0 0 2 2 0.7 2 2.6 4 1.0 Y1092X 0 1 1 2 0.7 1 1.3 3 0.8 G551D 0 0 0 0 0 0 0 0 0 W1089X 0 0 1 1 0.3 0 0 1 0.3 6211G®T 0 1 0 1 0.3 0 0 1 0.3 Q1238X 0 1 0 1 0.3 0 0 1 0.3 711-1G®T 0 1 0 1 0.3 0 0 1 0.3 R347P 1 0 0 1 0.3 0 0 1 0.3 189811G®A 1 0 0 1 0.3 0 0 1 0.3 I507 0 0 1 1 0.3 0 0 1 0.3 Subtotal 91 73 86 250 80.7 16 21.1 266 68.9 Alleles with CFTR 5 27 28 60 19.4 60 79.0 120 31.1 mutations not detected Total 96 100 114 310 100.0 76 100.0 386 100.0 Detection rate (%) 94.8 73.0 75.4 250 80.7 16 21.1 266 68.9 The following 70 CFTR mutations were selected and tested on the basis of frequency in various populations, known association with CF, or predicted deleterious effect on the CFTR protein product; DF508, G542X, N1303K, G551D, R553X, DI507, A455E, A559T, C524X, D1270N, E60X, G178R, G330X, G85E, 2307insA, I148T, K710X, P574H, Q1238X, Q493X, Q890X, R1158X, R1162X, R117H, R334W, R347H, R347P 2307insA, I148T, K710X, P574H, Q1238X, Q493X, Q890X, R1158X, R1162X, R117H, R334W, R347H, R347P 2307insA, 1148T, K710X, P574H, Q1238X, Q493X, Q890X, R1158X, R1162X, R117H, R334W, R347H, R347P, R352Q, R560T, S1196X, S1255X, S364P, S549N, S549R, V520F, W1089X, W1282X, W1310X, W1316X, Y1092X, Y122X, Y563D, 1078delT,1677delTA,1717-1G-A,1812-1G-A,1898 1 1G-A, 2043delG,2183delAA-G, 2184delA, 2789 1 5G-A, 2869insG, 2909delT, 3120 1 1G-A, 3120G-A, 3358delAC, 3659delC, 3662delA, 3750delAG, 3791delC, 3821delT, 3849 1 10KbC-T, 3849 1 4A-G, 3905insT, 405 1 1G-A, 444delA, 556delA, 574delA, 621 1 1G-T, and 711 1 1G-T. aSC, Santa Catarina State; PR, Parana State; MG, Minas Gerais State; n, number of chromosomes. Login to comment

[hide] Emerging drug treatments for cystic fibrosis. Expert Opin Emerg Drugs. 2003 Nov;8(2):523-35. Zeitlin PL
Emerging drug treatments for cystic fibrosis.
Expert Opin Emerg Drugs. 2003 Nov;8(2):523-35., [PMID:14662004]

Abstract [show]
Cystic fibrosis (CF) is one of the most common life-shortening inherited disorders. Mutations in the cystic fibrosis transmembrane regulator (CFTR) gene disrupt the localisation and function of the cAMP-mediated chloride channel. Most of the morbidity and mortality arise from the lung disease which is characterised by excessive inflammation and chronic infection. Research into the mechanisms of wild-type and mutant CFTR biogenesis suggest that multiple drug targets can be identified. This review explores the current understanding of the nature of the different mutant CFTR forms and the potential for repair of the chloride channel defect. High-throughput screening, pharmacogenomics and proteomics bring recent technological advances to the field.

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63 R117H, R334W and R347P are examples of mutations that appear to yield a milder clinical phenotype even when in combination with a more severe allele. Login to comment
88 Class of mutation Molecular mechanism Pancreatic status (if known) Examples 1 No CFTR protein synthesis PI W1282X, G542X, R553X, 621 + 1 G→T, 1717-1 G→A, 3905insT, 394delTT 2 Abnormal CFTR processing and trafficking PI ∆F508, N1303K, P574H 3 Defective CFTR regulation (normal trafficking) PI G551D, G551S, G1349D, S1255P 4 Decreased CFTR chloride conductance PS R117H, R334W, R347P, P547H 5 Reduced synthesis and trafficking of normal CFTR PS A455E, 3849 + 10kb C→T, (5T) 6A Reduced apical stability PI S1455X, Q1412S, 4326delTC, 4279insA 6B Defective regulation of other ion channels PI G551D Note that the G551D is placed in Class 3 for defective regulation and Class 6B for defective regulation of the outwardly rectifying chloride channel. Login to comment

[hide] Neonatal screening for cystic fibrosis: France ris... J Inherit Metab Dis. 2003;26(8):729-44. Farriaux JP, Vidailhet M, Briard ML, Belot V, Dhondt JL
Neonatal screening for cystic fibrosis: France rises to the challenge.
J Inherit Metab Dis. 2003;26(8):729-44., [PMID:14739679]

Abstract [show]
This paper describes the adjustments to the French neonatal screening programme required by the introduction of systematic screening for cystic fibrosis (CF), taking into account both the legal and statutory framework and the lessons of a pilot study carried out 10 years ago. The French association for the screening and prevention of infant handicaps (AFDPHE) has been mandated by its regulatory agencies to organize screening for CF in France (metropolitan and overseas territories). During the year 2001, expert groups (Technical Aspects, Information, Ethics and Genetics, Criteria for CF Centres, Protocol for the Care of a Newborn with CF) issued recommendations for the establishment of a national programme that would guarantee efficiency and adequate patient care from the time of diagnosis onward. The programme is based on a strategy combining immunoreactive trypsin (IRT) assay and the analysis of DNA mutations in dried blood samples obtained at 3 days of age. When an elevated IRT value is found, DNA analysis is performed on the same sample. Owing to the relative regional heterogeneity existing in France, 30 selected mutations are used, which provide 85% coverage. The Ethics and Genetics Committee recommended that, in order to avoid arousing anxiety by a recall, informed consent, according to the French legislation on bioethics, should be obtained for all neonates at birth by having the parents sign directly on the sampling paper. Information brochures for parents and health professionals have been designed. A new organization of patient care, involving the creation of CF centres recognized by the Ministry of Health, has been decided; all children diagnosed are to be referred to such centres, where they can be well cared for by a trained staff with sufficient means. The programme was implemented region by region in France, from the beginning of the year 2002 to early 2003. The expert groups still meet periodically to evaluate the implementation of the programme and to check that the terms of the agreement between the AFDPHE and the Social Security Agency are complied with.

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114 In its present version, the kit allows screening for 20 CFTR gene mutations (F508del, G542X, N1303K, 1717-1G>A, G551D, W1282X, R553X, I507del, 1078delT, 2183AA>G, 3849 þ 10kbC>T, R1162X, 621 þ 1G>T, R334W, R347P, 3659delC, R117H, S1251N, E60X, A455E) in one workday; moreover, it does not require any speci'c equipment. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Hum Reprod. 2004 Feb;19(2):250-3. Wu CC, Hsieh-Li HM, Lin YM, Chiang HS
Cystic fibrosis transmembrane conductance regulator gene screening and clinical correlation in Taiwanese males with congenital bilateral absence of the vas deferens.
Hum Reprod. 2004 Feb;19(2):250-3., [PMID:14747162]

Abstract [show]
BACKGROUND: In Taiwan, an area with a very low incidence of cystic fibrosis (CF), we first screened for the most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and looked for clinical correlations in 27 patients with clinically diagnosed congenital bilateral absence of the vas deferens (CBAVD). METHODS AND RESULTS: The clinical results showed that none of the 27 patients had CF symptoms. We did not detect any definite renal anomaly ultrasonographically. Mutation analysis was carried out on these 27 cases and 46 normal fertile males as controls. No mutations of Delta F508 or R117H were identified in any of the samples analysed. In the screening of IVS8-poly T, five of the 27 CBAVD patients showed the homozygous genotype for 5T/5T, 14 showed the heterozygous genotype for 5T/7T and eight showed the homozygous genotype for 7T/7T. The frequency of 5T alleles was 44.4%, which was significantly higher than in the 46 normal fertile males, for which there was a 5T frequency of 5.4%. CONCLUSIONS: The absence of major mutations of CFTR genes could be related to the much lower CF incidence in Taiwan. Further investigations into differences in the mutation spectrum of other CFTR genes are needed for a better understanding of the development of Taiwanese-Oriental CBAVD.

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42 Screening by an INNO-LiPA CFTR17+Tn kit For further con®rmation, we used a commercial kit (INNO-LiPA CFTR17+Tn; Innogenetics, Ghent, Belgium) that allowed the detection of 17 mutations (including 394delTT, G85E, E60X, 621+1G®T, R117H, 711+5G®A, 1078delT, R347P, R334W, A455E, 2143delT, 2183AA®G, 2184delA, 2789+5G®A, R1162X, 3659delC and 3849+10kbC®T) associated with IVS8-Tn polymorphisms (5T/7T/9T) in the CFTR gene to analyse our 27 patients and 46 normal, fertile control males. Login to comment

[hide] Improved detection of cystic fibrosis mutations in... Hum Reprod. 2004 Mar;19(3):540-6. Epub 2004 Jan 29. Danziger KL, Black LD, Keiles SB, Kammesheidt A, Turek PJ
Improved detection of cystic fibrosis mutations in infertility patients with DNA sequence analysis.
Hum Reprod. 2004 Mar;19(3):540-6. Epub 2004 Jan 29., [PMID:14998948]

Abstract [show]
BACKGROUND: Accurate determination of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is critical for genetic counselling and treatment of obstructive azoospermia. Of concern is that detection rates with routine CFTR mutation panels vary widely depending on patient ancestry; and such panels have limited value for azoospermic patients, who are more likely to carry rare mutations. An alternative approach offers comprehensive, CFTR mutation analysis by a DNA sequence method. We investigated whether this method could improve CFTR detection rates in men with obstructive azoospermia in a prospective study of men with obstructive azoospermia and their partners who were referred for genetic counselling and testing at one of two institutions. METHODS: Sixteen patients with congenital absence of the vas deferens (CAVD, n = 14) or idiopathic obstructive azoospermia (n = 2) were studied. DNA from all patients was analysed for mutations by the DNA sequence method. In addition to this method, six men underwent CFTR analysis by a common 25 or 31 mutation panel coupled with poly T analysis. In 10 subjects, common mutation panel findings were inferred from DNA sequence method results. RESULTS: Overall, 12/16 (75%) azoospermic patients had one or more CFTR mutations and/or 5T alleles, including 12 mutations in 10 patients (two compound heterozygotes) and seven 5T alleles in six patients (one homozygote). The sequence method detected all mutations and three variants of unknown significance. By comparison, the common mutation panels detected only 3/12 mutations (25%) and 0/3 variants. CONCLUSION: The DNA sequence method detects more CFTR mutations than common mutation panels. Given the serious, clinical consequences of transmitting such mutations, this study underscores the importance of accurate, CFTR mutation detection in men with obstructive azoospermia and their partners.

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59 Polyacrylamide gels were analysed for the presence of mutations following staining in ethidium bromide (EtBr) and image capture under UV using the Gel Doc 1000 system Table I. List of CFTR mutations included in common mutation panels American College of Medical Genetics CF panel (25 mutations) DF508 G542X G551D R117H W1282X N1303K R1162X 3849+10kbC®T DI507 R553X 1717-1G®A 621+1G®T R560T 3659delC 3120+1G®A I148T G85E R334W A455E 1898+1G®A 2148delA 711+1G®T 2789+5G®A R347P 1078delT Six additional mutations and one polymorphism in UCSF panel (31 mutations) Y1092X R347H 3849+4 Q493X 3905insT S549N F508C (polymorphism) (BioRad). Login to comment

[hide] Direct visualization of cystic fibrosis transmembr... Clin Chem. 2004 May;50(5):836-45. Epub 2004 Mar 9. Strom CM, Clark DD, Hantash FM, Rea L, Anderson B, Maul D, Huang D, Traul D, Chen Tubman C, Garcia R, Hess PP, Wang H, Crossley B, Woodruff E, Chen R, Killeen M, Sun W, Beer J, Avens H, Polisky B, Jenison RD
Direct visualization of cystic fibrosis transmembrane regulator mutations in the clinical laboratory setting.
Clin Chem. 2004 May;50(5):836-45. Epub 2004 Mar 9., [PMID:15010427]

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BACKGROUND: The recommendation for population- based cystic fibrosis (CF) carrier screening by the American College of Medical Genetics for the 25 most prevalent mutations and 6 polymorphisms in the CF transmembrane regulatory gene has greatly increased clinical laboratory test volumes. We describe the development and technical validation of a DNA chip in a 96-well format to allow for high-throughput genotype analysis. METHODS: The CF Portrait chip contains an 8 x 8 array of capture probes and controls to detect all requisite alleles. Single-tube multiplex PCR with 15 biotin-labeled primer pairs was used to amplify sequences containing all single-nucleotide polymorphisms to be interrogated. Detection of a thin-film signal created by hybridization of multiplex PCR-amplified DNA to complementary capture probes was performed with an automated image analysis instrument, NucleoSight. Allele classification, data formatting, and uploading to a laboratory information system were fully automated. RESULTS: The described platform correctly classified all mutations and polymorphisms and can screen approximately 1300 patient samples in a 10-h shift. Final validation was performed by two separate 1000-sample comparisons with Roche CF Gold line probe strips and the Applera CF OLA, Ver 3.0. The CF Portrait Biochip made no errors during this validation, whereas the Applera assay made seven miscalls of the IVS-8 5T/7T/9T polymorphism CONCLUSIONS: The CF Portrait platform is an automated, high-throughput, DNA chip-based assay capable of accurately classifying all CF mutations in the recommended screening panel, including the IVS-8 5T/7T/9T polymorphism.

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178 The optimal spotting conditions for each probe are indicated by the boxes around spots in C. wild-type controls and heterozygotes for each ACMG mutation and polymorphism, DNA from 12 compound heterozygotes (⌬F508/1898 ϩ 1GϾA, 711 ϩ 1GϾT/⌬F508, G85E/621 ϩ 1GϾT, 3659delC/⌬F508, 3120 ϩ 1GϾA/ 621 ϩ 1GϾT, R347P/G551D, A455E/⌬F508, R560T/ dF508, R553X/⌬F508, 621 ϩ 1GϾT/⌬F508, 621 ϩ 1GϾT/ 711 ϩ 1GϾT, R117H/⌬F508, and I506V/⌬F508) and DNA from 4 homozygous patients (⌬F508 and 2789 ϩ 5GϾA, 3849 ϩ 10kbCϾT, and G542X) was used in validation experiments. Login to comment
199 In this series, there were 17 ⌬F508 heterozygous patient samples, 1 ⌬F508 homozygous sample, 2 R117H heterozygous samples, and 1 heterozygous patient sample each for I148T, G542X, R553X, R347P, and 2789 ϩ 5GϾA, for a total of 26 mutant alleles. Additional mutant alleles detected in the control samples included three fixed control samples (⌬F508 homozygous, 5T/WT, 3659delC/⌬F508) on every plate and two heterozygous samples (R560T and 1078delT) and one heterozygous sample each for R334W, A455E, R347P, R117H, ⌬I507, I507V, G551D, and 1717-1GϾA as rotating controls. Login to comment

[hide] New therapeutic key for cystic fibrosis: a role fo... Nat Immunol. 2004 Apr;5(4):357-8. Takai D, Nagase T, Shimizu T
New therapeutic key for cystic fibrosis: a role for lipoxins.
Nat Immunol. 2004 Apr;5(4):357-8., [PMID:15052263]

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14 In some types of mutations (for example, R347P), mutant molecules can reach the cell membrane and show partial chloride conductance. Login to comment

[hide] Molecular analysis using DHPLC of cystic fibrosis:... BMC Med Genet. 2004 Apr 14;5:8. D'Apice MR, Gambardella S, Bengala M, Russo S, Nardone AM, Lucidi V, Sangiuolo F, Novelli G
Molecular analysis using DHPLC of cystic fibrosis: increase of the mutation detection rate among the affected population in Central Italy.
BMC Med Genet. 2004 Apr 14;5:8., 2004-04-14 [PMID:15084222]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is a multisystem disorder characterised by mutations of the CFTR gene, which encodes for an important component in the coordination of electrolyte movement across of epithelial cell membranes. Symptoms are pulmonary disease, pancreatic exocrine insufficiency, male infertility and elevated sweat concentrations. The CFTR gene has numerous mutations (>1000) and functionally important polymorphisms (>200). Early identification is important to provide appropriate therapeutic interventions, prognostic and genetic counselling and to ensure access to specialised medical services. However, molecular diagnosis by direct mutation screening has proved difficult in certain ethnic groups due to allelic heterogeneity and variable frequency of causative mutations. METHODS: We applied a gene scanning approach using DHPLC system for analysing specifically all CFTR exons and characterise sequence variations in a subgroup of CF Italian patients from the Lazio region (Central Italy) characterised by an extensive allelic heterogeneity. RESULTS: We have identified a total of 36 different mutations representing 88% of the CF chromosomes. Among these are two novel CFTR mutations, including one missense (H199R) and one microdeletion (4167delCTAAGCC). CONCLUSION: Using this approach, we were able to increase our standard power rate of mutation detection of about 11% (77% vs. 88%).

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89 Table 1: Primers and DHPLC (oven temperature, gradient) analysis conditions for 6b and 9 exons of the CFTR gene exon Primer 5' → 3' Amplicon length Oven temp (°C) % B buffer start/end 6b F - CAGAGATCAGAGAGCTGGG 323 56 55/63 R - GAGGTGGAAGTCTACCATGA 9 F - GGGATTTGGGGAATTATTTG 279 55 54/62 R - TCTCCAAAAATACCTTCCAG Table 2: CF mutations identified in cohort of 290 patients from the Central Italy Mutation Nucleotide change Exon/intron N % Method delF508 1652delCTT 10 328 56.36 INNO-LiPA, DHPLC N1303K 4041 C to G 21 51 8.76 INNO-LiPA, DHPLC G542X 1756 G to T 11 42 7.21 INNO-LiPA, DHPLC W1282X 3978 G to A 20 15 2.60 INNO-LiPA, DHPLC S549R 1779 T to G 11 8 1.37 DHPLC 621+1G-T 621+1 G to T Intron 4 7 1.20 INNO-LiPA, DHPLC 1717-1G-A 1717-1 G to A Intron 10 5 0.86 INNO-LiPA, DHPLC G85E 386 G to A 3 4 0.69 INNO-LiPA, DHPLC R553X 1789 C to T 11 4 0.69 INNO-LiPA, DHPLC H139R 548 A to G 6a 3 0.51 DHPLC R347P 1172 G to C 7 3 0.51 INNO-LiPA, DHPLC L1065P 3326 T to C 17b 3 0.51 DHPLC L1077P 3362 T to C 17b 3 0.51 DHPLC S4X 143 C to A 1 2 0.34 DHPLC D110H 460 G to C 4 2 0.34 DHPLC R334W 1132 C to T 7 2 0.34 INNO-LiPA, DHPLC M348K 1175 T to A 7 2 0.34 DHPLC 1259insA 1259 ins A 8 2 0.34 DHPLC S549N 1778 G to A 11 2 0.34 DHPLC L558S 1805 T to C 11 2 0.34 DHPLC 2183+AA-G 2183 A to G and 2184 del A 13 2 0.34 INNO-LiPA, DHPLC 2789+5G-A 2789+5 G to A Intron 14b 2 0.34 INNO-LiPA, DHPLC R1066C 3328 C to T 17b 2 0.34 DHPLC 3667ins4 3667insTCAA 19 2 0.34 DHPLC S42F 257 C to T 2 2 0.34 DHPLC R117L 482 G to T 4 1 0.17 DHPLC H199R 728 A to G 6a 1 0.17 DHPLC R334L 1133 G to T 7 1 0.17 DHPLC T338I 1145 C to T 7 1 0.17 DHPLC G551D 1784 G to A 11 1 0.17 INNO-LiPA, DHPLC Q552X 1786 C to T 11 1 0.17 INNO-LiPA, DHPLC D614G 1973 A to G 13 1 0.17 DHPLC A1006E 3149 C to A 17a 1 0.17 DHPLC 4016insT 4016 ins T 21 1 0.17 DHPLC 4040delA 4040 del A 21 1 0.17 DHPLC 4167del7 4167 delCTAAGCC 22 1 0.17 DHPLC Detected 511 88.10 Unknown 69 11.90 Total 580 100.00 N = number of CF chromosomes; % = frequency. Login to comment

[hide] A finger sweat chloride test for the detection of ... Pancreas. 2004 Apr;28(3):e80-5. Naruse S, Ishiguro H, Suzuki Y, Fujiki K, Ko SB, Mizuno N, Takemura T, Yamamoto A, Yoshikawa T, Jin C, Suzuki R, Kitagawa M, Tsuda T, Kondo T, Hayakawa T
A finger sweat chloride test for the detection of a high-risk group of chronic pancreatitis.
Pancreas. 2004 Apr;28(3):e80-5., [PMID:15084988]

Abstract [show]
OBJECTIVES: Mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with chronic pancreatitis in Caucasians. We developed a simple method for measuring finger sweat chloride concentration to test whether CFTR dysfunction underlies chronic pancreatitis in Japan where cystic fibrosis (CF) is rare. METHODS: We studied 25 patients with chronic (21 alcoholic and 4 idiopathic) pancreatitis and 25 healthy volunteers. Sweat chloride concentrations were measured by a finger sweat chloride test. We analyzed DNA for 20 common CFTR mutations in Europeans, 9 CF-causing mutations in Japanese, and 2 polymorphic loci, a poly-T tract and (TG) repeats, at intron 8. RESULTS: Thirteen patients (52%) had sweat chloride levels >60 mmol/L, a level consistent with CF, while only 4 (16%) healthy subjects exceeded this level. The 29 CF mutations and the 5T allele were detected in neither the patients nor controls. The (TG) 12 allele was common in both the patients (58%) and controls (48%). The (TG) 12/12 genotype was common in alcoholic pancreatitis (29%) compared with the (TG) 11/11 (10%). Patients with the (TG) 12/12 genotype had significantly higher sweat chloride concentrations than the controls. CONCLUSION: CFTR dysfunction as evidenced by a finger sweat chloride test is present in about half of Japanese patients with chronic pancreatitis, suggesting that this test may be useful for detecting the high-risk group. A higher proportion of the (TG) 12 allele may be a genetic background for elevated sweat chloride concentrations in Japanese patients.

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50 The DNA samples were analyzed using an amplification refractory mutation system kit for 20 common major CFTR mutations (E60X, R117H, R334W, R347P, A455E, ⌬I507, ⌬F508, G542X, G551D, R553X, 621+1G>T, 1078delT, R1162X, S1251N, W1282X, N1303K, 1717-1G>A, 2183AA>G, 3659delC, 3849+10kbC>T) (Elucigene CF 20, AstraZeneca Diagnostics, Abingdon, UK) following the standard procedures recommended by the manufacturer. Login to comment

[hide] Genetic evidence for CFTR dysfunction in Japanese:... J Med Genet. 2004 May;41(5):e55. Fujiki K, Ishiguro H, Ko SB, Mizuno N, Suzuki Y, Takemura T, Yamamoto A, Yoshikawa T, Kitagawa M, Hayakawa T, Sakai Y, Takayama T, Saito M, Kondo T, Naruse S
Genetic evidence for CFTR dysfunction in Japanese: background for chronic pancreatitis.
J Med Genet. 2004 May;41(5):e55., [PMID:15121783]

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218 The 20 most common CF mutations (E60X, R117H, R334W, R347P, A455E, DI507, DF508, G542X, G551D, R553X, 621+1GRT, 1078delT, R1162X, S1251N, W1282X, N1303K, 1717-1GRA, 2183AARG, 3659delC, and 3849+10kbCRT) were tested by an Elucigene CF20 kit (AstraZeneca Diagnostics, Abingdon, Oxfordshire, UK). Login to comment

[hide] Population-based newborn screening for genetic dis... Pediatrics. 2004 Jun;113(6):1573-81. Comeau AM, Parad RB, Dorkin HL, Dovey M, Gerstle R, Haver K, Lapey A, O'Sullivan BP, Waltz DA, Zwerdling RG, Eaton RB
Population-based newborn screening for genetic disorders when multiple mutation DNA testing is incorporated: a cystic fibrosis newborn screening model demonstrating increased sensitivity but more carrier detections.
Pediatrics. 2004 Jun;113(6):1573-81., [PMID:15173476]

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OBJECTIVES: Newborn screening for cystic fibrosis (CF) provides a model to investigate the implications of applying multiple-mutation DNA testing in screening for any disorder in a pediatric population-based setting, where detection of affected infants is desired and identification of unaffected carriers is not. Widely applied 2-tiered CF newborn screening strategies first test for elevated immunoreactive trypsinogen (IRT) with subsequent analysis for a single CFTR mutation (DeltaF508), systematically missing CF-affected infants with any of the >1000 less common or population-specific mutations. Comparison of CF newborn screening algorithms that incorporate single- and multiple-mutation testing may offer insights into strategies that maximize the public health value of screening for CF and other genetic disorders. The objective of this study was to evaluate technical feasibility and practical implications of 2-tiered CF newborn screening that uses testing for multiple mutations (multiple-CFTR-mutation testing). METHODS: We implemented statewide CF newborn screening using a 2-tiered algorithm: all specimens were assayed for IRT; those with elevated IRT then had multiple-CFTR-mutation testing. Infants who screened positive by detection of 1 or 2 mutations or extremely elevated IRT (>99.8%; failsafe protocol) were then referred for definitive diagnosis by sweat testing. We compared the number of sweat-test referrals using single- with multiple-CFTR-mutation testing. Initial physician assessments and diagnostic outcomes of these screened-positive infants and any affected infants missed by the screen were analyzed. We evaluated compliance with our screening and follow-up protocols. All Massachusetts delivery units, the Newborn Screening Program, pediatric health care providers who evaluate and refer screened-positive infants, and the 5 Massachusetts CF Centers and their affiliated genetic services participated. A 4-year cohort of 323 506 infants who were born in Massachusetts between February 1, 1999, and February 1, 2003, and screened for CF at approximately 2 days of age was studied. RESULTS: A total of 110 of 112 CF-affected infants screened (negative predictive value: 99.99%) were detected with IRT/multiple-CFTR-mutation screening; 2 false-negative screens did not show elevated IRT. A total of 107 (97%) of the 110 had 1 or 2 mutations detected by the multiple- CFTR-mutation screen, and 3 had positive screens on the basis of the failsafe protocol. In contrast, had we used single-mutation testing, only 96 (87%) of the 110 would have had 1 or 2 mutations detectable by single-mutation screen, 8 would have had positive screens on the basis of the failsafe protocol, and an additional 6 infants would have had false-negative screens. Among 110 CF-affected screened-positive infants, a likely "genetic diagnosis" was made by the multiple-CFTR-mutation screen in 82 (75%) versus 55 (50%) with DeltaF508 alone. Increased sensitivity from multiple-CFTR-mutation testing yielded 274 (26%) more referrals for sweat testing and carrier identifications than testing with DeltaF508 alone. CONCLUSIONS: Use of multiple-CFTR-mutation testing improved sensitivity and postscreening prediction of CF at the cost of increased referrals and carrier identification.

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79 The 16-mutation panel included ⌬F508, R117H, G551D, G542X, W1282X, N1303K, R334W, 621 ϩ 1GϾT, R553X, ⌬I507, 1717-1GϾA, R347P, R560T, 3849 ϩ 10kbCϾT, A455E, and S549N. Login to comment

[hide] Risk of pancreatitis with mutation of the cystic f... Am J Gastroenterol. 2004 Jul;99(7):1358-63. Choudari CP, Imperiale TF, Sherman S, Fogel E, Lehman GA
Risk of pancreatitis with mutation of the cystic fibrosis gene.
Am J Gastroenterol. 2004 Jul;99(7):1358-63., [PMID:15233679]

Abstract [show]
BACKGROUND: Between 5% and 15% of patients with recurrent pancreatitis have no identified etiology after routine investigation and advanced endoscopic evaluation. OBJECTIVE: To determine whether mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene is a risk factor for idiopathic pancreatitis. METHODS: We compared the frequency of CFTR mutations as measured by DNA probe analysis in a case group of persons with idiopathic pancreatitis and a control group without pancreatitis, all of whom underwent endoscopic retrograde cholangiopancreatography. A separate analysis compared the prevalence of CFTR mutations between the case group and controls with pancreatitis of known etiology. A subgroup comparison was made between cases of pancreas divisum with pancreatitis and controls with pancreas divisum and no pancreatitis. RESULTS: CFTR mutations were present in 19 (19%) of 96 cases and 7 (3.5%) of 198 controls without pancreatitis (odds ratio, OR = 6.7; 95% CI, 2.8-16.3; p < 0.00001). Compared to the controls with a known cause of pancreatitis (N = 78), cases had a higher prevalence of CFTR mutations (19% vs 2.6%, OR = 9.4; CI, 2.1-41.7; p= 0.0005). Among subjects with pancreas divisum, CFTR mutations were present in 8 (22%) of 37 cases compared to 0 (0%) of 20 controls (OR = 11.8; CI, 8.9-14.7; p= 0.02). CONCLUSION: The risk of idiopathic pancreatitis is greater among persons with CFTR mutations as compared to persons without CFTR mutations. Among persons with pancreas divisum, CFTR mutations appear to increase the risk for pancreatitis.

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130 In a study of more than 500 CF patients, five mutations (R117H, R334W, R347P, A455E, and P574H) were found exclusively in pancreatic sufficient patients (8). Login to comment

[hide] The role of CFTR and SPINK-1 mutations in pancreat... AIDS. 2004 Jul 23;18(11):1521-7. Felley C, Morris MA, Wonkam A, Hirschel B, Flepp M, Wolf K, Furrer H, Battegay M, Bernasconi E, Telenti A, Frossard JL
The role of CFTR and SPINK-1 mutations in pancreatic disorders in HIV-positive patients: a case-control study.
AIDS. 2004 Jul 23;18(11):1521-7., 2004-07-23 [PMID:15238770]

Abstract [show]
OBJECTIVE: Pancreatic disorders in HIV-positive patients are frequent. CFTR and SPINK-1 mutations have been reported to increase the risk of pancreatitis, but no data are available in HIV-positive patients. This study will evaluate the frequency of CFTR mutations and SPINK-1 polymorphisms in HIV-positive patients with clinical pancreatitis or asymptomatic elevation of serum pancreatic enzymes. METHOD: Cases (patients with hyperamylasemia) were identified during a toxicity study conducted in August 1999 among 1152 participants of the Swiss HIV Cohort Study. We designed a case-control study in which each case was matched one to one to an HIV-infected control according to sex, age, CD4 cell count, viraemia and medication use. CFTR mutations and SPINK-1 polymorphisms were studied using polymerase chain reaction techniques. RESULTS: Fifty-one HIV-positive patients with hyperamylasemia were detected among 1152 participants in the toxicity study (4.4%). There were 13 carriers of CFTR and SPINK-1 mutations (12.7%). Amylase levels were 316 +/- 130 U/l for the group with mutations, and 135 +/- 18 U/l for non-carriers (P = 0.79). However, among patients with hyperamylasemia, those with CFTR or SPINK-1 mutations had 648 +/- 216 U/l amylase levels compared with 232 +/- 28 U/l for those without (P = 0.025). Ten patients had acute pancreatitis, four of whom had CFTR mutations or SPINK-1 polymorphisms (40%) compared with seven of the control patients (14%) (P = 0.01). CONCLUSION: CFTR mutations and SPINK-1 polymorphisms are frequent among HIV-positive patients suffering from acute pancreatitis. These mutations may increase the susceptibility to pancreatitis when exposed to environmental risk factors.

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42 Samples were tested: (i) for 20 common CFTR mutations (delF508, 621+1G.T, G542X, 3849+10kbC.T, N1303K, 3659delC, 1717-1G.A, 1078delT, W1282X, R347P, G551D, A455E, R553X, S1251N, R1162X, delF507, R334W, 2183AA.G, R117H, and E60X; Elucigene CF20; Orchid Biosciences, Abingdon, UK); (ii) for the CFTR IVS8 5T variant (Elucigene CF Poly-T; Orchid); and (iii) for the SPINK-1 N34S polymorphism, by poly- Copyright (c) Lippincott Williams & Wilkins. Login to comment

[hide] Relation of sweat chloride concentration to severi... Pediatr Pulmonol. 2004 Sep;38(3):204-9. Davis PB, Schluchter MD, Konstan MW
Relation of sweat chloride concentration to severity of lung disease in cystic fibrosis.
Pediatr Pulmonol. 2004 Sep;38(3):204-9., [PMID:15274098]

Abstract [show]
In cystic fibrosis (CF), sweat chloride concentration has been proposed as an index of CFTR function for testing systemic drugs designed to activate mutant CFTR. This suggestion arises from the assumption that greater residual CFTR function should lead to a lower sweat chloride concentration, as well as protection against severe lung disease. This logic gives rise to the hypothesis that the lower the sweat chloride concentration, the less severe the lung disease. In order to test this hypothesis, we studied 230 patients homozygous for the DeltaF508 allele, and 34 patients with at least one allele associated with pancreatic sufficiency, born since January 1, 1955, who have pulmonary function data and sweat chloride concentrations recorded in our CF center database, and no culture positive for B. cepacia. We calculated a severity index for pulmonary disease, using an approach which takes into account all available pulmonary function data as well as the patient's current age and survival status. Patients with alleles associated with pancreatic sufficiency had significantly better survival (P = 0.0083), lower sweat chloride concentration (81.4 +/- 23.8 vs. 103.2 +/- 14.2 mEq/l, P < 0.0001), slower rate of decline of FEV(1) % predicted (-0.75 +/- 0.34 vs. -2.34 +/- 0.17% predicted per year), and a better severity index than patients homozygous for the DeltaF508 allele (median 73rd percentile vs. median 55th percentile, P = 0.0004). However, the sweat chloride concentration did not correlate with the severity index, either in the population as a whole, or in the population of patients with alleles associated with pancreatic sufficiency, who are thought to have some residual CFTR function. These data suggest that, by itself, sweat chloride concentration does not necessarily predict a milder pulmonary course in patients with cystic fibrosis.

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28 T and R347P alleles. Login to comment

[hide] Cystic fibrosis as a cause of infertility. Reprod Biol. 2004 Jul;4(2):119-29. Jarzabek K, Zbucka M, Pepinski W, Szamatowicz J, Domitrz J, Janica J, Wolczynski S, Szamatowicz M
Cystic fibrosis as a cause of infertility.
Reprod Biol. 2004 Jul;4(2):119-29., [PMID:15297887]

Abstract [show]
Cystic fibrosis (CF) is one of the autosomal recessive diseases, caused by mutations in a gene known as cystic fibrosis transmembrane regulator (CFTR). The majority of adult males with CF (99%) is characterized by congenital bilateral absence of vas deferens (CBAVD). CBAVD is encountered in 1-2% of infertile males without CF. Females with CF are found to be less fertile than normal healthy women. In females with CF, delayed puberty and amenorrhoea are common due to malnutrition. CFTR mutations are also associated with congenital absence of the uterus and vagina (CAUV). The National Institutes of Health recommend genetic counseling for any couple seeking assisted reproductive techniques with a CF male or obstructive azoospermia which is positive for a CF mutation.

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58 CFTR screening includes the most frequent CFTR mutations, for example in the German population: ΔF508, R347P, G542X, S549I, N, R (A→C), G551D, R553X, N1303K, 3849+10kbC→T [11]. Login to comment

[hide] Use of fecal elastase-1 to classify pancreatic sta... J Pediatr. 2004 Sep;145(3):322-6. Borowitz D, Baker SS, Duffy L, Baker RD, Fitzpatrick L, Gyamfi J, Jarembek K
Use of fecal elastase-1 to classify pancreatic status in patients with cystic fibrosis.
J Pediatr. 2004 Sep;145(3):322-6., [PMID:15343184]

Abstract [show]
OBJECTIVE: To test the hypothesis that some patients with cystic fibrosis (CF) are misclassified as pancreatic insufficient, using fecal elastase-1 (FE-1) to define pancreatic status. STUDY DESIGN: Subjects with CF at 33 CF centers filled out questionnaires and submitted a stool specimen that was analyzed for FE-1. Subjects taking pancreatic enzyme supplements (PES) were asked to discontinue them and perform a 3-day fecal fat balance study if their FE-1 was >200 microg/g stool and they had never had pancreatitis. RESULTS: The median value for FE-1 in 1215 subjects was 0 microg/g stool (range, 0-867). There was a significant difference between patients who had been prescribed PES (n=1131) and those who had FE-1 <200 microg/g stool (n=1074; P<.0001). Sixty-seven subjects met criteria for discontinuation of PES. The mean coefficient of fat absorption for these subjects was 96.1%. CONCLUSIONS: FE-1 is an accurate, easily obtained screening test to classify pancreatic status in patients with CF. This information is important for prognostication, treatment, and to avoid misclassification in clinical research. Measurement of FE-1 should become a standard of care for patients with CF.

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116 FE-1 values in subjects with CFTR mutations associated with pancreatic sufficiency11 N Mean (mg/g stool) Median (mg/g stool) Range (mg/g stool) Subjects with at least one PS allele* FE-1 >200 mg/g stool 16 584 582.9 349-773 FE-1 <200 mg/g stool 5 64.4 74.8 0-125 Subjects with at least one PS variable alleley FE-1>200 mg/g stool 29 496.2 493.6 224-798 FE-1 <200 mg/g stool 13 76.1 65.9 0-187 *Pancreatic sufficient dominant CF alleles G551S R117H R347H P574H R334W R352Q T3381 yVariable pancreatic sufficient CF mutations G85E 3849 + 10 kb C fi T R347P 2789 + 5G fi A A455E In summary, FE-1 is an accurate, easily obtained screening test to classify patients with CF as PI or PS. Login to comment

[hide] Cystic fibrosis screening: lessons learned from th... Genet Med. 2004 May-Jun;6(3):136-40. Strom CM, Crossley B, Redman JB, Buller A, Quan F, Peng M, McGinnis M, Sun W
Cystic fibrosis screening: lessons learned from the first 320,000 patients.
Genet Med. 2004 May-Jun;6(3):136-40., [PMID:15354331]

Abstract [show]
PURPOSE: To examine the data from > 335,000 Cystic fibrosis (CF) tests to detect unsuspected findings and obtain clinical data when indicated to optimize genetic counseling. METHODS: A proprietary database containing 335,204 consecutive CF DNA tests and 445 CF prenatal diagnostic tests was queried. Clinical information was obtained for prenatal and selected nonprenatal cases by telephone contact with physician offices. RESULTS: The mutation 1078delT was found in much lower frequency than expected with rates of only 1:55,867 tests and 0.06% of CF mutations. This level is below the threshold set by the American College of Medical Genetics. Homozygosity was observed for 2789+5G>A in a 29-year-old women and compound heterozygosity with delta F408 in a 40-year-old woman with isolated chronic sinusitis. Many patients elected prenatal diagnosis when not at a 1:4 risk due to echogenic bowel or IVS-8 5T issues. CONCLUSIONS: With the exception of 1078delT, all CF mutations in the ACMG panel were detected with a frequency of > 0.1% of CF chromosomes. When ACMG guidelines are strictly adhered to, population-based CF carrier screening will accurately identify couples at risk for having children with CF.

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47 Frequency, all tests Frequency, CF mutations (%) delta F508 7610 1:44 75% R117H/7T or 9T 1030 1:325 NAb R117H/5T 103 1:3,254 0.51c W1282X 529 1:625 5.2 G542X 382 1:909 3.8 G551D 278 1:1,250 2.7 N1303K 201 1:1,668 2.0 3849ϩ10kb CϾT 167 1:2,007 1.6 1717-1 GϾA 102 1:3,286 1.0 R553X 102 1:3,286 1.0 621ϩ1 GϾT 98 1:3,420 0.97 2789ϩ5 GϾA 82 1:4,087 0.80 3120ϩ1 GϾA 73 1:4,591 0.72 R1162X 54 1:6,207 0.53 R334W 54 1:6,207 0.53 685E 52 1:6,446 0.51 R560T 52 1:6,446 0.51 Delta I507 51 1:6,572 0.50 711ϩ1 GϾT 40 1:8,380 0.39 1898ϩ1 GϾA 37 1:9,059 0.36 3659 del C 36 1:9,311 0.36 A455E 34 1:9,858 0.33 R347P 33 1:10,158 0.32 2184 del A 14 1:23,943 0.14 1078 del T 6 1:55,867 0.06 a I148T has been eliminated from these data. Login to comment

[hide] Cystic fibrosis population carrier screening: 2004... Genet Med. 2004 Sep-Oct;6(5):387-91. Watson MS, Cutting GR, Desnick RJ, Driscoll DA, Klinger K, Mennuti M, Palomaki GE, Popovich BW, Pratt VM, Rohlfs EM, Strom CM, Richards CS, Witt DR, Grody WW
Cystic fibrosis population carrier screening: 2004 revision of American College of Medical Genetics mutation panel.
Genet Med. 2004 Sep-Oct;6(5):387-91., [PMID:15371902]

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70 It has been ar- Table 1 CFTR mutation frequency among individuals with clinically diagnosed cystic fibrosis by racial/ethnic group and in a pan-ethnic U.S. population CFTR mutation Mutation frequency among individuals with clinically diagnosed cystic fibrosis (%) Non-Hispanic Caucasian Hispanic Caucasian African American Asian American Ashkenazi Jewish Pan-Ethnic Population5 delF508 72.42 54.38 44.07 38.95 31.41 66.31 G542X 2.28 5.10 1.45 0.00 7.55 2.64 W1282X 1.50 0.63 0.24 0.00 45.92 2.20 G551D 2.25 0.56 1.21 3.15 0.22 1.93 621ϩ1GϾT 1.57 0.26 1.11 0.00 0.00 1.30 N1303K 1.27 1.66 0.35 0.76 2.78 1.27 R553X 0.87 2.81 2.32 0.76 0.00 1.21 dell507 0.88 0.68 1.87 0.00 0.22 0.90 3849ϩ10kbCϾT 0.58 1.57 0.17 5.31 4.77 0.85 3120ϩ1GϾT 0.08 0.16 9.57 0.00 0.10 0.86 R117H 0.70 0.11 0.06 0.00 0.00 0.54 1717-1GϾT 0.48 0.27 0.37 0.00 0.67 0.44 2789ϩ5GϾA 0.48 0.16 0.00 0.00 0.10 0.38 R347P 0.45 0.16 0.06 0.00 0.00 0.36 711ϩ1GϾT 0.43 0.23 0.00 0.00 0.10 0.35 R334W 0.14 1.78 0.49 0.00 0.00 0.37 R560T 0.38 0.00 0.17 0.00 0.00 0.30 R1162X 0.23 0.58 0.66 0.00 0.00 0.30 3569delC 0.34 0.13 0.06 0.00 0.00 0.28 A455E 0.34 0.05 0.00 0.00 0.00 0.26 G85E 0.29 0.23 0.12 0.00 0.00 0.26 2184delA 0.17 0.16 0.05 0.00 0.10 0.15 1898ϩ1GϾA 0.16 0.05 0.06 0.00 0.10 0.13 l148T 0.09 0.09 0.05 0.00 0.10 0.08 1078delT 0.02 0.09 0.00 0.00 0.00 0.03 Total 88.40 71.90 64.51 48.93 94.14 84.00 gued that a laboratory is obligated to report any and all information that is gleaned from a test system, however, there is no regulatory requirement and practice varies. Login to comment

[hide] CFTR mutation distribution among U.S. Hispanic and... Genet Med. 2004 Sep-Oct;6(5):392-9. Sugarman EA, Rohlfs EM, Silverman LM, Allitto BA
CFTR mutation distribution among U.S. Hispanic and African American individuals: evaluation in cystic fibrosis patient and carrier screening populations.
Genet Med. 2004 Sep-Oct;6(5):392-9., [PMID:15371903]

Abstract [show]
PURPOSE: We reviewed CFTR mutation distribution among Hispanic and African American individuals referred for CF carrier screening and compared mutation frequencies to those derived from CF patient samples. METHODS: Results from CFTR mutation analyses received from January 2001 through September 2003, were analyzed for four populations: Hispanic individuals with a CF diagnosis (n = 159) or carrier screening indication (n = 15,333) and African American individuals with a CF diagnosis (n = 108) or carrier screening indication (n = 8,973). All samples were tested for the same 87 mutation panel. RESULTS: In the Hispanic population, 42 mutations were identified: 30 in the patient population (77.5% detection rate) and 33 among carrier screening referrals. Five mutations not included in the ACMG/ACOG carrier screening panel (3876delA, W1089X, R1066C, S549N, 1949del84) accounted for 7.55% detection in patients and 5.58% among carriers. Among African American referrals, 33 different mutations were identified: 21 in the patient population (74.4% detection) and 23 in the carrier screening population. Together, A559T and 711+5G>A were observed at a detection rate of 3.71% in CF patients and 6.38% in carriers. The mutation distribution seen in both the carrier screening populations reflected an increased frequency of mutations with variable expression such as D1152H, R117H, and L206W. CONCLUSIONS: A detailed analysis of CFTR mutation distribution in the Hispanic and African American patient and carrier screening populations demonstrates that a diverse group of mutations is most appropriate for diagnostic and carrier screening in these populations. To best serve the increasingly diverse U.S. population, ethnic-specific mutations should be included in mutation panels.

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35 87 mutation panel The following mutations were included in the panel: ⌬F508, ⌬F311, ⌬I507, A455E, A559T, C524X, D1152H, D1270N, E60X, G178R, G330X, G480C, G542X, G551D, G85E, G91R, I148T, K710X, L206W, M1101K, N1303K, P574H, Q1238X, Q359K/T360K, Q493X, Q552X, Q890X, R1066C, R1158X, R1162X, R117C, R117H, R1283M, R334W, R347H, R347P, R352Q, R553X, R560T, S1196X, S1251N, S1255X, S364P, S549I, S549N, S549R, T338I, V520F, W1089X, W1282X, Y1092X, Y563D, 1078delT, 1161delC, 1609delCA, 1677delTA, 1717-1GϾA, 1812-1GϾA, 1898ϩ1GϾA, 1898ϩ5GϾT, 1949del84, 2043delG, 2143delT, 2183delAAϾG, 2184delA, 2307insA, 2789ϩ5GϾA, 2869insG, 3120ϩ1GϾA, 3120GϾA, 3659delC, 3662delA, 3791delC, 3821delT, 3849ϩ10kbCϾT, 3849ϩ4AϾG, 3905insT, 394delTT, 405ϩ1GϾA, 405ϩ3AϾC, 444delA, 574delA, 621ϩ1GϾT, 711ϩ1GϾT, 711ϩ5GϾA, 712-1GϾT, 3876delA CFTR mutation analysis Genomic DNA was extracted from peripheral blood lymphocytes, buccal cell swabs, or bloodspots by Qiagen QIAmp 96 DNA Blood Kit. Specimens were tested for 87 mutations by a pooled allele-specific oligonucleotide (ASO) hybridization method as previously described.16,17 Two multiplex chain reactions (PCR) were used to amplify 19 regions of the CFTR gene. Login to comment

[hide] Clinical sensitivity of prenatal screening for cys... Genet Med. 2004 Sep-Oct;6(5):405-14. Palomaki GE, FitzSimmons SC, Haddow JE
Clinical sensitivity of prenatal screening for cystic fibrosis via CFTR carrier testing in a United States panethnic population.
Genet Med. 2004 Sep-Oct;6(5):405-14., [PMID:15371905]

Abstract [show]
PURPOSE: To estimate CFTR mutation frequencies, clinical sensitivities (proportions of carrier couples or affected fetuses detected), and birth prevalence estimates for broad racial/ethnic groups and for a panethnic U.S. population. METHODS: Published sources of information were identified, corrected when appropriate, and summarized. Combining racial/ethnic-specific mutation frequencies and birth prevalence estimates allowed the computation of panethnic estimates. RESULTS: Two of the 25 recommended mutations do not meet the 0.1% threshold in a panethnic population set by the American College of Medical Genetics. The clinical sensitivities are estimated to be 71.9%, 51.7%, 41.6%, 88.6%, and 23.4% for non-Hispanic Caucasians, Hispanic Caucasian, African American, Ashkenazi Jewish Caucasian, and Asian American couples, respectively. Birth prevalence estimates are 1:2,500, 1:13,500, 1:15,100, 1:2,270, and 1:35,100, whereas the number of couples needed to screen to detect an affected fetus are about 3,200, 26,120; 36,040; 2,600, and 129,600, respectively, for the same racial/ethnic groups. CONCLUSIONS: Overall, the panethnic estimates for CFTR mutation frequencies are similar to those for non-Hispanic Caucasians. However, large differences in both clinical sensitivity and birth prevalence exist between the broad racial/ethnic groups examined. Whether and how the differences in the numbers of couples needed to screen to detect an affected fetus are to be included in prenatal screening for cystic fibrosis needs to be more explicitly addressed.

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32 Data from the International Cystic Fibrosis Consortium were taken from Table 1 of its publication.4 Data from the Cystic Fibrosis Foundation National Patient Registry were taken from the year 1999 and stratified according to whether or not the patient was seen Table 1 CFTR mutation frequencies among Hispanic Caucasians with cystic fibrosis within the recommended minimum testing panel Ordera Mutation Mutation frequency (%) CF Consortiumb CF Foundationc Average Cumulative 1 delF508 45.51 63.25 54.38 54.38 2 G542X 5.11 5.09 5.10 59.48 8 delI507 0.59 5.02 2.81 62.29 22 R334W 2.25 1.31 1.78 64.07 6 N1303K 1.65 1.67 1.66 65.73 10 3849 ϩ 10kbC Ͼ T 1.60 1.53 1.57 67.30 7 R553X 0.63 0.73 0.68 67.98 5 W1282X 0.53 0.73 0.63 68.61 19 R1162X 0.57 0.58 0.58 69.19 3 G551D 0.31 0.80 0.56 69.75 12 1717 - 1G Ͼ T 0.10 0.44 0.27 70.02 4 621 ϩ 1G Ͼ T 0.00 0.51 0.26 70.28 14 711 ϩ 1G Ͼ T 0.10 0.36 0.23 70.51 18 G85E 0.10 0.36 0.23 70.74 11 2789 ϩ 5G Ͼ A 0.10 0.22 0.16 70.90 13 R347P 0.10 0.22 0.16 71.06 20 2184delA 0.10 0.22 0.16 71.22 24 3120 ϩ 1G Ͼ T 0.10 0.22 0.16 71.38 17 3569delC 0.10 0.15 0.13 71.51 9 R117H 0.00 0.22 0.11 71.62 23 I148T 0.10 0.07 0.09 71.71 25 1078delT 0.10 0.07 0.09 71.80 16 A455E 0.10 0.00 0.05 71.85 21 1898 ϩ 1G Ͼ A 0.10 0.00 0.05 71.90 15 R560T 0.00 0.00 0.00 71.90 All 25 59.95 83.77 71.90 a The order is based on that found for non-Hispanic Caucasians.3 b Based on between 178 and 958 chromosomes (International Cystic Fibrosis Genetic Analysis Consortium.4 c Based on 1374 chromosomes from clinically diagnosed persons registered in the Cystic Fibrosis Foundation National Patient Registry. Login to comment
80 The larger data- Table 2 CFTR mutation frequencies among African American individuals with cystic fibrosis within the recommended minimum testing panel Ordera Mutation Mutation frequency (%) CF Consortiumb CF Foundationc Average Cumulative 1 delF508 35.50 52.63 44.07 44.07 24 3120 ϩ 1G Ͼ T 12.50 6.64 9.57 53.64 8 delI507 0.74 3.89 2.32 55.96 7 R553X 2.37 1.37 1.87 57.83 2 G542X 1.18 1.72 1.45 59.28 3 G551D 0.59 1.83 1.21 60.49 4 621 ϩ 1G Ͼ T 1.18 1.03 1.11 61.60 19 R1162X 0.74 0.57 0.66 62.26 22 R334W 0.74 0.23 0.49 62.75 12 1717 - 1G Ͼ T 0.74 0.00 0.37 63.12 6 N1303K 0.00 0.69 0.35 63.47 5 W1282X 0.00 0.47 0.24 63.71 10 3849 ϩ 10kbC Ͼ T 0.00 0.34 0.17 63.88 15 R560T 0.00 0.34 0.17 64.05 18 G85E 0.00 0.23 0.12 64.17 9 R117H 0.00 0.11 0.06 64.23 13 R347P 0.00 0.11 0.06 64.29 17 3569delC 0.00 0.11 0.06 64.35 21 1898 ϩ 1G Ͼ A 0.00 0.11 0.06 64.41 20 2184delA 0.10 0.00 0.05 64.46 23 I148T 0.10 0.00 0.05 64.51 11 2789 ϩ 5G Ͼ A 0.00 0.00 0.00 64.51 14 711 ϩ 1G Ͼ T 0.00 0.00 0.00 64.51 16 A455E 0.00 0.00 0.00 64.51 25 1078delT 0.00 0.00 0.00 64.51 All 25 56.46 72.42 64.51 a The order is based on that found for non-Hispanic Caucasians.3 b Based on between 79 and 169 chromosomes reported by the International Cystic Fibrosis Genetic Analysis Consortium.4 c Based on 874 chromosomes from clinically diagnosed persons registered in the Cystic Fibrosis Foundation National Patient Registry. Login to comment
107 An earlier article10 reported that 97% of mutations were identified in 90 chromosomes from Ashkenazi Jewish individ- Table 3 CFTR mutation frequencies among Ashkenazi Jewish Caucasian individuals with cystic fibrosis within the recommended minimum testing panel Ordera Mutation Mutation frequency (%) CF Consortiumb Cumulative 5 W1282X 45.92 45.92 1 delF508 31.41 77.33 2 G542X 7.55 84.88 10 3849 ϩ 10kbC Ͼ T 4.77 89.65 6 N1303K 2.78 92.43 12 1717 - 1G Ͼ T 0.67 93.10 7 R553X 0.22 93.32 3 G551D 0.22 93.54 24 3120 ϩ 1G Ͼ T 0.10 93.64 21 1898 ϩ 1G Ͼ A 0.10 93.74 20 2184delA 0.10 93.84 23 I148T 0.10 93.94 11 2789 ϩ 5G Ͼ A 0.10 94.04 14 711 ϩ 1G Ͼ T 0.10 94.14 8 delI507 0.00 94.14 19 R1162X 0.00 94.14 22 R334W 0.00 94.14 4 621 ϩ 1G Ͼ T 0.00 94.14 15 R560T 0.00 94.14 18 G85E 0.00 94.14 9 R117H 0.00 94.14 13 R347P 0.00 94.14 17 3569delC 0.00 94.14 16 A455E 0.00 94.14 25 1078delT 0.00 94.14 Sum 94.14 a The order is based on that found for non-Hispanic Caucasians.3 b Based on between 57 and 503 chromosomes reported by the International Cystic Fibrosis Genetic Analysis Consortium.4 uals with cystic fibrosis, using a panel of 11 mutations. Login to comment
115 In an- Table 4 CFTR mutation frequencies among Asian American individuals with cystic fibrosis within the recommended minimum testing panel Ordera Mutation Mutation frequency (%) Heim et al.1b CF Foundationc Average Cumulative 1 delF508 18.80 59.09 38.95 38.95 10 3849 ϩ 10kbC Ͼ T 0.00 10.61 5.31 44.26 3 G551D 6.30 0.00 3.15 47.41 6 N1303K 0.00 1.52 0.76 48.17 8 delI507 0.00 1.52 0.76 48.93 2 G542X 0.00 0.00 0.00 48.93 4 621 ϩ 1G Ͼ T 0.00 0.00 0.00 48.93 5 W1282X 0.00 0.00 0.00 48.93 7 R553X 0.00 0.00 0.00 48.93 9 R117H 0.00 0.00 0.00 48.93 11 2789 ϩ 5G Ͼ A 0.00 0.00 0.00 48.93 12 1717 - 1G Ͼ T 0.00 0.00 0.00 48.93 13 R347P 0.00 0.00 0.00 48.93 14 711 ϩ 1G Ͼ T 0.00 0.00 0.00 48.93 15 R560T 0.00 0.00 0.00 48.93 16 A455E 0.00 0.00 0.00 48.93 17 3569delC 0.00 0.00 0.00 48.93 18 G85E 0.00 0.00 0.00 48.93 19 R1162X 0.00 0.00 0.00 48.93 20 2184delA 0.00 0.00 0.00 48.93 21 1898 ϩ 1G Ͼ A 0.00 0.00 0.00 48.93 22 R334W 0.00 0.00 0.00 48.93 23 I148T 0.00 0.00 0.00 48.93 24 3120 ϩ 1G Ͼ T 0.00 0.00 0.00 48.93 25 1078delT 0.00 0.00 0.00 48.93 Sum 25.10 72.74 48.93 a The order is based on that found for non-Hispanic Caucasians.3 b Based on 20 chromosomes. Login to comment
173 For exam- Table 7 Estimated number of carriers of the 25 recommended CFTR mutations by racial/ethnic group and weighted average, representing the panethnic population in the United States for 2002 Order CFTR mutation Number of CFTR Mutation Carriers Panethnic frequency, % Non-Hispanic Caucasian Hispanic Caucasian African American Asian American Ashkenazi Jewish Total 1 delF508 64,779 8,207 4,272 886 796 78,940 66.31 2 G542X 2,039 770 141 0 191 3,141 2.64 5 W1282X 1,342 95 23 0 1,164 2,624 2.20 3 G551D 2,013 85 117 72 6 2,293 1.93 4 621 ϩ 1G Ͼ T 1,404 39 108 0 0 1,551 1.30 6 N1303K 1,136 251 34 17 70 1,508 1.27 7 R553X 778 424 225 17 0 1,444 1.21 8 delI507 787 103 181 0 6 1,077 0.90 10 3849 ϩ 10kbC Ͼ T 519 237 16 121 121 1,014 0.85 24 3120 ϩ 1G Ͼ T 72 24 928 0 3 1,027 0.86 9 R117H 626 17 6 0 0 649 0.55 12 1717 - 1G Ͼ T 429 41 36 0 17 523 0.44 11 2789 ϩ 5G Ͼ A 429 24 0 0 3 456 0.38 13 R347P 403 24 6 0 0 433 0.36 14 711 ϩ 1G Ͼ T 385 35 0 0 3 423 0.36 22 R334W 125 269 47 0 0 441 0.37 15 R560T 340 0 16 0 0 356 0.30 19 R1162X 206 88 64 0 0 358 0.30 17 3569delC 304 20 6 0 0 330 0.28 16 A455E 304 8 0 0 0 312 0.26 18 G85E 259 35 12 0 0 306 0.26 20 2184delA 152 24 5 0 3 184 0.15 21 1898 ϩ 1G Ͼ A 143 8 6 0 3 160 0.13 23 I148T 80 14 5 0 3 102 0.09 25 1078delT 18 14 0 0 0 32 0.03 All 79,072 10,856 6,193 1,113 2,389 99,684 84.00 Bolded numbers indicate mutations that are more likely to be found in a racial/ethnic group other than non-Hispanic Caucasians. Login to comment

[hide] Use of MALDI-TOF mass spectrometry in a 51-mutatio... Genet Med. 2004 Sep-Oct;6(5):426-30. Buyse IM, McCarthy SE, Lurix P, Pace RP, Vo D, Bartlett GA, Schmitt ES, Ward PA, Oermann C, Eng CM, Roa BB
Use of MALDI-TOF mass spectrometry in a 51-mutation test for cystic fibrosis: evidence that 3199del6 is a disease-causing mutation.
Genet Med. 2004 Sep-Oct;6(5):426-30., [PMID:15371908]

Abstract [show]
PURPOSE: We developed a 51-mutation extended cystic fibrosis (CF) panel that incorporates the 25 previously recommended CFTR mutations, plus 26 additional mutations including 3199del6, which was associated with I148T. METHODS: This assay utilizes an integrated matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry system. RESULTS: CF testing was performed on over 5,000 individuals, including a 3-year-old Hispanic-American patient with a compound heterozygous G542X/3199del6 genotype. He is negative for I148T, or other mutations assessed by CFTR gene sequencing. CONCLUSION: These results demonstrate the successful implementation of MALDI-TOF mass spectrometry in CF clinical testing, and establish 3199del6 as a disease-causing CF mutation.

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77 This assay also demonstrated heterozygosity for the G542X mutation, and reflex testing for the 5T variant at CFTR intron 8 showed a genotype of 7T/9T in this patient (data not Table 3 Description of the 16 multiplex assays designed to analyze 51 CFTR mutations Multiplex Mutations Exon 1 1078delT, G314E, R352Q, G330X 7 2 R347H, R347P, R334W, 1717-1A 7, 11 3 R553X, S549N, R1162X 11, 19 4 A559T, R560T, G551D 11 5 G542X, S549R, 621ϩ1T, Y122X 4, 11 6 W1282X, 3876delA, 3905insT, D1152H 18, 20 7 3849ϩ4G, 3659delC, 1898ϩ1A 12, 19 8 405ϩ1A, 405ϩ3C, 3120A, 3120ϩ1A 3, 16 9 394delTT, E60X, G85E 3 10 A455E, ⌬F508a 9, 10 11 G480C, Q493X, V520F 10 12 711ϩ1T, G178R, 3199del6 5, 17a 13 2143delT, 2184delA, K710X, F316L 7, 13 14 I148T, R117H, R117C 4 15 N1303K, 2789ϩ5A, 3849ϩ10kbT 14b, intron19, 21 16 ⌬I507a 10 17 5Tb intron 8 a F508C and I507V, I506V, I506M variants are tested for concurrently with the ⌬F508 and ⌬I507 assays respectively. Login to comment

[hide] Cystic fibrosis carrier screening: validation of a... Genet Med. 2004 Sep-Oct;6(5):431-8. Edelmann L, Hashmi G, Song Y, Han Y, Kornreich R, Desnick RJ
Cystic fibrosis carrier screening: validation of a novel method using BeadChip technology.
Genet Med. 2004 Sep-Oct;6(5):431-8., [PMID:15371909]

Abstract [show]
PURPOSE: To validate a novel BeadChip assay system for cystic fibrosis (CF) mutation testing using the panel of 25 ACMG recommended mutations and D1152H. METHODS: DNA from 519 individuals originally tested for CF mutation status by allele specific oligonucleotide hybridization (ASOH) were blindly analyzed by the BeadChip assay and the results were compared. The elongation mediated multiplexed analysis of polymorphisms (eMAP) protocol, which combines multiplex amplification of genomic DNA and multiplex detection of mutations on color-coded bead arrays, was used to analyze 26 CF mutations in two separate groups. RESULTS: The system accurately distinguished the 26 CF genotypes and had 100% concordance with the ASOH technique with an assay failure rate of 1.7%. Benign variants of exon 10 codons 506, 507, and 508 did not interfere with mutation identification and reflex testing for the 5/7/9T IVS8 polymorphism was performed on a separate array. CONCLUSIONS: The BeadChip assay system provided accurate and rapid identification of the ACMG recommended CF mutations.

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35 Mutation controls included DNA from previously identified positive patient samples (I148T, D1152H, W1282X, R117H, G85E, A455E, delF508, N1303K) and DNA from NIGMS Human Genetic Cell Repositories (Coriell Cell Repositories) (delF508, delI507, G542X, R560T, 3849ϩ10kbCϾT, N1303K, G85E; G551D, R553X, 621ϩ1GϾT, 1717-1GϾA, A455E, R334W, R347P, R1162X, 3659delC; 711ϩ1GϾT, 2789ϩ5GϾA, 3120ϩ1GϾA). Login to comment
46 Mutant ASOs were end-labeled with ␥-32 P-ATP and pooled into three subgroups (IA-IC) for Group I and four subgroups (IIA-IID) for Group II mutations with the following breakdown of mutations: IA: delF508, delI507, W1282X, R117H; IB: G542X, R560T, 3849ϩ10kbCϾT, N1303K, G85E; IC: G551D, R553X, 621ϩ1GϾT, 1717-1GϾA, I148T; IIA: A455E, R334W, D1152H; IIB: R347P, 1078delT, R1162X, 3659delC; IIC: 711ϩ1GϾT, 1898ϩ1GϾA, 2789ϩ5GϾA, 3120ϩ1GϾA; IID: 2184delA. Login to comment

[hide] Destabilization of the transmembrane domain induce... J Biol Chem. 2005 Feb 11;280(6):4968-74. Epub 2004 Nov 10. Choi MY, Partridge AW, Daniels C, Du K, Lukacs GL, Deber CM
Destabilization of the transmembrane domain induces misfolding in a phenotypic mutant of cystic fibrosis transmembrane conductance regulator.
J Biol Chem. 2005 Feb 11;280(6):4968-74. Epub 2004 Nov 10., 2005-02-11 [PMID:15537638]

Abstract [show]
Two phenotypic missense mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) channel pore (L346P and R347P in transmembrane (TM) segment 6) involve gain of a proline residue, but only L346P represents a significant loss of segment hydropathy. We show here that, for synthetic peptides corresponding to sequences of CFTR TM6 segments, circular dichroism spectra of wild type and R347P TM6 in membrane mimetic environments are virtually identical, but L346P loses approximately 50% helicity, implying a membrane insertion defect in the latter mutant. A similar defect was observed in the corresponding double-spanning ("hairpin") TM5/6-L346P synthetic peptide. Examination of the biogenesis of CFTR revealed that the full-length protein harboring the L346P mutation is rapidly degraded at the endoplasmic reticulum (ER), whereas the wild type and the R347P protein process normally. Furthermore, a second site mutation (R347I) that restores in vitro membrane insertion and folding of the TM5/6-L346P peptide also rescues the folding and cell surface chloride channel function of full-length L346P CFTR. The correlated in vitro/in vivo results demonstrate that destabilizing local hydrophobic character represents a sufficient signal for marking CFTR as a non-native protein by the ER quality control, with accompanying deleterious consequences to global protein folding events.

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0 Destabilization of the Transmembrane Domain Induces Misfolding in a Phenotypic Mutant of Cystic Fibrosis Transmembrane Conductance Regulator* Received for publication, September 1, 2004, and in revised form, November 8, 2004 Published, JBC Papers in Press, November 10, 2004, DOI 10.1074/jbc.M410069200 Mei Y. Choi‡§¶, Anthony W. Partridge‡§ʈ, Craig Daniels**‡‡, Kai Du**‡‡, Gergely L. Lukacs**‡‡§§, and Charles M. Deber‡§ §§ From the ‡Division of Structural Biology and Biochemistry and **Program in Cell and Lung Biology, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 1X8 and the Departments of §Biochemistry and ‡‡Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada Two phenotypic missense mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) channel pore (L346P and R347P in transmembrane (TM) segment 6) involve gain of a proline residue, but only L346P represents a significant loss of segment hydropathy. Login to comment
1 We show here that, for synthetic peptides corresponding to sequences of CFTR TM6 segments, circular dichroism spectra of wild type and R347P TM6 in membrane mimetic environments are virtually identical, but L346P loses ϳ50% helicity, implying a membrane insertion defect in the latter mutant. Login to comment
3 Examination of the biogenesis of CFTR revealed that the full-length protein harboring the L346P mutation is rapidly degraded at the endoplasmic reticulum (ER), whereas the wild type and the R347P protein process normally. Login to comment
15 A number of mutations occurring in TM5/6 have been found to cause mild (usually pancreatic sufficient) forms of CF, two of which involve introduction of a proline residue: L346P, a mutation that was identified in two unrelated Cypriot patients in 1994 (10); and a second sequentially adjacent CF-phenotypic mutant, R347P (11). Login to comment
36 In the case of R347P, the Arg positive charge is lost, but this mutation exchanges a polar residue (Arg ranks 14th, at -2.77) with one of comparable hydrophilicity. Login to comment
37 In the present work, we have used solid-phase peptide synthesis to prepare sequences corresponding to TM6 segments of wild type (WT) and mutants L346P and R347P of CFTR, along with some corresponding double-spanning TM5/6 peptides for comparative structural analyses. Login to comment
38 In parallel, we examined the relative effects of L346P versus R347P on cellular processing of full-length CFTR. Login to comment
58 Construction and Expression of CFTR Variants in Mammalian Cells-The L346P, R347P, and R347H CFTR mutants were constructed FIG. 1. Login to comment
60 A, wild type sequence; B, TM5/6-L346P; C, TM5/6-R347P; and D, TM5/6-L346P-R347I. Login to comment
70 Baby hamster kidney (BHK) cells were stably transfected with the pNUT expression plasmids, containing the wild type (WT), L346P, or R347P CFTR, harboring an HA-epitope in the C-terminal tail of CFTR (CFTR-CintHA) (21). Login to comment
84 RESULTS Hydrophobicity Threshold of CF-phenotypic Mutant TM Segments-Although both L346P and R347P represent a gain of a Pro residue in CFTR TM6, the resulting local 346/347 diads (PR and LP, respectively) differ significantly in hydrophobic character. Login to comment
89 However, unlike L346P, the R347P mutation doesn`t involve a significant change in hydrophobicity, and TM Finder predicts that the R347P mutant has the same membrane-inserted amino acid stretch (residues 330-349) as the WT TM6 sequence (Fig. 1C). Login to comment
93 A, CD spectra of TM6-WT, TM6-L346P, and TM6-R347P peptides in lysophosphatidylcholine (LPC) detergent micelles. B, CD spectra for TM5/ 6-WT and TM5/6-L346P peptides in LPC micelles. Login to comment
99 synthesized Lys-tagged versions of the TM6-WT and the two mutant (L346P and R347P) sequences (Table I). Login to comment
103 In contrast, the CD spectra of TM6-R347P and the TM6-WT peptides are virtually superimposable. Login to comment
116 WT, L346P, R347P, L346P/R347I, and R347H CFTR expression was assayed by immunoblotting, using the mouse monoclonal anti-HA Ab. Login to comment
135 Because impaired post-translational folding of the CFTR usually causes its biosynthetic processing arrest, we examined the processing of full-length L346P- and R347P-CFTR by immunoblotting and pulse-chase analysis of BHK cells, which stably express CFTR. Login to comment
137 As shown in Fig. 3A, immunoblot analysis of equal amounts of cell extracts demonstrated that the L346P, but not the R347P, mutation, prevented the expression of the complex-glycosylated CFTR. Login to comment
164 Thus, despite the similarity of the two mutations and their adjacent positions in the sequence, the TM6-L346P peptide displayed only ϳ50% of the helicity observed for the TM6-WT sequence, whereas the TM6-R347P retained WT character, indicating that the ability of the L346P peptide to properly insert into the apolar milieu has been significantly compromised (Fig. 2A). Login to comment
209 In contrast, the effects of the R347P mutation present an alternate scenario. Login to comment
211 Thus, the loss of a WT interhelical salt bridge (12) in R347P may contribute to the underlying defect. Login to comment
215 However, loss of an Arg residue at the adjacent position appears to induce a more downstream event, viz., R347P may promote changes in the selectivity or effectiveness of the channel pore of CFTR stemming from loss of side-chain positive character (43-46), rather than preventing post-translational folding. Login to comment

[hide] Late diagnosis defines a unique population of long... Am J Respir Crit Care Med. 2005 Mar 15;171(6):621-6. Epub 2004 Dec 10. Rodman DM, Polis JM, Heltshe SL, Sontag MK, Chacon C, Rodman RV, Brayshaw SJ, Huitt GA, Iseman MD, Saavedra MT, Taussig LM, Wagener JS, Accurso FJ, Nick JA
Late diagnosis defines a unique population of long-term survivors of cystic fibrosis.
Am J Respir Crit Care Med. 2005 Mar 15;171(6):621-6. Epub 2004 Dec 10., 2005-03-15 [PMID:15591474]

Abstract [show]
Although the median survival for patients with cystic fibrosis (CF) is 32.9 years, a small group of patients live much longer. We analyzed the genotype and phenotype of CF patients 40 years and older seen between 1992 and 2004 at the National Jewish Medical and Research Center (n = 55). These patients were divided into two groups according to age at diagnosis: an early diagnosis (ED) group, median age at diagnosis 2.0 years (range 0.1-15 years, n = 28), and a late diagnosis (LD) group, median age of diagnosis 48.8 years (range 24-72.8 years, n = 27). Consistent with the hypothesis that the CFTR genotype affects the age at diagnosis, CFTR DeltaF508 homozygous individuals were more common in the ED group. Although patients in the ED group were predominantly male, the majority of LD patients were female. Patients with CF diagnosed late had a significantly lower prevalence of pancreatic insufficiency and CF-related diabetes, and better lung function. Fewer patients in the LD groups were infected with Pseudomonas aeruginosa, whereas a greater percentage had cultures positive for nontuberculous mycobacteria. This is the largest cohort of older patients with CF described to date, and our findings indicate that patients diagnosed as adults differ distinctly from survivors of long-term CF diagnosed as children.

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117 GENOTYPE DISTRIBUTION Early Diagnosis Late Diagnosis ⌬F508/⌬F508 10 1 ⌬F508/⌬I507 1 ⌬F508/G551D 1 ⌬F508/M1101K 1 ⌬F508/P67L/11027T 1 ⌬F508/3120G-A 1 ⌬F508/2789ϩ5G-A 1 2 ⌬F508/W1282X 1 ⌬F508/621ϩ1G-T 1 ⌬F508/R347P 1 ⌬F508/3849ϩ10kbC-T 1 1 ⌬F508/A455E 2 ⌬F508/R347H 2 ⌬F508/D1152H 1 ⌬508/I148T 1 ⌬F508/R117H 1 ⌬F508/Y109N 1 ⌬F508/IVS8-5T 1 ⌬F508/unknown 3 5 S1251N/D1152H 1 G542X/R117C 1 R117H/G551D 1 W1282X/D1152H 1 Unknown 4 4 Values represent number of individuals in each diagnostic group with each genotype. Login to comment

[hide] Comprehensive cystic fibrosis mutation epidemiolog... Ann Hum Genet. 2005 Jan;69(Pt 1):15-24. Castaldo G, Polizzi A, Tomaiuolo R, Cazeneuve C, Girodon E, Santostasi T, Salvatore D, Raia V, Rigillo N, Goossens M, Salvatore F
Comprehensive cystic fibrosis mutation epidemiology and haplotype characterization in a southern Italian population.
Ann Hum Genet. 2005 Jan;69(Pt 1):15-24., [PMID:15638824]

Abstract [show]
We screened the whole coding region of the cystic fibrosis transmembrane regulator (CFTR) gene in 371 unrelated cystic fibrosis (CF) patients from three regions of southern Italy. Forty-three mutations detected 91.5% of CF mutated chromosomes by denaturing gradient gel electrophoresis analysis, and three intragenic CFTR polymorphisms predicted a myriad of rare mutations in uncharacterized CF chromosomes. Twelve mutations are peculiar to CF chromosomes from southern Italy: R1158X, 4016insT, L1065P and 711 + 1G > T are present in 6.3% of CF chromosomes in Campania; G1244E and 852del22 are present in 9.6% of CF chromosomes in Basilicata and 4382delA, 1259insA, I502T, 852del22, 4016insT, D579G, R1158X, L1077P and G1349D are frequent in Puglia (19.6% of CF alleles). Several mutations frequently found in northern Italy (e.g., R1162X, 711 + 5G > T) and northern Europe (e.g., G551D, I507del and 621 + 1G > T) are absent from the studied population. The I148T-3195del6 complex allele was present in two CF chromosomes, whereas I148T was present in both alleles (as a single mutation) in another CF patient and in five CF carriers; this could result from crossover events. The haplotype analysis of three intragenic polymorphisms (IVS8CA, IVS17bTA and IVS17bCA) compared with data from other studies revealed that several mutations (3849 + 10kbC > T, 1717-1G > A, E585X, 3272-26G > A, L558S, 2184insA and R347P) originated from multiple events, whereas others (R1158X and S549R) could be associated with one or more intragenic recombinant events. Given the large population migration from southern Italy, knowledge of the CF molecular epidemiology in this area is an important contribution to diagnosis, counselling and interlaboratory quality control for molecular laboratories worldwide.

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5 The haplotype analysis of three intragenic polymorphisms (IVS8CA, IVS17bTA and IVS17bCA) compared with data from other studies revealed that several mutations (3849+10kbC>T, 1717-1G>A, E585X, 3272-26G>A, L558S, 2184insA and R347P) originated from multiple events, whereas others (R1158X and S549R) could be associated with one or more intragenic recombinant events. Login to comment
62 A procedure for the large-scale analysis of several mutations peculiar to southern Italy is also indicated Mutation Analytical CF alleles Campania Basilicata Puglia Total procedure n = 340 n = 52 n = 350 n = 742 DF508 55.6 55.8 46.8 51.5 N1303K 7.3 3.8 7.7 7.3 G542X 5.0 3.8 7.1 5.9 W1282X 3.5 3.8 0.6 2.2 2183 AA>G 2.3 5.8 0.8 1.9 852del22 0 5.8 3.2 1.9 3% agarose 1717-1G>A 2.3 1.9 1.1 1.8 4382delA 0 0 3.7 1.8 RE (Ear I -) 1259insA 0 0 3.1 1.5 4016insT 2.1 0 1.1 1.5 ASO R553X 1.5 0 1.7 1.5 R1158X 1.5 0 1.3 1.2 ASO or RE (Sfa N 1 -) L1077P 0.6 0 1.9 1.2 I502T 0.3 0 2.0 1.1 RE (Mse I -) 3849+10kbC>T 0 1.9 1.6 0.9 D579G 0 0 1.6 0.8 RE (Avr II +) G1244E 0.9 3.8 0.3 0.8 ASO or RE (Mbo II +) G1349D 0 0 1.7 0.8 RE (Sty I -) 2789+5 G>A 0.6 0 0.8 0.7 711+1 G>T 1.5 0 0 0.7 ASO L1065P 1.2 0 0 0.5 ASO or RE (Mnl I +) R347P 0.3 0 0.9 0.5 2522insC 0.9 0 0 0.4 E585X 0.6 0 0 0.3 G85E 0.6 0 0 0.3 G178R 0.6 0 0 0.3 D1152H 0.3 0 0.3 0.3 I148T-3195del6 0.6 0 0 0.3 I148T (alone) 0 0 0.3 0.1 R334W 0 0 0.3 0.1 DI507 0 0 0.3 0.1 I1005R 0 0 0.3 0.1 3272-26A>G 0.3 0 0 0.1 2711delT 0.3 0 0 0.1 L558S 0 1.9 0 0.1 W1063X 0 0 0.3 0.1 D110H 0.3 0 0 0.1 S549R (A>C) 0 1.9 0 0.1 2184insA 0.3 0 0 0.1 3131del22 0.3 0 0 0.1 R709N 0 0 0.3 0.1 A349V 0 0 0.3 0.1 4015insA 0 0 0.3 0.1 Y849X 0 1.9 0 0.1 Cumulative 91.6 92.1 91.7 91.5 Unknown 8.4 7.9 8.3 8.5 Total 100,0 100,0 100,0 100,0 RE: restriction enzyme (-/+: abolition or introduction of a RE site); ASO: allele specific oligonucleotide Figure 2 Multiplex denaturing gradient gel electrophoretic analysis of exons 8, 5 and 18 of the cystic fibrosis transmembrane regulator gene in a cystic fibrosis patient (case n. Login to comment
97 Due to the presence of 'local` mutations, the detection rate with commercial kits for CF chromosomes in Table 3 Mutations linked to different haplotypes possibly due to slippage events, characteryzed at the level of three CFTR intragenic loci (IVS8CA, IVS17bTA, IVS17bCA) by the indication of the repeats number Present study Other studies Cases Haplotype cases (n) (n. of repeats) (n) Haplotype references* (n. of repeats) R347P 4/4 16-32-13 3 16-32-13 1,2,3 1 16-31-13 3 2 17-28-13 1 1 16-45-13 1 L1077P 3/3 17-7-17 1 17-7-17 1 1 17-7-16 1 G85E 2/2 16-24-13 9 16-24-13 2,3 1 16-25-13 2 2183AA>G 14/14 16-31-13 1 16-31-13 3 4 16-30-13 1 R553X 6/11 17-55-13 3 17-58-13 3 3/11 18-55-13 1 17-57-11 1 1/11 16-55-13 2 17-55-13 1,3 1/11 16-55-11 6 17-55-11 1 1 17-52-11 1 1 17-54-11 1 1 17-56-13 3 G1244E 5/6 16-32-13 1 17-34-13 1 1/6 16-34-13 711 +1 G>T 5/5 16-25-13 7 16-25-13 1,2,3 1 16-26-13 1 G1349D 5/6 16-30-13 1/6 16-32-13 G178R 1/2 16-32-13 1 16-30-13 3 1/2 16-32-13 2 16-32-13 1 * References 1: Morral et al. 1996. Login to comment
117 A recurrent origin has also been postulated for R347P (Morral et al. 1994; Claustres et al. 1996) since it lies on a triplet with a high mutation rate, and different microsatellite alleles have been associated with this mutation. Login to comment

[hide] Rational approach to genetic testing of cystic fib... Andrologia. 2005 Feb;37(1):1-9. Mennicke K, Klingenberg RD, Bals-Pratsch M, Diedrich K, Schwinger E
Rational approach to genetic testing of cystic fibrosis (CF) in infertile men.
Andrologia. 2005 Feb;37(1):1-9., [PMID:15644056]

Abstract [show]
Male infertility as a result of isolated congenital bilateral absence of the vas deferens (CBAVD) is one primary genital form of cystic fibrosis (CF) and occurs in 1-2% of infertile men. Assisted fertilization in patients with CBAVD increases the risk of transmitting mutations in the CF gene. We developed a rational approach to genetic CF testing in infertile men. A total of 282 infertile male patients were screened for the most common CF mutations (DeltaF508, R117H, IVS8-5T). Clinical data including medical history, examination, semen analysis, sweat tests, karyotypes and hormonal values were analysed. We identified 23 patients carrying mutations in the CF gene (DeltaF508: 10 patients; R117H: six patients; IVS8-5T: 11 patients). Two patients were compound heterozygote for DeltaF508/R117H, two others for DeltaF508/IVS8-5T. Correlating these molecular analyses with the clinical data pertaining to serum follicle-stimulating hormone concentration, semen pH, sperm count and total testicular volume, we were able to develop a score with a high specificity (98.4) for the presence of a cystic fibrosis transmembrane conductance regulator (CFTR) mutation, but only with a low sensitivity (positive post-test likelihood: 62.5%; negative post-test likelihood: 6.3%). With regard to the low sensitivity and the high number of CFTR mutations found in this heterogeneous group of infertile men, we still recommend genetic CF testing before assisted fertilization.

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51 Two further mutations common in CBAVD were screened as well (mutation R347P: primers used: forward: 5' -ACA CTG GTA CTT TCA TTG T-3' ; reverse: 5' -AGA GAA ATG CTA GGA AAA G-3' : the presence of the mutation destroys a HhaI restriction site and creates an NcoI site; Dean et al., 1990; mutation 3849 + 10 kb: primers used: forward: 5' -TTG ATC TGT CAT CTT GAT TTC-3' ; reverse: 5' -CAT TTT AAT ACT GCA ACA GAT-3' , followed by a HphI digestion; Highsmith et al., 1994). Login to comment

[hide] Molecular pathology of the CFTR locus in male infe... Reprod Biomed Online. 2005 Jan;10(1):14-41. Claustres M
Molecular pathology of the CFTR locus in male infertility.
Reprod Biomed Online. 2005 Jan;10(1):14-41., [PMID:15705292]

Abstract [show]
Congenital bilateral absence of the vas deferens (CBAVD) is a form of infertility with an autosomal recessive genetic background in otherwise healthy males. CBAVD is caused by cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations on both alleles in approximately 80% of cases. Striking CFTR genotypic differences are observed in cystic fibrosis (CF) and in CBAVD. The 5T allele is a CBAVD mutation with incomplete penetrance. Recent evidence confirmed that a second polymorphic locus exists and is a major CFTR modifier. The development of minigene models have led to results suggesting that CFTR exon 9 is skipped in humans because of unusual suboptimal 5' splice sites. An extremely rare T3 allele has been reported and it has recently been confirmed that the T3 allele dramatically increases exon 9 skipping and should be considered as a 'CF' mutation. Routine testing for the most prevalent mutations in the CF Caucasian population will miss most CFTR gene alterations, which can be detected only through exhaustive scanning of CFTR sequences. Finally, a higher than expected frequency of CFTR mutations and/or polymorphisms is now found in a growing number of monosymptomatic disorders, which creates a dilemma for setting nosologic boundaries between CF and diseases related to CFTR.

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174 R334W or R347P. Login to comment

[hide] The CFTR 3849+10kbC->T and 2789+5G->A alleles are ... Eur Respir J. 2005 Mar;25(3):468-73. Dugueperoux I, De Braekeleer M
The CFTR 3849+10kbC->T and 2789+5G->A alleles are associated with a mild CF phenotype.
Eur Respir J. 2005 Mar;25(3):468-73., [PMID:15738290]

Abstract [show]
Most cystic fibrosis (CF) transmembrane receptor mutations are rare. The French CF Registry offers an opportunity to study the genotype-phenotype relationship of these rare alleles. Since 1992, 39 CF patients carrying one copy of the 3849+10kbC->T mutation and 88 the 2789+5G->A allele have been seen at least once in a CF care centre. Among them, 16 carrying the 3849+10kbC->T/Delta F508 genotype and 34 with the 2789+5G->A/Delta F508 genotype were seen in 2000. Their age at diagnosis, sweat chloride concentration, anthropometric and lung function results, and clinical aspects were compared with those homozygous for the Delta F508 mutation matched for sex, age and CF care centre. Major differences, most of them statistically significant, in the age at diagnosis, prevalence of pancreatic insufficiency, and other clinical signs, anthropometric and lung function measures were observed between both compound heterozygote groups and their matched Delta F508/Delta F508 groups. The mean sweat chloride concentration was also lower (close to normal values) among 3849+10kbC->T/Delta F508 patients, but not among 2789+5G->A/Delta F508 patients. In conclusion, both mutations studied here are associated with a milder course of cystic fibrosis disease. The 3849+10kbC->T and 2789+5G->A alleles are splice site mutations, leading to abnormal mRNA; however, a small amount of normally spliced transcripts can also be detected. The presence of these small amounts of normal cystic fibrosis transmembrane receptor protein in these cystic fibrosis patients is likely to be responsible for the milder severity of disease and a better life expectancy.

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63 Although only borderline significant, lung function was definitely better in the 3849+10kbC-.T/DF508 group (FEV1 83.0% and FVC 91.6% pred) than in the DF508 homozygote group (FEV1 59.9% TABLE 1 Genotypes identified among cystic fibrosis patients sharing the 3849+10kbC-.T or the 2789+5G-.A mutation Genotypes 3849+10kbC-.T 2789+5G-.A DI507 2 DF508 27 61 1525-1G-.A 1 1717-1G.A 1 2183AA.G 3 3129del4 1 3659delC 1 G542X 4 6 G551D 1 G970R 2 G1244E 2 L558S 1 M1V 1 N1303K 1 R347P 1 R553X 1 1 R1066C 1 S1251N 1 Unknown 1 6 Total 39 88 I. DUGUE´PE´ROUX AND M. DE BRAEKELEER MILD PHENOTYPE ASSOCIATED WITH TWO CFTR MUTATIONS c and FVC 76.9% pred). Login to comment

[hide] Cystic fibrosis: an overview. J Clin Gastroenterol. 2005 Apr;39(4):307-17. Turcios NL
Cystic fibrosis: an overview.
J Clin Gastroenterol. 2005 Apr;39(4):307-17., [PMID:15758625]

Abstract [show]
Cystic fibrosis (CF) is one of the most common inherited disorders of white populations. The isolation and cloning of the gene in CF that encodes the production of a transport protein that acts as an apical membrane chloride channel, termed cystic fibrosis transmembrane conductance regulator (CFTR), have improved our understanding of the disorder's pathophysiology and has aided diagnosis, but has also revealed the disease's complexity. Gene replacement therapy is still far from being used in patients with CF, mostly because of difficulties in targeting the appropriate cells. Life expectancy of patients with this disorder has greatly improved over past decades because of better symptomatic treatment strategies. This article summarizes advances in understanding and treatment of CF.

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55 Pancreatic Sufficient CF Mutations Dominant Pancreatic-Sufficient Variable Pancreatic-Sufficient G551S G85E P574H R347P R117H 3849 + 10kb C ! Login to comment

[hide] Pancreatitis among patients with cystic fibrosis: ... Pediatrics. 2005 Apr;115(4):e463-9. Epub 2005 Mar 16. De Boeck K, Weren M, Proesmans M, Kerem E
Pancreatitis among patients with cystic fibrosis: correlation with pancreatic status and genotype.
Pediatrics. 2005 Apr;115(4):e463-9. Epub 2005 Mar 16., [PMID:15772171]

Abstract [show]
OBJECTIVE: Pancreatitis is an infrequent complication among patients with cystic fibrosis (CF). It has mainly been reported for patients with pancreatic sufficiency (PS). Previous studies involved only a small number of patients because they contained data from single centers. The aim of this study was to evaluate the incidence of pancreatitis in a large heterogeneous CF population, to determine the relationship with pancreatic function, and to assess whether pancreatitis is associated with specific CFTR mutations. METHODS: Physicians caring for patients with CF were approached through the CF Thematic Network or through the European Cystic Fibrosis Foundation newsletter. They were asked to provide data on their current patient cohort through a standardized questionnaire and to report how many patients they had ever diagnosed as having pancreatitis. A detailed questionnaire was then sent, to be filled out for all of their patients for whom pancreatitis had ever occurred. We defined pancreatitis as an episode of acute abdominal pain associated with serum amylase levels elevated above the ranges established by each participating center's laboratory. General clinical data included age, genotype, age at diagnosis of CF, sweat chloride concentrations, pancreatic status, biometric findings, and respiratory status. CFTR mutations were also reported according to the functional classification of classes I to V. Patients were categorized as having PS, pancreatic insufficiency (PI), or PI after an initial period of PS. PI was defined as a 72-hour stool fat loss of >7 g/day, fat absorption of <93%, or fecal elastase levels of <200 microg/g feces. Clinical data on pancreatitis included age at the first episode, amylase and lipase levels, possible triggers, and occurrence of relapses or complications. RESULTS: A total of 10071 patients with CF, from 29 different countries, who were undergoing follow-up monitoring in 2002 were surveyed. Among this group, pancreatitis had ever been diagnosed for 125 patients (1.24%; 95% confidence interval [CI]: 1.02-1.46%). There was variability in the reported rates of pancreatitis for different countries. Twenty-six centers in 15 different countries sent detailed clinical data on their patients with pancreatitis and on their whole CF clinic. This involved 3306 patients with CF and 61 cases of pancreatitis, leading to a prevalence of 1.84% (95% CI: 1.39-2.30%). The mean age of the patients with pancreatitis ever was 24.4 years (SD: 10.8 years). The first episode of pancreatitis occurred at a mean age of 19.9 years (SD: 9.6 years). The median serum amylase level at the time of pancreatitis was 746 IU/L (interquartile range: 319-1630 IU/L), and the median lipase level was 577 IU/L (interquartile range: 229-1650 IU/L). The majority of patients had PS (34 of 61 patients, 56%; 95% CI: 43-68%). Pancreatitis occurred for 15 patients with PI (25%; 95% CI: 14-35%). Eight patients developed PI after initial PS. The occurrence of pancreatitis among patients with PS was 34 cases per 331 patients, ie, 10.27% (95% CI: 7.00-13.55%); the occurrence of pancreatitis among patients with PI was 15 cases per 2971 patients, ie, 0.5% (95% CI: 0.25-0.76%). The mean age (in 2002) of the CF cohort with pancreatitis did not differ between the PS and PI subgroups. The forced expiratory volume in 1 second was significantly lower among the patients with PI than among the patients with PS, ie, 65% (SEM: 7%) vs 79% (SEM: 4%). The mean age at the occurrence of pancreatitis and the amylase and lipase levels during pancreatitis were not different for patients with pancreatitis and PI versus PS. In the group with PS, 31 of 34 patients carried at least 1 class IV or V CFTR mutation. In the groups with PI and PI after PS, 5 of 15 patients and 3 of 8 patients, respectively, carried 2 class I, II, or III CFTR mutations. Relapses and/or evolution to chronic pancreatitis occurred for 42 patients. Pancreatitis preceded the diagnosis of CF in 18 of 61 cases. These patients were significantly older than the rest of the cohort, ie, age of 28.4 years (SEM: 3.4 years) vs 22.7 years (SEM: 1.3 years). Their median age at the diagnosis of CF was also significantly greater, ie, 21.5 years (interquartile range: 11.9-31 years) vs 7.6 years (interquartile range: 0.4-17.0 years). However, the ages at the occurrence of pancreatitis were similar, ie, 21.0 years (SEM: 3.0 years) vs 19.5 years (SEM: 1.2 years). CONCLUSIONS: This study of 10071 patients with CF from 29 different countries revealed an estimated overall occurrence of pancreatitis among patients with CF of 1.24% (95% CI: 1.02-1.46%). The incidence of pancreatitis was much higher among patients with PS. However, pancreatitis was also reported for 15 patients with PI from 11 centers in 9 different countries. A correct diagnosis of pancreatitis for the reported patients with PI was supported by amylase and lipase levels increased above 500 IU/L, similar to those for patients with PS and pancreatitis. A correct diagnosis of PI for these patients with pancreatitis was supported by the adequacy of the methods used. We chose the cutoff values used to distinguish between patients with PI and control subjects without gastrointestinal disease. For one half of the patients, the diagnosis of PI was established on the basis of low levels of stool elastase (mean: 97 mug/g stool). With a cutoff value of 200 microg/g stool, this noninvasive test has high sensitivity (>95%) and high specificity (>90%) to differentiate patients with PI from control subjects with normal pancreatic function. For the other one half of the patients with PI in the cohort, the pancreatic status was determined on the basis of the 3-day fecal fat balance, with the widely used cutoff value of >7 g of fat loss per day. The most likely reason for pancreatitis occurring among patients with PI is that some residual pancreatic tissue is present among these patients. Pancreatitis is a rare complication among patients with CF. It occurred for 1.24% (95% CI: 1.02-1.46%) of a large CF cohort. Pancreatitis occurs mainly during adolescence and young adulthood. It is much more common among patients with CF and PS (10.3%), but it can occur among patients with PI (0.5%). Pancreatitis can be the first manifestation of CF. Pancreatitis was reported for patients carrying a wide range of mutations.

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171 Mutations Found Among Patients With CF and Pancreatitis PS PI PI after PS Not classified 3849ϩ10-kbCϾT*/F508del† (3) F508del†/F508del† F508del†/2789ϩ5GϾA† F508del†/3849ϩ10-kbCϾT* 3849ϩ10-kbCϾT*/W1282X† F508del†/I336K† F508del†/G628RϩGϾA† F508del†/unknown D1152H*/F508del† (2) F508del†/2789ϩ5GϾA† W1282X†/G85E† F508del†/S945L D1152H*/W1282X† G551D†/N1303K† F508del†/R117H*ϩ7T Unknown/unknown R334W*/F508del† (2) I507del†/G1069R† F508del†/3849ϩ10-kbCϾT* R334W*/G542X† F508del†/D1152H* (2) F508del†/R347P R334W*/Q890X F508del†/A455E* R1162X†/R334W* R117H*ϩ7T/L997F†ϩ7T F508del†/R1066H* R347H*/2118del4 R117H*/F508del† F508del†/S13F* P205S*/G542X† F508del†/1898ϩ3AϾG* D1270NϩR74W*/I507del† Y1092X†/A455E* R352Q*/1812-1GϾA F508del†/I1005R L206W*/F508del† G542X†/unknown 5T*/W1282X† Refused testing 5T*/F508del† 5T*/7T* 7T*/F508del† 2789ϩ5GϾA†/unknown W1282X†/unknown (3) F508del†/unknown (6) F508del†/V232D† 2789ϩ5GϾA†/N1303K† 2347delG†/1341GϾA† Patients are grouped according to pancreatic status. Login to comment

[hide] Lack of association of common cystic fibrosis tran... Am J Gastroenterol. 2005 Apr;100(4):874-8. Gallegos-Orozco JF, E Yurk C, Wang N, Rakela J, Charlton MR, Cutting GR, Balan V
Lack of association of common cystic fibrosis transmembrane conductance regulator gene mutations with primary sclerosing cholangitis.
Am J Gastroenterol. 2005 Apr;100(4):874-8., [PMID:15784035]

Abstract [show]
BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic progressive cholestatic liver disease of uncertain etiology. However, the histologic features of PSC liver disease can resemble those in cystic fibrosis (CF), an inherited disorder caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. We sought to determine if PSC patients have a higher frequency of common CF alleles than disease controls. METHODS: DNA was extracted from peripheral lymphocytes of patients with end-stage liver disease. Samples were obtained before liver transplantation from 59 PSC patients and from three groups of control patients (20 each with primary biliary cirrhosis, autoimmune hepatitis, or hepatitis C). DNA samples were genotyped for 32 common CF mutations, the intron 8 T tract variants, and the M470V variant. RESULTS: One of 59 PSC patients (1.7%) had the common CF mutation (DeltaF508) in one CFTR gene. Two controls (3.3%) carried a single CF mutation (DeltaF508 in one primary biliary cirrhosis patient; W1282X in one hepatitis C patient). These rates do not differ from expected in the general population. The frequency of CFTR variants (5T and M470V) was also similar between PSC patients and controls. CONCLUSIONS: Despite anatomical similarities between CF liver disease and PSC, we could not confirm that PSC patients carried common CF mutations or common CFTR variants in higher than expected frequencies. These data suggest that CFTR dysfunction does not influence the pathogenesis of PSC.

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55 CFTR Mutations and Associated Phenotype Classic Nonclassic Cystic Fibrosis Cystic Fibrosis Variant Normal 621 + 1G→T R117H G85E* 7T 711 + 1G→T R334W 5T† 9T 1078delT R347P M470V‡ F508C I507 A455E I507V F508 2789 + 5G → A I506V 1717 - 1G→A 3849 + 10kbC→T G542X G551D R553X R560T R1162X 3659delC W1282X N1303K * Classic cystic fibrosis and nonclassic cystic fibrosis. Login to comment

[hide] Cystic fibrosis prenatal screening in genetic coun... J Genet Couns. 2005 Feb;14(1):1-15. Langfelder-Schwind E, Kloza E, Sugarman E, Pettersen B, Brown T, Jensen K, Marcus S, Redman J
Cystic fibrosis prenatal screening in genetic counseling practice: recommendations of the National Society of Genetic Counselors.
J Genet Couns. 2005 Feb;14(1):1-15., [PMID:15789152]

Abstract [show]
For over a decade, prenatal screening for cystic fibrosis (CF) has been considered a model for the integration of genetic testing into routine medical practice. Data from pilot studies and public policy discourse have led to recommendations by some professional organizations that CF screening should be offered or made available to pregnant women and their partners, and to couples planning a pregnancy. It is crucial that genetic counselors gain thorough understanding of the complexities of CF and the implications of positive test results, so that they may serve as a reliable, educated referral base and resource for health care providers and their patients. While not all pregnant women will be referred for genetic counseling prior to CF carrier testing, genetic counselors often will be asked to counsel clients after they have a positive test result, or who are found to be at increased risk. Genetic counselors can play an important role in providing accurate and current information as well as support for patients' informed decisions. These recommendations were created by a multicenter working group of genetic counselors with expertise in CF and are based on personal clinical experience, review of pertinent English language medical articles, and reports of expert committees. The recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of a particular client.

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156 Mutations described as "mild", for example, R117H, R334W, R347P, and A455E (Kristidis et al., 1992; The CF genotype-phenotype consortium, 1993), are more likely to be associated with pancreatic sufficiency regardless of the class of the second mutation. Login to comment

[hide] Genetic factors in pancreatitis. Rom J Gastroenterol. 2005 Mar;14(1):53-61. Grigorescu M, Grigorescu MD
Genetic factors in pancreatitis.
Rom J Gastroenterol. 2005 Mar;14(1):53-61., [PMID:15800694]

Abstract [show]
The understanding of pathogenesis of acute and chronic pancreatitis has benefited from the progress made in genetic investigations. The discoveries of the gain of function mutations of cationic trypsinogen gene (PRSS1) and the loss of function mutations of pancreatic secretory trypsin inhibitor (SPINK 1) or other potential defects in genes that regulate pancreatic secretory function or modulate inflammatory response to pancreatic injury has changed our current concepts on the pathogenesis of pancreatitis. Genetic factors play an important role in the susceptibility to pancreatic injury, severity and evolution of inflammatory process, leading in some cases to chronic inflammation and/or fibrosis. Acute pancreatitis is viewed as an event and chronic pancreatitis as a process, sequentially linked, reflecting a complex interaction between genetic and environmental factors.

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98 More than 1200 CFTR gene polymorphism have been reported which can be divided into six classes, based on the functional consequences of the polymorphisms on channel function: - class I-III mutations are severe (CFTRsev ), comprising: class I: defective protein synthesis (R553X, W1282X, 3950 del T); class II: abnormal processing trafficking (del 508, N1303K); class III: defective activation (G551D) and all result in functional loss of CFTR from the epithelial cell surface; - class IV mutations (R117H, R347P, D1152H) are mild-variable mutations (CFTRm-v ) and result in reduction but not absence of channel ion conductance; - class V mutations (3849+10KbC >T) diminish protein synthesis or stability and - class VI mutations may affect the regulatory function of CFTR on other ion channels (71-73). Login to comment

[hide] Time-motion analysis of 6 cystic fibrosis mutation... Clin Chem. 2005 Jul;51(7):1116-22. Epub 2005 Apr 28. Krafft AE, Lichy JH
Time-motion analysis of 6 cystic fibrosis mutation detection systems.
Clin Chem. 2005 Jul;51(7):1116-22. Epub 2005 Apr 28., [PMID:15860566]

Abstract [show]
BACKGROUND: A dramatic increase in requests for routine cystic fibrosis (CF) carrier screening prompted us to conduct a time-motion analysis comparing commercially available CF testing platforms. Questions addressed in the study included: (a) How much time is required to perform each step involved in carrying out the assay procedure? (b) Which system requires the minimum number of manual manipulations to complete a typical run? (c) What workflow benefits can be achieved by automation? METHODS: We used a 96-sample run for comparisons and analyzed each of the 6 methods to determine the number of pipetting steps and manual manipulations, the labor and instrument time, and the total time required to perform the assay. The survey participants included a staff of 4 technologists who perform complex molecular assays regularly. Time required for each procedure was determined by direct observation and from work logs completed by the technologists. RESULTS: The total number of pipetting motions varied from 78 to 344. Labor time ranged from 2.6 to 8.4 h, and total assay time from 7.6 to 13.7 h. CONCLUSION: Time-motion analysis allowed identification of a method that minimized pipetting motions and thus reduced the risk of repetitive stress injury.

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43 These included 58 patient DNA samples initially characterized by CF Gold 1.0, of which 28 were wild type and 30 contained 1 of the following 16 mutant alleles: F508del, R553X, 2184delA, 3120 ϩ 1GϾA, I507del, G542X, G551D, W1282X, N1303K, 621 ϩ 1GϾT, R117H, 1717-1GϾA, R560T, R334W, R347P, and I148T. Login to comment

[hide] Cystic fibrosis lung disease: genetic influences, ... Pediatr Radiol. 2005 Aug;35(8):739-57. Epub 2005 May 3. Moskowitz SM, Gibson RL, Effmann EL
Cystic fibrosis lung disease: genetic influences, microbial interactions, and radiological assessment.
Pediatr Radiol. 2005 Aug;35(8):739-57. Epub 2005 May 3., [PMID:15868140]

Abstract [show]
Cystic fibrosis (CF) is a multiorgan disease caused by mutation of the CF transmembrane conductance regulator (CFTR) gene. Obstructive lung disease is the predominant cause of morbidity and mortality; thus, most efforts to improve outcomes are directed toward slowing or halting lung-disease progression. Current therapies, such as mucolytics, airway clearance techniques, bronchodilators, and antibiotics, aim to suppress airway inflammation and the processes that stimulate it, namely, retention and infection of mucus plaques at the airway surface. New approaches to therapy that aim to ameliorate specific CFTR mutations or mutational classes by restoring normal expression or function are being investigated. Because of its sensitivity in detecting changes associated with early airway obstruction and regional lung disease, high-resolution CT (HRCT) complements pulmonary function testing in defining disease natural history and measuring response to both conventional and experimental therapies. In this review, perspectives on the genetics and microbiology of CF provide a context for understanding the increasing importance of HRCT and other imaging techniques in assessing CF therapies.

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51 Class 4 alleles (fifth panel) reach the surface and can be activated but with decreased channel conductance and possibly also abnormal regulation of other membrane channels; they are exemplified by replacement of arginine by proline at codon 347 (R347P allele). Login to comment

[hide] Screening of mutations in the CFTR gene in 1195 co... Eur J Hum Genet. 2005 Aug;13(8):959-64. Stuppia L, Antonucci I, Binni F, Brandi A, Grifone N, Colosimo A, De Santo M, Gatta V, Gelli G, Guida V, Majore S, Calabrese G, Palka C, Ravani A, Rinaldi R, Tiboni GM, Ballone E, Venturoli A, Ferlini A, Torrente I, Grammatico P, Calzolari E, Dallapiccola B
Screening of mutations in the CFTR gene in 1195 couples entering assisted reproduction technique programs.
Eur J Hum Genet. 2005 Aug;13(8):959-64., [PMID:15870824]

Abstract [show]
Genetic testing of the cystic fibrosis transmembrane conductance (CFTR) gene is currently performed in couples undergoing assisted reproduction techniques (ART), because of the high prevalence of healthy carriers in the population and the pathogenic relationship with congenital bilateral absence of vas deferens (CBAVD). However, discordant data have been reported concerning the usefulness of this genetic test in couples with no family history of cystic fibrosis (CF). In this study, we report the results of CFTR molecular screening in 1195 couples entering ART. Genetic testing was initially carried out in a single partner of each couple. CFTR mutations were detected in 55 subjects (4.6%), a percentage that overlaps with the one reported in the general population. However, significantly higher frequencies of were found in CBAVD individuals (37.5%) and in males with nonobstructive azoospermia (6.6%). The 5T allele was found in 78 patients (6.5%). This figure was again significantly different in males with nonobstructive-azoospermia (9.9%) and in those with CBAVD (100%). All together, 139 subjects (11.6%) had either a CFTR mutation or the 5T allele. Subsequent molecular analysis of their partners disclosed a CFTR mutation or 5T allele in nine cases (6.5%). However, none of these couples had CFTR alterations in both members, a CFTR mutation being invariably present in one partner and the 5T allele in the other. In order to improve genetic counselling of these couples, the TG-M470V-5T association was analyzed, and a statistically significant relationship between 12TG-V470 and CBAVD was detected.

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64 of detected carriers Prevalence among detected CFTR mutations DF508 40 (3.34%) 65.58% DI507 0 0 G542X 6 (0.50%) 9.84% 1717-1G-A 1 (0.08%) 1.64% G551D 0 0 R553X 0 0 R560T 0 0 Q552X 0 0 W1282X 7 (0.58 %) 11.48% S1251N 0 0 N1303K 3 (0.20%) 4.91% 394delTT 0 0 G85E 3 (0.25%) 4.91% E60X 0 0 621+1G-T 0 0 R117H 0 0 1078delT 0 0 R347P 0 0 R334W 0 0 2143delT 0 0 2183AA-G 0 0 2184delA 0 0 711+5G-A 0 0 2789+5G-A 1 (0.08%) 1.64% R1162X 0 0 3659del5 0 0 3849+10kbC-T 0 0 A455E 0 0 5T 78 (6.52%) Table 2 Distribution of CFTR mutations and 5T allele according to phenotype for the 1195 individuals Phenotype CF/WT 5T/WT CF/5T WT/WT Infertile males (non-CBAVD), N ¼ 304 20 (6.58%) 30 (9.87%) 0 254 (83.55%) Infertile males (CBAVD), N ¼ 16 0 10 (62.50%) 6 (37.50 %) 0 Infertile females, N ¼ 93 5 (5.37%) 7 (7.53%) 0 81 (87.10%) Unexplained infertility, N ¼ 782 30 (3.84%) 31 (3.96%) 0 721 (92.20%) Total ¼ 1195 55 (4.60%) 78 (5.50%) 6 (0.50%) 1056 (88.40%) CFTR alteration was detected, including a mutation in three cases and the 5T polymorphism in the remaining six. Login to comment

[hide] Pharmacological induction of CFTR function in pati... Pediatr Pulmonol. 2005 Sep;40(3):183-96. Kerem E
Pharmacological induction of CFTR function in patients with cystic fibrosis: mutation-specific therapy.
Pediatr Pulmonol. 2005 Sep;40(3):183-96., [PMID:15880796]

Abstract [show]
CFTR mutations cause defects of CFTR protein production and function by different molecular mechanisms. Mutations can be classified according to the mechanisms by which they disrupt CFTR function. This understanding of the different molecular mechanisms of CFTR dysfunction provides the scientific basis for the development of targeted drugs for mutation-specific therapy of cystic fibrosis (CF). Class I mutations are nonsense mutations that result in the presence of a premature stop codon that leads to the production of unstable mRNA, or the release from the ribosome of a short, truncated protein that is not functional. Aminoglycoside antibiotics can suppress premature termination codons by disrupting translational fidelity and allowing the incorporation of an amino acid, thus permitting translation to continue to the normal termination of the transcript. Class II mutations cause impairment of CFTR processing and folding in the Golgi. As a result, the mutant CFTR is retained in the endoplasmic reticulum (ER) and eventually targeted for degradation by the quality control mechanisms. Chemical and molecular chaperones such as sodium-4-phenylbutyrate can stabilize protein structure, and allow it to escape from degradation in the ER and be transported to the cell membrane. Class III mutations disrupt the function of the regulatory domain. CFTR is resistant to phosphorylation or adenosine tri-phosphate (ATP) binding. CFTR activators such as alkylxanthines (CPX) and the flavonoid genistein can overcome affected ATP binding through direct binding to a nucleotide binding fold. In patients carrying class IV mutations, phosphorylation of CFTR results in reduced chloride transport. Increases in the overall cell surface content of these mutants might overcome the relative reduction in conductance. Alternatively, restoring native chloride pore characteristics pharmacologically might be effective. Activators of CFTR at the plasma membrane may function by promoting CFTR phosphorylation, by blocking CFTR dephosphorylation, by interacting directly with CFTR, and/or by modulation of CFTR protein-protein interactions. Class V mutations affect the splicing machinery and generate both aberrantly and correctly spliced transcripts, the levels of which vary among different patients and among different organs of the same patient. Splicing factors that promote exon inclusion or factors that promote exon skipping can promote increases of correctly spliced transcripts, depending on the molecular defect. Inconsistent results were reported regarding the required level of corrected or mutated CFTR that had to be reached in order to achieve normal function.

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58 C-D565G II DF508 D1507 S549R S549I S549N S549R S945D S945L H1054D G1061R L1065P R1066C R1066M L1077P H1085R N1303K G85E III G551D S492F V520F R553G R560T R560S Y569D IV R117H, R117C, R117P, R117L D1152H, L88S, G91R, E92K, Q98R, P205S, L206W, L227R, F311L, G314E, R334W, R334Q, I336K, T338I, L346P, R347C, R347H, R347L, R347P, L927P, R1070W, R1070Q V 3849 þ 10 kb C ! Login to comment
198 R117H, R334W, and R347P are class IV mutants with reduced single-channel conductance.65 Increases in the overall cell surface content of these mutants might overcome the relative reduction in conductance. Alternatively, restoring native chloride pore characteristics pharmacologically might be effective. Login to comment

[hide] Multiple mutation analysis of the cystic fibrosis ... Mol Hum Reprod. 2005 Jun;11(6):463-8. Epub 2005 May 20. Sanchez-Garcia JF, Benet J, Gutierrez-Mateo C, Luis Seculi J, Monros E, Navarro J
Multiple mutation analysis of the cystic fibrosis gene in single cells.
Mol Hum Reprod. 2005 Jun;11(6):463-8. Epub 2005 May 20., [PMID:15908456]

Abstract [show]
PGD is becoming an alternative to prenatal diagnosis. The combination of IVF techniques with the PCR technology allows for the detection of genetic abnormalities in first polar bodies from oocytes and blastomeres from cleavage-stage embryos. Dealing with a genetic disease with a heterogeneous spectrum of mutations like cystic fibrosis, one of the objectives of centres offering PGD is the application of simple and efficient protocols that allow for the detection of a wide range of mutations with a single procedure. In the present work, 29 normal loci and the 31 most frequent cystic fibrosis transmembrane conductance regulator (CFTR) mutations in Southern Europe could be detected at the same time in single cells applying a modified and improved primer extension preamplification-PCR. Two different Taq polymerases were tested in isolated buccal cells heterozygous for several mutations. The protocol that gave statistically significant better results was also successful in oocytes and their first polar bodies.

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38 Cell samples Isolated buccal cells were collected by mouthwashes from three normal individuals, three patients affected by mutations DF508, DF508/1078delT and DF508/3849þ10kbC.T and five heterozygous carriers for CFTR mutations DF508, N1303K, G542X, R347P and 2183AA.G. Login to comment
62 G, R1162X, 3659delC, W1282X, 3905insT, N1303K, 1078delT, R347P, R347H and R334W labelled with TET (green) and A455E, 1898þ1G.A, 2183AA.G, 2789þ5G.A, G85E, 621þ1G.T, R117H, Y122X and 711þ1G.T labelled with HEX (yellow). Login to comment
89 Heterozygous cells for the R347P mutation successfully amplified both alleles with the proofreading Taq. Login to comment
109 Locus R347P reached a 100% amplification rate, while most of the heterozygous loci displayed efficiencies barely over 90%, suggesting that as PCR primers have to be shared between the two alleles, heterozygous samples seem to have less amplification than homozygotes. Login to comment
121 250 S549 20 25 60 15 75 30 13.3 46.7 40 86.7 R553 20 15 65 20 85 30 6.7 46.7 46.7 93.3 G551 20 15 70 15 85 30 10 46.7 43.3 90 V520 20 5 40 55 95 30 0 13.3 86.7 100 I507 20 5 45 50 95 30 0 26.7 73.3 100 F508 20 10 80 10 90 30 10 50 40 90 dF508 (*) 12 25 66.7 8.3 75 19 10.5 52.6 36.8 89.5 Q493 20 10 75 15 90 30 10 56.7 33.3 90 1717-G1 20 25 60 15 75 30 6.7 46.7 46.7 93.3 G542 20 20 65 15 80 30 10 50 40 90 G542X (*) 2 50 50 0 50 7 14.3 85.7 0 85.7 R560 20 20 50 30 80 30 6.7 43.3 50 93.3 R347 20 5 70 25 95 30 0 16.7 83.3 100 R347P (*) - - - - - 3 0 33.3 66.7 100 3849 þ 4A 20 15 55 30 85 30 3.3 50 46.7 96.7 W1282 20 20 40 40 80 30 13.3 30 56.7 86.7 R334 20 10 75 15 90 30 0 13.3 86.7 100 1078 20 25 60 15 75 30 0 13.3 86.7 100 1078 del T (*) 2 0 100 0 100 - - - - - 3849 þ 10kbC 20 20 65 15 80 30 3.3 56.7 40 96.7 3849 þ 10kbC . Login to comment

[hide] Complete cystic fibrosis transmembrane conductance... Gut. 2005 Oct;54(10):1456-60. Epub 2005 Jun 29. Weiss FU, Simon P, Bogdanova N, Mayerle J, Dworniczak B, Horst J, Lerch MM
Complete cystic fibrosis transmembrane conductance regulator gene sequencing in patients with idiopathic chronic pancreatitis and controls.
Gut. 2005 Oct;54(10):1456-60. Epub 2005 Jun 29., [PMID:15987793]

Abstract [show]
BACKGROUND: Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene-many of which cause cystic fibrosis-have also been reported in patients with chronic pancreatitis. The authors examine whether mild or severe CFTR mutations, homozygous or compound heterozygous CFTR mutations, or even simple cystic fibrosis carrier status alone increases the risk of developing pancreatitis. METHODS: After exclusion of patients with trypsinogen (PRSS1) mutations, cystic fibrosis, or pulmonary disease, and with known risk factors for pancreatitis 67 patients with idiopathic chronic pancreatitis (ICP) from northwest Germany and 60 geographically and ethnically matched controls were recruited. The entire coding region of the CFTR gene was sequenced in all patients and controls. ICP patients were also analysed for serine protease inhibitor Kazal type 1 (SPINK1) gene mutations. RESULTS: Abnormal CFTR alleles were found to be twice as frequent in ICP patients as in controls (25/134 v 11/120; p<0.05). Three of four severe CFTR mutations detected in patients were compound heterozygous with another abnormal CFTR allele, whereas among controls three severe CFTR mutations were found in heterozygous cystic fibrosis carriers. In ICP patients 19 uncommon/mild mutations, including combinations of the 5T allele with 12TG repeats, were identified compared with only five in controls (p = 0.012). Heterozygous SPINK1 mutations were detected in eight ICP patients (15% v 1% in controls) but only one also carried an additional mild CFTR mutation. CONCLUSIONS: These data show that not only compound heterozygosity, but also cystic fibrosis carrier status for different types of CFTR mutations, including uncommon/mild mutations, significantly increase the risk of developing pancreatitis. Although 45% of the study's ICP patients carried predisposing genetic risk factors (for example, mutations in CFTR or SPINK1), the authors found no evidence that the risk conveyed by CFTR mutations depends on co-inherited SPINK1 mutations.

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237 In the group of ICP patients being heterozygous for a single CFTR mutation one severe (2184insA, this insertion causes a frame shift) and eight mild/uncommon mutations (26 S1235R, R31C, R75Q, R347P, G576A, M348V, and V754M) were identified. Login to comment
256 The reason why numbers for compound heterozygous ICP patients in these studies are diverse (4/67 = 6% in our study) may be due to differences Table 1 CFTR and SPINK1 sequence variations identified in 30 of the 67 ICP patients PatientSex CFTR mutation T allele TG repeats PSTI mutation 1 M DF508/R117H 7/7 9/10 -/- 2 W DF508/A1087P 7/9 10/11 -/- 3 M DF508/D1152H 7/9 10/10 -/- 4 M S1235R/R668C 7/7 11/12 -/- 5 M 2184insA/- 7/7 10/12 -/- 6 M R31C/- 7/7 10/11 -/- 7 M R75Q/- 7/7 11/11 -/- 8 M R347P/- 7/7 11/12 -/- 9 M S1235R/- 7/7 11/12 -/- 10 W S1235R/- 7/7 11/12 -/- 11 M G576A/- 7/7 10/10 -/- 12 W M348V/- 7/9 10/10 -/- 13 M V754M/- 7/7 10/11 -/- 14 M -/- 5/7 11/12 -/- 15 W -/- 5/7 11/12 -/- 16 M -/- 5/7 11/12 -/- 17 W -/- 5/9 11/12 -/- 18 M -/- 5/7 11/12 -/- 19 M -/- 5/7 10/10 -/- 20 W -/- 5/7 10/10 -/- 21 W -/- 5/7 11/12 N34S/- 22 W -/- 7/7 10/11 N34S/- 23 M -/- 7/9 10/11 N34S/- 24 M -/- 7/7 11/11 N34S/- 25 M -/- 7/7 11/11 N34S/- 26 W -/- 7/7 11/11 N34S/- 27 M -/- 7/7 11/11 N34S/- 28 W -/- 7/7 10/11 N34S/- 29 W -/- 7/7 11/11 P55S/- 30 W -/- 7/7 11/11 IVS3+2TC/- Table 2 CFTR sequence variations identified in 11 of 60 healthy controls Control group Number DF508/- 3 R117H/- 2 I148T/- 1 L997F/- 1 5T/12TG 1 5T/11TG 3 in patient recruitment, the catchment populations, or the stringency with which cystic fibrosis patients were excluded. Login to comment

[hide] Genetics of cystic fibrosis. Semin Respir Crit Care Med. 2003 Dec;24(6):629-38. Gallati S
Genetics of cystic fibrosis.
Semin Respir Crit Care Med. 2003 Dec;24(6):629-38., [PMID:16088579]

Abstract [show]
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, which encodes a protein expressed in the apical membrane of exocrine epithelial cells. CFTR functions principally as a cyclic adenosine monophosphate (cAMP)-induced chloride channel and appears capable of regulating other ion channels. Mutations affect CFTR through a variety of molecular mechanisms, which can produce little or no functional gene product at the apical membrane. More than 1000 different disease-causing mutations within the CFTR gene have been described. The potential of a mutation to contribute to the phenotype depends on its type, localization in the gene, and the molecular mechanism as well as on interactions with secondary modifying factors. Genetic testing can confirm a clinical diagnosis of CF and can be used for infants with meconium ileus, for carrier detection in individuals with positive family history and partners of proven CF carriers, and for prenatal diagnostic testing if both parents are carriers. Studies of clinical phenotype in correlation with CFTR genotype have revealed a very complex relationship demonstrating that some phenotypic features are closely determined by the underlying mutations, whereas others are modulated by modifier genes, epigenetic mechanisms, and environment.

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43 Mutations (missense, nonsense, frameshift, splice, small and large in-frame deletions or insertions) con- Table 1 Distribution of theWorldwide 24 Most Common Cystic Fibrosis Mutationsa Exon/ Northern Southern North South Austral- Relative Mutation Intron Europe Europe America America asia Africa Asia Frequency G85E E 03 30 14 16 n.a. n.a. 0 7 0.15 R117H E 04 62 3 61 n.a. 7 0 0 0.30 621+1G→T I 04 97 37 154 n.a. 27 0 0 0.72 711+1G→T I 05 15 13 21 n.a. n.a. n.a. 0 0.11 1078delT E 07 53 2 1 n.a. 1 n.a. 0 0.13 R334W E 07 18 21 12 n.a. 2 0 0 0.12 R347P E 07 55 24 26 n.a. 1 0 0 0.24 A455E E 09 35 0 27 n.a. n.a. n.a. 0 0.14 ⌬I507 E 10 57 5 20 2 9 0 0 0.21 ⌬F508 E 10 14,866 4007 6901 342 2309 351 173 66.02 1717-1G→A I 10 160 65 44 n.a. 12 0 3 0.65 G542X E 11 439 259 234 38 56 9 27 2.42 S549N E 11 18 2 5 1 3 1 0 0.07 G551D E 11 356 37 206 1 117 0 0 1.64 R553X E 11 165 44 96 5 11 1 0 0.73 R560T E 11 40 0 24 0 3 0 0 0.15 1898+1G→A I 12 41 10 2 n.a. n.a. n.a. 0 0.12 2184delA E 13 14 7 8 n.a. n.a. n.a. 0 0.07 2789+5G→A I 14b 27 10 17 n.a. n.a. n.a. 0 0.12 R1162X E 19 36 68 19 0 2 0 0 0.28 3659delC E 19 39 1 14 n.a. n.a. n.a. 0 0.12 3849+10kbC→T I 19 23 8 57 n.a. n.a. n.a. 16 0.24 W1282X E 20 120 43 245 n.a. 6 2 120 1.22 N1303K E 21 209 179 130 11 23 8 29 1.34 Chromosomes 21,154 7281 10438 758 3095 515 608 screened Detection rate 80.2 66.7 79.9 52.8 83.7 72.2 61.7 aAccording to the Cystic Fibrosis Genetic Analysis Consortium, http://www.genet.sickkids.on.ca/cftr/. Login to comment
58 The missense mutations R117H, R334W, and R347P were shown to form a chloride channel with a normal phosphorylation and ATP-dependent regulation, but with reduced single-channel currents.20 Alleles in this class are typically associated with a milder clinical phenotype. Login to comment

[hide] Intracellular chloride channels: critical mediator... Curr Pharm Des. 2005;11(21):2753-64. Suh KS, Yuspa SH
Intracellular chloride channels: critical mediators of cell viability and potential targets for cancer therapy.
Curr Pharm Des. 2005;11(21):2753-64., [PMID:16101453]

Abstract [show]
The passage of ions to form and maintain electrochemical gradients is a key element for regulating cellular activities and is dependent on specific channel proteins or complexes. Certain ion channels have been the targets of pharmaceuticals that have had impact on a variety of cardiovascular and neurological diseases. Chloride channels regulate the movement of a major cellular anion, and in so doing they in part determine cell membrane potential, modify transepithelial transport, and maintain intracellular pH and cell volume. There are multiple families of chloride channel proteins, and respiratory, neuromuscular, and renal dysfunction may result from mutations in specific family members. Interest in chloride channels related to cancer first arose when the multidrug resistance protein (MDR/P-glycoprotein) was linked to volume-activated chloride channel activity in cancer cells from patients undergoing chemotherapy. More recently, CLC, CLIC, and CLCA intracellular chloride channels have been recognized for their contributions in modifying cell cycle, apoptosis, cell adhesion, and cell motility. Moreover, advances in structural biology and high-throughput screening provide a platform to identify chemical compounds that modulate the activities of intracellular chloride channels thereby influencing chloride ion transport and altering cell behavior. This review will focus on several chloride channel families that may contribute to the cancer phenotype and suggest how they may serve as novel targets for primary cancer therapy.

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86 A variety of other mutations have been detected in CF patients [39] leading to ablation of protein synthesis (nonsense G542X, frameshift 394delTT, or splice junction 1717 G/A), blocked protein processing (missense N1303K or AA deletion in F508), blocked protein regulation (missense at G551D), altered conductance (missense R117H or R347P), and reduced protein synthesis (missense A455E, alternative splicing 3849 + 10kbC/T) [40]. Login to comment

[hide] Modifier genetics: cystic fibrosis. Annu Rev Genomics Hum Genet. 2005;6:237-60. Cutting GR
Modifier genetics: cystic fibrosis.
Annu Rev Genomics Hum Genet. 2005;6:237-60., [PMID:16124861]

Abstract [show]
Cystic fibrosis (CF) is the most common lethal autosomal recessive disorder in the Caucasian population, affecting about 30,000 individuals in the United States. The gene responsible for CF, the CF transmembrane conductance regulator (CFTR), was identified 15 years ago. Substantial variation in the many aspects of the CF phenotype among individuals with the same CFTR genotype demonstrates that factors independent of CFTR exert considerable influence on outcome in CF. To date, the majority of published studies investigating the cause of disease variability in CF report associations between candidate genes and some aspect of the CF phenotype. However, a definitive modifier gene for CF remains to be identified. Despite the challenges posed by searches for modifier effects, studies of affected twins and siblings indicate that genetic factors play a substantial role in intestinal manifestations. Identifying the factors contributing to variation in pulmonary disease, the primary cause of mortality, remains a challenge for CF research.

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614 Pancreatic insufficiency and pulmonary disease in German and Slavic cystic fibrosis patients with the R347P mutation. Hum. Mutat. 6:219-25 123. Login to comment

[hide] Gender-sensitive association of CFTR gene mutation... Mol Hum Reprod. 2005 Aug;11(8):607-14. Epub 2005 Aug 26. Morea A, Cameran M, Rebuffi AG, Marzenta D, Marangon O, Picci L, Zacchello F, Scarpa M
Gender-sensitive association of CFTR gene mutations and 5T allele emerging from a large survey on infertility.
Mol Hum Reprod. 2005 Aug;11(8):607-14. Epub 2005 Aug 26., [PMID:16126774]

Abstract [show]
Human infertility in relation to mutations affecting the cystic fibrosis transmembrane regulator (CFTR) gene has been investigated by different authors. The role of additional variants, such as the possible forms of the thymidine allele (5T, 7T and 9T) of the acceptor splice site of intron 8, has in some instances been considered. However, a large-scale analysis of the CFTR gene and number of thymidine residues, alone and in combination, in the two sexes had not yet been addressed. This was the aim of this study. Two groups were compared, a control group of 20,532 subjects being screened for perspective reproduction, and the patient group represented by 1854 idiopathically infertile cases. Analyses involved PCR-based CFTR mutations assessment, reverse dot-blot IVS8-T polymorphism analyses, denaturing gradient gel electrophoresis (DGGE) and DNA sequencing. The expected 5T increase in infertile men was predominantly owing to the 5/9 genotypic class. The intrinsic rate of 5T fluctuated only slightly among groups, but some gender-related differences arose when comparing their association. Infertile men showed a significantly enriched 5T + CFTR mutation co-presence, distributed in the 5/9 and 5/7 classes. In contrast, females, from both the control and the infertile groups, showed a trend towards a pronounced reduction of such association. The statistical significance of the difference between expected and observed double occurrence of 5T + CFTR traits in women suggests, in line with other reports in the literature, a possible survival-hampering effect. Moreover, regardless of the 5T status, CFTR mutations appear not to be involved in female infertility. These results underline the importance of (i) assessing large sample populations and (ii) considering separately the two genders, whose genotypically opposite correlations with these phenomena may otherwise tend to mask each other.

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47 CFTR gene alterations were first scored by PCR and reverse dot blot (Chehab and Wall, 1992), targeted to the detection of the following mutations: ∆F508, G85E, 541∆C, D110H, R117H, 621+1G→T, 711+5G→A, R334W, R334Q, T338I, 1078∆T, R347H, R352Q, ∆I507, 1609∆CA, E527G, 1717-1G→A, 1717-8G→A, G542X, R347P, S549N, S549R A→C, Q552X, R553X, A559T, D579G, Y577F, E585X, 1898+3A→G, 2183AA→G, R709X, 2789+5G→A, 3132∆TG, 3272-26A→G, L1077P, L1065P, R1070Q, R1066H, M1101K, D1152H, R1158X, R1162X, 3849+10KbC→T, G1244E, W1282R, W1282X, N1303K and 4016∇T. Login to comment

[hide] A comparison of high-resolution melting analysis w... Am J Clin Pathol. 2005 Sep;124(3):330-8. Chou LS, Lyon E, Wittwer CT
A comparison of high-resolution melting analysis with denaturing high-performance liquid chromatography for mutation scanning: cystic fibrosis transmembrane conductance regulator gene as a model.
Am J Clin Pathol. 2005 Sep;124(3):330-8., [PMID:16191501]

Abstract [show]
High-resolution melting analysis (HRMA) was compared with denaturing high-performance liquid chromatography (dHPLC) for mutation scanning of common mutations in the cystic fibrosis transmembrane conductance regulator gene. We amplified (polymerase chain reaction under conditions optimized for melting analysis or dHPLC) 26 previously genotyped samples with mutations in exons 3, 4, 7, 9, 10, 11, 13, 17b, and 21, including 20 different genotypes. Heterozygous mutations were detected by a change in shape of the melting curve or dHPLC tracing. All 20 samples with heterozygous mutations studied by both techniques were identified correctly by melting (100% sensitivity), and 19 were identified by dHPLC (95% sensitivity). The specificity of both methods also was good, although the dHPLC traces of exon 7 consistently revealed 2 peaks for wild-type samples, risking false-positive interpretation. Homozygous mutations could not be detected using curve shape by either method. However, when the absolute temperatures of HRMA were considered, G542X but not F508del homozygotes could be distinguished from wild type. HRMA easily detected heterozygotes in all single nucleotide polymorphism (SNP) classes (including A/T SNPs) and 1- or 2-base-pair deletions. HRMA had better sensitivity and specificity than dHPLC with the added advantage that some homozygous sequence alterations could be identified. HRMA has great potential for rapid, closed-tube mutation scanning.

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18 Materials and Methods Sample Source and Study Design Eleven commercially genotyped samples were obtained from Coriell Cell Repositories, Coriell Institute for Medical Research, Camden, NJ (Y122X, R334W, R347P, A455E, I507del, F508del, F508C, G542X/G542X, R553X, R560T, and M1101K). Login to comment
31 ❚Table 1❚ Mutations Analyzed in the Study Position From 5' Exon (or Intron) Genotype* No. of Samples Nucleotide Change SNP Class† End/Amplicon Size (bp) 3 394delTT 1 Del‡ - 132/234 4 R117H 1 G→A 1 83/270 Y122X 1 T→A 4 99/270 I148T 2 T→C 1 176/270 Intron 4 621+1 2 G→T 2 233/270 7 R334W 1 C→T 1 208/345 R347P 1 G→C 3 248/345 9 A455E 2 C→A 2 155/263 10 I507del 1 Del‡ - 171/292 F508del 3 Del‡ - 174/292 F508del/F508del 1 Del - 174/292 F508C 1 T→G 2 175/292 11 G542X 1 G→T 2 90/175 G542X/G542X 1 G→T 2 90/175 G551D 1 G→A 1 118/175 R553X 2 C→T 1 123/175 R560T 1 G→C 3 145/175 13 2184delA 1 Del‡ - 356/458 17b M1101K 1 T→A 4 196/292 21 N1303K 1 C→G 3 175/250 bp, base pairs; SNP, single nucleotide polymorphism. Login to comment
59 Exon 7 was amplified as a longer PCR amplicon (345 bp) and included 2 single base heterozygotes, R334W and R347P. Login to comment
65 In contrast, different melting shapes were observed for R334W and R347P in the higher melting domain (Figure 2C), as expected from the location of the mutations. Login to comment
68 Under these conditions, R334W and R347P had elution peaks that were different from that for the wild-type and were identified correctly as heterozygotes ❚Figure 2D❚. Login to comment
81 Nearest-neighbor calculations predict that the ∆Tm between wild type and G542X homozygotes is Time (min) Absorbance(mV) 0 1 2 3 4 5 20 - 19 - 18 - 17 - 16 - 15 - 14 - 13 - 12 - 11 - 10 - 9 - 8 - 7 - 6 - 5 - 4 - 3 - 2 - 1 - 0 - R347P het R334W het WT Temperature (°C) Fluorescence 82 83 84 85 86 87 100 - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20 - 10 - 0 - R334W het C::A T::G R347P het C::C G::G WT G::C Temperature (°C) Fluorescence 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 100 - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20 - 10 - 0 - WT 0 50 100 150 200 250 300 350 100 90 80 70 60 50 40 30 20 10 Temperature(°C) Base Pairs Temperature (°C) Fluorescence 75 76 77 78 79 80 100 - 90 - 80 - 70 - 60 - 50 - 40 - 30 - 20 - 10 - 0 - A B C D ❚Figure 2❚ High-resolution melting and denaturing high-performance liquid chromatography (dHPLC) analysis of exon 7 of the cystic fibrosis transmembrane conductance regulator gene. Login to comment
84 B, Low melting domain (75°C-80°C) comparison of heterozygous (het) R334W, R347P, and the WT control sample. C, High melting domain (82°C-87°C) comparison of heterozygous R334W, R347P, and the WT control sample. D,The dHPLC profile of the homozygous WT, heterozygous R334W, and heterozygous R347P genotypes. Login to comment

[hide] Newborn screening for cystic fibrosis in Wisconsin... J Pediatr. 2005 Sep;147(3 Suppl):S73-7. Rock MJ, Hoffman G, Laessig RH, Kopish GJ, Litsheim TJ, Farrell PM
Newborn screening for cystic fibrosis in Wisconsin: nine-year experience with routine trypsinogen/DNA testing.
J Pediatr. 2005 Sep;147(3 Suppl):S73-7., [PMID:16202788]

Abstract [show]
OBJECTIVE: To describe the development and follow-up confirmatory results of the routine cystic fibrosis (CF) newborn screening (NBS) program in Wisconsin. METHODS: CF NBS has been performed on a routine clinical basis in Wisconsin since July 1994. The 2-tiered immunoreactive trypsinogen (IRT)/DNA technique was used on dried blood on filter paper spots. From July 1994 to February 2002, mutation analysis was for the DeltaF508 allele. Beginning in March 2002, multimutation analysis of 25 CF mutations was performed. Infants with a positive result on NBS were seen in certified CF centers for sweat testing by means of quantitative pilocarpine iontophoresis, and families received genetic counseling. RESULTS: From July 1994 to February 2002, there were 120 cases of CF detected by means of NBS (509,794 infants screened), with 53 DeltaF508 homozygotes and 67 compound heterozygotes. There were 8 clinically diagnosed cases of CF (no DeltaF508 allele). The CF incidence was 1:3983 (95%CI, 1:3373-1:4774). From March 2002 to June 2003, multimutation analysis identified 21 cases of classic CF (90,142 infants screened). Sweat tests were successfully performed in infants younger than 1 month. CONCLUSIONS: Early diagnosis of CF through NBS was successfully performed, with an estimated sensitivity rate of 99% using the IRT/25 CFTR multimutation assay.

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30 Mutations included in this assay are 2184delA, A455E, DI507, DF508, G542X, G551D, R553X, R560T, 1717-1G>A, R1162X, 3659delC, N1303K, W1282X, R334W, R347P, 1078delT, R117H, I148T, 62111G>T, 278915G>A, 3849110kbC>T, G85E, 109811G>A, 71111G>T and 312011G>A. Login to comment
56 §Eight cases of DF508/DF508, 1 case of DF508/312011G>A, 1 case of DF508/3849110kbC>T, 1 case of DF508/W1282X, 1 case of DF508/ R347P, 1 case of DF508/278915G>A, 1 case of DF508/I148T. Login to comment
59 sufficient, genotype: R347P/unknown; and 4) CF diagnosed at 3 months, pancreatic insufficient, genotype: R553X/unknown. Login to comment

[hide] Two-tiered immunoreactive trypsinogen-based newbor... J Pediatr. 2005 Sep;147(3 Suppl):S83-8. Sontag MK, Hammond KB, Zielenski J, Wagener JS, Accurso FJ
Two-tiered immunoreactive trypsinogen-based newborn screening for cystic fibrosis in Colorado: screening efficacy and diagnostic outcomes.
J Pediatr. 2005 Sep;147(3 Suppl):S83-8., [PMID:16202790]

Abstract [show]
OBJECTIVE: To examine immunoreactive trypsinogen (IRT)-based screening for cystic fibrosis (CF) for recall rate, genotype distribution, and "borderline" sweat test results. STUDY DESIGN: CF newborn screening in Colorado began in 1982, and >1,153,000 infants were screened through 2002 with an IRT-based screen (IRT/IRT). RESULTS: We have identified 313 infants with CF, giving an overall incidence of 1 in 3684 and a Hispanic incidence of 1 in 6495. Fifty-five infants with meconium ileus (17.6%) were excluded from analysis. Fourteen infants with false-negative results were identified (5.4%). The average recall rate was 0.6%, with a positive predictive value of 4.7%. Ninety-three percent of the infants had at least 1 DeltaF508 mutation, and 98% of the infants had at least 1 mutation from the American College of Medical Genetics recommended panel. Six infants had hypertrypsinogenemia and borderline results on sweat tests (30-60 mmol/L). Increased variability in sweat chloride levels were seen in these infants compared with infants with homozygous DeltaF508. Three children with initial borderline results on sweat tests had CF diagnosed. CONCLUSIONS: The recall and false-negative rates of our IRT/IRT CF screening program are reported. Additionally, genotypes of the patients identified mirror the CF population genotypes, reflecting similar disease severity in the screened population. Finally, infants with persistent hypertrypsinogenemia and borderline sweat test results need long-term follow-up.

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86 The pancreatic sufficient mutations identified were 18981 5G>T, 278915G>A, A455E, G551S, G85E, I336K, P67L, R117C, R117H, R334W, R347P. Login to comment

[hide] Markedly elevated neonatal immunoreactive trypsino... Arch Dis Child. 2006 Mar;91(3):222-5. Epub 2005 Oct 21. Massie J, Curnow L, Tzanakos N, Francis I, Robertson CF
Markedly elevated neonatal immunoreactive trypsinogen levels in the absence of cystic fibrosis gene mutations is not an indication for further testing.
Arch Dis Child. 2006 Mar;91(3):222-5. Epub 2005 Oct 21., [PMID:16243854]

Abstract [show]
AIMS: To investigate the immunoreactive trypsinogen (IRT) values above the usual 99th centile laboratory cut-off and determine the value of offering further testing to those infants with a markedly elevated IRT but no cystic fibrosis transmembrane regulator (CFTR) gene mutation identified by the screening programme. METHODS: All babies born in Victoria, Australia, between 1991 and 2003, were screened by IRT followed by CF gene mutation analysis. RESULTS: Of the 806,520 babies born, 9268 with the highest IRT levels had CFTR mutation analysis. There were 123 DeltaF508 homozygotes and 703 heterozygotes (86 with CF, 617 carriers). A total of 8442 babies had no CFTR gene mutation, of whom 18 (0.21%) had CF. The total number of CF babies with IRT greater than the laboratory cut-off was 227 (2.4%). The IRT results of the CF patients were distributed normally, with the majority above the laboratory cut-off of newborn IRT results. There was no evidence of an excess of babies with CF in the very highest levels of IRT above the 99th centile. CONCLUSIONS: Only a small proportion of babies with a neonatal IRT >99th centile have CF. Additional CF testing for infants with an elevated IRT but no CFTR gene mutation has an extremely low yield, no matter how high the IRT result.

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222 *All patients underwent an extended CFTR mutation analysis for the following mutations in addition to DF508: G551D, R553X, G542X, R117H, N1303K, 621+1G-T, A455E, V520F, 1717-1G-A, W1282X, R1162X, 3849+10kbC-T, R347P, R334W, R560T, S549N. Login to comment

[hide] Mutations of the CFTR gene in idiopathic pancreati... Pancreas. 2005 Nov;31(4):350-2. Gullo L, Mantovani V, Manca M, Migliori M, Bastagli L, Pezzilli R
Mutations of the CFTR gene in idiopathic pancreatic hyperenzymemia.
Pancreas. 2005 Nov;31(4):350-2., [PMID:16258369]

Abstract [show]
OBJECTIVES: Idiopathic pancreatic hyperenzymemia is a new syndrome that is characterized by a chronic increase of serum pancreatic enzymes in the absence of pancreatic disease. The aim of this study was to assess whether mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene may have a role in the etiology of this hyperenzymemia. METHODS: Seventy subjects with idiopathic pancreatic hyperenzymemia, 44 men and 26 women (mean age, 48 years; range, 8-74 years), were studied. Thirteen of these 70 subjects had the familial form of the syndrome. The mutation analysis of the CFTR gene was carried out using diagnostic commercial kits for the simultaneous detection of 29 mutations and Tn polymorphism. RESULTS: Among the 70 subjects studied, 7 (10.0%) had CFTR gene mutations. None of these 7 subjects had the familial form of pancreatic hyperenzymemia. These mutations were DeltaF 508 in 1 subject, 2789 + 5 G > A in another subject, and T5 allele in the remaining 5. All these mutations were heterozygous, with the exception of 1 T5 allele that was homozygous in 1 subject. CONCLUSIONS: The frequencies of the mutations of the CFTR gene found in these subjects are similar to the carrier frequencies in the general Italian population. This finding does not support a role for CFTR gene mutations in the etiology of idiopathic pancreatic hyperenzymemia.

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52 A (i) 5 1078delT, R347P, R334W 7 A455E, Tn (i) 8, 9 DF508, DI507 10 G542X, 1717-1 G . Login to comment

[hide] Indirect CFTR mutation identification by PCR/OLA a... Genet Test. 2005 Winter;9(4):285-91. Stanziale P, Savino M, De Bonis P, Granatiero M, Zelante L, Bisceglia L
Indirect CFTR mutation identification by PCR/OLA anomalous electropherograms.
Genet Test. 2005 Winter;9(4):285-91., [PMID:16379540]

Abstract [show]
Mutations of CFTR gene are responsible for cystic fibrosis (CF) and other clinical conditions such as congenital absence of the vas deferens (CAVD), chronic pancreatitis (IP), and idiopathic disseminated bronchiectasis (DBE) classified as CFTR-related disorders. The PCR/OLA assay is designed to detect 31 known mutations including the 24 most common CF mutations worldwide, as identified by the CF Consortium. In order to define the CFTR genotype a series of 1812 individuals from central-southern Italy with and without CF manifestations were screened by using the PCR/OLA assay. Here we report the description of five cases of anomalous electropherograms obtained after PCR/OLA analysis, that led to the identification, in the homozygous state, of two point mutations (D110H and S589N) not included in the assay test panel, a large gene deletion (CFTRdel14b_17b), and an exonic polymorphism (c.4002A > G). Haplotype and real time PCR analysis were also performed in the subject carrying the large CFTR deletion. The study demonstrates that the PCR/OLA assay, besides being an efficient and user-friendly method to screen known mutations in the CFTR gene, may also function as a mutation/polymorphism-scanning assay, at least for certain nucleotide changes located in some critical regions of the gene.

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50 FREQUENCY DISTRIBUTION OF CFTR MUTATIONS IDENTIFIED IN 116 PATIENTS WITH CYSTIC FIBROSIS ORIGINATING FROM CENTRAL-SOUTHERN ITALY Mutations Allele frequency (%) F508del 47.41 G542X 9.48 N1303K 5.60 G85E 5.17 2789ϩ5GϾA 1.29 621ϩ1G-ϾT 1.29 R347P 1.29 R553X 1.29 S589N 1.29 W1282X 1.29 CFTRdele14b-17b 0.86 1717-1G-ϾA 0.43 2183 AA-ϾG 0.43 R1162X 0.43 R334W 0.43 711ϩ5G-ϾA 0.43 3849ϩ1OKbC-ϾT 0.43 Unidentified 21.12 A B C D GTTG-3Ј), 14bF (5Ј-GGGAGGAATAGGTGAAGAT-3Ј) and 14bR (5Ј-AATCCACTATGTTTGTATGTA-3Ј), 17bF (5Ј-AA- TGACATTTGTGATATGAT-3Ј) and 17bR (5Ј-ACTTTAG- CTAAGCATTTAAG-3Ј), respectively. Login to comment

[hide] [New concepts of pathophysiology and therapy in cy... Pneumologie. 2005 Nov;59(11):811-8. Hirche TO, Loitsch S, Smaczny C, Wagner TO
[New concepts of pathophysiology and therapy in cystic fibrosis].
Pneumologie. 2005 Nov;59(11):811-8., [PMID:16385442]

Abstract [show]
Today, the majority of cystic fibrosis (CF) patients treated in Germany have reached adulthood. However, with increasing age the morbidity and frequency of severe pulmonary complications continues to rise. Further optimization of conventional therapy alone will be insufficient to compensate for this development. In recent years, there has been impressive progress in our understanding of the molecular basis of the CF gene and its product, the cystic fibrosis transmembrane conductance regulator (CFTR). This knowledge can now be applied to develop new therapeutic strategies. However, important questions remain to be solved, i. e., little is known about the pathways that link the malfunctioning of the CFTR protein with the observed clinical phenotype. This review briefly touches on CF genetics as it applies to lung disease and will focus on the current hypotheses of CFTR (dys)function and its impact on pulmonary fluid homeostasis. New treatment options that target the molecular basis of the disease will be discussed.

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61 1 Verteilung und Klassifikation der 10 häufigsten CFTR Mutationen in Deutschland 2003 (modifiziert nach [2]) CFTR Mutation identifizierte Mutationen häufigste Mutationen CFTR Mutationsklassea n (%) (%) I II III IV V ˜F508 6593 65,8 88,0 X R553X 172 1,7 2,3 X G542X 160 1,6 2,1 X N1303K 154 1,5 2,0 X G551D 141 1,4 1,9 X R347P 100 1,0 1,3 X 1717 ±1G fi A 61 0,6 0,8 X 3849 + 10 Kb C fi T 49 0,5 0,7 X W1282X 35 0,4 0,5 X R117H 25 0,3 0,4 X andere 524 5,1 gesamt n = 8014 79,9% 100% 7,6%b 88,0% 1,9% 1,7% 0,8% a Zur Einteilung der CFTR Mutationsklassen vergleiche Abb. 3. b Anteil der CFTR Mutationsklasse an den 10 häufigsten Mutationen [%] teinsynthese proportional zu der Schwere der pulmonalen Erkrankung war. Login to comment

[hide] Association of common haplotypes of surfactant pro... Pediatr Pulmonol. 2006 Mar;41(3):255-62. Choi EH, Ehrmantraut M, Foster CB, Moss J, Chanock SJ
Association of common haplotypes of surfactant protein A1 and A2 (SFTPA1 and SFTPA2) genes with severity of lung disease in cystic fibrosis.
Pediatr Pulmonol. 2006 Mar;41(3):255-62., [PMID:16429424]

Abstract [show]
Most individual cystic fibrosis transmembrane conductance regulator (CFTR) mutations appear not to correlate directly with severity of lung damage in cystic fibrosis (CF). Components of innate immunity, namely, mannose-binding lectin (MBL2), and surfactant protein A1 and A2 genes (SFTPA1 and SFTPA2), were shown to be critical in pulmonary host defenses. A pilot association study was conducted to identify genetic modifiers of lung disease in adult patients with CF. The structural and promoter (-221x/y) variants of MBL2, variants at codons 19, 50, 62, and 219 of SFTPA1, and at codons 9, 91, and 223 for SFTPA2, were studied in 135 adults with CF and compared to their forced expired volume in 1 sec (FEV1), diffusion of CO (DLCO), and other pulmonary scores. Predicted FEV1 was significantly lower in adults with the SFTPA1 6A3 allele and SFTPA2 1A1) allele (P = 0.01 and 0.009, respectively). The extended haplotype 6A3/1A1, which includes SFTPA1 and SFTPA2, was associated with lower pulmonary function, using FEV1 (P = 0.005) and poor pulmonary scores which were determined by American Medical Association, American Thoracic Society, and modified Shwachman-Kulczycki scores. Lower FEV1 and DLCO values were associated with MBL2 coding variants in those who had the DeltaF508 CFTR mutation (P = 0.03 and 0.004, respectively). These results support the current hypothesis that variants in pulmonary host defense molecules are potentially genetic modifiers of pulmonary disease in CF. Further work in larger populations is required to provide important new insights into the pathogenesis of CF.

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33 Complementary mutations were identified in 51 CF subjects: R117H (4), R347H (1), R347P (1), G542X (7), G551D (4), 1717-1G-A (2), 2789 þ 5G > A(3), 3120 þ 1G > A (2), 3659delC (3), 3849 þ 10kbC>T (6), 394delTT (1), 621 þ 1G>T (4), 711 þ 1G > T (1), G85E (1), I507 (1), N1303K (2), R352Q (1), R553X (2), R560T (1), and W1282X (4). Login to comment

[hide] Detection of F508del mutation in cystic fibrosis t... Singapore Med J. 2006 Feb;47(2):129-33. Zilfalil BA, Sarina S, Liza-Sharmini AT, Oldfield NJ, Stenhouse SA
Detection of F508del mutation in cystic fibrosis transmembrane conductance regulator gene mutation among Malays.
Singapore Med J. 2006 Feb;47(2):129-33., [PMID:16435054]

Abstract [show]
INTRODUCTION: Cystic fibrosis (CF) is one of the common genetic disorders in the western world. It has been reported to be very rare in Asian populations. According to the Cystic Fibrosis Genetic Analysis Consortium, more than 1,000 mutations of the CF gene have been identified. The CF gene, named the cystic fibrosis transmembrane conductance regulator (CFTR), is located on chromosome 7 and composed of 27 exons. This study aims to detect possible CFTR gene mutations in Malays. METHODS: We analysed 50 blood samples from healthy Malays with no symptoms of CF. DNA was extracted from blood using commercially available extraction kits (Eppendorf, Germany). Identification of CFTR gene mutation was performed using the CF OLA (Oligonucleotide Ligation Assay) kit (Applied Biosystems, USA). The PCR-ligation products were electrophoresed on eight percent sequagel using an ABI PRISM 377 genetic analyser (Applied Biosystems, USA). Electrophoresis data was analysed using the Genotyper software and a report of the CF genotype for all loci tested was created using the CF Genotyper Template software. Out of 50, one sample (two percent) was detected to have the F508del mutation (3bp deletion at exon 10), which is one of the most common CFTR gene mutations in Caucasians. RESULTS: The F508del mutation allele was detected in one subject. This indicates that she was a CF carrier. CONCLUSION: We report the finding of a carrier of the F508del mutation of the CFTR gene in the Malay population. Our finding revealed that CF could also affect the Malay population. Larger studies are necessary to determine the exact gene frequency of this population.

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55 MUTATIONS R553X G551D 1507 del F508 del 1717-1 G>A G542X R560T R347P W1282X R334W 1078 Del T 3849 + 10KB C>T R1162X N1303K 3659 Del C A455E R117H 2183 AA>G 2789+5 G>A 1898 +1 G>A 621+1 G>T 711+1 G>T G85E S549N S549R V520F Q493X R347H 3849 +4 A>G 3905 INS T Y122X 4 software before running the gel electrophoresis in 1X TBE using ABI PRISM® 377 Genetic Analyzer (Applied Biosystems, USA) for 45 minutes. Login to comment

[hide] Rescue of DeltaF508-CFTR trafficking and gating in... Am J Physiol Lung Cell Mol Physiol. 2006 Jun;290(6):L1117-30. Epub 2006 Jan 27. Van Goor F, Straley KS, Cao D, Gonzalez J, Hadida S, Hazlewood A, Joubran J, Knapp T, Makings LR, Miller M, Neuberger T, Olson E, Panchenko V, Rader J, Singh A, Stack JH, Tung R, Grootenhuis PD, Negulescu P
Rescue of DeltaF508-CFTR trafficking and gating in human cystic fibrosis airway primary cultures by small molecules.
Am J Physiol Lung Cell Mol Physiol. 2006 Jun;290(6):L1117-30. Epub 2006 Jan 27., [PMID:16443646]

Abstract [show]
Cystic fibrosis (CF) is a fatal genetic disease caused by mutations in cftr, a gene encoding a PKA-regulated Cl(-) channel. The most common mutation results in a deletion of phenylalanine at position 508 (DeltaF508-CFTR) that impairs protein folding, trafficking, and channel gating in epithelial cells. In the airway, these defects alter salt and fluid transport, leading to chronic infection, inflammation, and loss of lung function. There are no drugs that specifically target mutant CFTR, and optimal treatment of CF may require repair of both the folding and gating defects. Here, we describe two classes of novel, potent small molecules identified from screening compound libraries that restore the function of DeltaF508-CFTR in both recombinant cells and cultures of human bronchial epithelia isolated from CF patients. The first class partially corrects the trafficking defect by facilitating exit from the endoplasmic reticulum and restores DeltaF508-CFTR-mediated Cl(-) transport to more than 10% of that observed in non-CF human bronchial epithelial cultures, a level expected to result in a clinical benefit in CF patients. The second class of compounds potentiates cAMP-mediated gating of DeltaF508-CFTR and achieves single-channel activity similar to wild-type CFTR. The CFTR-activating effects of the two mechanisms are additive and support the rationale of a drug discovery strategy based on rescue of the basic genetic defect responsible for CF.

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387 Genotype/phenotype correlations of Cl-channel function with disease severity show that mutations resulting in a only modest recovery toward wild-type levels (e.g., 5-30%) increase in CFTR expression or activity (e.g., A455E, 2,789 ϩ 5G3A, 5T, R334W, R347P, and R117H) and are typically associated with pancreatic sufficiency, a slower rate of pulmonary function decline, and a better severity index than that shown in patients with severe disease genotypes (5, 6, 10, 36, 49). Login to comment

[hide] The relevance of sweat testing for the diagnosis o... Clin Biochem Rev. 2005 Nov;26(4):135-53. Mishra A, Greaves R, Massie J
The relevance of sweat testing for the diagnosis of cystic fibrosis in the genomic era.
Clin Biochem Rev. 2005 Nov;26(4):135-53., [PMID:16648884]

Abstract [show]
Cystic fibrosis (CF) is the most common inherited disorder of childhood. The diagnosis of CF has traditionally been based on clinical features with confirmatory evidence by sweat electrolyte analysis. Since 1989 it has been possible to also use gene mutation analysis to aid the diagnosis. Cloning of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has advanced our understanding of CF, in particular the molecular basis of an expanded CF phenotype. However, because there are over 1000 mutations and 200 polymorphisms, many without recognised effects on CFTR, the molecular diagnosis can be troublesome. This has necessitated measurement of CFTR function with renewed interest in the sweat test. This review provides an overview of the clinical features of CF, the diagnosis and complex genetics. We provide a detailed discussion of the structure and function of CFTR and the classification of CFTR mutations. Sweat electrolyte analysis is discussed, from the physiology of sweating to the rigours of a properly performed sweat test and its interpretation. With this information it is possible to understand the relevance of the sweat test in the genomic era.

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115 CFTR is also regulated by phosphorylation of the regulatory domain but there appear to be fewer mutations in this domain than in other parts.59 Class IV: Defective Conduction Many missense mutations have been identified in the membrane spanning domains, where the CFTR gene encodes a protein that is correctly trafficked to the cell membrane and responds to stimuli but generates a reduced chloride current.59 Some examples include mutations in which arginine is replaced by histidine at residue at 117 (R117H), tryptophan at 334 (R334W), or proline at 347 (R347P). Login to comment

[hide] Variants in the glutamate-cysteine-ligase gene are... Am J Respir Crit Care Med. 2006 Aug 15;174(4):415-9. Epub 2006 May 11. McKone EF, Shao J, Frangolias DD, Keener CL, Shephard CA, Farin FM, Tonelli MR, Pare PD, Sandford AJ, Aitken ML, Kavanagh TJ
Variants in the glutamate-cysteine-ligase gene are associated with cystic fibrosis lung disease.
Am J Respir Crit Care Med. 2006 Aug 15;174(4):415-9. Epub 2006 May 11., 2006-08-15 [PMID:16690975]

Abstract [show]
BACKGROUND: Chronic progressive lung disease is the most serious complication of cystic fibrosis (CF). Glutathione plays an important role in the protection of the CF lung against oxidant-induced lung injury. OBJECTIVES: We hypothesized that a polymorphism in a novel candidate gene that regulates glutathione synthesis might influence CF lung disease. METHODS: In a cross-sectional study, subjects were recruited from CF clinics in Seattle and multiple centers in Canada. We tested for an association between CF lung disease and a functional polymorphism in the glutamate-cysteine ligase catalytic subunit (GCLC) gene. Multiple linear regression was used to test for association between polymorphisms of GCLC and severity of CF lung disease while adjusting for age, Pseudomonas aeruginosa infection, and cystic fibrosis transmembrane conductance regulator (CFTR) genotype. Analysis was repeated for patients with CF stratified by CFTR genotype. MEASUREMENTS AND MAIN RESULTS: A total of 440 subjects with CF participated in the study (51% male; mean [+/- SD] age, 26 +/- 11 yr; mean FEV(1), 62 +/- 28% predicted). In the total population, there was a trend toward an association between GCLC genotypes and CF lung disease (linear regression coefficient [SEM], 1.68 [1.0]; p = 0.097). In the stratified analysis, there was a highly significant association between GCLC genotype and CF lung function in subjects with a milder CFTR genotype (linear regression coefficient [SEM], 5.5 (1.7); p = 0.001). CONCLUSIONS: In patients with CF with a milder CFTR genotype, there is a strong association between functional polymorphisms of the GCLC gene and CF lung disease severity.

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63 Mild CFTR mutations (Class IV and V) ϭ R117H, R334W, G85E, R347P, 3849ϩ10KbC→T, 2789ϩ5G→A, A455E. Login to comment

[hide] CFTR genotype as a predictor of prognosis in cysti... Chest. 2006 Nov;130(5):1441-7. McKone EF, Goss CH, Aitken ML
CFTR genotype as a predictor of prognosis in cystic fibrosis.
Chest. 2006 Nov;130(5):1441-7., [PMID:17099022]

Abstract [show]
STUDY RATIONALE: Certain CFTR genotypes are associated with reduced mortality. The accuracy of using CFTR genotype as a predictor of survival and the mechanisms through which CFTR genotype influences survival are unknown. PARTICIPANTS: All patients with cystic fibrosis (CF) enrolled in the US Cystic Fibrosis Foundation national registry between 1993 and 2002. DESIGN: We examined the prognostic value of CFTR genotype, grouped into "high-risk" and "low-risk" categories based on the effect of their CFTR genotype on phenotype and protein production. MEASUREMENTS AND RESULTS: Clinical and genetic data were available from 15,651 patients with CF. Patients with a high-risk CFTR genotype had a greater than twofold increased risk of death compared to patients with a low-risk CFTR genotype (relative risk, 2.25; 95% confidence interval [CI], 1.77 to 2.84; p < 0.001). This association was partly explained by lung function, nutritional status, pancreatic insufficiency, and Pseudomonas aeruginosa colonization. Of the 1,672 patients who died, median age at death for the high-risk CFTR genotype was 24.2 years (interquartile range, 18.4 to 32.0 years) and for the low-risk CFTR genotype was 37.6 years (interquartile range, 28.8 to 47.9 years; p < 0.001). The positive predictive value of this classification method as a test to identify patients who died before or after their 30th birthday was 69% (95% CI, 67 to 72%) with a negative predictive value of 71% (95% CI, 60 to 80%). CONCLUSIONS: Grouping patients into high-risk and low-risk CFTR genotype categories is associated with significant differences in survival and median age at death. These differences are not fully explained by lung function, nutritional measures, pancreatic insufficiency, or P aeruginosa colonization. Modest reassurance about the likelihood of a milder than average course can be provided for CF patients with a low-risk CFTR genotype, although it should be acknowledged that substantial phenotypic variability exists.

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46 Alleles High-risk CFTR genotype Class I 2,131 G542X, R553X, W1282X, R1162X, 621-1G3T, 1717-1G3A, 1078⌬T, 3659⌬C Class II 11,231 ⌬F508, ⌬I507, N1303K, S549N, G85E Class III 783 G551D, R560T Low-risk CFTR genotype Class IV 391 R117H, R334W, R347P Class V 421 3849 ϩ 10KbC3T, 2789 ϩ 5G3A, A455E *Patients with both CFTR alleles in either class I, class II, or class III were grouped together as a high-risk genotype, while patients with at least one mutant allele in class IV and V were considered to have low-risk genotypes; 380 patients had both mutations in either class I, II, or III, while 314 patients had both mutations in either class IV or V (total, n ϭ 15,651). Login to comment

[hide] Validation of cystic fibrosis mutation analysis us... Diagn Mol Pathol. 2007 Mar;16(1):57-9. Huang CK, Pan Q
Validation of cystic fibrosis mutation analysis using ABI 3130XL genetic analyzer.
Diagn Mol Pathol. 2007 Mar;16(1):57-9., [PMID:17471160]

Abstract [show]
Cystic fibrosis (CF) is one of the most common autosomal recessive diseases in the white population, with a prevalence estimate of 1 in 2500 to 3300 live births. CF is characterized by viscous mucus in the lungs with involvement of digestive and reproductive systems as well as sweat glands (excess salt loss). Treatment for CF patients is palliative. Over 1300 mutations have been identified in the CFTR gene. However, most of the mutations are at frequencies of <0.1% or represent private mutations. Although other methodologies are available for CF testing, the oligonucleotide ligation assay is a unique approach to mutation detection of point mutations, small deletions, and small insertions, and consists of 2 phases. Applied Biosystems 3130 Series Genetic Analyzers are the next-generation platform for low to medium throughput laboratories and deliver improved performance. One disadvantage of the Genetic Analyzers is that there is no template of instrument settings for POP-6 polymer using 36-cm array. The Abbott CF oligonucleotide ligation assay ASRs can be run only using POP-6 polymer. We are the first to have optimized the instrument settings for POP-6 polymer based on the template of Rapidseq36-POP6 for Abbott Diagnostics CF V3 ASRs. Several conditions were tried, and the conditions of sample injection voltage at 10,000 v and sample injection time at 5 seconds gave better results, which were with clearer peaks and lower background signals. Twenty cell line DNA samples from Coriell were analyzed, and the results were matched. In addition, Synthetic Controls from AcroMetrix were analyzed, and the results were same as expected. Also, about 1500 clinical samples were analyzed, and high-quality reportable results were obtained. In conclusion, our modified protocol is robust and reliable on this ABI 3130XL instrument.

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58 Mutation controls: to specifically assess the detection of CF mutations, 20 cell line DNA samples with mutations of R553X, 3659delC/delF508, delF508/Q493X, 711+ 1G>T/621+1G>T, 621+1G>T/delF508, G85E/ 621+1G>T, R560T/delF508, A455E/621+1G>T, N1303K, W1282X, G551D/R553X, 2789+5G>A/ 2789+5G>A, 3849+10C>T/3849+10C>T, 1717-1G>A, delF508/delF508, R347P/G551D, R334W, V520F, R117H/delF508/5T/9T, or G542X/G542X, respectively, from the Coriell Cell Repositories were analyzed. Login to comment

[hide] Does cystic fibrosis neonatal screening detect aty... Clin Genet. 2007 Jul;72(1):39-46. Narzi L, Ferraguti G, Stamato A, Narzi F, Valentini SB, Lelli A, Delaroche I, Lucarelli M, Strom R, Quattrucci S
Does cystic fibrosis neonatal screening detect atypical CF forms? Extended genetic characterization and 4-year clinical follow-up.
Clin Genet. 2007 Jul;72(1):39-46., [PMID:17594398]

Abstract [show]
The neonatal screening protocol for cystic fibrosis (CF) is based on a first determination of blood immunoreactive trypsin (IRT1), followed by a first level genetic test that includes the 31 worldwide most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene (DNA31), and a second determination of blood immunoreactive trypsin (IRT2). This approach identifies, in addition to affected subjects, a high proportion of newborns with hypertrypsinaemia at birth, in whom only one mutation is identified and who have a negative or borderline sweat test and pancreatic sufficiency. Although it has been suggested that hypertrypsinaemia may be caused by a single CFTR mutation, whether such neonates should be merely considered as healthy carriers remains a matter of debate as hypertrypsinaemia at birth may be a biochemical marker of a CFTR malfunction because of a second mild mutation. We analyzed, by means of an extended sequencing protocol, 32 newborns who tested positive at an IRT1/DNA31/IRT2 screening protocol and in whom only one CFTR mutation was found. The results obtained demonstrate that 62.5% of these newborns were also carrying a second mild CFTR mutation. The high proportion of compound heterozygous subjects, combined with the results of a 4-year follow-up in nine of these subjects all of whom displaying initial CF clinical symptoms, suggest that it may be possible to use the IRT1/DNA31/IRT2 protocol of neonatal screening to identify newborns with atypical forms of CF. In view of these findings, an extended genetic search for subjects with compound heterozygosity and a periodic clinical assessment should be considered.

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43 Five of the 31 mutations included in the basic genetic panel were found to occur in more than 1 of the 64 alleles examined (Table 1 and Fig. 1): F508del in 15 alleles (23.4%), N1303K in four alleles (6.3%), 2789 1 5G-.A in two alleles (3.1%), R117H in two alleles (3.1%), and R347P in two alleles (3.1%). Login to comment
48 CFTR genotypes, IRT2 and sweat test values of the 32 newborns analyzed Newborn CFTR genotype IRT2 Sweat test (mmol/l [Cl2 ]) at enrolment True heterozygous subjects 1 N1303K/1 Negative 18 2 2183AAtoG/1 Negative 11 3 G85E/1 Positive 19 4 F508del/1 Negative 21 5 F508del/1 Negative 20 6 R117H/1 Negative 6 7 1717-1GtoA/1 Positive 7 8 W1282X/1 Negative 14 9 278915GtoA/1 Negative 23 10 N1303K/1 Negative 19 11 F508del/1 Negative 14 12 G542X/1 Negative 39 % of positivity ¼ 16.7% Average Æ SD ¼ 18 Æ 9 Compound heterozygous subjects 13 F508del/D806G Positive 24 14 F508del/D836Y Negative 12 15 R347P/R1162L Negative 18 16 F508del/P5L (TG)11T5 Negative 16 17 F508del/L997F Positive 32 18 R347P/D1152H Positive 42 19 F508del/P5L Negative 42 20 278915GtoA/71113AtoG Positive 33 21 F508del/P5L Positive 39 22 F508del (TG)12T7/(TG)12T5 Negative 23 23 N1303K/S1235R (TG)12T7 Negative 30 24 F508del/L997F Positive 34 25 F508del/(TG)12T5 Negative 34 26 R117H/(TG)12T7 Positive 22 27 F508del/P1013L Positive 8 28 F508del/L997F Negative 28 29 N1303K/(TG)12T5 Positive 13 30 F508del/L997F Positive 50 31 R1162X/P5L Negative 31 32 L997F/S549R(AtoC) Positive 38 % of positivity ¼ 55.0% Average Æ SD ¼ 29 Æ 12 CFTR, cystic fibrosis transmembrane conductance regulator. Login to comment
75 Discussion The majority of the mutations found (F508del, R347P, D1152H, 2789 1 5G-.A, 711 1 3A-.G, N1303K, R117H, R1162X, S549R(A-.C), 2183AA-.G, G85E, 1717-1G-.A, G542X, and W1282X) have an established pathogenic role (26-44). Login to comment

[hide] Analysis of cystic fibrosis gene mutations and ass... Genet Test. 2007 Summer;11(2):133-8. Knezevic J, Tanackovic G, Matijevic T, Barisic I, Pavelic J
Analysis of cystic fibrosis gene mutations and associated haplotypes in the Croatian population.
Genet Test. 2007 Summer;11(2):133-8., [PMID:17627383]

Abstract [show]
The aim of this study was to reveal the CFTR gene mutation status in the Croatian population as well as to establish the haplotypes associated with cystic fibrosis (CF) and those associated with specific gene mutations. A total of 48 unrelated CF patients from Croatia were examined. Among 96 tested alleles, we found nine different mutations: DeltaF508, 58.33%; G542X, 3.12%; N1303K, 2.08%; R1162X; 621 + 1G --> T; G85E; Y569C; E585X; and S466X, 1.04%. Analysis of three polymorphic loci revealed 15 different haplotypes. Two of them (21-23-13 and 21-17-13) occurred with a higher frequency (40% and 24%). Both of these haplotypes also carried a CFTR gene mutation (DeltaF508 or G542X) on 27 out of 32 chromosomes. Among 12 (of all together 29) CF alleles on which no mutations were found, we detected 10 different haplotypes. Because there are still no published data on the distribution of polymorphic loci in Croatia, nor haplotypes associated with mutations in the CFTR gene, our results greatly contribute to knowledge regarding the genetic background of CF in this region.

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39 INNOGENETICS INNO-LIPA CFTR 12 and INNO-LIPA CFTR 7 ϩ Tn diagnostic kits were used to assess the presence of the 29 mutations in CF patients; ⌬F508, ⌬I507, G542X, N1303K, 1717-1G Ǟ A, W1282X, G551D, R553X, S1251N, R560T, 3905insT, Q552X, 394delTT, G85E, E60X, 621 ϩ 1G Ǟ T, R117H, 1078delT, R347P, R334W, 2143delT, 2183AA Ǟ G, 2184delA, 711 ϩ 5G Ǟ A, 2789 ϩ 5G Ǟ A, R1162X, 3659delC, 3849 ϩ 10kbC Ǟ T, and A455E. Login to comment

[hide] Negative genetic neonatal screening for cystic fib... Clin Genet. 2007 Oct;72(4):374-7. Girardet A, Guittard C, Altieri JP, Templin C, Stremler N, Beroud C, des Georges M, Claustres M
Negative genetic neonatal screening for cystic fibrosis caused by compound heterozygosity for two large CFTR rearrangements.
Clin Genet. 2007 Oct;72(4):374-7., [PMID:17850636]

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34 If IRT at day 3 is positive (.65 ng/ml), the card is subjected to an ARMS Elucigen kit (Tepnel) testing for 30 common CF mutations (F508del, Y1092X, 1717-1G.A, G542X, W1282X, N1303K, 3849110kbC.T, 394delTT, 62111G.T, S1251N, G551D, R117H, R1162X, R334W, A455E, 2183AA.G, 3659delC, 1078delT, I507del, R347P, R553X, E60X, 1 8 1 1 11 . Login to comment

[hide] Scanning the cystic fibrosis transmembrane conduct... Clin Chem. 2007 Nov;53(11):1891-8. Epub 2007 Sep 21. Montgomery J, Wittwer CT, Kent JO, Zhou L
Scanning the cystic fibrosis transmembrane conductance regulator gene using high-resolution DNA melting analysis.
Clin Chem. 2007 Nov;53(11):1891-8. Epub 2007 Sep 21., [PMID:17890437]

Abstract [show]
BACKGROUND: Complete gene analysis of the cystic fibrosis transmembrane conductance regulator gene (CFTR) by scanning and/or sequencing is seldom performed because of the cost, time, and labor involved. High-resolution DNA melting analysis is a rapid, closed-tube alternative for gene scanning and genotyping. METHODS: The 27 exons of CFTR were amplified in 37 PCR products under identical conditions. Common variants in 96 blood donors were identified in each exon by high-resolution melting on a LightScanner(R). We then performed a subsequent blinded study on 30 samples enriched for disease-causing variants, including all 23 variants recommended by the American College of Medical Genetics and 8 additional, well-characterized variants. RESULTS: We identified 22 different sequence variants in 96 blood donors, including 4 novel variants and the disease-causing p.F508del. In the blinded study, all 40 disease-causing heterozygotes (29 unique) were detected, including 1 new probable disease-causing variant (c.3500-2A>T). The number of false-positive amplicons was decreased 96% by considering the 6 most common heterozygotes. The melting patterns of most heterozygotes were unique (37 of 40 pairs within the same amplicon), the exceptions being p.F508del vs p.I507del, p.G551D vs p.R553X, and p.W1282X vs c.4002A>G. The homozygotes p.G542X, c.2789 + 5G>A, and c.3849 + 10kbC>T were directly identified, but homozygous p.F508del was not. Specific genotyping of these exceptions, as well as genotyping of the 5T allele of intron 8, was achieved by unlabeled-probe and small-amplicon melting assays. CONCLUSIONS: High-resolution DNA melting methods provide a rapid and accurate alternative for complete CFTR analysis. False positives can be decreased by considering the melting profiles of common variants.

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145 2 223CϾT R31C 3 355CϾT R75X 386GϾA G85E 4 482GϾA R117H 575TϾC I148T 621 ؉ 1GϾTb 5 711 ؉ 1GϾT 7 1078delT 1132CϾT R334W 1150delA 1172GϾC R347P 8 1341 ϩ 18AϾCc 9 1496CϾA A455E 10 1651-1653del I507del 1653-1655del F508deld 11 1717 - 1GϾA 1756GϾT G542Xe 1784GϾA G551Db 1789CϾT R553Xf 1811GϾC R560T 12 1898 ؉ 1GϾA 13 2184delA 14b 2789 ؉ 5GϾAe 16 3120 ؉ 1GϾA 18 3500 - 2AϾTg 19 3616CϾT R1162X 3659delC Intron 19 3849 ؉ 10kbCϾTe 20 3978GϾA W1282X 21 4041CϾG N1303K 22 4178GϾA G1349Dc a Disease-causing variants recommended for genotyping by the ACMG (4) are in bold. Login to comment

[hide] One multiplex control for 29 cystic fibrosis mutat... Genet Test. 2007 Fall;11(3):256-68. Lebo RV, Bixler M, Galehouse D
One multiplex control for 29 cystic fibrosis mutations.
Genet Test. 2007 Fall;11(3):256-68., [PMID:17949287]

Abstract [show]
A simple approach is described to synthesize and clone an inexhaustible supply of any homozygous and/or heterozygous controls diluted with yeast genomic DNA to mimic human genome equivalents for use throughout the entire multiplex mutation assay. As a proof of principle, the 25 cystic fibrosis mutation panel selected by the American College of Medical Genetics and four additional mutant sequences were prepared as a single control mixture. The 29 CFTR mutations were incorporated into 17 gene fragments by PCR amplification of targeted sequences using mutagenic primers on normal human genomic DNA template. Flanking primers selected to bind beyond all published PCR primer sites amplified controls for most assay platforms. The 17 synthesized 433-933-bp CFTR fragments each with one to four homozygous mutant sequences were cloned into nine plasmid vectors at the multiple cloning site and bidirectionally sequenced. Miniplasmid preps from these nine clones were mixed and diluted with genomic yeast DNA to mimic the final nucleotide molar ratio of two CFTR genes in 6 x 10(9) bp total human genomic DNA. This mixture was added to control PCR reactions prior to amplification as the only positive control sample. In this fashion >200 multiplex clinical PCR analyses of >4,000 clinical patient samples have been controlled simultaneously for PCR amplification and substrate specificity for 29 tested mutations without cross contamination. This clinically validated multiplex cystic fibrosis control can be modified readily for different test formats and provides a robust means to control for all mutations instead of rotating human genomic controls each with a fraction of the mutations. This approach allows scores of additional mutation controls from any gene loci to be added to the same mixture annually.

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133 Instead, our laboratory has prepared multiplex controls from aliquots of lin- MULTIPLEX CYSTIC FIBROSIS CONTROL 261 1 2 3 4 5 6 7 8 9 EXON/INTRON 4F4 R4 F11 R11INTRON 10/EXON 11 EXON 7R7 F7 R5 F9INTRON 5 R347P R334W 1078delT EXON 10R10 F10 R11 F11EXON 11/INTRON 10 INTRON 16R16 F16 R14b F14bINTRON 14b EXON 19F19 R19 F20 R20EXON 20 R1162X 3659delC INTRON 8/EXON 9F9 R9 F119 R119INTRON 19 5T A455E F21 R21EXON 21 N1303K EXON 10F10 R10 F3 R3EXON 3 1507 INTRON 12F12 R12 EXON 13R13 F13 2184delA FIG. 2. Login to comment

[hide] Misfolding of the cystic fibrosis transmembrane co... Biochemistry. 2008 Feb 12;47(6):1465-73. Epub 2008 Jan 15. Cheung JC, Deber CM
Misfolding of the cystic fibrosis transmembrane conductance regulator and disease.
Biochemistry. 2008 Feb 12;47(6):1465-73. Epub 2008 Jan 15., 2008-02-12 [PMID:18193900]

Abstract [show]
Understanding the structural basis for defects in protein function that underlie protein-based genetic diseases is the fundamental requirement for development of therapies. This situation is epitomized by the cystic fibrosis transmembrane conductance regulator (CFTR)-the gene product known to be defective in CF patients-that appears particularly susceptible to misfolding when its biogenesis is hampered by mutations at critical loci. While the primary CF-related defect in CFTR has been localized to deletion of nucleotide binding fold (NBD1) residue Phe508, an increasing number of mutations (now ca. 1,500) are being associated with CF disease of varying severity. Hundreds of these mutations occur in the CFTR transmembrane domain, the site of the protein's chloride channel. This report summarizes our current knowledge on how mutation-dependent misfolding of the CFTR protein is recognized on the cellular level; how specific types of mutations can contribute to the misfolding process; and describes experimental approaches to detecting and elucidating the structural consequences of CF-phenotypic mutations.

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115 WT, L346P, R347P, L346P/R347I, and R347H CFTR expression was assayed by immunoblotting, using the mouse monoclonal anti-HA Ab. Equal loading of proteins was verified by visualizing the Na+/K+-ATPase (lower panel). Login to comment
135 We therefore examined two CF-phenotypic missense mutations in the CFTR channel pore [L346P and R347P in TM6] that involve gain of a Pro residue, but where only the nonconservative mutation L346P represents a significant loss of segment hydropathy. Login to comment
137 When the biogenesis of corresponding full-length CFTR mutants was examined in this context, the protein harboring the L346P mutation was found to be unstable, while the wild type, R347P, along with the R347H mutant protein, processed normally (Figure 4A). Login to comment

[hide] Distribution of CFTR mutations in Saguenay- Lac-Sa... Genet Med. 2008 Mar;10(3):201-6. Madore AM, Prevost C, Dorfman R, Taylor C, Durie P, Zielenski J, Laprise C
Distribution of CFTR mutations in Saguenay- Lac-Saint-Jean: proposal of a panel of mutations for population screening.
Genet Med. 2008 Mar;10(3):201-6., [PMID:18344710]

Abstract [show]
PURPOSE: Saguenay-Lac-Saint-Jean is a region located in the northeastern part of the Province of Quebec, Canada, and is characterized by a founder effect. In this region, it has been documented that the incidence of cystic fibrosis reached 1/902 live births between 1975 and 1988, three times higher than the average incidence of 1/2500 live births reported in other Caucasian populations. This corresponds to a carrier rate of 1/15. METHODS: Using genotyping data from the Canadian Consortium for Cystic Fibrosis Genetic Studies, this article describes the cystic fibrosis transmembrane conductance regulator profile of the cystic fibrosis population living in the Saguenay-Lac-Saint-Jean region and compares it with cystic fibrosis populations living in three other regions of the Province of Quebec. RESULTS: Significant differences in allelic frequencies of common mutations (as DeltaF508, 621 + 1G>T and A455E), and in percentage of covered allele with three or six mutations, were found in Saguenay-Lac-Saint-Jean compared to other regions. Based on this result, two mutation panels exceeding 90% sensitivity threshold are now proposed for cystic fibrosis carrier screening in this region. CONCLUSION: The implementation of the proposed carrier screening program could diminish the incidence of this disease in this region and allow future parents to make informed decisions about family planning.

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48 Altogether, the six mutations represent 95.89% of the CFTR allele of CF patients in the SLSJ population, whereas the proportions are 86.85, 85.27, and Table 2 Cystic fibrosis mutations present in the four populations studied Mutationa Allelic frequency (number of alleles [%]) Populationb 1 2 3 4 „F508 106 (62.35) 55 (72.37) 398 (72.36) 67 (57.78) 621 ؉ 1G>T 42 (24.71) 6 (7.89) 30 (5.45) 1 (0.85) A455E 12 (7.06) 2 (2.63) 14 (2.55) 1 (0.85) 3199del6 1 (0.59) 1 (1.32) 7 (1.27) 1 (0.85) 711 ؉ 1G>T 1 (0.59) 1 (1.32) 15 (2.73) 1 (0.85) Y1092X 1 (0.59) 1 (1.32) 5 (0.91) 0 R117C 2 (1.18) 0 0 0 ‚I507 1 (0.59) 2 (2.63) 10 (1.82) 0 L206W 1 (0.59) 1 (1.32) 9 (1.64) 0 R1158X 1 (0.59) 0 0 0 S489X 1 (0.59) 0 1 (0.18) 0 R553X 0 2 (2.63) 2 (0.36) 0 R334W 0 1 (1.32) 2 (0.36) 0 G542X 0 0 10 (1.82) 0 G85E 0 0 6 (1.09) 5 (4.24) N1303K 0 0 5 (0.91) 1 (0.85) IVS8-5T 0 0 4 (0.73) 0 W1282X 0 0 3 (0.55) 7 (5.93) R347P 0 0 1 (0.18) 2 (1.69) V520F 0 0 1 (0.18) 0 I1027T 0 0 1 (0.18) 0 R1066C/IVS 0 0 1 (0.18) 0 Q1313X 0 0 1 (0.18) 0 1898ϩ3GϾA 0 0 1 (0.18) 0 2183AAϾG 0 0 1 (0.18) 0 2951insA 0 0 1 (0.18) 0 G551D 0 0 0 2 (1.69) 1525-iG-A 0 0 0 2 (1.69) Y109C 0 0 0 1 (0.85) S549N 0 0 0 1 (0.85) 3154del1G 0 0 0 1 (0.85) UNKNOWN 1 (0.59) 4 (5.26) 20 (3.82) 25 (21.19) Number of alleles genotypedc 170 (100) 76 (100) 550 (100) 118 (100) a The six mutations included in the panels proposed are in bold. Login to comment

[hide] Mutations at arginine 352 alter the pore architect... J Membr Biol. 2008 Mar;222(2):91-106. Epub 2008 Apr 18. Cui G, Zhang ZR, O'Brien AR, Song B, McCarty NA
Mutations at arginine 352 alter the pore architecture of CFTR.
J Membr Biol. 2008 Mar;222(2):91-106. Epub 2008 Apr 18., [PMID:18421494]

Abstract [show]
Arginine 352 (R352) in the sixth transmembrane domain of the cystic fibrosis transmembrane conductance regulator (CFTR) previously was reported to form an anion/cation selectivity filter and to provide positive charge in the intracellular vestibule. However, mutations at this site have nonspecific effects, such as inducing susceptibility of endogenous cysteines to chemical modification. We hypothesized that R352 stabilizes channel structure and that charge-destroying mutations at this site disrupt pore architecture, with multiple consequences. We tested the effects of mutations at R352 on conductance, anion selectivity and block by the sulfonylurea drug glipizide, using recordings of wild-type and mutant channels. Charge-altering mutations at R352 destabilized the open state and altered both selectivity and block. In contrast, R352K-CFTR was similar to wild-type. Full conductance state amplitude was similar to that of wild-type CFTR in all mutants except R352E, suggesting that R352 does not itself form an anion coordination site. In an attempt to identify an acidic residue that may interact with R352, we found that permeation properties were similarly affected by charge-reversing mutations at D993. Wild-type-like properties were rescued in R352E/D993R-CFTR, suggesting that R352 and D993 in the wild-type channel may interact to stabilize pore architecture. Finally, R352A-CFTR was sensitive to modification by externally applied MTSEA+, while wild-type and R352E/D993R-CFTR were not. These data suggest that R352 plays an important structural role in CFTR, perhaps reflecting its involvement in forming a salt bridge with residue D993.

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21 Alternatively, Cotten and Welsh (1999) reported that R347 plays an important role in regulating the overall structure of the CFTR pore; R347P-CFTR exhibited significantly decreased single-channel conductance and unstable channel openings, while R347H-CFTR displayed a pH-dependent conductance and anomalous mole-fraction behavior. Login to comment

[hide] Evaluation and use of a synthetic quality control ... Hum Mutat. 2008 Aug;29(8):1063-70. Berwouts S, Gordon JT, Rundell CA, Barton DE, Dequeker E
Evaluation and use of a synthetic quality control material, included in the European external quality assessment scheme for cystic fibrosis.
Hum Mutat. 2008 Aug;29(8):1063-70., [PMID:18470946]

Abstract [show]
Assuring high quality within the field of genetic testing is fundamental, as the results can have considerable impact on the patient and his or her family. The use of appropriate quality control (QC) samples is therefore essential. Diagnostic laboratories mainly use patient samples as QC material, which of course include a maximum of two mutations per sample. Bearing in mind that some assays (such as for cystic fibrosis [CF] testing) can test for more than 100 mutations, multiplex QC materials including more than two mutations could save valuable time and reagents. Based on this need, synthetic multiplex controls have been developed by Maine Molecular Quality Controls, Inc. (MMQCI) for CF. A synthetic control, containing six homozygous mutations and one polymorphism for CF transmembrane conductance regulator (CFTR), was evaluated by distributing it through the CF external quality assessment (EQA) scheme, along with the EQA samples in 2005. A total of 197 participants returned results of the yearly EQA scheme and 133 laboratories participated in the evaluation of the synthetic sample. Respectively, 76% and 73% of the participants were assigned as successful. This evaluation study revealed that the multiplex QC material performed well in the majority of assays and could be useful in method validation, as a tool to challenge interpretation skills, and as potential proficiency testing (PT) material.

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135 Mutations 2183AA4G (c.2051_2052delAAinsG, p.Lys684fs) and R347 H (c.1040G4A, p.Arg347His) cross-react with 2184delA (c.2052delA, p.Lys684fs) and R347P (c.1040G4C, p.Arg347Pro), respectively, in many CFTR detection methods. Login to comment
136 This explains why seven laboratories made genotype errors (missing 2183AA4G (c.2051_2052delAAinsG, p.Lys684fs) and R347 H (c.1040G4A, p.Arg347His)) and/or reported mutations not present in the QCS (2184delA (c.2052delA, p.Lys684fs) and R347P (c.1040G4C, p.Arg347Pro)); they encountered difficulties in interpreting typical cross-reaction patterns that are explained in the manual of the assays. Login to comment
157 ErrorTypes for the QCS in More Detail, for the LaboratoriesThat Used Only One Detection AssayÃ Genotype error Genotype Detection assay Number of labs Expected Reported Comment OLA-CFASR v2.0 1 R117 H hom ^ Correct on raw data INNO-LiPA CFTR36 1 R117 H hom R117 H het No signal for wt R117 H visible on copy of the raw data, could be very weak on original raw data INNO-LiPA CFTR36 1 R553X hom R553X het No signal for wt R553X visible on copy of the raw data, could be very weak on original raw dataI507del hom I507del/F508del Sequencing 2 R347 H hom ^ No complete raw data received Sequencing 1 I507del hom ^ No raw data received Additional mutation(s) reported Detection assay Number of labs Additional mutation(s) Comment OLA-CFASR v3.0 US 1 2184delAa hom Software called it INNO-LiPA CFTR36 3 A455E het (3labs), F508del (1lab) No signal for mut A455E visible on copy of the raw data, could be very weak on original raw data ARMS-ElucigeneTM CF29 3 2184delAa (3labs), R347P (3labs), 1717-1G4A (3labs), 3849110kbC4T (2labs) Cross reaction with 2183AA4Gb and R347 H and no full compatibility of MMQCI-CF-P1and ARMS method: no control bands visible ARMS-ElucigeneTM CF29 1CF-HT 1 2184delAa , R347P Cross reaction with 2183AA4Gb and R347H Sequencing 1 W1282X het, N1303 K het No raw data received ASPE-CFTR 4014 Tag-It 1 71111G4T het No raw data received Genotype error 1 additional mutation(s) reported Genotype Detection assay Number of labs Expected Reported Comment Additional mutation(s) Comment OLA-CFASR v3.0 EU 1 R117 H hom ^ No raw data received; probably 2183AA4Gb missed, but 2184delAa reported due to cross reaction 2184delAa hom No raw data received, probably due to cross-reaction with 2183AA4Gb 394delTTc hom 394delTTc het 2183AA4Gb hom ^ INNO-LiPA CFTR36 1 R553X hom I507del hom R553X het I507del/ F508del No signal for wt R553X visible on copy of the raw data, could be very weak on original raw data G542X het A455E het No signal for mut G542X and mut A455E visible on copy of the raw data, could be very weak on original raw data INNO-LiPA CFTR36 1 Italian regional 1 R553X hom R553X het No signal for wt R553X visible on copy of the raw data, could be very weak on original raw data Q552X het Misinterpretation: wt and mut signal for Q552X not visible, but this is a normal reaction pattern when R553X is hom present; the lab reported R553X het ARMS-ElucigeneTM CF29 1 I507del hom ^ No full compatibility of MMQCI- CF-P1 and ARMS method: no control bands R347P Cross-reaction with R347H2183AA4Gb hom ^ ÃIf the zygosity is not mentioned in the table, the laboratory did not report it. Login to comment

[hide] Atypical cystic fibrosis and CFTR-related diseases... Clin Rev Allergy Immunol. 2008 Dec;35(3):116-23. Paranjape SM, Zeitlin PL
Atypical cystic fibrosis and CFTR-related diseases.
Clin Rev Allergy Immunol. 2008 Dec;35(3):116-23., [PMID:18493878]

Abstract [show]
Cystic fibrosis (CF), which is among the most common life-shortening recessive illnesses, is caused by mutations of the CF transmembrane conductance regulator (CFTR) and typically involves chronic infection and progressive obstruction of the respiratory tract as well as pancreatic exocrine insufficiency. Disease severity, to some extent, correlates with organ sensitivity to CFTR dysfunction and to the amount of functional protein, which is influenced by the type of mutation. Atypical CF represents approximately 2% of affected individuals, and includes cases presenting in adolescence or adulthood with pancreatic exocrine sufficiency, normal or borderline sweat chloride concentrations, or with a single predominant clinical feature. This review briefly describes diagnostic methods and phenotypic characteristics of classic and atypical CF, as well as CFTR-related diseases, conditions in which mutated CFTR may contribute to the pathogenesis but do not strictly fit established diagnostic criteria.

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64 Determination of the transepithelial nasal potential difference has been beneficial in establishing a CF Table 1 Mutations, sites, and molecular consequences associated with either an atypical presentation of CF respiratory disease or pancreatic sufficiency or late-onset pancreatic insufficiency (http:// www.genet.sickkids.on.ca) Mutation Site Consequence Atypical presentation M1210I Exon 19 Met to Ile at 1210 S1455X Exon 24 Ser to Stop at 1455 1811+18G→A Intron 11 mRNA splicing defect L346P Exon 7 Leu to Pro at 346 Y161D Exon 4 Tyr to Asp at 161 R31C Exon 2 Arg to Cys at 31 I752S Exon 13 Ile to Ser at 752 2811G/T Exon 15 Sequence variation Pancreatic sufficiency or late-onset pancreatic insufficiency R600G Exon 13 Arg to Gly at 600 D1152H Exon 18 Asp to His at 1152 Y89C Exon 3 Tyr to Cys at 89 R117H Exon 4 Arg to His at 117 D110E Exon 4 Asp to Glu at 110 296 + 3insT Intron 2 mRNA splicing defect E217G Exon 6a Glu to Gly at 217 V392G Exon 8 Val to Gly at 392 N1088D Exon 17b Asn to Asp at 1088 S737F Exon 13 Missense 1716+1G→A Intron 10 mRNA splicing defect R334W Exon 7 Arg to Trp at 334 R347P Exon 7 Arg to Pro at 347 A455E Exon 9 Ala to Glu at 455 P574H Exon 12 Pro to His at 574 3850-3T→G Intron 19 mRNA splicing defect diagnosis in many atypical cases. Login to comment

[hide] Genetic determinants and epidemiology of cystic fi... Diabetes Care. 2008 Sep;31(9):1789-94. Epub 2008 Jun 5. Adler AI, Shine BS, Chamnan P, Haworth CS, Bilton D
Genetic determinants and epidemiology of cystic fibrosis-related diabetes: results from a British cohort of children and adults.
Diabetes Care. 2008 Sep;31(9):1789-94. Epub 2008 Jun 5., [PMID:18535191]

Abstract [show]
OBJECTIVE: Longer survival of patients with cystic fibrosis has increased the occurrence of cystic fibrosis-related diabetes (CFRD). In this study we documented the incidence of CFRD and evaluated the association between mutations responsible for cystic fibrosis and incident CFRD, while identifying potential risk factors. RESEARCH DESIGN AND METHODS: This was a population-based longitudinal study of 50 cystic fibrosis speciality clinics in the U.K. Subjects included 8,029 individuals aged 0-64 years enrolled in the U.K. Cystic Fibrosis Registry during 1996-2005. Of these, 5,196 with data and without diabetes were included in analyses of incidence, and 3,275 with complete data were included in analyses of risk factors. Diabetes was defined by physician diagnosis, oral glucose tolerance testing, or treatment with hypoglycemic drugs. RESULTS: A total of 526 individuals developed CFRD over 15,010 person-years. The annual incidence was 3.5%. The incidence was higher in female patients and in patients with mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in classes I and II. In a multivariate model of 377 cases of 3,275 patients, CFTR class (relative risk 1.70 [95% CI 1.16-2.49], class I or II versus others), increasing age, female sex, worse pulmonary function, liver dysfunction, pancreatic insufficiency, and corticosteroid use were independently associated with incident diabetes. CONCLUSIONS: The incidence of CFRD is high in Britain. CFTR class I and II mutations increase the risk of diabetes independent of other risk factors including pancreatic exocrine dysfunction.

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54 Genotypes associated with cystic fibrosis were coded into five established classes reflecting CFTR function of defective production, processing, regulation, conductance, and quantity of CFTR protein (12) as follows: I: G542X, R553X, W1282X, R1162X, 621-1G3T, 1717- 1G3 A, 1078⌬T, and 3659⌬C; II: ⌬F508, ⌬I507, N1303K, and S549N; III: G551Dand R560T; IV: R117H, R334W, G85E, and R347P; V: 3849ϩ5G3A, and A455E; and unknown: 711ϩIG3 T, 2184DA, and 1898ϩIG3 A. Login to comment

[hide] Atomic model of human cystic fibrosis transmembran... Cell Mol Life Sci. 2008 Aug;65(16):2594-612. Mornon JP, Lehn P, Callebaut I
Atomic model of human cystic fibrosis transmembrane conductance regulator: membrane-spanning domains and coupling interfaces.
Cell Mol Life Sci. 2008 Aug;65(16):2594-612., [PMID:18597042]

Abstract [show]
We describe herein an atomic model of the outward-facing three-dimensional structure of the membrane-spanning domains (MSDs) and nucleotide-binding domains (NBDs) of human cystic fibrosis transmembrane conductance regulator (CFTR), based on the experimental structure of the bacterial transporter Sav1866. This model, which is in agreement with previous experimental data, highlights the role of some residues located in the transmembrane passages and directly involved in substrate translocation and of some residues within the intracellular loops (ICL1-ICL4) making MSD/NBD contacts. In particular, our model reveals that D173 ICL1 and N965 ICL3 likely interact with the bound nucleotide and that an intricate H-bond network (involving especially the ICL4 R1070 and the main chain of NBD1 F508) may stabilize the interface between MSD2 and the NBD1F508 region. These observations allow new insights into the ATP-binding sites asymmetry and into the molecular consequences of the F508 deletion, which is the most common cystic fibrosis mutation.

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181 This helix contains several basic residues (R334, K335, R347 and R352), mutations of two of them (R334W and R347P) being associated with mild CF characterized by altered pore properties [63]. Login to comment

[hide] Guidelines for diagnosis of cystic fibrosis in new... J Pediatr. 2008 Aug;153(2):S4-S14. Farrell PM, Rosenstein BJ, White TB, Accurso FJ, Castellani C, Cutting GR, Durie PR, Legrys VA, Massie J, Parad RB, Rock MJ, Campbell PW 3rd
Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic Fibrosis Foundation consensus report.
J Pediatr. 2008 Aug;153(2):S4-S14., [PMID:18639722]

Abstract [show]
Newborn screening (NBS) for cystic fibrosis (CF) is increasingly being implemented and is soon likely to be in use throughout the United States, because early detection permits access to specialized medical care and improves outcomes. The diagnosis of CF is not always straightforward, however. The sweat chloride test remains the gold standard for CF diagnosis but does not always give a clear answer. Genotype analysis also does not always provide clarity; more than 1500 mutations have been identified in the CF transmembrane conductance regulator (CFTR) gene, not all of which result in CF. Harmful mutations in the gene can present as a spectrum of pathology ranging from sinusitis in adulthood to severe lung, pancreatic, or liver disease in infancy. Thus, CF identified postnatally must remain a clinical diagnosis. To provide guidance for the diagnosis of both infants with positive NBS results and older patients presenting with an indistinct clinical picture, the Cystic Fibrosis Foundation convened a meeting of experts in the field of CF diagnosis. Their recommendations, presented herein, involve a combination of clinical presentation, laboratory testing, and genetics to confirm a diagnosis of CF.

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142 Recommended panel of CF-causing mutations Missense, deletion, stop mutations Splicing, frameshift mutations G85E I507del R560T 621ϩ1GϾT 2789ϩ5GϾA R117H F508del R1162X 711ϩ1GϾT 3120ϩ1GϾA R334W G542X W1282X 1717-1GϾA 3659delC R347P G551D N1303K 1898ϩ1GϾA 3849ϩ10kbCϾT A455E R553X 2184delA Revised from the mutation panel for population screening for CF developed by the ACMG.77 Additional or alternative mutations present at significant frequencies in an ethnic population served by an NBS program may be added. Login to comment

[hide] Colonic wall redundancy at CT in patients with cys... Radiology. 2008 Sep;248(3):869-75. Epub 2008 Jul 22. Webb EM, Kleinhenz ME, Coakley FV, Chang CI, Westphalen AC, Yeh BM
Colonic wall redundancy at CT in patients with cystic fibrosis.
Radiology. 2008 Sep;248(3):869-75. Epub 2008 Jul 22., [PMID:18647844]

Abstract [show]
PURPOSE: To describe the appearance, prevalence, and possible associations of colonic wall redundancy in patients with cystic fibrosis (CF). MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study. Abdominal computed tomographic (CT) images of 38 consecutive patients with CF and a control group of 38 consecutive potential renal donors were retrospectively identified. Three readers independently recorded presence and location of colonic wall redundancy and wall thickness of the ascending, transverse, and descending colon. Interobserver agreement for colonic wall redundancy was determined with the kappa statistic. Colonic wall thicknesses were compared between patient groups with the Student t test. Proportions of adult and pediatric patients with and those without colonic wall redundancy and prevalence of specific gene mutations were compared between groups with the Fisher exact test. CT findings were compared with radiologic reports and clinical records. RESULTS: Each reviewer found colonic wall redundancy in 11 of 28 adults with CF but in none of the children with CF (P < .05 for each reviewer). There was excellent interobserver agreement for identification of colonic wall redundancy (kappa = 0.91, P < .001). Mean thickness of the wall of the ascending colon was significantly greater in patients with CF who had colonic wall redundancy (4.0 mm) than in those without this finding (1.8 mm, P < .05) or in control patients (1.2 mm, P < .05). Among adult patients with CF, DeltaF508 mutation was the predominant mutant allele in 10 of 13 patients with normal colons at CT, whereas more uncommon non-DeltaF508 mutations were seen in seven of 10 patients with colonic wall redundancy (P < .05). Asymptomatic colonic wall redundancy at CT was prospectively misinterpreted as acute colonic disease in five adult patients. CONCLUSION: Proximal colonic wall redundancy is seen frequently in adults with CF and may be more common in those with non-DeltaF508 CFTR gene mutations. This finding provides a starting point for further investigation of the molecular basis of colonic phenotype in CF.

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96 * Non-⌬F508 gene mutations include G542X, 3905insT, R347P, 711ϩ1GϾT, 3120ϩ1GϾA, W1282X, and 1161delC. Login to comment

[hide] Best practice guidelines for molecular genetic dia... Eur J Hum Genet. 2009 Jan;17(1):51-65. Epub 2008 Aug 6. Dequeker E, Stuhrmann M, Morris MA, Casals T, Castellani C, Claustres M, Cuppens H, des Georges M, Ferec C, Macek M, Pignatti PF, Scheffer H, Schwartz M, Witt M, Schwarz M, Girodon E
Best practice guidelines for molecular genetic diagnosis of cystic fibrosis and CFTR-related disorders--updated European recommendations.
Eur J Hum Genet. 2009 Jan;17(1):51-65. Epub 2008 Aug 6., [PMID:18685558]

Abstract [show]
The increasing number of laboratories offering molecular genetic analysis of the CFTR gene and the growing use of commercial kits strengthen the need for an update of previous best practice guidelines (published in 2000). The importance of organizing regional or national laboratory networks, to provide both primary and comprehensive CFTR mutation screening, is stressed. Current guidelines focus on strategies for dealing with increasingly complex situations of CFTR testing. Diagnostic flow charts now include testing in CFTR-related disorders and in fetal bowel anomalies. Emphasis is also placed on the need to consider ethnic or geographic origins of patients and individuals, on basic principles of risk calculation and on the importance of providing accurate laboratory reports. Finally, classification of CFTR mutations is reviewed, with regard to their relevance to pathogenicity and to genetic counselling.

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144 A (T)5 variant can either be associated with (TG)11, (TG)12, (TG)13, and rarely (TG)15 repeats.74 When (T)5 is found in diagnostic testing, for example, for CBAVD or atypical presentation, determination of Table 4 Classification of CFTR mutations with regard to their potential for causing disease Mutation group Examples CF-causing F508del Mainly nonsense, frameshift, splicing (invariant dinucleotide): G542X, R553X, W1282X, 2183AA4G, 3659delC, 1717-1G4A, 3120+1G4A Missense that severely affects CFTR synthesis or function: G551D, N1303K, R347P 2789+5G4A, 3849+10kbC4T, 3272-26A4G, L206Wa , D1152Ha , (TG)13(T)5a CFTR-related disorders associated L206Wa , D1152Ha , (TG)13(T)5a [R117H;(T)7], (TG)12(T)5, L997F, V562I, [R668C;G576A;D443Y], [R74W;D1270N] (TG)11(T)5b , S1235Rb No clinical consequences 875+40A4G, M470V (1540A4G), I506V (1648A4G), F508C (1655T4G), 1716G4A, 2694T4G, 4002A4G, 2752-15G4C (TG)11(T)5b , S1235Rb Unproven or uncertain clinical relevance Mainly missense mutations G622D, R170H, V938G, I125T Putative splice mutations: 406-6T4C, 2752-26A4G, 3601-17T4C Only a fraction of mutations and patients have been characterized in detail and, with the exception of frequent mutations, only small numbers of patients have been available for the study of most mutations. Login to comment

[hide] Identification and characterization of CFTR gene m... Ann Hum Genet. 2009 Jan;73(1):26-33. Epub 2008 Sep 8. Sharma N, Singh M, Kaur G, Thapa BR, Prasad R
Identification and characterization of CFTR gene mutations in Indian CF patients.
Ann Hum Genet. 2009 Jan;73(1):26-33. Epub 2008 Sep 8., [PMID:18782298]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. This study was performed on Indian CF patients (n = 50) to investigate the spectrum of mutations in the CFTR gene and their association with intragenic and extragenic marker haplotypes. We report identification of 14 previously known and eight novel mutations, namely 3986-3987delC, 876-6del4, 1792InsA, L69H, S158N, Q493L, I530L and E1329Q. The frequency of delta F508 was found to be 27%. Absolute linkage between delta F508 and the KM.19-GATT-TUB9-M470V-T854T haplotype (2-2-1-1-1) predicts a relatively recent appearance of delta F508 in Indian CF patients. Low frequency of delta F508 mutation and detection of eight novel and thirteen rare mutations reflect a heterogeneous spectrum of mutations in Indian CF patients. Failure to detect mutations in 34% of alleles indicates the possible presence of gross deletions involving one or more exons or may indicate the location of the molecular defects in either the noncoding parts of the gene or in the promoter region, which warrants analysis of those regions.

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42 CFTR mutations investigated by restriction analysis of PCR products were R334W (MspI), R347P (NcoI), A455E (AciI), 2789+5G-A (SSPI), R1162X (DdeI), and 3849+10kb C-T (HphI) (Gasparini et al., 1991; Dean et al., 1990; Kerem et al., 1990; Highsmith et al., 1990). Login to comment

[hide] Implication of the cystic fibrosis transmembrane c... Biochem Genet. 2008 Dec;46(11-12):847-56. Epub 2008 Sep 23. Sharma N, Singh M, Acharya N, Singh SK, Thapa BR, Kaur G, Prasad R
Implication of the cystic fibrosis transmembrane conductance regulator gene in infertile family members of Indian CF patients.
Biochem Genet. 2008 Dec;46(11-12):847-56. Epub 2008 Sep 23., [PMID:18810634]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene. Among males with CF, 95% are infertile due to congenital absence of the vas deferens. We investigated the role of family history of infertility among CF subjects and characterized mutations in them. Among 50 CF subjects, four had a family history of infertility. A homozygous c.1521_1523delCTT mutation was detected in one, two had a compound heterozygous genotype (c.1521_1523delCTT/c.3717 + 10 kbC>T), and c.1521_1523delCTT mutation was identified on one allele of fourth CF subject. Genetic analysis of each infertile family members of CF subjects revealed the c.1521_1523delCTT mutation on one allele; however, no mutation could be identified on other allele. Haplotype analysis of the infertile family members showed that at least one of the alleles shared the same haplotype as that of the index case. It is suggested that the CFTR gene is implicated in the infertile members of the CF families. Failure to detect mutations on the other allele by SSCP analysis demands direct gene sequencing to detect mutations in the intronic or promoter region.

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41 CFTR mutations were investigated by restriction analysis of PCR products R334W (MspI), R347P (NcoI), A455E (AciI), 2789 ? Login to comment

[hide] Clinical and radiological outcome of patients suff... Pancreas. 2008 Nov;37(4):371-6. Frulloni L, Scattolini C, Graziani R, Cavestro GM, Pravadelli C, Amodio A, Manfredi R, Scarpa A, Vantini I
Clinical and radiological outcome of patients suffering from chronic pancreatitis associated with gene mutations.
Pancreas. 2008 Nov;37(4):371-6., [PMID:18953248]

Abstract [show]
OBJECTIVES: Cystic fibrosis transmembrane conductance regulator (CFTR), cationic trypsinogen gene (PRSS1), and serine protease inhibitor kazal type 1 (SPINK1) gene mutations have been associated with chronic pancreatitis (CP). The aim of this study was to compare clinical and radiological findings in sporadic CP with (CPgm) and without (CPwt) gene mutations. METHODS: Data from patients observed between 2001 and 2006 were collected. All patients were tested for 25 CFTR gene mutations, for R122H and N29I on the PRSS1 gene, and for N34S mutation on the SPINK1 gene. RESULTS: We found 34 (17.2%) of 198 patients with CPgm, 23 (11.6%) of them on the CFTR gene, 11 (5.6%) on the SPINK1, and none on the PRSS1 gene. The age at clinical onset was younger in CPgm (36.2 +/- 17.2 years) than in CPwt (44 +/- 12.6 years; P = 0.005). There were more heavy drinkers among CPwt (33%) than among CPgm (9%; P = 0.003), and the same applied to smokers (69% vs 33%, respectively; P < 0.0001). In CPgm group, the onset of pancreatic calcifications was observed more frequently in drinkers and/or smokers. Exocrine and endocrine insufficiency occurred less frequently and later in CPgm than in CPwt patients. CONCLUSIONS: Clinical and radiological outcome differ in CPgm compared with CPwt. Alcohol, even in small quantities, and cigarette smoking influence the onset of pancreatic calcifications.

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31 All patients were tested for 25 CFTR gene mutations ($F508, $I507, R117H, R1162X, 2183AAYG, N1303K, 3849 + 10KbCYT, G542X, G551D, 1717-1GYA, R347P, R352Q, R553X, Q552X, G85E, 711 + 5GYA, W1282X, 3272-26AYG, 3132delTG, R334W, I148T, 3659del_C, 3120 + 1GYA, 1898 + 1GYA, and 2789 + 5GYA), which cover approximately 72% of the cystic fibrosis mutations in the Italian population. Login to comment

[hide] Sweat chloride testing in infants identified as he... J Pediatr. 2008 Dec;153(6):857-9. Soultan ZN, Foster MM, Newman NB, Anbar RD
Sweat chloride testing in infants identified as heterozygote carriers by newborn screening.
J Pediatr. 2008 Dec;153(6):857-9., [PMID:19014821]

Abstract [show]
The reference ranges for sweat [C1(-)] were reevaluated in 300 infants referred to our Center as carriers of at least 1 cystic fibrosis mutation identified through newborn screening. The recommended borderline range of 30 to 59 mmol/L failed to identify all individuals who were compound heterozygotes. Our data support using a borderline range of 24 to 59 mmol/L.

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54 Sweat [Cl- ] and the results of genetic screening of 11 patients with [Cl- ] > 24 mmol/L Patients Sweat [Cl- ] mmol/L Mutations Poly T-TG Repeats 1 89 91 R347P CFTRdel 17a-18 7T/9T 2 85 82 ⌬F508 2622ϩ1 GϾT 9T/9T 3 71 - G542X Y1014del 7T/9T 4 69 65 ⌬F508 c.759AϾG 9T/7T 5 58 49 ⌬F508 L206W 9T/9T 6 44 27 ⌬F508 R352W, P750L - 7 38 41 ⌬F508 - 9T-TG10 5T-TG12 8 24 - ⌬F508 - 9T-TG10 5T-TG12 9 25 27 ⌬F508 - 9T-TG10 5T-TG12 10 24 25 ⌬F508 - 9T-TG12 5T-TG12 11 35 26 ⌬F508 - 9T 9T Soultan et al The Journal of Pediatrics • December 2008 should be followed. Login to comment

[hide] Clinical practice and genetic counseling for cysti... Genet Med. 2008 Dec;10(12):851-68. Moskowitz SM, Chmiel JF, Sternen DL, Cheng E, Gibson RL, Marshall SG, Cutting GR
Clinical practice and genetic counseling for cystic fibrosis and CFTR-related disorders.
Genet Med. 2008 Dec;10(12):851-68., [PMID:19092437]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator-related disorders encompass a disease spectrum from focal male reproductive tract involvement in congenital absence of the vas deferens to multiorgan involvement in classic cystic fibrosis. The reproductive, gastrointestinal, and exocrine manifestations of cystic fibrosis transmembrane conductance regulator deficiency are correlated with CFTR genotype, whereas the respiratory manifestations that are the main cause of morbidity and mortality in cystic fibrosis are less predictable. Molecular genetic testing of CFTR has led to new diagnostic strategies and will enable targeting of molecular therapies now in development. Older diagnostic methods that measure sweat chloride and nasal potential difference nonetheless remain important because of their sensitivity and specificity. In addition, the measurement of immunoreactive trypsinogen and the genotyping of CFTR alleles are key to newborn screening programs because of low cost. The multiorgan nature of cystic fibrosis leads to a heavy burden of care, thus therapeutic regimens are tailored to the specific manifestations present in each patient. The variability of cystic fibrosis lung disease and the variable expressivity of mild CFTR alleles complicate genetic counseling for this autosomal recessive disorder. Widespread implementation of newborn screening programs among populations with significant cystic fibrosis mutation carrier frequencies is expected to result in increasing demands on genetic counseling resources.

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56 Liver disease is second to pulmonary disease (plus organ transplantation complications) as a cause of mortality in CF (1.7% of deaths).26 Table 3 Core mutation panel carrier recommended by the ACMG for routine CF diagnostic testing and carrier screening of the general population7 Intronic mutations Exonic mutations Missense Nonsense In-Frame Deletion 621ϩ1GϾT G85E G542X ⌬I507 711ϩ1GϾT R117H R553X ⌬F508 1717-1GϾA R334W R1162X 1898ϩ1GϾA R347P W1282X 2184delA A455E 2789ϩ5GϾA G551D 3120ϩ1GϾA R560T 3659delC N1303K 3849ϩ10kbCϾT Endocrine manifestations of CF CF-related diabetes mellitus (CFRDM) may present in adolescence. Login to comment

[hide] Heterogenous spectrum of CFTR gene mutations in In... Hum Reprod. 2009 May;24(5):1229-36. Epub 2009 Jan 30. Sharma N, Acharya N, Singh SK, Singh M, Sharma U, Prasad R
Heterogenous spectrum of CFTR gene mutations in Indian patients with congenital absence of vas deferens.
Hum Reprod. 2009 May;24(5):1229-36. Epub 2009 Jan 30., [PMID:19181743]

Abstract [show]
BACKGROUND: Mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene can cause congenital bilateral absence of vas deferens. Yet, the spectrum and frequency of CFTR mutations in Indian males with congenital absence of vas deferens (CAVD) is unknown. METHODS: We investigated 50 Indian males, diagnosed with unilateral or bilateral absence of vas deferens at the PGIMER, Chandigarh, for the presence of the most common CFTR gene mutations as well as unknown mutations by single-strand conformation polymorphism followed by sequence analysis. RESULTS: This study led to the identification of 12 CFTR gene mutations on 48% of 100 Indian CAVD chromosomes. CFTR mutations were identified on both alleles in 11 patients (22%) and on one allele in 26 patients (52%). Novel CFTR mutations identified were L69H, F87I, G126S, F157C, E543A, Y852F and D1270E. The T5 allele (25%) and F508del (11%) were the most common mutations identified. The most common intragenic marker haplotype for F508del was 2111 (GATT, TUB9, M470V and T854T). No mutations could be detected in 13 CAVD patients (26%), including 4 with renal malformations. CONCLUSIONS: This study confirms the molecular heterogeneity of CFTR mutations in CAVD. Although the mutation detection rate is indeed lower in Indian CAVD patients, 74% of the patients tested had at least one CFTR mutation. CAVD alleles with no mutations suggest that other changes may be located at the non-screened sites that require extensive search by direct sequencing. Furthermore, the novel CFTR mutations identified require functional studies in a cell-based system.

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56 CFTR mutations investigated by restriction analysis of PCR products were R334W (MspI), R347P (NcoI), A455E (AciI), 2789 þ 5 . Login to comment

[hide] A novel approach to CFTR mutation testing by pyros... Clin Chem. 2009 Jun;55(6):1083-91. Epub 2009 Apr 16. Bickmann JK, Kamin W, Wiebel M, Hauser F, Wenzel JJ, Neukirch C, Stuhrmann M, Lackner KJ, Rossmann H
A novel approach to CFTR mutation testing by pyrosequencing-based assay panels adapted to ethnicities.
Clin Chem. 2009 Jun;55(6):1083-91. Epub 2009 Apr 16., [PMID:19372188]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is a common autosomal recessive genetic disorder caused by a variety of sequence alterations in the CFTR gene [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)]. Because the relative prevalence of mutations strongly depends on the ethnic background, first-level testing of CF as defined by recent consensus recommendations ought to be adaptable to the ethnicity of patients. METHODS: We therefore developed and implemented a diagnostic approach to first-level testing for CF based on published mutation frequencies and Pyrosequencing (PSQ) technology that we complemented with standard procedures of mutation detection at the second level. RESULTS: The current test system of PSQ assays for 46 target CF mutations [including CFTRdele2,3 (21 kb) and 1342-6 (T)(n) (5T/7T/9T)] permits recombinations of single assays to optimize sensitivities for certain ethnicities. By easy expansion of the original mutation panel, the first-level test sensitivities with other ethnic groups would be increased, provided that the mutation frequencies are known. The test was validated with our local, ethnically mixed, but mainly German population (155 patients). The mutation-detection rate for the 92 patients whose CF was confirmed by the sweat test was 89.0% for the patients of German descent (73 of the 92 patients) and 73.7% for the patients of any other origin (19 of the 92 patients). Ethnicity-adapted testing panels for our foreign CF patients would increase the sensitivities for the respective groups by approximately 5%. CONCLUSIONS: PSQ-based genotyping is a reliable, convenient, highly flexible, and inexpensive alternative to conventional methods for first-level testing of CFTR, facilitating flexible adaptation of the analyzed mutation panel to any local ethnic group.

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62 We had initially focused on CF mutations potentially prevalent in our local, ethnically mixed, but mainly German population: F508del, I507del, 1677delTA, R347P, G542X, G551D, R553X, N1303K, 1717-1GϾA, 3849ϩ10kb CϾT, CFTRdele2,3 (21 kb), R117H, 1342-6 (T)n (5T/7T/9T) (reported by our laboratory only if a R117H allele was present, unless genetic analysis served to investigate a case of CBAVD or atypical mild CF), and the (TG)n region starting at base position 1342-12 of IVS 8 (exclusively tested in the case of a 5T allele) (Fig. 1, boldface text), with an expected sensitivity of 85% among German patients. Login to comment
100 Diagnostic evaluation of the PSQ-based first-level testing of a predominantly German CF population.a Panethnic population Clinical diagnosis All patients Sweat test-confirmed CF Suspected atypical CF Carrier screening Chromosomes, n 310 184 96 30 PSQ screen 168 (54.2%) 158 (85.9%) 5 (5.2%) 5 (33.3%) Conventional sequencing 25 (8.1%) 25 (13.6%) 0 (0%) 0 (0%) Total detected alleles 193 (62.3%) 183 (99.5%) 5 (5.2%) 5 (33.3%) German ethnicity Other ethnicities Clinical diagnosis Sweat test-confirmed CF Sweat test-confirmed CF Chromosomes, n 146 38 PSQ screen F508del 106 (72.6%) 14 (36.8%) I507del 1 (0.7%) 1 (2.6%) 1677delTA 0 (0%) 2 (5.3%) G551D 6 (4.1%) 0 (0%) R553X 2 (1.4%) 0 (0%) Q552X 1 (0.7%) 0 (0%) G542X 2 (1.4%) 1 (2.6%) S549N 0 (0%) 2 (5.3%) W1282X 1 (0.7%) 3 (7.9%) R117H 1 (0.7%) 0 (0%) 1342-12 (TG)11-5T 0 (0%) 0 (0%) R347P 2 (1.4%) 1 (2.6%) 3849ϩ10kb CϾT 2 (1.4%) 0 (0%) N1303K 3 (2.1%) 3 (7.9%) 1717-1 GϾA 1 (0.7%) 0 (0%) CFTRdele2,3 (21 kb) 2 (1.4%) 1 (2.6%) Sum 130 (89.0%) 28 (73.7%) Conventional sequencing 16 (11.0%) 9 (23.7%) Total detected alleles 146 (100%) 37 (97.4%) a Data are presented as the number of chromosomes (percent). Login to comment

[hide] Sweat gland bioelectrics differ in cystic fibrosis... Thorax. 2009 Nov;64(11):932-8. Epub 2009 Sep 3. Gonska T, Ip W, Turner D, Han WS, Rose J, Durie P, Quinton P
Sweat gland bioelectrics differ in cystic fibrosis: a new concept for potential diagnosis and assessment of CFTR function in cystic fibrosis.
Thorax. 2009 Nov;64(11):932-8. Epub 2009 Sep 3., [PMID:19734129]

Abstract [show]
BACKGROUND: For nearly 50 years the diagnosis of cystic fibrosis (CF) has depended on measurements of sweat chloride concentration. While the validity of this test is universally accepted, increasing diagnostic challenges and the search for adequate biomarker assays to support curative-orientated clinical drug trials have created a new demand for accurate, reliable and more practical CF tests. A novel concept is proposed that may provide a more efficient real-time method for assessing CFTR function in vivo. METHODS: Cholinergic and beta-adrenergic agonists were iontophoresed to stimulate sweating. The bioelectric potential from stimulated sweat glands (SPD) was measured in vivo using a standard ECG electrode applied to the skin surface. SPD and sweat chloride concentrations were compared in cohorts predicted to express a range of CFTR function as presented by healthy controls (HC), heterozygotes (Hz), pancreatic sufficient (CFPS) and pancreatic insufficient patients with CF (CFPI). RESULTS: The median SPD was hyperpolarized in patients with CF compared with control subjects (-47.4 mV vs -14.5 mV, p<0.001). In distinguishing between control and CF subjects, SPD (area under receiver operator curve (AUC) = 0.997) was similar to sweat chloride concentration (AUC = 0.986). Sequential cholinergic/beta-adrenergic sweat stimulation dramatically depolarised the SPD in patients with CF (p<0.001) but had no effect in control subjects (p = 0.6) or on the sweat chloride concentration in either group (p>0.5). Furthermore, the positive SPD response was larger in CFPI than in CFPS subjects (p = 0.04). CONCLUSION: These results support the concept that skin surface voltages arising from stimulated sweat glands can be exploited to assess expressed CFTR function in vivo and may prove to be a useful diagnostic tool.

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68 Table 1 Summary of study subjects ID Category Sex Age Genotype ID Category Sex Age Genotype 1 HC F 49 +/+ 21 CFPS M 46 deltaF508/P67L 2 HC F 39 +/+ 22 CFPS F 41 deltaF508/R117C 3 HC M 32 +/+ 23 CFPS F 57 G542X/D1152H 4 HC M 23 +/+ 24 CFPS M 34 deltaF508/M1101K 5 HC F 28 +/+ 25 CFPS F 29 deltaF508/L1335P 6 HC M 26 +/+ 26 CFPS F 48 deltaF508/+ 7 HC M 26 R75Q/+ 27 CFPS M 26 deltaF508/R117H 8 HC M 30 +/+ 28 CFPS M 44 deltaF508/3272_26A.G 9 HC M 22 +/+ 29 CFPS M 46 deltaF508/R117H 5T 10 HC M 22 +/+ 30 CFPS M 48 R347P/2753-2A.G 11 Hz F 26 deltaF508/+ 31 CFPI M 29 deltaF508/deltaF508 12 Hz F 54 deltaF508/+ 32 CFPI M 29 deltaF508/2194inA 13 Hz F 24 deltaF508/+ 33 CFPI F 40 G551D/621+1 G.T 14 Hz F 33 deltaF508/+ 34 CFPI M 33 deltaF508/deltaF508 15 Hz M 25 deltaF508/+ 35 CFPI M 27 deltaF508/deltaF508 16 Hz F 37 deltaF508/+ 36 CFPI M 25 deltaF508/deltaF508 17 Hz F 49 deltaF508/+ 37 CFPI M 27 deltaF508/deltaF508 18 Hz M 49 deltaF508/+ 38 CFPI M 29 deltaF508/deltaF508 19 Hz F 55 deltaF508/+ 20 Hz M 61 deltaF508/+ CFPI, pancreatic-insufficient CF patients; CFPS, pancreatic-sufficient CF patients; HC, healthy controls; Hz, heterozygotes. Login to comment

[hide] Genetics of cystic fibrosis. Semin Respir Crit Care Med. 2009 Oct;30(5):531-8. Epub 2009 Sep 16. Lommatzsch ST, Aris R
Genetics of cystic fibrosis.
Semin Respir Crit Care Med. 2009 Oct;30(5):531-8. Epub 2009 Sep 16., [PMID:19760540]

Abstract [show]
Cystic fibrosis (CF) is a complicated disease involving many organ systems. Identification of the cystic fibrosis transmembrane regulator (CFTR) genetic code has not only enhanced our understanding of the mechanism of CF pathology but has also provided explanations for phenotypic variation. Additionally, genetic testing has refined our ability to identify patients with CF and CF-related illnesses. Genetic mutations may be grouped by class (I-VI) and are directly related to the quantity of CFTR protein produced. This has direct implications regarding the severity of disease and has suggested organ-specific sensitivity to the presence of normally functioning CFTR. Further, it has improved understanding of the mechanism behind seemingly organ-specific manifestations of CF, such as congenital bilateral absence of the vas deferens (CBVAD).

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65 Class III mutations cause defective protein regulation due to alterations of NBD1 and NBD2 that prevent channel activation by cyclic adenosine monophosphate (cAMP) or adenosine triphosphate (ATP).6-8 Additionally, some mutations within this class alter the function of ion channels regulated by CFTR such as the outwardly rectifying chloride chan- nel26 and the ROMK2 potassium channel.27 Class IV mutations, such as R347P, R117H, and R334W, yield conduction abnormalities resulting in diminished chloride conductance. Login to comment

[hide] Non-classic cystic fibrosis associated with D1152H... Clin Genet. 2010 Apr;77(4):355-64. Epub 2009 Oct 15. Burgel PR, Fajac I, Hubert D, Grenet D, Stremler N, Roussey M, Siret D, Languepin J, Mely L, Fanton A, Labbe A, Domblides P, Vic P, Dagorne M, Reynaud-Gaubert M, Counil F, Varaigne F, Bienvenu T, Bellis G, Dusser D
Non-classic cystic fibrosis associated with D1152H CFTR mutation.
Clin Genet. 2010 Apr;77(4):355-64. Epub 2009 Oct 15., [PMID:19843100]

Abstract [show]
BACKGROUND: Limited knowledge exists on phenotypes associated with the D1152H cystic fibrosis transmembrane conductance regulator (CFTR) mutation. METHODS: Subjects with a D1152H allele in trans with another CFTR mutation were identified using the French Cystic Fibrosis Registry. Phenotypic characteristics were compared with those of pancreatic insufficient (PI) and pancreatic sufficient (PS) cystic fibrosis (CF) subjects in the Registry (CF cohort). RESULTS: Forty-two subjects with D1152H alleles were identified. Features leading to diagnosis included chronic sinopulmonary disease (n = 25), congenital absence of the vas deferens (n = 11), systematic neonatal screening (n = 4), and genetic counseling (n = 2). Median age at diagnosis was 33 [interquartile range (IQR, 24-41)] years in D1152H subjects. Median sweat chloride concentrations were 43.5 (39-63) mmol/l in D1152H subjects and were markedly lower than in PI and PS CF subjects (p < 0.05). Bronchiectasis was present in 67% of D1152H subjects, but Pseudomonas aeruginosa colonization and pancreatic insufficiency were present in <30% of subjects. Estimated rates of decline in forced expiratory volume in 1 s (FEV(1)) were lower in D1152H subjects vs PI CF subjects (p < 0.05). None of the D1152H subjects identified since 1999 had died or required lung transplantation. CONCLUSIONS: When present in trans with a CF-causing mutation, D1152H causes significant pulmonary disease, but all subjects had prolonged survival.

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42 The CF genetic analysis panel used in France seeks for 32 mutations: G85E, 394delTT, 621+1G>T, 711+1G>T, R334W, R347P, R347H, 1078delT, 5T/7T/9T, A455E, F508del, I507del, V520F, 1717-1G>A, G542X, G551D, R553X, R560T, S549R (T>G), S549N, 1898+1G>A, 2183AA>G, 2184delA, 2789+5G>A, 3120+1G>A, R1162X, 3659delC, 3849+10kbC>T, W1282X, 3905insT, 3876delA, N1303K. Login to comment

[hide] A 10-year large-scale cystic fibrosis carrier scre... J Cyst Fibros. 2010 Jan;9(1):29-35. Epub 2009 Nov 7. Picci L, Cameran M, Marangon O, Marzenta D, Ferrari S, Frigo AC, Scarpa M
A 10-year large-scale cystic fibrosis carrier screening in the Italian population.
J Cyst Fibros. 2010 Jan;9(1):29-35. Epub 2009 Nov 7., [PMID:19897426]

Abstract [show]
BACKGROUND: Cystic Fibrosis (CF) is one of the most common autosomal recessive genetic disorders, with the majority of patients born to couples unaware of their carrier status. Carrier screenings might help reducing the incidence of CF. METHODS: We used a semi-automated reverse-dot blot assay identifying the 47 most common CFTR gene mutations followed by DGGE/dHPLC analysis. RESULTS: Results of a 10-year (1996-2006) CF carrier screening on 57,999 individuals with no prior family history of CF are reported. Of these, 25,104 were couples and 7791 singles, with 77.9% from the Italian Veneto region. CFTR mutations were found in 1879 carriers (frequency 1/31), with DeltaF508 being the most common (42.6%). Subjects undergoing medically assisted reproduction (MAR) had significantly (p<0.0001) higher CF carrier frequency (1/22 vs 1/32) compared to non-MAR subjects. CONCLUSIONS: If coupled to counselling programmes, CF carrier screening tests might help reducing the CF incidence.

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48 Forty-seven different CFTR mutations/gene alterations were chosen and analysed: ΔF508, G85E, 541delC, D110H, R117H, 621+1G→T, 711+5G→A, R334W, R334Q, T338I, R347H, R347P, R352Q, S466X, ΔI507, E527G, 1717-1G→A, 1717-8G→A, G542X, S549N, S549R A→C, G551D, Q552X, R553X, D579G, 1874insT, E585X, 1898+3A→G, 2183AA→G, 2184delA, R709X, 2789+5G→A, 3132delTG, 3199del6, 3272-26A→G, L1077P, L1065P, R1066H, M1101K, D1152H, R1158X, R1162X, 3849+10KbC→T, G1244E, W1282X, N1303K and 4016insT. Login to comment

[hide] CFTR allelic heterogeneity in Brazil: historical a... J Hum Genet. 2010 Feb;55(2):71-6. Epub 2009 Nov 27. Faucz FR, Souza DA, Olandoski M, Raskin S
CFTR allelic heterogeneity in Brazil: historical and geographical perspectives and implications for screening and counseling for cystic fibrosis in this country.
J Hum Genet. 2010 Feb;55(2):71-6. Epub 2009 Nov 27., [PMID:19942933]

Abstract [show]
The goal of the present study was to provide a complete and updated spectrum of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene mutations in the Brazilian population combining all available in silico data for patients with CF in Brazil, including founder background and migration flow that consisted of the actual genetic pool of the Brazilian population. Information sources in international databases (PUBMED and SCIELO) were searched. The Brazilian population shows a wide variation in the frequency of CFTR mutations in states Rio Grande do Sul (RS), Santa Catarina (SC), Parana (PR), Sao Paulo (SP), Rio de Janeiro (RJ), Minas Gerais (MG), Para (PA) and Bahia (BA); this variation includes the most common mutation p.F508del. Apparently, this frequency variation is because of the different ethnic compositions. States such as SC and PR have a greater European admixture with almost 90% of CF alleles identified. In other states, such as BA, higher frequency of alleles that are common among African populations is seen. Overall, the CFTR mutational spectrum indicates the presence of European, African and Amerindian ethnic groups in the contemporary Brazilian CF patients. Here, we present an analysis of the CFTR allelic heterogeneity and discuss the origin of its genetic composition, in an attempt to provide improved perspective for the CF population screening in Brazil and genetic counseling.

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168 38 Morral, N., Llevadot, R., Casals, T., Gasparini, P., Macek, M., Do¨rk, T. et al. Independent origins of cystic fibrosis mutations R334W, R347P, R1162X and 3849+10kbC-T provide evidence of mutation recurrence in the CFTR gene. Am. J. Hum. Genet. 55, 890-898 (1994). Login to comment

[hide] Do common in silico tools predict the clinical con... Clin Genet. 2010 May;77(5):464-73. Epub 2009 Jan 6. Dorfman R, Nalpathamkalam T, Taylor C, Gonska T, Keenan K, Yuan XW, Corey M, Tsui LC, Zielenski J, Durie P
Do common in silico tools predict the clinical consequences of amino-acid substitutions in the CFTR gene?
Clin Genet. 2010 May;77(5):464-73. Epub 2009 Jan 6., [PMID:20059485]

Abstract [show]
Computational methods are used to predict the molecular consequences of amino-acid substitutions on the basis of evolutionary conservation or protein structure, but their utility in clinical diagnosis or prediction of disease outcome has not been well validated. We evaluated three popular computer programs, namely, PANTHER, SIFT and PolyPhen, by comparing the predicted clinical outcomes for a group of known CFTR missense mutations against the diagnosis of cystic fibrosis (CF) and clinical manifestations in cohorts of subjects with CF-disease and CFTR-related disorders carrying these mutations. Owing to poor specificity, none of tools reliably distinguished between individual mutations that confer CF disease from mutations found in subjects with a CFTR-related disorder or no disease. Prediction scores for CFTR mutations derived from PANTHER showed a significant overall statistical correlation with the spectrum of disease severity associated with mutations in the CFTR gene. In contrast, PolyPhen- and SIFT-derived scores only showed significant differences between CF-causing and non-CF variants. Current computational methods are not recommended for establishing or excluding a CF diagnosis, notably as a newborn screening strategy or in patients with equivocal test results.

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64 Mutations in the CFTR gene grouped by clinical category Cystic fibrosis CFTR-related disease No disease T338I D614G L320V V920L L90S M470V H199R S1251N I203M G550R P111A I148T Q1291H R560K L1388Q L183I R170H I1027T S549R D443Y P499A L1414S T908N R668C S549N A455E E1401K Q151K G27E I1234L Y563N R347P C866R S1118C P1290S R75Q A559T V520F P841R M469V E1401G P67L G85E S50Y E1409K R933G G458V G178R Y1032C R248T I980K G85V V392G L973P L137H T351S R334W I444S V938G R792G R560T R555G L1339F D1305E P574H V1240G T1053I D58G G551D L1335P I918M F994C S945L L558S F1337V R810G D1152H G1247R P574S R766M D579G W1098R H949R F200I R352Q L1077P K1351E M244K L206W M1101K D1154G L375F N1303K R1066C E528D D110Y R347H R1070Q A800G P1021S S549K A1364V V392A damaging` (is supposed to affect protein function or structure) and 'probably damaging` (high confidence of affecting protein function or structure). Login to comment
57 PI prevalence and in silico prediction scores for 13 most frequent missense mutations identified in Canadian CF patients Mutation Total PI Total (PI + PS) PI prevalence Class PANTHER scorea POLYPHENa SIFTa p.R334W 1 9 0.11 CF-PS -7.4419 Possibly damaging 0.01 p.P67L 2 14 0.14 CF-PS -4.1736 Probably damaging 0 p.R347P 2 12 0.17 CF-PS -7.5259 Possibly damaging 0.01 p.R347H 1 5 0.20 CF-PS -6.8327 Possibly damaging 0 p.A455E 8 39 0.21 CF-PS -8.8641 Probably damaging 0 p.L206W 4 19 0.21 CF-PS -8.5817 Possibly damaging 0 p.P574H 4 7 0.57 CF-PI/PSb -8.1252 Probably damaging 0 p.G85E 15 24 0.63 CF-PI/PSb -7.3194 Possibly damaging 0 p.M1101K 22 33 0.67 CF-PI/PSb -5.8849 Probably damaging 0.01 p.R1066C 7 8 0.88 CF-PI -7.7424 Probably damaging 0 p.G551D 56 59 0.95 CF-PI -9.5654 Probably damaging 0 p.N1303K 47 49 0.96 CF-PI -9.7687 Probably damaging 0 p.V520F 7 7 1.00 CF-PI -7.1652 Benign 0 aPANTHER scores range from zero to negative values (maximum -12). Login to comment
122 However, it completely misclassified other well-established mutations with low PI prevalence scores (p.L206W, p.R334W, p.R347P and p.A455E). Login to comment
126 However, two mutations with low PI prevalence scores (p.R347P and p.R334W) were also predicted to be deleterious (Fig. S1b, supporting information online). Login to comment
129 A disparity in prediction scores between two mild CF-PS mutations (p.R347H and p.R347P) that confer an amino acid change in the same position of the protein points to another limitation of these tools. Login to comment

[hide] Incidence, prevalence, etiology, and prognosis of ... Dig Dis Sci. 2010 Oct;55(10):2988-98. Epub 2010 Jan 28. Joergensen M, Brusgaard K, Cruger DG, Gerdes AM, de Muckadell OB
Incidence, prevalence, etiology, and prognosis of first-time chronic pancreatitis in young patients: a nationwide cohort study.
Dig Dis Sci. 2010 Oct;55(10):2988-98. Epub 2010 Jan 28., [PMID:20108119]

Abstract [show]
BACKGROUND/AIMS: Publications on etiology of chronic pancreatitis (CP) are infrequent. Etiologies today encompass genetic disorders. We wanted to describe etiologies of today and identify patients with genetic disorders like hereditary pancreatitis (HP), mutations in Serine Protease Inhibitor Kazal type1 (SPINK1), and the Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) among patients formerly considered to have idiopathic CP. METHODS: Data on patients diagnosed with first-time CP < 30 years of age in Denmark identified in the Danish National Registry of Patients were retrieved. Patients previously considered to have idiopathic pancreatitis were offered genetic counseling and evaluation for HP, SPINK1, and CFTR mutations. RESULTS: In the period 1980-2004, 580 patients < 30 years of age presented with CP, the standardized prevalence ratio of CP increased from 11.7 per 100,000 person years in 1980-1984 to 17.0 per 100,000 in 2000-2004 (p < 0.001). The odds ratio (OR) having gallstone-related CP increased in the latter time period, especially in women, that of alcohol-induced CP decreased over time. OR having idiopathic CP increased in the latter period; 50% of patients with idiopathic pancreatitis accepted genetic reevaluation; 28 patients had a genetic mutation that totally or partly could explain their pancreatitis, nine of these had two, and 11 patients had HP. CONCLUSION: The prevalence of CP, especially in women, increased over time. Genetic causes that partly or totally could explain the CP were found in 54.90% (95% CI (40.45-68.62)) of those with idiopathic CP, as a minimum estimation 1.9% (95% CI (1.00-3.47)) of the total cohort had HP.

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49 1G [ T, F508del, S549 N, I507del, S549R, 2184delA, G551D, G85E, N1303 K, R560T, R117H, R347H, R347P, R334 W, 2789 ? Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Am J Respir Crit Care Med. 2010 May 15;181(10):1078-84. Epub 2010 Feb 18. Bienvenu T, Sermet-Gaudelus I, Burgel PR, Hubert D, Crestani B, Bassinet L, Dusser D, Fajac I
Cystic fibrosis transmembrane conductance regulator channel dysfunction in non-cystic fibrosis bronchiectasis.
Am J Respir Crit Care Med. 2010 May 15;181(10):1078-84. Epub 2010 Feb 18., 2010-05-15 [PMID:20167849]

Abstract [show]
RATIONALE: Although in patients with diffuse bronchiectasis (DB) and a normal sweat test the presence of one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is frequently observed, its pathogenic role in the development of DB remains unclear. OBJECTIVES: To evaluate the association between CFTR heterozygosity and CFTR protein dysfunction in the airways of patients with DB. METHODS: Nasal potential difference was measured in 122 patients with DB of unknown origin and with a normal sweat test (Cl(-) < 60 mmol/L). They were classified according to the presence of CFTR mutations: zero (85 patients), one (22 patients), or two mutations (15 patients). Control groups comprised 26 healthy subjects, 38 obligate heterozygotes for CFTR, and 92 patients with classic cystic fibrosis (CF) with an abnormal sweat test (Cl(-) > or = 60 mmol/L). Patients classified as mild-CF were carrying at least one mild mutation and patients classified as severe-CF were homozygous for the F508del mutation. MEASUREMENTS AND MAIN RESULTS: There was a continuum of airway CFTR dysfunction in the study population as shown by nasal potential difference measurements, ranging from normal values in healthy subjects, to intermediate values in subjects with DB, to highly abnormal values in subjects classified as severe-CF. This continuum of airway CFTR dysfunction was thus strongly associated with defects in the CFTR gene. Moreover, among patients with DB, a similar continuum in intermediate nasal potential difference was identified that was associated with the bearing of zero, one, or two CFTR mutations. These electrophysiological phenotypes and CFTR genotypes were also associated with the clinical phenotype, as shown by the frequency of Staphylococcus aureus and Pseudomonas aeruginosa bronchial colonization. CONCLUSIONS: Our study supports the hypothesis that a unique CFTR mutation may have pathogenic consequences in patients with DB.

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58 In DB-1, 12 patients carried a severe loss-of-function mutation: 3 patients carried a class 1 mutation (G542X, 2183AA.G, and W1282X), and 9 patients carried the F508del class 2 mutation; 10 patients carried a mild mutation predicted to retain some residual CFTR function: 7 patients carried the IVS8-5T class 5 mutation, and 3 patients carried a class 4 mutation (S1235R, R347P-I148T, and R117H-7T) (Table 1). Login to comment
79 GENOTYPE AND PHENOTYPE OF PATIENTS WITH DIFFUSE BRONCHIECTASIS BEARING ONE CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR MUTATION Patient No. Age (yr) Sex (M/F) CFTR Mutation Sweat Cl2 (mmol/L) Basal PD (mV) NPD Index Age at Onset (yr) FEV1 (% pred) Bacterial Colonization 1 46 F F508del/2 10 215 0.44 20 124 Pa 2 51 M S1235R/2 8 219 0.56 10 40 Sa/Pa 3 19 F R347P-I148T/2 13 219 0.48 10 91 None 4 31 F F508del/2 35 220 0.20 2 76 None 5 34 M IVS8-5T/2 10 221 0.51 2 27 None 6 49 F IVS8-5T/2 15 222 0.30 40 92 None 7 20 F IVS8-5T/2 13 223 0.42 16 90 None 8 38 M F508del/2 9 224 0.85 20 ND None 9 65 M F508del/2 21 224 0.88 60 99 None 10 52 F F508del/2 20 226 0.37 5 91 Pa 11 72 F G542X/2 15 226 0.37 40 68 None 12 67 F IVS8-5T/2 26 226 0.82 40 97 None 13 51 F W1282X/2 17 228 0.12 29 27 Pa 14 59 M R117H-7T/2 31 229 0.88 49 89 None 15 56 F F508del/2 17 230 0.41 40 75 None 16 49 F F508del/2 21 232 0.58 45 67 None 17 46 F 2183AA.G/2 23 233 0.26 45 132 None 18 19 F IVS8-5T/2 19 234 0.45 5 82 None 19 70 M IVS8-5T/2 20 238 0.34 50 64 None 20 22 F F508del/2 25 241 0.86 20 82 Sa 21 77 M IVS8-5T/2 26 242 1.00 65 86 None 22 73 M F508del/2 21 245 0.91 25 70 Pa Definition of abbreviations: Cl2 5 chloride; F 5 female; M 5 male; ND 5 not determined; NPD index 5 nasal potential difference index 5 e(response to øCl2 and iso/response to amil); a cut off . Login to comment

[hide] Impact of gene patents and licensing practices on ... Genet Med. 2010 Apr;12(4 Suppl):S194-211. Chandrasekharan S, Heaney C, James T, Conover C, Cook-Deegan R
Impact of gene patents and licensing practices on access to genetic testing for cystic fibrosis.
Genet Med. 2010 Apr;12(4 Suppl):S194-211., [PMID:20393308]

Abstract [show]
Cystic fibrosis is one of the most commonly tested autosomal recessive disorders in the United States. Clinical cystic fibrosis is associated with mutations in the CFTR gene, of which the most common mutation among Caucasians, DeltaF508, was identified in 1989. The University of Michigan, Johns Hopkins University, and the Hospital for Sick Children, where much of the initial research occurred, hold key patents on cystic fibrosis genetic sequences, mutations, and methods for detecting them. Several patents, including the one that covers detection of the DeltaF508 mutation, are jointly held by the University of Michigan and the Hospital for Sick Children in Toronto, with Michigan administering patent licensing in the United States. The University of Michigan broadly licenses the DeltaF508 patent for genetic testing with >60 providers of genetic testing to date. Genetic testing is now used in newborn screening, diagnosis, and for carrier screening. Interviews with key researchers and intellectual property managers, a survey of laboratories' prices for cystic fibrosis genetic testing, a review of literature on cystic fibrosis tests' cost-effectiveness, and a review of the developing market for cystic fibrosis testing provide no evidence that patents have significantly hindered access to genetic tests for cystic fibrosis or prevented financially cost-effective screening. Current licensing practices for cystic fibrosis genetic testing seem to facilitate both academic research and commercial testing. More than 1000 different CFTR mutations have been identified, and research continues to determine their clinical significance. Patents have been nonexclusively licensed for diagnostic use and have been variably licensed for gene transfer and other therapeutic applications. The Cystic Fibrosis Foundation has been engaged in licensing decisions, making cystic fibrosis a model of collaborative and cooperative patenting and licensing practice.

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182 The ACMG specifically indicated that "Asian-Americans and Native Americans without significant Caucasian admixture should be informed of Table 1 Recommended core mutation panel for cystic fibrosis carrier screening in the general population Standard mutation panel R560T, ⌬F508a , R553Xb , R1162X, ⌬I507, 2184delA, G542X, G551Db , W1282X, N1303K, 621ϩ1G⌬T, R117H, 1717-1G⌬A, A455E, G85E, R334W, R347P, 711ϩ1G⌬T, 1898ϩ1G⌬A, 3849ϩ10kbC⌬T, 2789ϩ5G⌬A, 3659delC, and 3120ϩ1G⌬A Additional testable mutations I506Vc , I507Vc , F508Cc , and 5T/ 7T/9Td a University of Michigan/HSC Patent No. US 5,776,677. b Johns Hopkins University, Patent No. US 5,407,796. c Benign variants. Login to comment

[hide] Carrier screening for cystic fibrosis. Obstet Gynecol Clin North Am. 2010 Mar;37(1):47-59, Table of Contents. Dungan JS
Carrier screening for cystic fibrosis.
Obstet Gynecol Clin North Am. 2010 Mar;37(1):47-59, Table of Contents., [PMID:20494257]

Abstract [show]
Cystic fibrosis is the first genetic disorder for which universal screening of preconceptional or prenatal patients became a component of standard prenatal care. The molecular genetics and mutation profile of the CFTR gene are complex, with a wide range of phenotypic consequences. Carrier screening can facilitate risk assessment for prospective parents to have an affected offspring, although there remains a small residual risk for carrying a mutation even with a negative screening result. There are ethnic differences with respect to disease incidence and effectiveness of carrier testing, which may complicate counseling.

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102 However, in instances of a positive family history of affected individuals, but with no known mutation, further Table 2 Mutation panel recommended by ACOG and ACMG (listed in order of decreasing frequency in non-Hispanic Caucasian population) F508 del delI507 R347P R1162X G542X R553X 71111G>T 2184delA G551D R117H R560T 189811G>A 62111G>T 3849110kbC>T 3569delC R334W W1282X 1717À1G>T A455E 312011G>T N1303K 278915G>A G85E Data from Watson MS, Cutting GR, Desnick RJ, et al. Cystic fibrosis population carrier screening: 2004 revision of American College of Medical Genetics mutation panel. Login to comment

[hide] Identification of the second CFTR mutation in pati... Asian J Androl. 2010 Nov;12(6):819-26. Epub 2010 Jul 26. Giuliani R, Antonucci I, Torrente I, Grammatico P, Palka G, Stuppia L
Identification of the second CFTR mutation in patients with congenital bilateral absence of vas deferens undergoing ART protocols.
Asian J Androl. 2010 Nov;12(6):819-26. Epub 2010 Jul 26., [PMID:20657600]

Abstract [show]
Congenital bilateral absence of vas deferens (CBAVD) is a manifestation of the mildest form of cystic fibrosis (CF) and is characterized by obstructive azoospermia in otherwise healthy patients. Owing to the availability of assisted reproductive technology, CBAVD patients can father children. These fathers are at risk of transmitting a mutated allele of the CF transmembrane conductance regulator (CFTR) gene, responsible for CF, to their offspring. The identification of mutations in both CFTR alleles in CBAVD patients is a crucial requirement for calculating the risk of producing a child with full-blown CF if the female partner is a healthy CF carrier. However, in the majority of CBAVD patients, conventional mutation screening is not able to detect mutations in both CFTR alleles, and this difficulty hampers the execution of correct genetic counselling. To obtain information about the most represented CFTR mutations in CBAVD patients, we analysed 23 CBAVD patients, 15 of whom had a single CFTR mutation after screening for 36 mutations and the 5T allele. The search for the second CFTR mutation in these cases was performed by using a triplex approach: (i) first, a reverse dot-blot analysis was performed to detect mutations with regional impact; (ii) next, multiple ligation-dependent probe amplification assays were conducted to search for large rearrangements; and (iii) finally, denaturing high-performance liquid chromatography was used to search for point mutations in the entire coding region. Using these approaches, the second CFTR mutation was detected in six patients, which increased the final detection rate to 60.8%.

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58 INNO-LiPA CFTR19 INNO-LiPA CFTR17 INNO-LiPA CFTR Italian regional [delta]F508 621+1G>T 1259insA G542X 3849+10kbC>T 4016insT N1303K 2183AA>G 4382delA W1282X 394delTT 852del22 G551D 2789+5G> A R1162X D579G 1717-1G>A 3659delC G1244E R553X R117H G1349D CFTRdele2,3 (21 kb) R334W I502T [delta]I507 R347P L1065P 711+1G>T G85E R1158X 3272-26A>G 3905insT 1078delT T338I R560T A455E S549R(A>C) 1898+1G>A S1251N 2143delA 711+5G>A 991del5 I148T E60X D1152H 3199del6 3120+1G>A 2184delA 1898+3A>G, R1070Q Q552X Poli-T tract variations R1066H R347H 621+3A>G R334Q E217G Abbreviation: CFTR, cystic fibrosis transmembrane conductance regulator. Login to comment

[hide] Mutations that permit residual CFTR function delay... Respir Res. 2010 Oct 8;11:140. Green DM, McDougal KE, Blackman SM, Sosnay PR, Henderson LB, Naughton KM, Collaco JM, Cutting GR
Mutations that permit residual CFTR function delay acquisition of multiple respiratory pathogens in CF patients.
Respir Res. 2010 Oct 8;11:140., [PMID:20932301]

Abstract [show]
BACKGROUND: Lung infection by various organisms is a characteristic feature of cystic fibrosis (CF). CFTR genotype effects acquisition of Pseudomonas aeruginosa (Pa), however the effect on acquisition of other infectious organisms that frequently precede Pa is relatively unknown. Understanding the role of CFTR in the acquisition of organisms first detected in patients may help guide symptomatic and molecular-based treatment for CF. METHODS: Lung infection, defined as a single positive respiratory tract culture, was assessed for 13 organisms in 1,381 individuals with CF. Subjects were divided by predicted CFTR function: 'Residual': carrying at least one partial function CFTR mutation (class IV or V) and 'Minimal' those who do not carry a partial function mutation. Kaplan-Meier estimates were created to assess CFTR effect on age of acquisition for each organism. Cox proportional hazard models were performed to control for possible cofactors. A separate Cox regression was used to determine whether defining infection with Pa, mucoid Pa or Aspergillus (Asp) using alternative criteria affected the results. The influence of severity of lung disease at the time of acquisition was evaluated using stratified Cox regression methods by lung disease categories. RESULTS: Subjects with 'Minimal' CFTR function had a higher hazard than patients with 'Residual' function for acquisition of 9 of 13 organisms studied (HR ranging from 1.7 to 3.78 based on the organism studied). Subjects with minimal CFTR function acquired infection at a younger age than those with residual function for 12 of 13 organisms (p-values ranging: < 0.001 to 0.017). Minimal CFTR function also associated with younger age of infection when 3 alternative definitions of infection with Pa, mucoid Pa or Asp were employed. Risk of infection is correlated with CFTR function for 8 of 9 organisms in patients with good lung function (>90%ile) but only 1 of 9 organisms in those with poorer lung function (<50%ile). CONCLUSIONS: Residual CFTR function correlates with later onset of respiratory tract infection by a wide spectrum of organisms frequently cultured from CF patients. The protective effect conferred by residual CFTR function is diminished in CF patients with more advanced lung disease.

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74 For Pa, the hazard ratio Table 1 Classification of CFTR alleles Category Mutation Specific mutations Class I Defective Protein Synthesis (nonsense, frameshift, aberrant splicing) 1078delT, 1154 insTC, 1525-2A > G, 1717-1G > A, 1898+1G > A, 2184delA, 2184 insA, 3007delG, 3120+1G > A, 3659delC, 3876delA, 3905insT, 394delTT, 4010del4, 4016insT, 4326delTC, 4374+1G > T, 441delA, 556delA, 621+1G > T, 621-1G > T, 711+1G > T, 875+1G > C, E1104X, E585X, E60X, E822X, G542X, G551D/R553X, Q493X, Q552X, Q814X, R1066C, R1162X, R553X, V520F, W1282X, Y1092X Class II Abnormal Processing and Trafficking A559T, D979A, ΔF508, ΔI507, G480C, G85E, N1303K, S549I, S549N, S549R Class III Defective Channel Regulation/Gating G1244E, G1349D, G551D, G551S, G85E, H199R, I1072T, I48T, L1077P, R560T, S1255P, S549 (R75Q) Class IV Decreased Channel Conductance A800G, D1152H, D1154G, D614G, delM1140, E822K, G314E, G576A, G622D, G85E, H620Q, I1139V, I1234V, L1335P, M1137V, P67L, R117C, R117P, R117H, R334W, R347H, R347P, R347P/ R347H, R792G, S1251N, V232D Class V Reduced Synthesis and/or Trafficking 2789+5G > A, 3120G > A, 3272-26A > G, 3849+10kbC > T, 5T variant, 621+3A > G, 711+3A > G, A445E, A455E, IVS8 poly T, P574H was increased 3 fold for those with 'Minimal` function when compared to those with 'Residual` function. Login to comment

[hide] Distribution of CFTR mutations in Eastern Hungaria... J Cyst Fibros. 2011 May;10(3):217-20. doi: 10.1016/j.jcf.2010.12.009. Epub 2011 Feb 4. Ivady G, Madar L, Nagy B, Gonczi F, Ajzner E, Dzsudzsak E, Dvorakova L, Gombos E, Kappelmayer J, Macek M Jr, Balogh I
Distribution of CFTR mutations in Eastern Hungarians: relevance to genetic testing and to the introduction of newborn screening for cystic fibrosis.
J Cyst Fibros. 2011 May;10(3):217-20. doi: 10.1016/j.jcf.2010.12.009. Epub 2011 Feb 4., [PMID:21296036]

Abstract [show]
BACKGROUND: The aim of this study was characterization of an updated distribution of CFTR mutations in a representative cohort of 40 CF patients with the classical form of the disease drawn from Eastern Hungary. Due to the homogeneity of the Hungarian population our data are generally applicable to other regions of the country, including the sizeable diaspora. METHODS: We utilized the recommended "cascade" CFTR mutation screening approach, initially using a commercial assay, followed by examination of the common "Slavic" deletion CFTRdele2,3(21kb). Subsequently, the entire CFTR coding region of the CFTR gene was sequenced in patients with yet unidentified mutations. RESULTS: The Elucigene CF29(Tm) v2 assay detected 81.25% of all CF causing mutations. An addition of the CFTRdele2,3(21kb) increased the mutation detection rate to 86.25%. DNA sequencing enabled us to identify mutations on 79/80 CF alleles. Mutations [CFTRdele2,3(21kb), p.Gln685ThrfsX4 (2184insA) were found at an unusually high frequency, each comprising 5.00% of all CF alleles. CONCLUSION: We have identified common CF causing mutations in the Hungarian population with the most common mutations (p.Phe508del, p.Asn1303Lys, CFTRdele2,3(21kb), 2184insA, p.Gly542X, and p.Leu101X), comprising over 93.75% of all CF alleles. Obtained data are applicable to the improvement of DNA diagnostics in Hungary and beyond, and are the necessary prerequisite for the introduction of a nationwide "two tier" CF newborn screening program.

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77 CFTR mutation Germany 1994 Romania 2008 Austria 1997 Slovakia 2008 Hungary 1992 This study deltaF508 (c.1521_1523 delCTT) 72.0% 56.3% 74.6% 38.2% 64.3% 70.0% G551D (c.1652 GNA) 1.0% N/F 1.6% N/F N/F N/F R553X (c.1657 CNT) 2.3% N/F N/F 1.2% 2.4% N/F G542X (c.1624 GNT) 1.4% 3.9% 2.4% 2.4% 1.2% 3.75% 621+1 GNT (c.489+1 GNT) 0.1% 0.8% N/F N/F N/F N/F 1717-1 GNA (c.1585-1 GNA) 0.9% N/F 0.8% 0.6% 1.2% 1.25% W1282X (c.3846 GNA) 0.7% 2.3% N/F N/F 1.2% N/F N1303K (c.3909 CNG) 2.3% 0.8% N/F 1.2% 1.2% 5.0% R347P (c.1040 GNC) 1.6% N/F 1.6% 1.2% N/A 1.25% CFTRdele2,3(21 kb) 1.5%a 1.6% 2.6%a 1.1%a N/A 5.0% 2184insA (c.2052_2053 insA) 0.6% N/F N/F 2.4% N/A 5.0% L101X (c.302 TNG) N/F N/F N/F N/F N/A 2.5% Q220X (c.658 CNT) N/F N/F N/F N/F N/A 1.25% S466X (c.1397 CNG) N/F N/F N/F N/F N/A 1.25% E831X (c.2491 GNT) N/F N/F N/F 0.6% N/A 1.25% Y1092X (c.3276 CNA) 0.3% N/F N/F N/F N/A 1.25% Legend: data for Germany [8], Romania [9], Austria [10], Slovakia [11] and Hungary [3]; N/A: not analyzed; N/F: not found, a frequencies reported by Dork et al. in 2000 [6], mutations included in the Elucigene CF29 v2 assay are formatted in italics; the original "legacy name" is followed by the recommended mutation nomenclature [17]. Login to comment
34 3528delC), p.Phe316LeufsX12 (c.948delT), p.Ile507del (c.1519_1521delATC), p.Arg347Pro (c.1040 G NC), p.Arg553X (c.1657 C NT), p.Glu60X (c.178 GNT), c.2988+1 GNA, c.2657+5 GNA, c.1766+1 GNA, c.579+1 GNT, p.Gly85Glu (c.254 GNA), c.p.Lys684AsnfsX38 (c.2052delA), and p.Arg560Thr (c.1679 GNC). Login to comment

[hide] Association between genotype and pulmonary phenoty... J Cyst Fibros. 2011 May;10(3):187-92. doi: 10.1016/j.jcf.2011.01.005. Epub 2011 Feb 26. Geborek A, Hjelte L
Association between genotype and pulmonary phenotype in cystic fibrosis patients with severe mutations.
J Cyst Fibros. 2011 May;10(3):187-92. doi: 10.1016/j.jcf.2011.01.005. Epub 2011 Feb 26., [PMID:21354377]

Abstract [show]
BACKGROUND: Despite numerous studies a clear relationship between genotype and pulmonary phenotype has not been established within the group pancreatic insufficient cystic fibrosis (CF) patients. We studied the relationship between class I and class II mutations and pulmonary function in Swedish patients with known CFTR functional classification. METHODS: 170 CF patients with two class II mutations, 18 with two class I mutations and 78 with a combination of class I and II mutations were included in the study. Spirometry was performed when patients were in an optimal clinical condition. RESULTS: Patients with two class I mutations had lower lung function (FEV(1) and FVC) compared to the group with either a combination of class I and II mutations or two class II mutations. CONCLUSION: CF patients carrying two class I mutations risk developing more severe lung disease compared to patients with at least one class II mutation.

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98 Class I Class II Class III Class IV Class V 1717-1 G-NA F508del G551D 297 C-NA 2789+5 G-NA 3659delC S945L R560T R117C 3849+10 kb CNT 394delTT R347P A455E R553X T 3381 3849+10 kb C-T 621+1 G-NT E60X G542X W79R W1282X decline of pulmonary function was more rapid in patients with pancreatic insufficiency, mainly class II mutations, compared to CF patients with normal pancreatic function [4]. Login to comment

[hide] Optimal DNA tier for the IRT/DNA algorithm determi... J Cyst Fibros. 2011 Jul;10(4):278-81. Epub 2011 Mar 8. Baker MW, Groose M, Hoffman G, Rock M, Levy H, Farrell PM
Optimal DNA tier for the IRT/DNA algorithm determined by CFTR mutation results over 14 years of newborn screening.
J Cyst Fibros. 2011 Jul;10(4):278-81. Epub 2011 Mar 8., [PMID:21388895]

Abstract [show]
BACKGROUND: There has been great variation and uncertainty about how many and what CFTR mutations to include in cystic fibrosis (CF) newborn screening algorithms, and very little research on this topic using large populations of newborns. METHODS: We reviewed Wisconsin screening results for 1994-2008 to identify an ideal panel. RESULTS: Upon analyzing approximately 1 million screening results, we found it optimal to use a 23 CFTR mutation panel as a second tier when an immunoreactive trypsinogen (IRT)/DNA algorithm was applied for CF screening. This panel in association with a 96th percentile IRT cutoff gave a sensitivity of 97.3%, but restricting the DNA tier to F508del was associated with 90% (P<.0001). CONCLUSIONS: Although CFTR panel selection has been challenging, our data show that a 23 mutation method optimizes sensitivity and is advantageous. The IRT cutoff value, however, is actually more critical than DNA in determining CF newborn screening sensitivity.

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46 Year Mutation 1 Mutation 2 IRTa Age at diagnosis Sweat test results (mmol/L)b Cause of false negative 1995 p. R553X Unknown 53 (56) 4 months old 94 IRT below the cut-off 1996 p. R553X p. R1161X 64 (56) 6 weeks old 109 F508del alone as the 2nd tier 1997 p. R347P Unknown 82 (56) 7 weeks old 108 F508del alone as the 2nd tier 2000 3007delG Unknown 99 (64) 9 months old 110 Rare mutations 2001 Unknown Unknown 44 (66) 7 years old 59 IRT below the cut-off 2002 p. G551D p. Q1291Hc 53 (64) 4 years old 77 IRT below the cut-off 2003 F508del F508del 45 (51) 1 year old 121 IRT below the cut-off 2004 p. R170Hc Unknown 13 (62) 3 years old 66 IRT below the cut-off a IRT was reported as ng/mL. Login to comment
75 CFTR mutationa Proportion of allele Frequency of allele (%) Cumulative detection (%)b F508del 137/214 64.02 92.52 3849+10KbCNT 6/214 2.80 92.52c G542X 5/214 2.34 94.39 N1303K 4/214 1.87 98.13 R117H 4/214 1.87 99.07 R553X 3/214 1.40 99.07 1717-1GNA 2/214 0.93 99.07 G551D 1/214 0.47 100 R347P 1/214 0.47 100 A455E 1/214 0.47 100 W1282X 1/214 0.47 100 621+1GNT 1/214 0.47 100 a The other 11 mutations in ACMG 23 mutation panel are G85E, 711+1GNT, R334W, I507del, R560T, 1898+1GNA, 2184delA, 2789+5GNA, 3120+1GNA, R1162X and 3659delC. Login to comment

[hide] Preconceptional identification of cystic fibrosis ... J Cyst Fibros. 2011 May;10(3):207-11. doi: 10.1016/j.jcf.2011.02.006. Epub 2011 Mar 22. Coiana A, Faa' V, Carta D, Puddu R, Cao A, Rosatelli MC
Preconceptional identification of cystic fibrosis carriers in the Sardinian population: A pilot screening program.
J Cyst Fibros. 2011 May;10(3):207-11. doi: 10.1016/j.jcf.2011.02.006. Epub 2011 Mar 22., [PMID:21429822]

Abstract [show]
BACKGROUND: In Sardinia the mutational spectrum of CFTR gene is well defined. A mutation detection rate of 94% can be achieved by screening for 15 CFTR mutations with a frequency higher than 0.5%. The efficiency of this molecular test suggests that Sardinians may represent a suitable population for a preconceptional screening. METHODS: Five hundred couples of Sardinia descent were screened for 38 mutations using a semi-automated reverse-dot blot and PCR-gel electrophoresis assays. This mutation panel included the 15 most frequent CF alleles in Sardinia. RESULTS: We identified 38 CF carriers, revealing an overall frequency of 1/25 (4%). The most common CF allele was the p.Thr338Ile (T338I) (65%), followed by the p.Phe508del (F508del) (22.5%). We also identified one couple at risk and an asymptomatic female homozygote for the p.Thr338Ile allele. CONCLUSIONS: In spite of the low number of the couples tested, the results herein reported demonstrate the efficacy and efficiency of the preconceptional screening program and the high participation rate of the Sardinian population (99%).

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88 Mutation nomenclaturea Alleles (%) T338I (p.Thr338Ile) 26 (65.0) F508del (p.Phe508del) 9 (22.5) N1303K (p.Asn1303Lys) 1 (2.5) 2183AANG (c.2051_2052delAAinsG) 1 (2.5) 621+1GNT (c.489+1GNT) 1 (2.5) exon 2 del (c.54-5811_164+2187del8108ins182) 1 (2.5) R347P (p.Arg347Pro) 1 (2.5) The 3849+10kbCNT (c.3717+12191CNT), G85E (p.Gly85Glu), 2789+5GNA (c.2657+5GNA), W1282X (p.Trp1282X), G1244E (p.Gly1244Glu), 711+5GNA (c.579+5GNA), 711+1GNT (c.579+1GNA), 4016insT (p.Ser1297PhefsX5), G542X (p.Gly542X), 1717-1GNA (c.1585-1GNA), R553X (p.Arg553X), Q552X (p.Gln552X), G551D (p.Gly551Asp), S549R (ANC) (p.Ser549Arg), I507del (p.Ile507del), F508C (p.Phe508Cys), I502T (p.Ile502Thr), 1706del17 (p.Gln525LeufsX37), 1677delTA (p.Tyr515X), R117H (p.Arg117His), D1152H (p.Asp1152His), L1065P (p.Leu1065Pro), R1066H (p.Arg1066His), L1077P (p.Leu1077Pro), 4382delA (p.Glu1418ArgfsX14), R1162X (p.Arg1162X), R1158X (p.Arg1158X), 1259 insA (p.Gln378AlafsX4), 852del22 (p.Gly241GlufsX13), S912X (p.Ser912X), and 991del5bp (p.Asn287LysfsX19) mutations included in the CF panel were not detected in the population tested. Login to comment
81 The p.Asn1303Lys, c.2051_2052delAAinsG, c.489+ 1GNT, c.54-5811_164+2187del8108ins182, and p.Arg347Pro mutations were found once, with a frequency of 2.5% each. Login to comment
82 The p.Arg347Pro mutation, never detected in Sardinian patients until now, was reported to have an overall frequency of 0.8% in the Italian population (WHO, [18]). Login to comment

[hide] Cystic fibrosis carrier testing in an ethnically d... Clin Chem. 2011 Jun;57(6):841-8. Epub 2011 Apr 7. Rohlfs EM, Zhou Z, Heim RA, Nagan N, Rosenblum LS, Flynn K, Scholl T, Akmaev VR, Sirko-Osadsa DA, Allitto BA, Sugarman EA
Cystic fibrosis carrier testing in an ethnically diverse US population.
Clin Chem. 2011 Jun;57(6):841-8. Epub 2011 Apr 7., [PMID:21474639]

Abstract [show]
BACKGROUND: The incidence of cystic fibrosis (CF) and the frequency of specific disease-causing mutations vary among populations. Affected individuals experience a range of serious clinical consequences, notably lung and pancreatic disease, which are only partially dependent on genotype. METHODS: An allele-specific primer-extension reaction, liquid-phase hybridization to a bead array, and subsequent fluorescence detection were used in testing for carriers of 98 CFTR [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)] mutations among 364 890 referred individuals with no family history of CF. RESULTS: One in 38 individuals carried one of the 98 CFTR mutations included in this panel. Of the 87 different mutations detected, 18 were limited to a single ethnic group. African American, Hispanic, and Asian individuals accounted for 33% of the individuals tested. The mutation frequency distribution of Caucasians was significantly different from that of each of these ethnic groups (P < 1 x 10(1)). CONCLUSIONS: Carrier testing using a broad mutation panel detects differences in the distribution of mutations among ethnic groups in the US.

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98 Of these mutations, p.R117H, c.3717ϩ 12191CϾT, and p.R347P are included in the ACMG panel, a finding consistent with that panel`s inclusion of mutations associated with mild or severe disease (19). Login to comment
123 CFTR mutationsa Individuals, n p.F508del/p.R117H 16 5T/9T 1 7T/9T 15 p.F508del/p.D1152H 3 p.R117H/p.R117H, 7T/7T 2 p.D1152H/p.D1152H 2 p.W1282X/p.D1152H 2 p.D1152H/p.G551D 1 c.3717ϩ12191CϾT/p.R352Q 1 c.3717ϩ12191CϾT/c.3717ϩ12191CϾT 1 p.F508del/c.3717ϩ12191CϾT 1 p.F508del/p.L206W 1 p.F508del/p.R117C 1 p.F508del/p.R347H 1 p.F508del/p.R347P 1 p.R117H/p.W1282X, 7T/7T 1 p.R117H/p.G551D, 7T/7T 1 p.R117H/p.G542X, 7T/9T 1 a Human Genome Variation Society nomenclature [Ogino et al. (23)]. Login to comment

[hide] Implementation of the first worldwide quality assu... Clin Chim Acta. 2011 Jul 15;412(15-16):1376-81. Epub 2011 Apr 14. Earley MC, Laxova A, Farrell PM, Driscoll-Dunn R, Cordovado S, Mogayzel PJ Jr, Konstan MW, Hannon WH
Implementation of the first worldwide quality assurance program for cystic fibrosis multiple mutation detection in population-based screening.
Clin Chim Acta. 2011 Jul 15;412(15-16):1376-81. Epub 2011 Apr 14., 2011-07-15 [PMID:21514289]

Abstract [show]
BACKGROUND: CDC's Newborn Screening Quality Assurance Program collaborated with several U.S. Cystic Fibrosis Care Centers to collect specimens for development of a molecular CFTR proficiency testing program using dried-blood spots for newborn screening laboratories. METHODS: Adult and adolescent patients or carriers donated whole blood that was aliquoted onto filter paper cards. Five blind-coded specimens were sent to participating newborn screening laboratories quarterly. Proficiency testing results were evaluated based on presumptive clinical assessment. Individual evaluations and summary reports were sent to each participating laboratory and technical consultations were offered if incorrect assessments were reported. RESULTS: The current CDC repository contains specimens with 39 different CFTR mutations. Up to 45 laboratories have participated in the program. Three years of data showed that correct assessments were reported 97.7% of the time overall when both mutations could be determined. Incorrect assessments that could have lead to a missed case occurred 0.9% of the time, and no information was reported 1.1% of the time due to sample failure. CONCLUSIONS: Results show that laboratories using molecular assays to detect CFTR mutations are performing satisfactorily. The programmatic results presented demonstrate the importance and complexity of providing proficiency testing for DNA-based assays.

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129 Allele Allele Allele Allele p.Gly85Glu G85E (0.26) p.Arg117His R117H (0.54) c.489+1 GNT 621+1 GNT (1.3) p.Phe508del F508del (66.31) p.Arg347Pro R347P (0.36) p.lle507del I507del (0.90) p.Gly551Asp G551D (1.93) c.2052delA 2184delA (0.15) c.1585-1 GNA 1717-1 GNA (0.44) p.Gly542X G542X (2.64) c.3528delC 3659delC (0.28) p.Asn1303Lys N1303K (1.27) p.Arg553X R553X (1.21) p.Arg560Thr R560T (0.30) p.Arg1162X R1162X (0.30) c.2657+5 GNA 2789+5 GNA (0.38) c.3717+12191 CNT 3849+10kbCNT (0.85) c.2988+1 GNA 3120+1 GNA (0.86) p.Trp1282X W1282X (2.20) p.Ala455Glu A455E (0.26) c.1766+1 GNA 1898+1 GNA (0.13) c.579+1 GNT 711+1 GNT (0.35) p.Arg334Trp R334W (0.37) c.54-5940 _273+10250del21kb CFTR dele2,3 p.Ser549Asn S549N (0.14) c.1584 GNA 1716 G→A c.2051_2052delAAinsG 2183AANG (0.1) c.3140-26ANG 3272-26ANG c.262_263delTT 394delTT p.Arg1066Cys R1066C (0.03) p.Arg1066His R1066H c.1022_1023insTC 1154insTC c.2989-1 GNA 3121-1 GNA c.(?_2989)_(3139_? Login to comment

[hide] Clinical outcomes in infants with cystic fibrosis ... Pediatr Pulmonol. 2011 Apr 29. doi: 10.1002/ppul.21475. Ren CL, Desai H, Platt M, Dixon M
Clinical outcomes in infants with cystic fibrosis transmembrane conductance regulator (CFTR) related metabolic syndrome.
Pediatr Pulmonol. 2011 Apr 29. doi: 10.1002/ppul.21475., 2011-04-29 [PMID:21538969]

Abstract [show]
An unavoidable outcome of cystic fibrosis newborn screening (CF NBS) programs is the detection of infants with an indeterminate diagnosis. The United States CF Foundation recently proposed the term cystic fibrosis transmembrane conductance regulator related metabolic syndrome (CRMS) to describe infants with elevated immunoreactive trypsinogen (IRT) on NBS who do not meet diagnostic criteria for CF. The objective of this study was to describe the clinical outcomes of infants with CRMS identified through an IRT/DNA algorithm. We reviewed the records of all infants with CRMS diagnosed at our CF Center from 2002 to 2010. We identified 12 infants, and compared them to 27 infants diagnosed with CF by NBS. Compared to CF patients, CRMS patients were more likely to be pancreatic sufficient as assessed by fecal elastase measurement (100% vs. 8%, P < 0.01). Their weight for age percentile was normal from birth. A positive oropharyngeal (OP) culture for Pseudomonas aeruginosa (Pa) was found in 25% of CRMS patients. One patient with the F508del/R117H/7T genotype was reassigned the diagnosis of CF after he had a positive OP culture for Pa, and his follow up sweat Cl at 1 year of life was 73 mmol/L. CF patients were more likely to receive oral antibiotics and be hospitalized for pulmonary symptoms. Our results indicate that CRMS patients can develop signs of CF disease, but have a milder clinical course than CF infants. Close initial monitoring of these patients is warranted. Pediatr. Pulmonol. (c) 2011 Wiley-Liss, Inc.

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60 Infants in both groups received treatment with inhaled tobramycin if they had a positive Pa OP culture, and treatment in both groups was associated with eradication of TABLE 1-CFTR Gene Mutation Panel Used by New York CF NBS Program F508del I50e7del G542X G551D W1282X N1303K R553X 621þ1G>T R117H 1717-1G>A A455E R560T R1162X G85E R334W R347P 711þ1G>T 1898þ1G>A 2184delA 1078delT 3849þ10kbC>T 2789þ5G>A 3659delC I148T 3120þ1G>A 3876delA V520F S549R S549N 3849þ4 A-G 3905insT R347H Reflex testing for 5T polymorphism is performed if R117H is detected. Login to comment
61 Infants in both groups received treatment with inhaled tobramycin if they had a positive Pa OP culture, and treatment in both groups was associated with eradication of TABLE 1- CFTR Gene Mutation Panel Used by New York CF NBS Program F508del I50e7del G542X G551D W1282X N1303K R553X 621þ1G>T R117H 1717-1G>A A455E R560T R1162X G85E R334W R347P 711þ1G>T 1898þ1G>A 2184delA 1078delT 3849þ10kbC>T 2789þ5G>A 3659delC I148T 3120þ1G>A 3876delA V520F S549R S549N 3849þ4 A-G 3905insT R347H Reflex testing for 5T polymorphism is performed if R117H is detected. Login to comment

[hide] Application of high-resolution single-channel reco... Methods Mol Biol. 2011;741:419-41. Cai Z, Sohma Y, Bompadre SG, Sheppard DN, Hwang TC
Application of high-resolution single-channel recording to functional studies of cystic fibrosis mutants.
Methods Mol Biol. 2011;741:419-41., [PMID:21594800]

Abstract [show]
The patch-clamp technique is a powerful and versatile method to investigate the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel, its malfunction in disease and modulation by small molecules. Here, we discuss how the molecular behaviour of CFTR is investigated using high-resolution single-channel recording and kinetic analyses of channel gating. We review methods used to quantify how cystic fibrosis (CF) mutants perturb the biophysical properties and regulation of CFTR. By explaining the relationship between macroscopic and single-channel currents, we demonstrate how single-channel data provide molecular explanations for changes in CFTR-mediated transepithelial ion transport elicited by CF mutants.

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287 As a result, these CF mutants (e.g. R334W and R347P; 59, 60) diminish single-channel current amplitude (i). Login to comment

[hide] Pharmacological therapy for cystic fibrosis: from ... J Cyst Fibros. 2011 Jun;10 Suppl 2:S129-45. Becq F, Mall MA, Sheppard DN, Conese M, Zegarra-Moran O
Pharmacological therapy for cystic fibrosis: from bench to bedside.
J Cyst Fibros. 2011 Jun;10 Suppl 2:S129-45., [PMID:21658632]

Abstract [show]
With knowledge of the molecular behaviour of the cystic fibrosis transmembrane conductance regulator (CFTR), its physiological role and dysfunction in cystic fibrosis (CF), therapeutic strategies are now being developed that target the root cause of CF rather than disease symptoms. Here, we review progress towards the development of rational new therapies for CF. We highlight the discovery of small molecules that rescue the cell surface expression and defective channel gating of CF mutants, termed CFTR correctors and CFTR potentiators, respectively. We draw attention to alternative approaches to restore epithelial ion transport to CF epithelia, including inhibitors of the epithelial Na(+) channel (ENaC) and activators of the Ca(2+)-activated Cl(-) channel TMEM16A. The expertise required to translate small molecules identified in the laboratory to drugs for CF patients depends on our ability to coordinate drug development at an international level and our ability to provide pertinent biological information using suitable disease models.

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49 For example, the conductance of an open wild-type CFTR Cl-channel is ~8 pS, whereas that of R347P is only 2 pS [13]. Login to comment

[hide] Recommendations for the classification of diseases... J Cyst Fibros. 2011 Jun;10 Suppl 2:S86-102. Bombieri C, Claustres M, De Boeck K, Derichs N, Dodge J, Girodon E, Sermet I, Schwarz M, Tzetis M, Wilschanski M, Bareil C, Bilton D, Castellani C, Cuppens H, Cutting GR, Drevinek P, Farrell P, Elborn JS, Jarvi K, Kerem B, Kerem E, Knowles M, Macek M Jr, Munck A, Radojkovic D, Seia M, Sheppard DN, Southern KW, Stuhrmann M, Tullis E, Zielenski J, Pignatti PF, Ferec C
Recommendations for the classification of diseases as CFTR-related disorders.
J Cyst Fibros. 2011 Jun;10 Suppl 2:S86-102., [PMID:21658649]

Abstract [show]
Several diseases have been clinically or genetically related to cystic fibrosis (CF), but a consensus definition is lacking. Here, we present a proposal for consensus guidelines on cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs), reached after expert discussion and two dedicated workshops. A CFTR-RD may be defined as "a clinical entity associated with CFTR dysfunction that does not fulfil diagnostic criteria for CF". The utility of sweat testing, mutation analysis, nasal potential difference, and/or intestinal current measurement for the differential diagnosis of CF and CFTR-RD is discussed. Algorithms which use genetic and functional diagnostic tests to distinguish CF and CFTR-RDs are presented. According to present knowledge, congenital bilateral absence of vas deferens (CBAVD), acute recurrent or chronic pancreatitis and disseminated bronchiectasis, all with CFTR dysfunction, are CFTR-RDs.

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323 Using biochemical (N) and functional (i and Po) data, the apical CFTR Cl- current generated by the CF-PI mutant p.F508del-CFTR and the CF-PS mutants p.R117H-, p.R334W-, p.R347P-, p.A455E- and p.P574H-CFTR were predicted [166,167]. Login to comment

[hide] Pathology of pancreatic and intestinal disorders i... J R Soc Med. 1998;91 Suppl 34:40-9. Wilschanski M, Durie PR
Pathology of pancreatic and intestinal disorders in cystic fibrosis.
J R Soc Med. 1998;91 Suppl 34:40-9., [PMID:9709387]

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152 A small number of more Table 1 Classification of cystic fibrosis gene mutation as severe, mild or indeterminate with respect to pancreatic function Severe Mild Variable (classes 1, I/ or 111) (classes IV or V) (classes IV or V) AF508 R117H G85E 1148T R334W 2789+5G-*A G480C R347P G551D A455E R560T P574H N1303K 3849+1 Okb C-+T G542X G551S W1282X P5748 621 +1 G-T R352Q 1717-1G-T T3381 556delA Adapted from Ref 20 with permission recently described mutations [G85E and 278+5G-÷AI are less clearly determinant with respect to the pancreatic sufficient and pancreatic insufficient phenotypes. Login to comment

[hide] Mutations of the cystic fibrosis gene in patients ... N Engl J Med. 1998 Sep 3;339(10):645-52. Sharer N, Schwarz M, Malone G, Howarth A, Painter J, Super M, Braganza J
Mutations of the cystic fibrosis gene in patients with chronic pancreatitis.
N Engl J Med. 1998 Sep 3;339(10):645-52., 1998-09-03 [PMID:9725921]

Abstract [show]
BACKGROUND: The pancreatic lesions of cystic fibrosis develop in utero and closely resemble those of chronic pancreatitis. Therefore, we hypothesized that mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene may be more common than expected among patients with chronic pancreatitis. METHODS: We studied 134 consecutive patients with chronic pancreatitis (alcohol-related disease in 71, hyperparathyroidism in 2, hypertriglyceridemia in 1, and idiopathic disease in 60). We examined DNA for 22 mutations of the CFTR gene that together account for 95 percent of all mutations in patients with cystic fibrosis in the northwest of England. We also determined the length of the noncoding sequence of thymidines in intron 8, since the shorter the sequence, the lower the proportion of normal CFTR messenger RNA. RESULTS: The 94 male and 40 female patients ranged in age from 16 to 86 years. None had a mutation on both copies of the CFTR gene. Eighteen patients (13.4 percent), including 12 without alcoholism, had a CFTR mutation on one chromosome, as compared with a frequency of 5.3 percent among 600 local unrelated partners of persons with a family history of cystic fibrosis (P<0.001). A total of 10.4 percent of the patients had the 5T allele in intron 8 (14 of 134), which is twice the expected frequency (P=0.008). Four patients were heterozygous for both a CFTR mutation and the 5T allele. Patients with a CFTR mutation were younger than those with no mutations (P=0.03). None had the combination of sinopulmonary disease, high sweat electrolyte concentrations, and low nasal potential-difference values that are diagnostic of cystic fibrosis. CONCLUSIONS: Mutations of the CFTR gene and the 5T genotype are associated with chronic pancreatitis.

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32 DNA Studies We extracted DNA from buccal cells obtained by having the patients rinse their mouths with 10 ml of 4 percent sucrose.19 The CFTR locus was examined for the 22 mutations that together account for 95 percent of all such mutations in patients with cystic fibrosis in the northwest of England.20 The amplification- refractory mutation system Elucigene CF(4)m kit (Zeneca Diagnostics, Macclesfield, United Kingdom) was used to detect the four most common mutations: ∆F508, G551D, G542X, and 621+1(G→T)21; the polymerase chain reaction, restriction-enzyme analysis, and allele-specific oligonucleotide hybridization facilitated the detection of R560T, R117H, 1898+1(G→A), R553X, S549N, 1717¡1(G→A), N1303K, W1282X, E60X, 1154insTC, R347P, 3659delC, Q493X, V520F, R334W, ∆I507, 3849+10Kb(C→T), and 1078delT. Login to comment

[hide] Relation between mutations of the cystic fibrosis ... N Engl J Med. 1998 Sep 3;339(10):653-8. Cohn JA, Friedman KJ, Noone PG, Knowles MR, Silverman LM, Jowell PS
Relation between mutations of the cystic fibrosis gene and idiopathic pancreatitis.
N Engl J Med. 1998 Sep 3;339(10):653-8., 1998-09-03 [PMID:9725922]

Abstract [show]
BACKGROUND: It is unknown whether genetic factors predispose patients to idiopathic pancreatitis. In patients with cystic fibrosis, mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene typically cause pulmonary and pancreatic insufficiency while rarely causing pancreatitis. We examined whether idiopathic pancreatitis is associated with CFTR mutations in persons who do not have lung disease of cystic fibrosis. METHODS: We studied 27 patients (mean age at diagnosis, 36 years), 22 of whom were female, who had been referred for an evaluation of idiopathic pancreatitis. DNA was tested for 17 CFTR mutations and for the 5T allele in intron 8 of the CFTR gene. The 5T allele reduces the level of functional CFTR and is associated with an inherited form of infertility in males. Patients with two abnormal CFTR alleles were further evaluated for unrecognized cystic fibrosis-related lung disease, and both base-line and CFTR-mediated ion transport were measured in the nasal mucosa. RESULTS: Ten patients with idiopathic chronic pancreatitis (37 percent) had at least one abnormal CFTR allele. Eight CFTR mutations were detected (prevalence ratio, 11:1; 95 percent confidence interval, 5 to 23; P<0.001). In three patients both alleles were affected (prevalence ratio, 80:1; 95 percent confidence interval, 17 to 379; P<0.001). These three patients did not have lung disease typical of cystic fibrosis on the basis of sweat testing, spirometry, or base-line nasal potential-difference measurements. Nonetheless, each had abnormal nasal cyclic AMP-mediated chloride transport. CONCLUSION: In a group of patients referred for evaluation of idiopathic pancreatitis, there was a strong association between mutations in the CFTR gene and pancreatitis. The abnormal CFTR genotypes in these patients with pancreatitis resemble those associated with male infertility.

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34 Pancreatograms were assessed for the severity of chronic pancreatitis according to published criteria by a reviewer who was unaware of the patients` histories (Table 1).19 DNA Studies We extracted DNA from blood samples20 and tested for 16 CFTR mutations - ∆F508, W1282X, R117H, 621+1(G→T), R334W, R347P, A455E, ∆I507, 1717¡1(G→A), G542X, S549N, G551D, R553X, R560T, N1303K, and 3849+10Kb(C→T) - using reverse dot blot strips (Roche Molecular Systems, Alameda, Calif.). Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Cell Biol. 1998 Nov 2;143(3):645-57. Jiang Q, Mak D, Devidas S, Schwiebert EM, Bragin A, Zhang Y, Skach WR, Guggino WB, Foskett JK, Engelhardt JF
Cystic fibrosis transmembrane conductance regulator-associated ATP release is controlled by a chloride sensor.
J Cell Biol. 1998 Nov 2;143(3):645-57., 1998-11-02 [PMID:9813087]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel that is defective in cystic fibrosis, and has also been closely associated with ATP permeability in cells. Using a Xenopus oocyte cRNA expression system, we have evaluated the molecular mechanisms that control CFTR-modulated ATP release. CFTR-modulated ATP release was dependent on both cAMP activation and a gradient change in the extracellular chloride concentration. Activation of ATP release occurred within a narrow concentration range of external Cl- that was similar to that reported in airway surface fluid. Mutagenesis of CFTR demonstrated that Cl- conductance and ATP release regulatory properties could be dissociated to different regions of the CFTR protein. Despite the lack of a need for Cl- conductance through CFTR to modulate ATP release, alterations in channel pore residues R347 and R334 caused changes in the relative ability of different halides to activate ATP efflux (wtCFTR, Cl >> Br; R347P, Cl >> Br; R347E, Br >> Cl; R334W, Cl = Br). We hypothesize that residues R347 and R334 may contribute a Cl- binding site within the CFTR channel pore that is necessary for activation of ATP efflux in response to increases of extracellular Cl-. In summary, these findings suggest a novel chloride sensor mechanism by which CFTR is capable of responding to changes in the extracellular chloride concentration by modulating the activity of an unidentified ATP efflux pathway. This pathway may play an important role in maintaining fluid and electrolyte balance in the airway through purinergic regulation of epithelial cells. Insight into these molecular mechanisms enhances our understanding of pathogenesis in the cystic fibrosis lung.

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6 Despite the lack of a need for Cl-conductance through CFTR to modulate ATP release, alterations in channel pore residues R347 and R334 caused changes in the relative ability of different halides to activate ATP efflux (wtCFTR, Cl ϾϾ Br; R347P, Cl ϾϾ Br; R347E, Br ϾϾ Cl; R334W, Cl ϭ Br). Login to comment
90 Mutants R334W and R347P were constructed by replacing a SpH I-Xba I segment in the PSP-CFTR with a corresponding segment cut out from mutants PTM-R334W and PTM-R347P (provided by Dr. M.J. Welsh; Sheppard et al., 1993), respectively. Login to comment
206 Mutations in the CFTR Channel Pore Alter the Halide Dependence of ATP Release To explore the mechanisms by which changes in the extracellular Cl-concentration affect activation of ATP release, we examined the CFTR mutants R334W, R347P, and R347E. Login to comment
208 Immunoprecipitation studies using a rabbit antisera raised against a synthetic peptide corresponding to residues 45-65 in the CFTR NH2 terminus demonstrated similar levels of protein expression in wtCFTR, R334W, R347P, and R347E cRNA-injected oocytes (Fig. 6 A). Login to comment
215 The stimulated Cl-conductance of R347P was comparable to that of the wtCFTR (⌬GcAMP ϭ 125 Ϯ 28 ␮s). Login to comment
242 The halide dependence of CFTR-modulated ATP release was similarly analyzed in R334W, R347P, and R347E cRNA-injected oocytes. Login to comment
244 The halide dependence of ATP release for R347P CFTR was similar to that of wtCFTR (Cl- ϾϾ Br- ); JATP in the presence of Cl- (2.0 Ϯ 0.98 pmoles/min) was eightfold greater than that in the presence of Br- (0.26 Ϯ 0.17 pmoles/min; Fig. 7 and Table II). Login to comment
295 Mutants of CFTR that alter charged arginine residues within the channel pore including R334W, R347E, and R347P were used. Login to comment
298 The Wc I/V relationships for wtCFTR, R347P, R347E, R334W cRNA, and water-injected oocytes are given in B. Login to comment
303 These results depict average I/V relationships from N experiments for wtCFTR (N ϭ 5), R347E (N ϭ 5), R347P (N ϭ 5), R334W (N ϭ 8), and water (N ϭ 7)-injected oocytes from at least two independent batches of oocytes. Login to comment
307 We therefore characterized the effects of arginine mutations R334W, R347P, and R347E on CFTR-modulated ATP release. Login to comment
338 Summary of Electrophysiologic Measurements on CFTR Mutants Wild type R347P R347E R334W Mock ⌬GCl (cAMP) (␮s) 121 Ϯ 35 125 Ϯ 28 5.3 Ϯ 2.1 32 Ϯ 20 -0.61 Ϯ 0.62 (N ϭ 5) (N ϭ 5) (N ϭ 5) (N ϭ 8) (N ϭ 7) GBr /GCl 0.93 Ϯ 0.01 1.12 Ϯ 0.01 2.36 Ϯ 0.23 1.12 Ϯ 0.03 (N ϭ 5) (N ϭ 5) (N ϭ 5) (N ϭ 8) - PBr /PCl 1.13 Ϯ 0.02 1.02 Ϯ 0.01 1.00 Ϯ 0.04 1.22 Ϯ 0.02 (N ϭ 5) (N ϭ 5) (N ϭ 5) (N ϭ 8) - JATP (Cl) 8.7 Ϯ 3.4 2.0 Ϯ 0.98 1.5 Ϯ 0.49 3.4 Ϯ 1.3 0.021 Ϯ 0.001 (N ϭ 15) (N ϭ 9) (N ϭ 11) (N ϭ 7) (N ϭ 15) JATP (Br) 1.9 Ϯ 0.51 0.26 Ϯ 0.17 11.0 Ϯ 4.8 3.7 Ϯ 1.5 0.013 Ϯ 0.006 (N ϭ 15) (N ϭ 9) (N ϭ 11) (N ϭ 7) (N ϭ 15) JATP (Br)/JATP (Cl) 0.22 0.13 7.3 1.1 - CFTR cRNAs were injected into Xenopus oocytes and evaluated for both electrophysiologic and ATP release characteristics. Login to comment
354 We thank Dr. Welsh for his mutant CFTR cDNAs R334W, R347E, and R347P, and his thoughtful review of this manuscript. Login to comment

[hide] Validation of double gradient denaturing gradient ... Clin Chem. 1999 Jan;45(1):35-40. Cremonesi L, Carrera P, Fumagalli A, Lucchiari S, Cardillo E, Ferrari M, Righetti SC, Zunino F, Righetti PG, Gelfi C
Validation of double gradient denaturing gradient gel electrophoresis through multigenic retrospective analysis.
Clin Chem. 1999 Jan;45(1):35-40., [PMID:9895335]

Abstract [show]
Among established techniques for the identification of either known or new mutations, denaturing gradient gel electrophoresis (DGGE) is one of the most effective. However, conventional DGGE is affected by major drawbacks that limit its routine application: the different denaturant gradient ranges and migration times required for different DNA fragments. We developed a modified version of DGGE for high-throughput mutational analysis, double gradient DGGE (DG-DGGE), by superimposing a porous gradient over the denaturant gradient, which maintains the zone-sharpening effect even during lengthy analyses. Because of this innovation, DG-DGGE achieves the double goals of retaining full effectiveness in the detection of mutations while allowing identical run time conditions for all fragments analyzed. Here we use retrospective analysis of a large number of well-characterized mutations and polymorphisms, spanning all predicted melting domains and the whole genomic sequence of three different genes--the cystic fibrosis transmembrane conductance regulator (CFTR), the beta-globin, and the p53 genes--to demonstrate that DG-DGGE may be applied to the rapid scanning of any sequence variation.

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31 Mutations and polymorphisms analyzed in the CFTR gene. Position Denaturant gradient Mutation Exon 1 40-90% 125G/Ca,b M1V (A3G at 133) 175insT 182delT Exon 3 10-60% W57G (T3G at 301) 356G/Aa G85E (G3A at 386) Exon 4 20-70% R117H (G3A at 482) 541delC 621ϩ1G3T I148T (T3C at 575) Exon 5 20-70% E193K (G3A at 709) Intron 5 20-70% 711ϩ3A3G Exon 7 20-70% 1078delT R334W (C3T at 1132) T338I (C3T at 1145) R347P (G3C at 1172)b R347H (G3A at 1172) R352Q (G3A at 1187) Exon 10 20-70% M470V (1540A/G)a ⌬F508 (del 3 bp at 1652) Intron 10 10-60% 1717-1G3A Exon 11 10-60% G542X (G3T at 1756) 1784delG R553X (C3T at 1789) Exon 12 10-60% D579G (A3G at 1868) E585X (G3T at 1885) Intron 12 10-60% 1898ϩ3A3G Exon 13 30-80% 2183AA3G E730X (G3T at 2320) L732X (T3G at 2327) 2347delG Exon 14a 10-60% T854T (2694T/G)a V868V (2736G/A)a Intron 14b 30-80% 2789ϩ5G3A Exon 15 20-70% M952I (G3C at 2988)b Exon 17a 20-70% L997F (G3C at 3123)b Exon 17b 20-70% F1052V (T3G at 3286) R1066C (C3T at 3328) R1066H (G3A at 3329) A1067T (G3A at 3331) Exon 18 20-70% D1152H (G3C at 3586)b Exon 19 30-80% R1158X (C3T at 3604) Exon 20 20-70% S1251N (G3A at 3384) W1282X (G3A at 3978) Exon 21 20-70% N1303K (C3G at 4041)b Exon 22 30-80% G1349D (G3A at 4178) 4382delA Exon 24 30-80% Y1424Y (4404C/T)a a Polymorphism. Login to comment

[hide] Structure and function of the CFTR chloride channe... Physiol Rev. 1999 Jan;79(1 Suppl):S23-45. Sheppard DN, Welsh MJ
Structure and function of the CFTR chloride channel.
Physiol Rev. 1999 Jan;79(1 Suppl):S23-45., [PMID:9922375]

Abstract [show]
Structure and Function of the CFTR Chloride Channel. Physiol. Rev. 79, Suppl.: S23-S45, 1999. - The cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ABC transporter family that forms a novel Cl- channel. It is located predominantly in the apical membrane of epithelia where it mediates transepithelial salt and liquid movement. Dysfunction of CFTR causes the genetic disease cystic fibrosis. The CFTR is composed of five domains: two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory (R) domain. Here we review the structure and function of this unique channel, with a focus on how the various domains contribute to channel function. The MSDs form the channel pore, phosphorylation of the R domain determines channel activity, and ATP hydrolysis by the NBDs controls channel gating. Current knowledge of CFTR structure and function may help us understand better its mechanism of action, its role in electrolyte transport, its dysfunction in cystic fibrosis, and its relationship to other ABC transporters.

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118 When expressed in heterologous epithelial cells, the CF-associatedpermeation is determined by the hydration energy of P27-8/ 9j0e$$ja08 01-13-99 14:54:54 prsa APS-Phys Rev mutants R334W and R347P were correctly processed and proteins play an important structural role by kinking a-helices (22). Login to comment
121 Analysis of the single-channel properties of R334W and R347P demonstrated that both mutants decrease sin- or indirectly to the formation of the CFTR pore (119). Login to comment
130 However, at pH 8.7, when histidine Knowledge of the structure and function of the CFTR pore has also emerged from studies using truncated andis uncharged, single-channel conductance was reduced to a similar extent as that of R347P, and the anomalous mole chimeric proteins (95, 116, 134). Login to comment

[hide] CFTR is a conductance regulator as well as a chlor... Physiol Rev. 1999 Jan;79(1 Suppl):S145-66. Schwiebert EM, Benos DJ, Egan ME, Stutts MJ, Guggino WB
CFTR is a conductance regulator as well as a chloride channel.
Physiol Rev. 1999 Jan;79(1 Suppl):S145-66., [PMID:9922379]

Abstract [show]
CFTR Is a Conductance Regulator as well as a Chloride Channel. Physiol. Rev. 79, Suppl.: S145-S166, 1999. - Cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-binding cassette (ABC) transporter gene family. Although CFTR has the structure of a transporter that transports substrates across the membrane in a nonconductive manner, CFTR also has the intrinsic ability to conduct Cl- at much higher rates, a function unique to CFTR among this family of ABC transporters. Because Cl- transport was shown to be lost in cystic fibrosis (CF) epithelia long before the cloning of the CF gene and CFTR, CFTR Cl- channel function was considered to be paramount. Another equally valid perspective of CFTR, however, derives from its membership in a family of transporters that transports a multitude of different substances from chemotherapeutic drugs, to amino acids, to glutathione conjugates, to small peptides in a nonconductive manner. Moreover, at least two members of this ABC transporter family (mdr-1, SUR) can regulate other ion channels in the membrane. More simply, ABC transporters can regulate somehow the function of other cellular proteins or cellular functions. This review focuses on a plethora of studies showing that CFTR also regulates other ion channel proteins. It is the hope of the authors that the reader will take with him or her the message that CFTR is a conductance regulator as well as a Cl- channel.

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102 Nevertheless, cAMP-stimulated ATP release andarginine mutations (R334W with R347P) into CFTR eliminated Cl0 channel activity but conferred cAMP ORCC regulatory interaction are interconnected in CF airway epithelial cells. Login to comment

[hide] Spectrum of mutations in the CFTR gene in cystic f... Ann Hum Genet. 2007 Mar;71(Pt 2):194-201. Alonso MJ, Heine-Suner D, Calvo M, Rosell J, Gimenez J, Ramos MD, Telleria JJ, Palacio A, Estivill X, Casals T
Spectrum of mutations in the CFTR gene in cystic fibrosis patients of Spanish ancestry.
Ann Hum Genet. 2007 Mar;71(Pt 2):194-201., [PMID:17331079]

Abstract [show]
We analyzed 1,954 Spanish cystic fibrosis (CF) alleles in order to define the molecular spectrum of mutations in the CFTR gene in Spanish CF patients. Commercial panels showed a limited detection power, leading to the identification of only 76% of alleles. Two scanning techniques, denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism/hetroduplex (SSCP/HD), were carried out to detect CFTR sequence changes. In addition, intragenic markers IVS8CA, IVS8-6(T)n and IVS17bTA were also analyzed. Twelve mutations showed frequencies above 1%, p.F508del being the most frequent mutation (51%). We found that eighteen mutations need to be studied to achieve a detection level of 80%. Fifty-one mutations (42%) were observed once. In total, 121 disease-causing mutations were identified, accounting for 96% (1,877 out of 1,954) of CF alleles. Specific geographic distributions for the most common mutations, p.F508del, p.G542X, c.1811 + 1.6kbA > G and c.1609delCA, were confirmed. Furthermore, two other relatively common mutations (p.V232D and c.2789 + 5G > A) showed uneven geographic distributions. This updated information on the spectrum of CF mutations in Spain will be useful for improving genetic testing, as well as to facilitate counselling in people of Spanish ancestry. In addition, this study contributes to defining the molecular spectrum of CF in Europe, and corroborates the high molecular mutation heterogeneity of Mediterranean populations.

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52 Mutation 0.46-0.35 9 c.1078delT #, p.R347P # 8 p.G85V, c.621 + 1G > T #, p.S549R (T > G) #, p.R553X #, c.3849 + 10kbC > T # 7 p.R347H #, c.1812-1G > A, p.R709X 0.30-0.10 6 p.H199Y, p.P205S, 5 p.R117H #, p.G551D #, p.W1089X, p.Y1092X, CFTR50kbdel 4 c.296 + 3insT, c.1717-1G > A #, c.1949del84, c.3849 + 1G > A 3 p.E92K, c.936delTA, c.1717-8G > A, c.1341G > A, p.A561E, c.2603delT, p.G1244E, [p.D1270N; p.R74W] 2 p.Q2X, p.P5L, CFTRdele2,3, p.S50P, p.E60K, c.405 + 1G > A, c.1677delTA, p.L558S, p.G673X, p.R851X, p.Y1014C, p.Q1100P, p.M1101K, p.D1152H, CFTRdele19, p.G1244V, p.Q1281X, p.Y1381X <0,1 1 c.124del23bp, p.Q30X, p.W57X, c.406-1G > A, p.Q98R, p.E115del, c.519delT, p.L159S, c.711 + 3A > T, p.W202X, c.875 + 1G > A, p.E278del, p.W361R, c.1215delG, p.L365P, p.A399D, c.1548delG, p.K536X, p.R560G, c.1782delA, p.L571S, [p.G576A; p.R668C], p.T582R, p.E585X, c.1898 + 1G > A, c.1898 + 3A > G, c.2051delTT, p.E692X, p.R851L, c.2711delT, c.2751 + 3A > G, c.2752-26A > G, p.D924N, p.S945L, c.3121-1G > A, p.V1008D, p.L1065R, [p.R1070W; p.R668C], [p.F1074L; 5T], p.H1085R, p.R1158X, c.3659delC #, c.3667del4, c.3737delA, c.3860ins31, c.3905insT #, c.4005 + 1G > A, p.T1299I, p.E1308X, p.Q1313X, c.4095 + 2T > A, rearrangements study (n = 4) Mutations identified in CF families with mixed European origin: c.182delT, p.L1254X, c.4010del4. Login to comment

[hide] Outcomes of a cystic fibrosis carrier testing clin... Med J Aust. 2009 Nov 2;191(9):499-501. Christie LM, Ingrey AJ, Turner GM, Proos AL, Watts GE
Outcomes of a cystic fibrosis carrier testing clinic for couples.
Med J Aust. 2009 Nov 2;191(9):499-501., 2009-11-02 [PMID:19883345]

Abstract [show]
OBJECTIVE: To review the outcomes of offering carrier testing for cystic fibrosis (CF) to couples considering pregnancy, and to women in early pregnancy and their partners. METHODS: An after-hours clinic was established in Newcastle for discussion of issues related to prenatal testing. Couples were offered CF carrier testing by extracting DNA from a mouthwash sample. An expanded one-step model was used with both partners being tested initially for the p.F508del cystic fibrosis transmembrane conductance regulator gene (CFTR) mutation. If one partner was a p.F508del carrier, the other partner was tested for an additional 28 CFTR mutations. RESULTS: Of 1000 individuals who were offered CF carrier testing, none declined. No re-collections of mouthwash samples were required, and results were available within 14 days. There were 730 individuals who had no family history of CF (73%); 27 were carriers (4%; 95% CI, 2.4%-5.3%), and there were two high-risk couples where both partners were carriers of p.F508del. There were 270 individuals who had an affected family member with CF or a child identified as a CF carrier through newborn screening; 126 were carriers (46%; 95% CI, 40.6%-52.8%), and there were two high-risk couples - one couple where both partners were carriers of p.F508del, and another couple where the woman was homozygous for p.F508del and the man was a p.F508del carrier. The information on carrier status led the four high-risk couples to change their reproductive decisions to avoid having a child with CF. CONCLUSION: CF carrier testing for couples using an expanded one-step model will detect about 80% of high-risk couples and enables various reproductive choices. We believe that all couples considering pregnancy, and women in early pregnancy and their partners, should be offered CF carrier testing.

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72 This provides each individual with information on their carrier status, and accurate residual risks of 1 CFTR mutations tested for in individuals whose partner was a carrier of p.F508del* p.F508del p.F316leufsX p.I507del p.R347P p.G542X p.S1251N p.G551D p.E60X p.N1303K p.W1282X c.1585-1G>A p.D1152H p.R553X c.2988+1G>A c.489+G>T c.2657+5G>A p.R117H c.1766+1G>A p.R1162X c.579+1G>A c.3717+10kbC>T p.G85E p.R334W p.K684fs p.A455E p.I148T p.K684fs p.R560T p.T1176fs CFTR = gene encoding cystic fibrosis transmembrane conductance regulator. Login to comment

[hide] Genetic, epidemiological, and clinical aspects of ... Am J Gastroenterol. 2010 Aug;105(8):1876-83. Epub 2010 May 25. Joergensen MT, Brusgaard K, Cruger DG, Gerdes AM, Schaffalitzky de Muckadell OB
Genetic, epidemiological, and clinical aspects of hereditary pancreatitis: a population-based cohort study in Denmark.
Am J Gastroenterol. 2010 Aug;105(8):1876-83. Epub 2010 May 25., [PMID:20502448]

Abstract [show]
OBJECTIVES: In a population-based, well-defined group of patients first regarded as having pancreatitis of unknown origin (PUO), we identified, described, and compared the clinical and genetic aspects of patients with hereditary pancreatitis (HP) and with cystic fibrosis transmembrane conductance regulator gene (CFTR) and serine protease inhibitor Kazal type 1 gene (SPINK1) mutations with patients who retained the diagnosis of true idiopathic pancreatitis (tIP) after genetic testing for HP, SPINK1, and CFTR mutations. METHODS: Patients with PUO were identified in the Danish National Registry of Patients or were referred by clinicians. DNA from blood was analyzed for cationic trypsinogen (PRSS1), SPINK1, and CFTR mutations. Considering the diagnosis of HP, a pedigree was drawn for each patient. RESULTS: A genetic mutation was found in 40% of 122 patients with PUO. After testing first-degree relatives of the 18 initially identified HP patients, 38 HP patients in total were identified, and 28 patients had SPINK1-CFTR mutations. Among HP patients, no p.N29I mutations were found and the p.A16V mutation was more frequent than previously reported, 45 and 32% had exocrine and endocrine insufficiency, respectively, and among tIP patients 9 and 12%, respectively. Pancreatic cancer was diagnosed in 5% of the HP families. CONCLUSIONS: The genotype of the Danish population with HP differs from that of previously described cohorts. The occurrence of exocrine and endocrine insufficiency is higher among patients with HP than in patients with SPINK1-CFTR mutations and tIP, and more HP families develop pancreatic cancer. Genetic testing thus helps to predict the prognosis of the pancreatitis.

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57 The samples were also tested for 33 CFTR mutations, and all 6 classeswererepresented:394delTT,p.R553X,621+1G>T,p.R1162X, 1717-1G>A,3659delC,p.G542X,2183AA>G,p.W1282X,1078delT, 711+1G>T, F508del, p.S549N, I507del, p.S549R, 2184delA, p.G551D, p.G85E, p.N1303K, p.R560T, p.R117H, p.R347H, p.R347P, p.R334W, 2789+5G>A, 3849+10kbC>T, p.A445E, 3120+1G>A, p.V520F,1898+1G>A,3876delA,3905insT,andIVS8-5T.DNAwas amplified by multiplex PCR (Hybaid 4 A62, Middlesex, UK). Login to comment

[hide] Cystic fibrosis in Chilean patients: Analysis of 3... J Cyst Fibros. 2011 Jan;10(1):66-70. Epub 2010 Oct 30. Lay-Son G, Puga A, Astudillo P, Repetto GM
Cystic fibrosis in Chilean patients: Analysis of 36 common CFTR gene mutations.
J Cyst Fibros. 2011 Jan;10(1):66-70. Epub 2010 Oct 30., [PMID:21036675]

Abstract [show]
BACKGROUND: CFTR gene mutations have worldwide differences in prevalence and data on Chilean patients is scarce. METHODS: We studied 36 of the most common CFTR mutations in Chilean patients from the CF National Program [Programa Nacional de Fibrosis Quistica (PNFQ)] of the Ministry of Health of Chile. RESULTS: Two hundred and eighty-nine patients were studied. Fourteen different mutations were identified with an overall allele detection rate of 42.0%. Mutations with frequencies greater than 1% were p.F508del (30.3% of alleles), p.R334W (3.3%), p.G542X (2.4%), c.3849+10Kb C>T (1.7%), and p.R553X (1.2%). A north to south geographical gradient was observed in the overall rate of detection. CONCLUSIONS: Southern European CFTR mutations predominate in the Chilean population, but a high percentage of alleles remain unknown. Geographical heterogeneity could be explained in part by admixture. Complementary analyses are necessary to allow for effective genetic counselling and improve cost-effectiveness of screening and diagnostic tests.

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81 Mutation This study Rios et al. [4] Molina et al. [5] Repetto et al. [6] Perez et al. [13] CFGAC [2] (n=578) (%) (n=72) (%) (n=36) (%) (n=100) (%) (n=4102) (%) (n=43,849) (%) Chile Chile Chile Chile Latin-Americaa Worldwide Unknown 58.0 66.6 61.1 34.0 36.7 22.7 p.F508del 30.6 29.2 30.6 45.0 47.1 66.0 p.R334W 3.1 - - 2.0 0.8 0.1 p.G542X 2.4 0 8.3 7.0 5.0 2.4 c.3849+10Kb CNT 1.7 - - 3.0 0.3 0.2 p.R553X 1.2 4.2 0 1.0 0.4 0.7 p.R1162X 0.9 - - 2.0 1.0 0.3 p.1078delT 0.5 - - 0 b0.1 0.1 p.G85E 0.5 - - - 0.8 0.2 p.W1282X 0.2 - - 5.0 1.0 1.2 c.3120+1 GNA 0.2 - - - 0.3 - c.711+1 GNT 0.2 - - - 0.1 0.1 p.R117H 0.2 - - 0 b0.1 0.3 p.A455E 0.2 - - 0 0 0.1 p.I148T 0.2 - - - - - p.G551D 0 0 0 1.0 0.1 1.6 p.N1303K 0 0 0 0 1.8 1.3 c.621+1 GNT 0 - - 0 0.2 0.7 c.1717-1 GNA 0 - - 0 0.3 0.6 p.I507del 0 - - 0 0.2 0.2 p.R347P 0 - - 0 0 0.2 c.2789+5 GNA 0 - - - 0.2 0.1 c.1898+1 GNA 0 - - - 0.1 0.1 c.2184delA 0 - - - b0.1 0.1 p.S549N 0 - 0 - 0.1 0.1 c.3659delC 0 - - 0 0.1 0.1 p.R560T 0 - - - 0 0.1 c.1811+1.6Kb ANG 0 - - - 0.4 - c.2183AANG 0 - - 0 0.1 - p.S549R 0 - - - 0.1 - c.3272-26 ANG 0 - - - 0.1 - c.3199del6 0 - - - b0.1 - p.E60X 0 - - 0 0 - c.3905insT 0 - - - 0 - p.S1251N 0 - - 0 - - CFTRdele2,3 0 - - - - - p.R347H 0 - - - - - p.V520F 0 - - - - - p.Q552X 0 - - - - - c.394delTT 0 - - - - - c.711+1 GNA 0 - - - - - c.2143delT 0 - - - - - c.3876delA 0 - - - - - a Data from Chilean patients published in Rios et al., Molina et al., and Repetto et al. [4-6] included in this publication were excluded in this table to avoid repetition. Login to comment

[hide] Genetic variation in the ABCA1 gene, HDL cholester... Atherosclerosis. 2010 Feb;208(2):305-16. Epub 2009 Jun 11. Frikke-Schmidt R
Genetic variation in the ABCA1 gene, HDL cholesterol, and risk of ischemic heart disease in the general population.
Atherosclerosis. 2010 Feb;208(2):305-16. Epub 2009 Jun 11., [PMID:19596329]

Abstract [show]
Epidemiological studies consistently demonstrate a strong inverse association between low levels of high-density lipoprotein (HDL) cholesterol and increased risk of ischemic heart disease (IHD). This review focuses on whether both rare and common genetic variation in ABCA1 contributes to plasma levels of HDL cholesterol and to risk of IHD in the general population, and further seeks to understand whether low levels of HDL cholesterol per se are causally related to IHD. Studies of the ABCA1 gene demonstrate a general strategy for detecting functional genetic variants, and show that both common and rare ABCA1 variants contribute to levels of HDL cholesterol and risk of IHD in the general population. The association between ABCA1 variants and risk of IHD appears, however, to be independent of plasma levels of HDL cholesterol. With the recent identification of the largest number of individuals heterozygous for loss-of-function mutations in ABCA1 worldwide, population studies suggests that genetically low HDL cholesterol per se does not predict an increased risk of IHD, and thus questions the causality of isolated low levels of HDL cholesterol for the development of IHD.

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2371 Furthermore, a mutation (R347P) causing cystic fibrosis has been identified in the CFTR gene (=ABCC7, another full ABC transporter) at a site that corresponds to residue 764 in ABCA1 [73], i.e. in close vicinity to the K776N mutation. Login to comment

[hide] Mutation in ABCA1 predicted risk of ischemic heart... J Am Coll Cardiol. 2005 Oct 18;46(8):1516-20. Epub 2005 Sep 23. Frikke-Schmidt R, Nordestgaard BG, Schnohr P, Steffensen R, Tybjaerg-Hansen A
Mutation in ABCA1 predicted risk of ischemic heart disease in the Copenhagen City Heart Study Population.
J Am Coll Cardiol. 2005 Oct 18;46(8):1516-20. Epub 2005 Sep 23., [PMID:16226177]

Abstract [show]
OBJECTIVES: We tested whether heterozygosity for the K776N mutation (frequency: 0.4%) in ATP-binding cassette transporter A1 (ABCA1) predicted ischemic heart disease (IHD) in the Copenhagen City Heart Study population. BACKGROUND: In a complex trait like IHD, genetic variation is considered to be conferred by common DNA polymorphisms, although rare mutations may have a larger impact. Tangier disease, a rare high-density lipoprotein cholesterol (HDL-C) deficiency syndrome with IHD, is caused by homozygous ABCA1 mutations. METHODS: We analyzed blood samples from a large cohort study of 9,076 Danish individuals followed for 24 years (167,287 person-years), during which 1,033 incident IHD events occurred. The hypothesis was retested in an independent case-control study comparing 562 IHD patients with 3,103 controls. RESULTS: The cumulative incidence of IHD as a function of age was increased in K776N heterozygotes compared with non-carriers (log-rank test: p = 0.005). At the age of 80 years, 48% of heterozygotes and 23% of non-carriers had IHD. Incidence rates in non-carriers and K776N heterozygotes were 61 and 157 per 10,000 person-years. The age-adjusted hazard ratio for IHD in K776N heterozygotes versus non-carriers was 2.4 (95% confidence interval 1.3 to 4.5). Adjusting for HDL-C, or for smoking, diabetes, and hypertension did not change the result, suggesting that genotype predicted risk of IHD beyond that offered by HDL-C, and by other conventional risk factors. Similar trends were obtained in an independent case-control study. CONCLUSIONS: Heterozygosity for an ABCA1 mutation (K776N) conferred two- to three-fold risk of IHD in 37 participants in the Copenhagen City Heart study.

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109 However, several arguments favor a true observation: 1) the involved amino acid residue is completely conserved between species and relatively conserved between 12 ABCAs with very different transport functions; 2) the amino acid substitution changes the charge of the side-chain, potentially leading to structural alterations of the protein, and consequently to altered protein interactions or transport properties; 3) in the CFTR (or ABCC7), a disease-causing mutation (R347P) has been identified at a site that corresponds to residue 764 in ABCA1 (15), and thus in close vicinity to K776N; 4) the present study is of a large cohort, and therefore includes only incident cases, avoiding the normal pitfalls of case reports and case-control studies (30); 5) we observed a similar trend on risk of IHD in a separate case-control study; 6) we have previously determined effects on lipids and lipoproteins of all non-synonymous SNPs identified in ABCA1 (R219K, V771M, V825I, I883M, E1172D, R1587K). Login to comment

[hide] Exploring the mechanisms of macrolides in cystic f... Respir Med. 2006 Apr;100(4):687-97. Epub 2005 Sep 26. Equi AC, Davies JC, Painter H, Hyde S, Bush A, Geddes DM, Alton EW
Exploring the mechanisms of macrolides in cystic fibrosis.
Respir Med. 2006 Apr;100(4):687-97. Epub 2005 Sep 26., [PMID:16185859]

Abstract [show]
Several studies have reported clinical improvements in cystic fibrosis (CF) patients on macrolide antibiotics although the mechanism of action remains unclear. We conducted an open-label study of azithromycin (500 mg daily for 2 weeks) in 9 adult CF patients to explore 3 possible mechanisms: up-regulation of the multi-drug resistance (MDR) or cystic fibrosis transmembrane regulator (CFTR) proteins, correction of epithelial ion transport and reduced bacterial adherence. End-points included nasal potential difference (PD) measurements, nasal epithelial MDR and CFTR mRNA levels and Pseudomonas aeruginosa adherence to nasal epithelium. Forced expiratory volume in the 1st second (FEV(1)) increased significantly after 2 weeks of azithromycin (pre- 41.1 [5.0]%; post- 44.6 [5.8]%; P<0.05), although improvements in forced vital capacity (FVC) did not reach significance (pre- 61.3 [4.0]%; post- 67.1 [5.4]%, NS). Before treatment all subjects had nasal PD measurements characteristic of CF. Treatment led to no significant group differences in any measures of either sodium absorption or chloride secretion. Neither CFTR nor MDR mRNA levels had altered significantly and the adherence of P. aeruginosa did not decrease. We conclude that these are unlikely to be significant contributing mechanisms accounting for the consistent beneficial results observed in clinical trials of macrolides in CF.

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78 Four patients were homozygous for the DF508 mutation, 4 were compound heterozygotes (DF508/ R347P, DF508/ G551D, DF508/À, DF508/À) and one patient had no identifiable mutations. Login to comment
104 Patient (M/F) Age (years) FEV1/FVC(%) CFTR genotype Pre-treatment (mean V1-V3) Post-treatment (V4) 1 (M) 42 26/63 26/63 DF508/ R347P 2 (M) 26 54.5/79 61/95 DF508/ DF508 3 (F) 25 61.5/66 66/72 DF508/G551D 4 (M) 19 27/48 29/50 DF508/À 5 (M) 30 31/49 31/46 DF508/ DF508 6 (M) 30 38.5/72 46/83 DF508/ DF508 7 (F) 21 45/63 48/71 DF508/- 8 (M) 37 61/89 68/- DF508/ DF508 9 (M) 34 25/51 26/52 À/À ARTICLE IN PRESS -10 -14 -16 -12 -8 -6 -4 -2 0 2 4 ∆PDmV p=0.37 V1-3 vs V4 P=0.09 V1-3 vs V5 -8 -6 -4 -2 0 2 4 6 8 ∆PDmV p=0.2 V1-3 vs V4 P=0.06 V1-3 vs V5 -8 -6 -4 -2 0 2 4 6 8 10 ∆PDmV p=0.5 V1-3 vs V4 P=0.26 V1-3 vs V5 V1-3 V4 V5 V6 V1-3 V4 V5 V6 V1-3 V4 V5 V6 -10 (a) (b) (c) Figure 1 Nasal PD (a) Baseline measurements, (b) responses to amiloride, (c) responses to low chloride solution and isoproterenol. Login to comment

[hide] Quantitative expression patterns of multidrug-resi... Eur J Biochem. 1992 May 15;206(1):137-49. Bremer S, Hoof T, Wilke M, Busche R, Scholte B, Riordan JR, Maass G, Tummler B
Quantitative expression patterns of multidrug-resistance P-glycoprotein (MDR1) and differentially spliced cystic-fibrosis transmembrane-conductance regulator mRNA transcripts in human epithelia.
Eur J Biochem. 1992 May 15;206(1):137-49., [PMID:1375156]

Abstract [show]
P-glycoprotein (MDR1), that confers multidrug resistance in cancer, and the cystic-fibrosis transmembrane-conductance regulator (CFTR), that is causative defective in cystic fibrosis, belong to the family of ATP-binding transport proteins. The expression of MDR1 and CFTR in human epithelial tissues and the cell lines T84 and HT29 was estimated by primer-directed reverse transcription (RT) and subsequent monitoring of the kinetics of cDNA product formation during the polymerase chain reaction (PCR). MDR1 mRNA was found in high levels, 15-50 amol mRNA/microgram RNA, in the intestine, kidney, liver and placenta, and in low levels, 0.2 amol/microgram RNA, in respiratory epithelium. Large amounts of CFTR mRNA were measured in the gastrointestinal tract, whereas the kidney, as the phenotypically normal organ, and the lung, as the most severely affected organ in cystic fibrosis, both contained low amounts, 3 amol CFTR/microgram RNA. CFTR transcript levels of 1-5 amol/microgram RNA were determined in lymphocytes and lymphoblast cell lines, suggesting that lymphoblasts are an accessible source for the study of the molecular pathogenesis of cystic fibrosis. When transcripts were scanned by overlapping RT/PCR analyses, only transcript of expected size was detected for MDR1 mRNA, where variable in-frame deletions of either exon 4, 9 or 12 were observed in CFTR mRNA. The complete loss of single exons was seen at proportions of 1-40% in all investigated tissues and cell lines with large donor-to-donor variation. Exons 9 and 12 of the CFTR gene encode parts of the evolutionarily well-conserved first nucleotide-binding fold including the two Walker motifs. Alternative splicing may give rise to various CFTR forms of different function and localization.

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138 After screening for the Phe508 deletion (Kerem et al., 1989), most CFTR mutations were investigated by restriction analysis of PCR products (R334W, R347P, A455E, G551D, R553X, R1162X, W1282X) (Cutting et al., 1990; Dean et al., 1990; Gasparini et al., 1991; Kerem et al., 1990; Vidaud et al., 1990). Login to comment
257 The CF patients were either dF508 homozygotes (n = I) or were dF508 compound heterozygotes (n = 3) with R347P (Dean et al., 1990), R553X (Cutting et al., 1990)or a yet-unpublished frameshift mutation in CFTR as the second CF-causing mutation. Login to comment

[hide] Cystic fibrosis: insight into CFTR pathophysiology... Clin Biochem. 2012 Oct;45(15):1132-44. doi: 10.1016/j.clinbiochem.2012.05.034. Epub 2012 Jun 12. Lubamba B, Dhooghe B, Noel S, Leal T
Cystic fibrosis: insight into CFTR pathophysiology and pharmacotherapy.
Clin Biochem. 2012 Oct;45(15):1132-44. doi: 10.1016/j.clinbiochem.2012.05.034. Epub 2012 Jun 12., [PMID:22698459]

Abstract [show]
Cystic fibrosis is the most common life-threatening recessively inherited disease in Caucasians. Due to early provision of care in specialized reference centers and more comprehensive care, survival has improved over time. Despite great advances in supportive care and in our understanding of its pathophysiology, there is still no cure for the disease. Therapeutic strategies aimed at rescuing the abnormal protein are either being sought after or under investigation. This review highlights salient insights into pathophysiology and candidate molecules suitable for CFTR pharmacotherapy. Clinical trials using Ataluren, VX-809 and ivacaftor have provided encouraging data. Preclinical data with inhibitors of phosphodiesterase type 5, such as sildenafil and analogs, have highlighted their potential for CFTR pharmacotherapy. Because sildenafil and analogs are in clinical use for other clinical applications, research on this class of drugs might speed up the development of new therapies for CF.

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982 Class Mutation prototypes Consequences Severe CF phenotype I G542X, W1282X, R553X, 3950delT CFTR is not synthesized because of stop codons or splicing defects II F508del, N1303K CFTR is synthesized but in an immature form (only partly glycosylated, misfolded, not released from the endoplasmic reticulum) and is mostly degraded by the ubiquitin-proteasomal pathway III G551D CFTR is synthesized and transported to the plasma membrane, but its activation and regulation by ATP or cAMP are disrupted Milder CF phenotype IV R334W, G314E, R347P, D1152H CFTR is synthesized and expressed at the plasma membrane, but chloride conductance is reduced V 3849+10 kb C>T, 3272-26 A>G CFTR synthesis or processing is partly defective Severe CF phenotype VI 1811+1.6 kb A>G CFTR is synthesized, but membrane stability or conductance of ions other than chloride is reduced Fig. 2. Login to comment

[hide] Hispanic Infants with cystic fibrosis show low CFT... J Genet Couns. 2012 Oct;21(5):671-5. doi: 10.1007/s10897-012-9481-2. Epub 2012 Feb 4. Watts KD, Layne B, Harris A, McColley SA
Hispanic Infants with cystic fibrosis show low CFTR mutation detection rates in the Illinois newborn screening program.
J Genet Couns. 2012 Oct;21(5):671-5. doi: 10.1007/s10897-012-9481-2. Epub 2012 Feb 4., [PMID:22311127]

Abstract [show]
States develop specific protocols for cystic fibrosis (CF) newborn screening to reflect the population served. We hypothesized that mutation distribution and detection rates would differ between Hispanic and non-Hispanic CF patients diagnosed by IL newborn screen with more Hispanic infants carrying mutations not detected by the state panel. Data from CF cases diagnosed via newborn screen in IL between 3/1/2008 and 10/31/2010 were reviewed. More Hispanic infants with CF had one or more undefined mutations after screening, in comparison to non-Hispanic Caucasian patients (40% vs. 9.5%; p < 0.002). The risk of having a positive diagnosis of CF with only one mutation noted by positive newborn screen increases 2-fold in Hispanic Caucasian versus non-Hispanic Caucasian infants (5% vs. 2.4%). Health care providers must be aware of the limitations of CF newborn screening to ensure appropriate counseling and prompt referral for a positive newborn screen, even when zero or one mutations are identified.

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39 Mutation Frequency Table 1 shows the mutations found in Illinois patients diagnosed with CF after a positive NBS and compares these to mutations documented in Hispanic Caucasian Table 1 CFTR mutation frequency detected by Illinois newborn screen Mutation IL Newborn Screen CFF Patient Registry Total alleles Non-Hispanic Caucasian Hispanic Caucasian African American Ethnicity/Race Missing Hispanic Caucasian ΔF508 63.9% 71.6% 36.7% 33.3% 58.3% 44.7% R117H 7.7% 10.1% 3.3% - - 0.3% G542X 1.9% 2.0% - - 4.2% 4.1% 3120+1G>A 1.9% 0.7% 3.3% 33.3% - 0.7% ΔI507 1.4% 0.7% - - 8.3% 1.3% G551D 1.4% 2.0% - - - 0.5% 3659delC 1.4% 1.3% 3.3% - - 0.1% 3849+10 kbC>T 1.4% - 6.7% 16.7% - 1.0% ΔF311 1.4% - 6.7% - 4.2% 0.03% 1288insT 0.5% - 3.3% - - 0% 621+1G>T 0.5% - 3.3% - - 0.4% G85E 1.0% - 3.3% - 4.2% 0.3% 2184delA 0.5% - 3.3% - - 0.2% S549N 0.5% - 3.3% - - 0.7% R334W 1.0% 0.7% - 16.7% - 1.0% N1303K 1.0% - - - 8.3% 1.6% Other 4.4% 6.2%a 0% 0% 0% 12.8%b Unknown 8.2% 4.7% 23.5% 0% 12.5% 15.7% a R347P, 1898+1G>A, 2789+5G>A, 3272-26A>G, 3876delA, CFTRdel2,3, W1282X occurred in non-Hispanic Caucasian patients only with an allele frequency of 0.5% of the entire IL NBS population b In the 2004 CFF Patient Registry 12.8% of alleles are not included in the above table because they occur in less than 1% of the population. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Cyst Fibros. 2012 Sep;11(5):355-62. doi: 10.1016/j.jcf.2012.05.001. Epub 2012 Jun 2. Ooi CY, Durie PR
Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis.
J Cyst Fibros. 2012 Sep;11(5):355-62. doi: 10.1016/j.jcf.2012.05.001. Epub 2012 Jun 2., [PMID:22658665]

Abstract [show]
BACKGROUND: The pancreas is one of the primary organs affected by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. While exocrine pancreatic insufficiency is a well-recognized complication of cystic fibrosis (CF), symptomatic pancreatitis is often under-recognized. RESULTS: The aim of this review is to provide a general overview of CFTR mutation-associated pancreatitis, which affects patients with pancreatic sufficient CF, CFTR-related pancreatitis, and idiopathic pancreatitis. The current hypothesis regarding the role of CFTR dysfunction in the pathogenesis of pancreatitis, and concepts on genotype-phenotype correlations between CFTR and symptomatic pancreatitis will be reviewed. Symptomatic pancreatitis occurs in 20% of pancreatic sufficient CF patients. In order to evaluate genotype-phenotype correlations, the Pancreatic Insufficiency Prevalence (PIP) score was developed and validated to determine severity in a large number of CFTR mutations. Specific CFTR genotypes are significantly associated with pancreatitis. Patients who carry genotypes with mild phenotypic effects have a greater risk of developing pancreatitis than patients carrying genotypes with moderate-severe phenotypic consequences at any given time. CONCLUSIONS: The genotype-phenotype correlation in pancreatitis is unique compared to other organ manifestations but still consistent with the complex monogenic nature of CF. Paradoxically, genotypes associated with otherwise mild phenotypic effects have a greater risk for causing pancreatitis; compared with genotypes associated with moderate to severe disease phenotypes. Greater understanding into the underlying mechanisms of disease is much needed. The emergence of CFTR-assist therapies may potentially play a future role in the treatment of CFTR-mutation associated pancreatitis.

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855 CFTR mutation Total PI Total PI + PS PIP score CFTR mutation Total PI Total PI + PS PIP score 621+1G>T 96 96 1.00 G542X 74 75 0.99 711+1G>T 36 36 1.00 F508del 1276 1324 0.96 I507del 34 34 1.00 1717-1G>A 20 21 0.95 R553X 24 24 1.00 W1282X 19 20 0.95 Q493X 11 11 1.00 N1303K 45 48 0.94 S489X 11 11 1.00 R1162X 12 13 0.92 1154insTC 10 10 1.00 Y1092X 12 13 0.92 3659delC 9 9 1.00 I148T 10 11 0.91 CFTRdele2 7 7 1.00 V520F 9 10 0.90 4016insT 7 7 1.00 G551D 59 67 0.88 E60X 7 7 1.00 L1077P 5 6 0.83 R560T 7 7 1.00 R1066C 5 6 0.83 R1158X 7 7 1.00 2184insA 9 12 0.75 3905insT 6 6 1.00 2143delT 3 4 0.75 I148T;3199del6 5 5 1.00 1161delC 3 4 0.75 2183AA>G 5 5 1.00 3120+1G>A 3 4 0.75 1898+1G>A 5 5 1.00 S549N 3 4 0.75 2347delG 4 4 1.00 G85E 16 22 0.73 Q1313X 3 3 1.00 R117C 2 3 0.67 Q220X 3 3 1.00 M1101K 19 30 0.63 2184delA 3 3 1.00 P574H 3 5 0.60 1078delT 3 3 1.00 474del13BP 1 2 0.50 L1254X 3 3 1.00 R352Q 1 2 0.50 E585X 3 3 1.00 Q1291H 1 2 0.50 3876delA 2 2 1.00 A455E 18 37 0.49 S4X 2 2 1.00 R347P 6 15 0.40 R1070Q 2 2 1.00 2789+5G>A 6 16 0.38 F508C 2 2 1.00 L206W 6 18 0.33 DELI507 2 2 1.00 IVS8-5T 4 16 0.25 Q1411X 2 2 1.00 3272-26A>G 1 4 0.25 365-366insT 2 2 1.00 R334W 1 10 0.10 R709X 2 2 1.00 3849+10kbC>T 2 22 0.09 1138insG 2 2 1.00 P67L 1 14 0.07 CFTRdele2-4 2 2 1.00 R117H 1 25 0.04 3007delG 2 2 1.00 R347H 0 5 0.00 Q814X 2 2 1.00 G178R 0 3 0.00 394delTT 2 2 1.00 E116K 0 2 0.00 406-1G>A 2 2 1.00 875+1G>C 0 2 0.00 R75X 2 2 1.00 V232D 0 2 0.00 CFTRdel2-3 2 2 1.00 D579G 0 2 0.00 E193X 2 2 1.00 L1335P 0 2 0.00 185+1G>T 2 2 1.00 Mild mutations (based on PIP scores) are shaded in gray. Login to comment

[hide] Newborn screening for cystic fibrosis: Polish 4 ye... Eur J Hum Genet. 2012 Aug 15. doi: 10.1038/ejhg.2012.180. Sobczynska-Tomaszewska A, Oltarzewski M, Czerska K, Wertheim-Tysarowska K, Sands D, Walkowiak J, Bal J, Mazurczak T
Newborn screening for cystic fibrosis: Polish 4 years' experience with CFTR sequencing strategy.
Eur J Hum Genet. 2012 Aug 15. doi: 10.1038/ejhg.2012.180., [PMID:22892530]

Abstract [show]
Newborn screening for cystic fibrosis (NBS CF) in Poland was started in September 2006. Summary from 4 years' experience is presented in this study. The immunoreactive trypsin/DNA sequencing strategy was implemented. The group of 1 212 487 newborns were screened for cystic fibrosis during the programme. We identified a total of 221 CF cases during this period, including, 4 CF cases were reported to be omitted by NBS CF. Disease incidence in Poland based on the programme results was estimated as 1/4394 and carrier frequency as 1/33. The frequency of the F508del was similar (62%) to population data previously reported. This strategy allowed us to identify 29 affected infants with rare genotypes. The frequency of some mutations (eg, 2184insA, K710X) was assessed in Poland for the first time. Thus, sequencing assay seems to be accurate method for screening programme using blood spots in the Polish population.European Journal of Human Genetics advance online publication, 15 August 2012; doi:10.1038/ejhg.2012.180.

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57 Mutations D537N and P731L have not been Period of NBS CF Method The most frequent mutations in Polish population under analysis September 2006 - December 2007 Estonia Asper Biotech assay E60X, G85E, 394delTT, R117H, R117P, R117L, I148T, 621G>A, 711+1G>T, 711+5G>A, 1078delT, R334W, R347H, R347P, R347L, IVS8-T, A455E, I507del, F508del, 1717-1G>A, G542X, p.G551D, Q552X, R553X, R553G, R560T, R560K, 1898+1G>A, 1898+1G>T, 1898+1G>C, 2143delT, 2184delA, 2183AA>G, 2789+5G>A, 3120+1G>A, 3199del6, 3272-26A>G, R1162X, 3659delC, 3849+10kbC>T, 3905insT, S1235R, S1251N, W1282X, W1282C, N1303K, CFTRdele2,3 January 2007 - June 2009 Sanger sequencing of exons: 4, 7, 10, 11, 13, 21, fragment of intron 19 F508del, CFTRdele2,3, 3849+10kbC>T, R117H+IVS8-T*, R334W, R347P, 1717-1G>A, G542X, R553X, K710X, 2184insA, 2143delT, 2183AA>G, N1303K July 2009 - currently Sanger sequencing of exons: 7, 10, 11, 13, 17b, 20, 21, fragment of intron 19 F508del, CFTRdele2,3, 3849+10kbC>T, R334W, R347P, 1717-1G>A, G542X, R553X, K710X, 2184insA, 2143delT, 2183AA>G, N1303K, 3272-26A>G**, W1282X** * removed from DNA analysis since July 2009 , **added into DNA analysis since July 2009 Figure 1 NBS CF in Poland. Login to comment
72 Table 2 Genotypes of CF newborns with mutations not included into common commercial kits applied in Poland and European countries* Genotype Number of cases [F508del]; [1767-8T4A*] 1 [F508del];[2184insA*] 6 [F508del];[E33X*] 1 [F508del];[F1286C*] 1 [F508del];[G314R*] 1 [F508del];[K710X*] 1 [F508del];[W1282R*] 1 [F508del];[1898 þ 1G4C*] 1 [F508del];[3600 þ 2insT*] 1 [F508del];[F1052V*] 1 [F508del];[V1240G*] 1 [F508del];[T582I*] 1 [2143delT];[R1102X*] 1 [2143delT];[2721del11*] 1 [3272-26A4G];[K967S*] 1 [CFTRdele2,3];[Y1092X*] 1 [K710X*];[K710X*] 1 [L732X*];[3600 þ 2insT*] 1 [N1303K];[2184insA*] 1 [N1303L];[T1036I*] 1 [R553X];[3182ins8*] 1 [2143delT];[V1240G*] 1 [R553X];[Trp356X*] 1 [L997F*];[1210-12T[5];1210-13G4T] 1 Total 29 Table 3 Frequency of CFTR mutations in Polish CF patients from newborns screening programme CFTR mutations Frequency according to Bobadilla et al15 Frequency according to NBS CF results (all ¼ 442 CF alleles) Name Position % % F508del Exon11 57.1 62.4 3849 þ 10kbC4T Intron 22 2.7 3.0 G542X Exon 12 2.6 1.6 1717-1G4A Intron 11 2.4 1.4 R553X Exon 12 1.9 2.5 CFTRdele2,3 Exons 2 and 3 1.8 6.2 N1303K Exon 24 1.8 2.1 2143delT Exon 14 No data 2.8 2184insA Exon 14 No data 1.8 2183AA4G Exon 14 No data 1.6 W1282X Exon 23 0.7 1.5 R334W Exon 8 No data 0.7 R347P Exon 8 No data 0.5 G551D Exon 12 0.5 0.0 K710X Exon 14 No data 0.7 3272-26A4G Intron 19 No data 0.7 3600 þ 2insT Intron 21 No data 0.5 1898 þ 1G4C Intron 13 No data 0.5 V1240G Exon 23 No data 0.5 Othersa - No data 10.0 Abbreviations: CF, cystic fibrosis; NBS CF, newborn screening for CF. Login to comment

[hide] Prospective and parallel assessments of cystic fib... Eur J Pediatr. 2012 Aug;171(8):1223-9. Epub 2012 May 12. Krulisova V, Balascakova M, Skalicka V, Piskackova T, Holubova A, Paderova J, Krenkova P, Dvorakova L, Zemkova D, Kracmar P, Chovancova B, Vavrova V, Stambergova A, Votava F, Macek M Jr
Prospective and parallel assessments of cystic fibrosis newborn screening protocols in the Czech Republic: IRT/DNA/IRT versus IRT/PAP and IRT/PAP/DNA.
Eur J Pediatr. 2012 Aug;171(8):1223-9. Epub 2012 May 12., [PMID:22581207]

Abstract [show]
Cystic fibrosis (CF) is a life-threatening disease for which early diagnosis following newborn screening (NBS) improves the prognosis. We performed a prospective assessment of the immunoreactive trypsinogen (IRT)/DNA/IRT protocol currently in use nationwide, versus the IRT/pancreatitis-associated protein (PAP) and IRT/PAP/DNA CF NBS protocols. Dried blood spots (DBS) from 106,522 Czech newborns were examined for IRT concentrations. In the IRT/DNA/IRT protocol, DNA-testing was performed for IRT >/= 65 ng/mL. Newborns with IRT >/= 200 ng/mL and no detected cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations were recalled for a repeat IRT. In the same group of newborns, for both parallel protocols, PAP was measured in DBS with IRT >/= 50 ng/mL. In PAP-positive newborns (i.e., >/=1.8 if IRT 50-99.9 or >/=1.0 if IRT >/= 100, all in ng/mL), DNA-testing followed as part of the IRT/PAP/DNA protocol. Newborns with at least one CFTR mutation in the IRT/DNA/IRT and IRT/PAP/DNA protocols; a positive PAP in IRT/PAP; or a high repeat IRT in IRT/DNA/IRT were referred for sweat testing. CONCLUSION: the combined results of the utilized protocols led to the detection of 21 CF patients, 19 of which were identified using the IRT/DNA/IRT protocol, 16 using IRT/PAP, and 15 using IRT/PAP/DNA. Decreased cut-offs for PAP within the IRT/PAP protocol would lead to higher sensitivity but would increase false positives. Within the IRT/PAP/DNA protocol, decreased PAP cut-offs would result in high sensitivity, an acceptable number of false positives, and would reduce the number of DNA analyses. Thus, we concluded that the IRT/PAP/DNA protocol would represent the most suitable protocol in our conditions.

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81 According to the protocol, this result indicated the sequencing of the Table 1 Parallel comparison of CF NBS protocols IRT/DNAa /IRT IRT/PAP IRT/PAP/DNAa Newborns screened (N) 106,522 106,522 106,522 IRT positives (N; %) 1,158 (1.09) 3,155 (2.96) 3,155 (2.96) PAP positives (N; %) - 260 (0.24) 260 (0.24) Median age (range) at the availability of DNA-testinga results (days) 36 (9-222b ) - 36 (9-222b ) 1 and/or 2 CF mutations detected (N; %) 76 (0.07) - 27 (0.03) Recalled newborns for repeated IRT examination (N; %) 47 (0.04) - - Positive CF NBS (N; %) 123 (0.12) 260 (0.24) 27 (0.03) Positive IRT in newborns recalled for repeated examination (N) 1 - - ST indicated (N; %) 77 (0.07) 260 (0.24) 27 (0.03) ST carried out (N; % of indicated ST) 72c (93.51) 204c (78.46) 24c (88.89) CF carriers (N) 55 - 12 Prevalence of CF carriers 1 in 21 - 1 in 22 Diagnosed CF patients (N) 19 16 15 False positives based on performed ST (N; % of all cases screened) 99d (0.09) 188 (0.18) 9 (0.01) Newborns with equivocal diagnosis [F508del/R117H-IVS-8 T(7) and ST<30 mmol/L; N] 2 - 0 False negatives (N) 2 5 6 Total of CF patients detected (N) 21e Median age (range) at diagnosis (days) 36 (9-57)e CF prevalence 1 in 5,072e Sensitivity (TP/TP+FN) 0.9048 0.7619 0.7142 Specificity (TN/TN+FP) 0.9991 0.9982 0.9999 PPV (TP/TP+FP) 0.1610 0.0784 0.625 N number, % of all cases screened, TP true positives, FN false negatives, TN true negatives, FP false positives, PPV positive predictive value, ST sweat test a CF-causing mutations covered by Elucigene assays ("legacy" nomenclature) with the CF-EU1Tm accounting for: p.Arg347Pro (R347P), c.2657+ 5G>A (2789+5G>A), c.2988+1G>A (3120+1G>A), c.579+1G>T (711+1G>T), p.Arg334Trp (R334W), p.Ile507del (I507del), p.Phe508del (F508del), c.3718-2477C>T (3849+10kbC>T), p.Phe316LeufsX12 (1078delT), p.Trp1282X (W1282X), p.Arg560Thr (R560T), p.Arg553X (R553X), p.Gly551Asp (G551D), p.Met1101Lys (M1101K), p.Gly542X (G542X), p.Leu1258PhefsX7 (3905insT), p.Ser1251Asn (S1251N), c.1585-1G>A (1717-1G>A), p.Arg117His (R117H), p.Asn1303Lys (N1303K), p.Gly85Glu (G85E), c.1766+1G>A (1898+1G>A), p.Lys684AsnfsX38 (2184delA), p.Asp1152His (D1152H), c.54-5940_273+10250del (CFTRdele2,3), p.Pro67Leu (P67L), p.Glu60X (E60X), p.Lys1177SerfsX15 (3659delC), c.489+1G>T (621+1G>T), p.Ala455Glu (A455E), p.Arg1162X (R1162X), p.Leu671X (2143delT), c.1210-12T[n] (IVS8-T(n) variant), including additional mutations in the CF-EU2Tm : p.Gln890X (Q890X), p.Tyr515X (1677delTA), p.Val520Phe (V520F), c.3140-26A>G (3272-26A>G), p.Leu88IlefsX22 (394delTT), p.Arg1066Cys (R1066C), p.Ile105SerfsX2 (444delA), p.Tyr1092X (C>A) (Y1092X(C>A)), p.Arg117Cys (R117C), p.Ser549Asn (S549N), p.Ser549ArgT>G (S549R T>G), p.Tyr122X (Y122X), p.Arg1158X (R1158X), p.Leu206Trp (L206W), c.1680-886A>G (1811+1.6kbA>G), p.Arg347His (R347H), p.Val739TyrfsX16 (2347delG) and p.Trp846X (W846X) b failed DNA isolation from DBS, including repetition of DNA-testing c deceased patient or non-compliance with referrals (five CF carriers in IRT/DNA/IRT, 56 newborns in IRT/PAP, three CF carriers in IRT/PAP/DNA) d comprising newborns with repeated IRT (47 newborns) e aggregate data from all protocols entire CFTR coding region in both newborns, and led to the identification of p.Ile336Lys (I336K) and p.Glu1104Lys (E1104K) mutations. Login to comment

[hide] Homozygous CFTR mutation M348K in a boy with respi... Eur J Pediatr. 2012 Jul;171(7):1039-46. doi: 10.1007/s00431-012-1672-1. Epub 2012 Jan 25. Hentschel J, Riesener G, Nelle H, Stuhrmann M, Schoner A, Sommerburg O, Fritzsching E, Mall MA, von Eggeling F, Mainz JG
Homozygous CFTR mutation M348K in a boy with respiratory symptoms and failure to thrive. Disease-causing mutation or benign alteration?
Eur J Pediatr. 2012 Jul;171(7):1039-46. doi: 10.1007/s00431-012-1672-1. Epub 2012 Jan 25., [PMID:22274833]

Abstract [show]
We report on a 6-month-old premature boy from consanguineous parents. He presented with respiratory distress, necrotizing enterocolitis and hyperbilirubinemia shortly after birth. Persisting respiratory symptoms and failure to thrive prompted cystic fibrosis diagnostics, which showed the lack of wild-type signal for the mutation R347P suggesting a homozygous deletion or an alteration different from the known mutation at this position. Sequencing of this region revealed the homozygous substitution 1175 T > A (HGVS: c.1043 T > A) in exon 7 resulting in the homozygous amino acid change M348K. This mutation has never been reported in homozygosity before. Computational analysis tools classified M348K as 'presumably disease causing.' In our patient, sweat testing and electrophysiological assessment of CFTR function in native rectal epithelium demonstrated normal Cl(-) secretion. Conclusion: We assume that the homozygous alteration M348K is a harmless variant rather than a CF-causing mutation.

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4 Persisting respiratory symptoms and failure to thrive prompted cystic fibrosis diagnostics, which showed the lack of wild-type signal for the mutation R347P suggesting a homozygous deletion or an alteration different from the known mutation at this position. Login to comment
64 Rte was determined from Vte deflections obtained by pulsed current injection Blank mutationcontrol patient Fig. 2 Results of the INNO LiPA CFTR17+Tn update analysis, which showed the lack of wild-type signal for the mutation R347P suggesting a homozygous deletion or an alteration different from the known mutation at this position Table 1 Result of STR analysis STR-Marker Chromosomal localizationa Allele distribution Allele distribution Allele distribution Interpretation Mother Father Child D7S3051 7p14 a-c b-c a-b Informative normal D7S2559 7p21.1 b-b a-b a-b Non-informative D7S817 7p14.3 a-c b-d c-d Informative normal D7S2846 7p14.1 a-c b-d a-d Informative normal D7S1830 7p12.1 a-c b-b a-b Informative normal D7S3046 7q11.22 b-d a-c a-b Informative normal D7S2204 7q21.11 a-a b-c a-b Informative normal D7S820 7q21.11 a-d b-c b-d Informative normal D7S1799 7q21.1 b-c a-c c-c Non-informative D7S821 7q21.3 a-b a-b b-b Non-informative D7S1804 7q32.2 b-c a-b b-b Non-informative D7S1824 7q34 a-a b-c a-c Informative normal D7S2461 7q36.1 b-c a-b b-b Non-informative D7S3058 7q36.2 a-c b-b b-c Informative normal a Chromosomal localisation according to www.genome.ucsc.edu [24] M F C M F C M F C M F C M F C GATA137H02 D7S3058D7S1824D7S2846D7S817 D7S820 (7q21.11) D7S1799 (7q21.1) D7S1804 (7q32.2) Mother Father Child D7S2461 (7q36.1) a b Fig. 3 a Uniparental disomy 7 (UPD 7) analysis. Login to comment
77 However, the wild-type signal for R347P was lost (Fig. 2). Login to comment
110 These properties can influence the conductance of the CFTR protein as it is published for mutation R347P [21]. Login to comment

[hide] Retrospective analysis of stored dried blood spots... J Cyst Fibros. 2012 Jul;11(4):332-6. doi: 10.1016/j.jcf.2012.01.001. Epub 2012 Feb 1. Barben J, Gallati S, Fingerhut R, Schoeni MH, Baumgartner MR, Torresani T
Retrospective analysis of stored dried blood spots from children with cystic fibrosis and matched controls to assess the performance of a proposed newborn screening protocol in Switzerland.
J Cyst Fibros. 2012 Jul;11(4):332-6. doi: 10.1016/j.jcf.2012.01.001. Epub 2012 Feb 1., [PMID:22300503]

Abstract [show]
BACKGROUND: Newborn screening (NBS) for Cystic Fibrosis (CF) has been introduced in many countries, but there is no ideal protocol suitable for all countries. This retrospective study was conducted to evaluate whether the planned two step CF NBS with immunoreactive trypsinogen (IRT) and 7 CFTR mutations would have detected all clinically diagnosed children with CF in Switzerland. METHODS: IRT was measured using AutoDELFIA Neonatal IRT-Kit in stored NBS cards. RESULTS: Between 2006 and 2009, 66 children with CF were reported, 4 of which were excluded for various reasons (born in another country, NBS at 6 months, no informed consent). 98% (61/62) had significantly higher IRT compared to matched control group. There was one false negative IRT result in an asymptomatic child with atypical CF (normal pancreatic function and sweat test). CONCLUSIONS: All children but one with atypical CF would have been detected with the planned two step protocol.

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80 CFTR mutations Alleles found Percentage of total Homozygous (n) F508del a 86 68.2 30 3905insT a 4 3.2 1 G542X a 3 2.4 - R553X a 3 2.4 1 W1282X a 2 1.6 - 1717-1 GNA a 2 1.6 - N1303K a 0 0.0 - S549R 3 2.4 1 Q525X 3 2.4 - Y1092X 2 1.6 - 3120+1 GNA b 2 1.6 1 2347delG 2 1.6 - 2176insC 1 0.8 - 3659delC 1 0.8 - 3359delCTCTG 1 0.8 - W1089X 1 0.8 - 711+1 GNT 1 0.8 - D1152H 1 0.8 - G1244E 1 0.8 - R1066C 1 0.8 - R31C 1 0.8 - R347P 1 0.8 - R74W 1 0.8 - S945L 1 0.8 - T501I 1 0.8 - K68X 1 0.8 - Total 126 100.0% 34 a Seven most common CF-gene mutations in Switzerland ("Swiss panel")=79.4% (100/126) of alleles. Login to comment

[hide] Improving test properties for neonatal cystic fibr... J Inherit Metab Dis. 2012 Jul;35(4):635-40. Cornel MC, Gille JJ, Loeber JG, Vernooij-van Langen AM, Dankert-Roelse J, Bolhuis PA
Improving test properties for neonatal cystic fibrosis screening in the Netherlands before the nationwide start by May 1st 2011.
J Inherit Metab Dis. 2012 Jul;35(4):635-40., [PMID:22302635]

Abstract [show]
When new technical possibilities arise in health care, often attunement is needed between different actors from the perspectives of research, health care providers, patients, ethics and policy. For cystic fibrosis (CF) such a process of attunement in the Netherlands started in a committee of the Health Council on neonatal screening in 2005. In the balancing of pros and cons according to Wilson and Jungner criteria, the advantages for the CF patient were considered clear, even though CF remains a severe health problem with treatment. Nevertheless, screening was not started then, mainly since the specificity of the tests available at that time was considered too low. Many healthy infants would have been referred for sweat testing and much uncertainty would arise in their parents. Also the limited sensitivity for immigrants and the detection of less severe phenotypes and carriers were considered problematic. The Health Council recommended a pilot screening project which was subsequently performed in some provinces, leading to a 4-step protocol: IRT, PAP, screening for a CFTR mutation panel, and sequencing of the CFTR gene. This would lead to the identification of 23 cases of classical CF, two infants with less severe forms and 12 carriers per year in the Netherlands. Thus many CF patients can be diagnosed early, while limiting the number of referrals, the number of infants with less severe forms diagnosed and the number of carriers identified. Technical solutions were found to limit the ethical problems. A nationwide program using this four step protocol started by 1 May 2011.

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69 This protocol was expected to identify 25 CF patients on an annual basis, additional to four infants already diagnosed because of meconium ileus (Health Council of 1 Using the LiPA test (INNO-LiPA CFTR 19 en INNO-LiPA CFTR 17+Tn; Innogenetics, Gent, Belgium) the following CFTR mutations can be detected: exon 2-3del (21 kb), 394delTT, E60X, G85E, R117H, 621+1G>T, 711+1G>T, 711+5G>A, 1078delT, R334W, R347P, A455E, I507del, F508del, 1717-1G>A, G542X, G551D, Q552X, R553X, R560T, 1898+1G>A, 2143delT, 2183AA>G, 2184delA, 2789+5G>A, 3120+1G>A, 3199del6, 3272-26A>G, 3659delC, R1162X, 3849+10kbC>T, 3905insT, S1251N, W1282X en N1303K. Login to comment
70 This test also identifies the CFTR polymorphism Tn in intron 8 which is important in cases where the mutation R117H is detected. Login to comment

[hide] Link between CFTR mutations and ABPA: a systematic... Mycoses. 2012 Jul;55(4):357-65. doi: 10.1111/j.1439-0507.2011.02130.x. Epub 2011 Oct 17. Agarwal R, Khan A, Aggarwal AN, Gupta D
Link between CFTR mutations and ABPA: a systematic review and meta-analysis.
Mycoses. 2012 Jul;55(4):357-65. doi: 10.1111/j.1439-0507.2011.02130.x. Epub 2011 Oct 17., [PMID:21999194]

Abstract [show]
Summary There is a biological plausibility on the link between cystic fibrosis transmembrane conductance regulator (CFTR) mutations and allergic bronchopulmonary aspergillosis (ABPA). The aim of the systematic review was to investigate this link by determining the frequency of CFTR mutations in ABPA. We searched the PubMed and EmBase databases for studies reporting CFTR mutations in ABPA. We pooled the odds ratio (OR) and 95% confidence intervals (CI) from individual studies using both fixed and random effects model. Statistical heterogeneity was evaluated using the I(2) test and the Cochran-Q statistic. Publication bias was assessed using both graphical and statistical methods. Our search yielded four studies (79 ABPA, 268 controls). The odds of encountering CFTR mutation was higher in ABPA compared with the control group (OR 10.39; 95% CI, 4.35-24.79) or the asthma population (OR 5.53; 95% CI 1.62-18.82). There was no evidence of statistical heterogeneity or publication bias. There is a possible pathogenetic link between CFTR mutations and ABPA. However, because of the small numbers of patients, further studies are required to confirm this finding. Future studies should adopt a uniform methodology and should screen for the entire genetic sequence of the CFTR gene.

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56 (1996)[30] 11ABPA53chronic bronchitis Asthma,pulmonaryinfiltrates,CB, immediateAfskintestpositivity,totalIgE >1000ngml)1 ,positiveAfprecipitins, elevatedAfIgG/IgE,bloodeosinophilia, sweatchloride<40mmoll)1 /(United States) BothgroupssixmutationsF508del, G542X,GS51D,R553X,W1282X andN1303K;ninemoremutations inABPA:R117H,R347P,R347H, R334W,A455E,G551S, 2789+5G>A,D1152H,and 3849+10kbC>T ReverseASOanalysis andDGGEwithDNA sequencing 1patientcarried2CF (F508del;R347H)and5 carried1CF(4F508del; 1R117H).Mutationsseenin 6/11ABPAvs.1/53 controls Aronetal. Login to comment
59 (2002)[33] 31ABPAHealthycontrols (n=34) Asthma(n=51) Asthma,positiveSPTtoAf,totalIgE >1000ngml)1 ,elevatedAf-IgE,positive precipitinstoAf,bloodeosinophilia >350ll)1 ,pulmonaryinfiltratesonCXR orCBonCT/(NewZealand) 16CFmutations-F508del,I507del, R117H,W1282X,621+1G>T, R334W,R347P,A455E, 1717-1G>A,G542X,5549N, G551D,R553X,R560T,N1303Kand 3849+10kbC>T ASOhybridisationand DGGEwithDNA sequencing 4/31(F508del[n=3], R117H[n=1])vs.2/51 asthma(F508del[n=1], R117H[n=1])vs.1/34 healthycontrols ABPA,allergicbronchopulmonaryaspergillosis;ARMS,amplificationrefractorymutationsystem;ASO,allele-specificoligonucleotide;CB,centralbronchiectasis;CFTR,cysticfibrosis transmembraneconductanceregulator;DGGE,denaturinggradientgelelectrophoresis;OR,oddsratio CFTRmutationclass(classI--1717-1G>A,R1162X,G542X;classII--F508del,N1303K;classIV--R347H,R117H). Login to comment

[hide] Rapid detection of the ACMG/ACOG-recommended 23 CF... J Biomol Tech. 2012 Apr;23(1):24-30. Elliott AM, Radecki J, Moghis B, Li X, Kammesheidt A
Rapid detection of the ACMG/ACOG-recommended 23 CFTR disease-causing mutations using ion torrent semiconductor sequencing.
J Biomol Tech. 2012 Apr;23(1):24-30., [PMID:22468138]

Abstract [show]
Cystic fibrosis (CF) is one of the most frequently diagnosed autosomal-recessive diseases in the Caucasian population. For general-population CF carrier screening, the American College of Medical Genetics (ACMG)/American College of Obstetricians and Gynecologists (ACOG) have recommended a core panel of 23 mutations that will identify 49-98% of carriers, depending on ethnic background. Using a genotyping technology that can rapidly identify disease-causing mutations is important for high-throughput general-population carrier screening, confirming clinical diagnosis, determining treatment options, and prenatal diagnosis. Here, we describe a proof-of-concept study to determine whether the Ion Torrent Personal Genome Machine (PGM) sequencer platform can reliably identify all ACMG/ACOG 23 CF transmembrane conductance regulator (CFTR) mutations. A WT CF specimen along with mutant DNA specimens representing all 23 CFTR mutations were sequenced bidirectionally on the Ion Torrent 314 chip to determine the accuracy of the PGM for CFTR variant detection. We were able to reliably identify all of the targeted mutations except for 2184delA, which lies in a difficult, 7-mer homopolymer tract. Based on our study, we believe PGM sequencing may be a suitable technology for identifying CFTR mutations in the future. However, as a result of the elevated rate of base-calling errors within homopolymer stretches, mutations within such regions currently need to be evaluated carefully using an alternative method.

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26 Amplicons were then pooled together in equimolar concentrations and purified using the T A B L E 1 Data Generation from Three PGM Runs Run Total number of reads Total bases (Mbp) AQ17 total bases (Mbp) AQ17 avg. read length CF WT 101,211 8.5 6.5 68 CF 23 pooled mutants 222,247 18.6 12.52 64 CF mutant 135,000 11.7 8.8 72 T A B L E 2 CFTR Variant Coverage, Mutant Read Percentage, and Base-Call Accuracy from a WT Library Using PGM Sequencing Variant cDNA position Coverage Mutant read % Accuracy/base G85E c.254G Ͼ A 408 0 99.5 R117H c.350G Ͼ A 3627 0 99.9 621 ϩ 1G Ͼ T c.489 ϩ 1G Ͼ T 245 0 99.6 711 ϩ 1G Ͼ T c.579 ϩ 1G Ͼ T 2660 0 99.9 R334W c.1000C Ͼ T 5419 0 99.7 R347P c.1040G Ͼ C 3562 0 99.4 A455E c.1364C Ͼ A 10,340 0 99.9 ⌬I507 c.1519_1521delATC 6507 0 98.6 ⌬F508 c.1521_1523delCTT 6507 0 99.4 1717-1G Ͼ A c.1585-1G Ͼ A 2086 0 99.2 G542X c.1624G Ͼ T 854 0 97.8 G551D c.1652G Ͼ A 3901 0 99 R553X c.1657C Ͼ T 3915 0 99.9 R560T c.1679G Ͼ C 3924 0 99.6 1898 ϩ 1G Ͼ A c.1766 ϩ 1G Ͼ A 1793 0 97.6 2184delAa c.2052delA 2001 35% 63.6 2789 ϩ 5G Ͼ A c.2657 ϩ 5G Ͼ A 293 0 100 3120 ϩ 1G Ͼ A c.2988 ϩ 1G Ͼ A 2408 0 100 R1162X c.3484C Ͼ T 9610 0 98.1 3659delC c.3528delC 9271 0 100 3849 ϩ 10kbC Ͼ T c.3717 ϩ 12191C Ͼ T 10,157 0 99.9 W1282X c.3846G Ͼ A 4789 0 95.6 N1303K c.3909C Ͼ G 3236 0 99.5 a The 2184delA variant lies in a homopolymer stretch of seven adenines and is not detected accurately as a result of homopolymer-length sequencing errors. Login to comment
67 For this data set, the PGM 314 chip output was 18.6 Mbp, with ϳ67% aligning to the CFTR T A B L E 3 PGM CFTR Variant Coverage and Mutant Read Percentage from a Pooled Mutant Library Representing All 23 ACMG/ACOG Mutations Variant cDNA position Coverage Mutant read % Predicted read % Genotype G85E c.254G Ͼ A 93 33 50 Het R117H c.350G Ͼ A 6228 39 50 Het 621 ϩ 1G Ͼ T c.489 ϩ 1G Ͼ T 1243 46 50 Het 711 ϩ 1G Ͼ T c.579 ϩ 1G Ͼ T 1352 29 50 Het R334W c.1000C Ͼ T 13,284 8 25 Het R347P c.1040G Ͼ C 9454 27 25 Het A455E c.1364C Ͼ A 19,527 43 50 Het ⌬I507 c.1519_1521delATC 15,587 14 25 Het ⌬F508 c.1521_1523delCTT 15,587 68 50 Homo 1717-1G Ͼ A c.1585-1G Ͼ A 3584 36 50 Het G542X c.1624G Ͼ T 610 41 50 Het G551D c.1652G Ͼ A 6714 16 17 Het R553X c.1657C Ͼ T 6670 15 17 Het R560T c.1679G Ͼ C 6395 22 17 Het 1898 ϩ 1G Ͼ A c.1766 ϩ 1G Ͼ A 3293 49 50 Het 2184delAa c.2052delA 2256 63 50 Het 2789 ϩ 5G Ͼ A c.2657 ϩ 5G Ͼ A 1765 54 50 Het 3120 ϩ 1G Ͼ A c.2988 ϩ 1G Ͼ A 7447 40 50 Het R1162X c.3484C Ͼ T 19,060 54 50 Het 3659delC c.3528delC 28,321 30 50 Het 3849 ϩ 10kbC Ͼ T c.3717 ϩ 12191C Ͼ T 27,102 46 50 Het W1282X c.3846G Ͼ A 9219 48 50 Het N1303K c.3909C Ͼ G 4842 49 50 Het a The 2184delA variant lies in a homopolymer stretch of seven adenines and is not accurately detected as a result of homopolymer-length sequencing errors. Login to comment
86 Using samples characterized previously, we analyzed the PGM`s data out- T A B L E 4 PGM CFTR Variant Coverage and Mutant Read Percentage from an Individual Harboring Two Disease-Causing CFTR Mutations Variant cDNA position Coverage Mutant read % G85E c.254G Ͼ A 237 0 R117H c.350G Ͼ A 3774 0 621 ϩ 1G Ͼ T c.489 ϩ 1G Ͼ T 936 0 711 ϩ 1G Ͼ T c.579 ϩ 1G Ͼ T 2018 0 R334W c.1000C Ͼ T 10,899 0 R347P c.1040G Ͼ C 7720 0 A455E c.1364C Ͼ A 14,525 0 ⌬I507 c.1519_1521delATC 8855 0 ⌬F508 c.1521_1523delCTT 8855 47 1717-1G Ͼ A c.1585-1G Ͼ A 2216 0 G542X c.1624G Ͼ T 2035 41 G551D c.1652G Ͼ A 4581 0 R553X c.1657C Ͼ T 4545 0 R560T c.1679G Ͼ C 4774 0 1898 ϩ 1G Ͼ A c.1766 ϩ 1G Ͼ A 2702 0 2184delAa c.2052delA 2837 18.5 2789 ϩ 5G Ͼ A c.2657 ϩ 5G Ͼ A 860 0 3120 ϩ 1G Ͼ A c.2988 ϩ 1G Ͼ A 4347 0 R1162X c.3484C Ͼ T 12,039 0 3659delC c.3528delC 7169 0 3849 ϩ 10kbC Ͼ T c.3717 ϩ 12191C Ͼ T 11,588 0 W1282X c.3846G Ͼ A 6187 0 N1303K c.3909C Ͼ G 4479 0 a The 2184delA variant lies in a homopolymer stretch of seven adenines and is not accurately detected as a result of homopolymer-length sequencing errors. Login to comment
66 For this data set, the PGM 314 chip output was 18.6 Mbp, with b03;67% aligning to the CFTR T A B L E 3 PGM CFTR Variant Coverage and Mutant Read Percentage from a Pooled Mutant Library Representing All 23 ACMG/ACOG Mutations Variant cDNA position Coverage Mutant read % Predicted read % Genotype G85E c.254G b0e; A 93 33 50 Het R117H c.350G b0e; A 6228 39 50 Het 621 af9; 1G b0e; T c.489 af9; 1G b0e; T 1243 46 50 Het 711 af9; 1G b0e; T c.579 af9; 1G b0e; T 1352 29 50 Het R334W c.1000C b0e; T 13,284 8 25 Het R347P c.1040G b0e; C 9454 27 25 Het A455E c.1364C b0e; A 19,527 43 50 Het èc;I507 c.1519_1521delATC 15,587 14 25 Het èc;F508 c.1521_1523delCTT 15,587 68 50 Homo 1717-1G b0e; A c.1585-1G b0e; A 3584 36 50 Het G542X c.1624G b0e; T 610 41 50 Het G551D c.1652G b0e; A 6714 16 17 Het R553X c.1657C b0e; T 6670 15 17 Het R560T c.1679G b0e; C 6395 22 17 Het 1898 af9; 1G b0e; A c.1766 af9; 1G b0e; A 3293 49 50 Het 2184delAa c.2052delA 2256 63 50 Het 2789 af9; 5G b0e; A c.2657 af9; 5G b0e; A 1765 54 50 Het 3120 af9; 1G b0e; A c.2988 af9; 1G b0e; A 7447 40 50 Het R1162X c.3484C b0e; T 19,060 54 50 Het 3659delC c.3528delC 28,321 30 50 Het 3849 af9; 10kbC b0e; T c.3717 af9; 12191C b0e; T 27,102 46 50 Het W1282X c.3846G b0e; A 9219 48 50 Het N1303K c.3909C b0e; G 4842 49 50 Het a The 2184delA variant lies in a homopolymer stretch of seven adenines and is not accurately detected as a result of homopolymer-length sequencing errors. Login to comment
85 Using samples characterized previously, we analyzed the PGM`s data out- T A B L E 4 PGM CFTR Variant Coverage and Mutant Read Percentage from an Individual Harboring Two Disease-Causing CFTR Mutations Variant cDNA position Coverage Mutant read % G85E c.254G b0e; A 237 0 R117H c.350G b0e; A 3774 0 621 af9; 1G b0e; T c.489 af9; 1G b0e; T 936 0 711 af9; 1G b0e; T c.579 af9; 1G b0e; T 2018 0 R334W c.1000C b0e; T 10,899 0 R347P c.1040G b0e; C 7720 0 A455E c.1364C b0e; A 14,525 0 èc;I507 c.1519_1521delATC 8855 0 èc;F508 c.1521_1523delCTT 8855 47 1717-1G b0e; A c.1585-1G b0e; A 2216 0 G542X c.1624G b0e; T 2035 41 G551D c.1652G b0e; A 4581 0 R553X c.1657C b0e; T 4545 0 R560T c.1679G b0e; C 4774 0 1898 af9; 1G b0e; A c.1766 af9; 1G b0e; A 2702 0 2184delAa c.2052delA 2837 18.5 2789 af9; 5G b0e; A c.2657 af9; 5G b0e; A 860 0 3120 af9; 1G b0e; A c.2988 af9; 1G b0e; A 4347 0 R1162X c.3484C b0e; T 12,039 0 3659delC c.3528delC 7169 0 3849 af9; 10kbC b0e; T c.3717 af9; 12191C b0e; T 11,588 0 W1282X c.3846G b0e; A 6187 0 N1303K c.3909C b0e; G 4479 0 a The 2184delA variant lies in a homopolymer stretch of seven adenines and is not accurately detected as a result of homopolymer-length sequencing errors. Login to comment

[hide] CFTR, SPINK1, CTRC and PRSS1 variants in chronic p... Gut. 2012 Mar 17. Rosendahl J, Landt O, Bernadova J, Kovacs P, Teich N, Bodeker H, Keim V, Ruffert C, Mossner J, Kage A, Stumvoll M, Groneberg D, Kruger R, Luck W, Treiber M, Becker M, Witt H
CFTR, SPINK1, CTRC and PRSS1 variants in chronic pancreatitis: is the role of mutated CFTR overestimated?
Gut. 2012 Mar 17., [PMID:22427236]

Abstract [show]
OBJECTIVE: In chronic pancreatitis (CP), alterations in several genes have so far been described, but only small cohorts have been extensively investigated for all predisposing genes. DESIGN: 660 patients with idiopathic or hereditary CP and up to 1758 controls were enrolled. PRSS1, SPINK1 and CTRC were analysed by DNA sequencing, and cystic fibrosis transmembrane conductance regulator (CFTR) by melting curve analysis. RESULTS: Frequencies of CFTR variants p.R75Q, p.I148T, 5T-allele and p.E528E were comparable in patients and controls. We identified 103 CFTR variants, which represents a 2.7-fold risk increase (p<0.0001). Severe cystic fibrosis (CF)-causing variants increased the risk of developing CP 2.9-fold, and mild CF-causing variants 4.5-fold (p<0.0001 for both). Combined CF-causing variants increased CP risk 3.4-fold (p<0.0001), while non-CF-causing variants displayed a 1.5-fold over-representation in patients (p=0.14). CFTR compound heterozygous status with variant classes CF-causing severe and mild represented an OR of 16.1 (p<0.0001). Notably, only 9/660 (1.4%) patients were compound heterozygotes in this category. Trans-heterozygosity increased CP risk, with an OR of 38.7, with 43/660 (6.5%) patients and 3/1667 (0.2%) controls being trans-heterozygous (p<0.0001). CONCLUSIONS: Accumulation of CFTR variants in CP is less pronounced than reported previously, with ORs between 2.7 and 4.5. Only CF-causing variants reached statistical significance. Compound and trans-heterozygosity is an overt risk factor for the development of CP, but the number of CFTR compound heterozygotes in particular is rather low. In summary, the study demonstrates the complexity of genetic interactions in CP and a minor influence of CFTR alterations in CP development.

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72 The following CFTR variants were analysed with specific FRET probes: p.E60X, p.R75Q, p.G85E, p.R117H, p.I148T, c.621 +1G>T (IVS4+1G>T), c.711+1G>T (IVS5+1G>T), c.1078delT, p.R334W, p.R347P, 9-13TG, 5-9T, p.A455E, p.M470V, p.F508del, c.1716G>A (p.E528E), c.1717-1G>A (IVS10-1G>A), p.G542X, p.S549N, p.R553X, p.R560T, c.1898+1G>A (IVS12 +1G>A), c.2143delT, c.2183AA>G, c.2562T>G, c.2657+5G>A (IVS14B+5G>A), p.L997F, p.I1005R, p.Y1092X, p.D1152H, p.R1162X, c.3659delC, p.S1235R, p.S1251N, p.W1282X, p.N1303K, and c.4389G>A. Login to comment
140 Variant distribution in patients aged >20 and <20 years In younger patients, overall PRSS1 variants were 2.9-fold more common (>20 years: 9/239, 3.8%; <20 years: 46/421, 10.9%; p¼0.001, OR 3.1, 95% CI 1.5 to 6.5), whereas overall SPINK1 variants were similarly distributed (56/239, 23.4%; 73/421, Table 2 CFTR variants detected by melting curve analysis Gene Variant Patients Controls p Value OR (95% CI) CFTR (CF-causing, severe) p.F508del 44/660 (6.7%) 48/1758 (2.7%) <0.0001 2.5 (1.7 to 3.9) p.R117H (5T/7T) 2/660 (0.3%) 1/1758 (0.06%) NS e p.G542X 1/660 (0.2%) 1/1758 (0.06%) NS e c.1717-1G>A 3/660 (0.5%) 1/1758 (0.06%) NS e p.E585X 0/660 1/1758 (0.06%) NS e c.2183AA>G 0/660 1/1758 (0.06%) NS e p.R1158X 1/660 (0.2%) 0/1758 NS e p.R1162X 1/660 (0.3%) 0/1758 NS e p.N1303K 3/660 (0.5%) 0/1758 NS e Total 55/660 (8.3%) 53/1758 (3%) <0.0001 2.9 (2 to 4.3) CFTR (CF-causing mild) p.R117H (7T/7T) 13/660 (2%) 8/1758 (0.5%) 0.0009 4.4 (1.8 to 10.7) p.R117H (7T/9T) 3/660 (0.5%) 1/1758 (0.06%) NS e p.R347H 1/660 (0.2%) 0/1758 NS e p.R347P 1/660 (0.2%) 0/1758 NS e p.A455E 1/660 (0.2%) 0/1758 NS e c.2657+5G>A 1/660 (0.2%) 0/1758 NS e p.D1152H 3/660 (0.5%) 5/1758 (0.3%) NS e Total 23/660 (3.5%) 14/1758 (0.8%) <0.0001 4.5 (2.3 to 8.8) CFTR (non CF-causing) p.R74Q 2/660 (0.3%) 0/1758 NS e p.R75Q (het)* 29/660 (4.4%) 59/1758 (3.4%) NS e p.R75Q (hom)* 2/660 (0.3%) 1/1758 (0.06%) NS e p.Y84H 0/660 1/1758 (0.06%) NS e p.A120T 0/660 1/1758 (0.06%) NS e p.I148T* 4/660 (0.6%) 11/1758 (0.6%) NS e p.I507V 1/660 (0.2%) 2/1758 (0.1%) NS e p.F508C 1/660 (0.2%) 0/1758 NS e c.1716+12T>C 0/660 1/1758 (0.06%) NS e p.E528E (het)* 36/660 (5.5%) 82/1758 (4.7%) NS e p.E528E (hom)* 0/660 2/1758 (0.1%) NS e c.1898+8C>G 0/660 1/1758 (0.06%) NS e p.H667Y 1/660 (0.2%) 0/1758 NS e p.R668C 5/660 (0.8%) 3/1758 (0.2%) NS e p.G691R 0/660 1/1758 (0.06%) NS e p.L997F 5/660 (0.8%) 6/1758 (0.3%) NS e p.S1235R 10/660 (1.5%) 18/1758 (1.0%) NS e Total (excluded)* 25/660 (3.8%) 45/1758 (2.6%) NS e CFTR (CF-causing) Total (all) 78/660 (11.8%) 67/1758 (3.8%) <0.0001 3.4 (2.4 to 4.8) CFTR (all) Total (excluded)* 103/660 (15.6%) 112/1758 (6.4%) <0.0001 2.7 (2 to 3.6) The table is divided into three parts. Login to comment
150 Table 4 Homozygous and compound heterozygous patients and controls with at least two CFTR, SPINK1 or CTRC variants Gene Variant Patients Controls p Value OR (95% CI) CFTR (CF-causing severe or CF-causing mild/CF-causing mild) p.F508del/p.R117H (7T/9T) 2/660 (0.3%) 1/1758 (0.06%) NS e p.F508del/p.R347H 1/660 (0.2%) 0/1758 NS e p.F508del/p.D1152Hy 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/c.2657+5G>A 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.R1158X 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/c.1717-1G>A 1/660 (0.2%) 0/1758 NS e p.R117H (7T/9T)/p.N1303K 1/660 (0.2%) 0/1758 NS e p.D1152Hy/p.N1303K 1/660 (0.2%) 0/1758 NS e Total 9/660 (1.4%) 1/1758 (0.06%) 0.002 16.1 (1.9 to 134.2) CFTR (CF-causing severe or CF-causing mild or non-CF-causing/Non-CF-causing) p.F508del/p.R75Q* 0/660 1/1758 (0.06%) NS e p.F508del/5T* 2/660 (0.3%) 1/1758 (0.06%) NS e p.F508del/p.E528E* 2/660 (0.3%) 2/1758 (0.1%) NS e p.R75Q*/5T* 1/660 (0.2%) 1/1758 (0.06%) NS e p.R75Q*/p.E528E* 2/660 (0.3%) 2/1758 (0.1%) NS e p.R117H (7T/7T)/p.R75Q* 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.E528E* 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.S1235R 1/660 (0.2%) 0/1758 NS e p.I148T*/5T* 0/660 1/1758 (0.06%) NS e p.R347P/p.E528E* 1/660 (0.2%) 0/1758 NS e p.E528E*/5T* 1/660 (0.2%) 4/1758 (0.23%) NS e p.H667Y/5T* 1/660 (0.2%) 0/1758 NS e p.L997F/5T* 1/660 (0.2%) 0/1758 NS e p.L997F/p.E528E* 0/660 1/1758 (0.06%) NS e p.D1152Hy/5T* 1/660 (0.2%) 0/1758 NS e p.S1235R/5T* 2/660 (0.3%) 1/1758 (0.06%) NS e Total 17/660 (2.6%) 14/1758 (0.8%) 0.001 3.3 (1.6 to 6.7) CFTR Total (all, excluded)* 10/660 (1.5%) 1/1758 (0.06%) <0.0001 27 (3.5 to 211.7) SPINK1 p.N34S (hom) 17/660 (2.6%) 0/1758 <0.0001 95.6 (5.7 to 1594) p.N34S (het)/c.(1-215G>A;194+2T>C) 7/660 (1.1%) 0/1758 <0.0001 40.4 (2.3 to 708.2) Total 24/660 (3.6%) 0/1758 <0.0001 135.4 (8.2 to 2231) CTRC p.R254W (hom) 1/546 (0.2%) 0/1700 NS e p.R254W/p.V235I 1/546 (0.2%) 0/1700 NS e Total 2/546 (0.4%) 0/1700 NS e For CFTR compound heterozygous carriers, calculations were performed for patients and controls carrying a combination of one CF-causing severe or a CF-causing mild in addition with one CF-causing mild variant (upper section). Login to comment
69 The following CFTR variants were analysed with specific FRET probes: p.E60X, p.R75Q, p.G85E, p.R117H, p.I148T, c.621 +1G>T (IVS4+1G>T), c.711+1G>T (IVS5+1G>T), c.1078delT, p.R334W, p.R347P, 9-13TG, 5-9T, p.A455E, p.M470V, p.F508del, c.1716G>A (p.E528E), c.1717-1G>A (IVS10-1G>A), p.G542X, p.S549N, p.R553X, p.R560T, c.1898+1G>A (IVS12 +1G>A), c.2143delT, c.2183AA>G, c.2562T>G, c.2657+5G>A (IVS14B+5G>A), p.L997F, p.I1005R, p.Y1092X, p.D1152H, p.R1162X, c.3659delC, p.S1235R, p.S1251N, p.W1282X, p.N1303K, and c.4389G>A. Login to comment
135 Variant distribution in patients aged >20 and <20 years In younger patients, overall PRSS1 variants were 2.9-fold more common (>20 years: 9/239, 3.8%; <20 years: 46/421, 10.9%; p&#bc;0.001, OR 3.1, 95% CI 1.5 to 6.5), whereas overall SPINK1 variants were similarly distributed (56/239, 23.4%; 73/421, Table 2 CFTR variants detected by melting curve analysis Gene Variant Patients Controls p Value OR (95% CI) CFTR (CF-causing, severe) p.F508del 44/660 (6.7%) 48/1758 (2.7%) <0.0001 2.5 (1.7 to 3.9) p.R117H (5T/7T) 2/660 (0.3%) 1/1758 (0.06%) NS e p.G542X 1/660 (0.2%) 1/1758 (0.06%) NS e c.1717-1G>A 3/660 (0.5%) 1/1758 (0.06%) NS e p.E585X 0/660 1/1758 (0.06%) NS e c.2183AA>G 0/660 1/1758 (0.06%) NS e p.R1158X 1/660 (0.2%) 0/1758 NS e p.R1162X 1/660 (0.3%) 0/1758 NS e p.N1303K 3/660 (0.5%) 0/1758 NS e Total 55/660 (8.3%) 53/1758 (3%) <0.0001 2.9 (2 to 4.3) CFTR (CF-causing mild) p.R117H (7T/7T) 13/660 (2%) 8/1758 (0.5%) 0.0009 4.4 (1.8 to 10.7) p.R117H (7T/9T) 3/660 (0.5%) 1/1758 (0.06%) NS e p.R347H 1/660 (0.2%) 0/1758 NS e p.R347P 1/660 (0.2%) 0/1758 NS e p.A455E 1/660 (0.2%) 0/1758 NS e c.2657+5G>A 1/660 (0.2%) 0/1758 NS e p.D1152H 3/660 (0.5%) 5/1758 (0.3%) NS e Total 23/660 (3.5%) 14/1758 (0.8%) <0.0001 4.5 (2.3 to 8.8) CFTR (non CF-causing) p.R74Q 2/660 (0.3%) 0/1758 NS e p.R75Q (het)* 29/660 (4.4%) 59/1758 (3.4%) NS e p.R75Q (hom)* 2/660 (0.3%) 1/1758 (0.06%) NS e p.Y84H 0/660 1/1758 (0.06%) NS e p.A120T 0/660 1/1758 (0.06%) NS e p.I148T* 4/660 (0.6%) 11/1758 (0.6%) NS e p.I507V 1/660 (0.2%) 2/1758 (0.1%) NS e p.F508C 1/660 (0.2%) 0/1758 NS e c.1716+12T>C 0/660 1/1758 (0.06%) NS e p.E528E (het)* 36/660 (5.5%) 82/1758 (4.7%) NS e p.E528E (hom)* 0/660 2/1758 (0.1%) NS e c.1898+8C>G 0/660 1/1758 (0.06%) NS e p.H667Y 1/660 (0.2%) 0/1758 NS e p.R668C 5/660 (0.8%) 3/1758 (0.2%) NS e p.G691R 0/660 1/1758 (0.06%) NS e p.L997F 5/660 (0.8%) 6/1758 (0.3%) NS e p.S1235R 10/660 (1.5%) 18/1758 (1.0%) NS e Total (excluded)* 25/660 (3.8%) 45/1758 (2.6%) NS e CFTR (CF-causing) Total (all) 78/660 (11.8%) 67/1758 (3.8%) <0.0001 3.4 (2.4 to 4.8) CFTR (all) Total (excluded)* 103/660 (15.6%) 112/1758 (6.4%) <0.0001 2.7 (2 to 3.6) The table is divided into three parts. Login to comment
144 Table 4 Homozygous and compound heterozygous patients and controls with at least two CFTR, SPINK1 or CTRC variants Gene Variant Patients Controls p Value OR (95% CI) CFTR (CF-causing severe or CF-causing mild/CF-causing mild) p.F508del/p.R117H (7T/9T) 2/660 (0.3%) 1/1758 (0.06%) NS e p.F508del/p.R347H 1/660 (0.2%) 0/1758 NS e p.F508del/p.D1152Hy 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/c.2657+5G>A 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.R1158X 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/c.1717-1G>A 1/660 (0.2%) 0/1758 NS e p.R117H (7T/9T)/p.N1303K 1/660 (0.2%) 0/1758 NS e p.D1152Hy/p.N1303K 1/660 (0.2%) 0/1758 NS e Total 9/660 (1.4%) 1/1758 (0.06%) 0.002 16.1 (1.9 to 134.2) CFTR (CF-causing severe or CF-causing mild or non-CF-causing/Non-CF-causing) p.F508del/p.R75Q* 0/660 1/1758 (0.06%) NS e p.F508del/5T* 2/660 (0.3%) 1/1758 (0.06%) NS e p.F508del/p.E528E* 2/660 (0.3%) 2/1758 (0.1%) NS e p.R75Q*/5T* 1/660 (0.2%) 1/1758 (0.06%) NS e p.R75Q*/p.E528E* 2/660 (0.3%) 2/1758 (0.1%) NS e p.R117H (7T/7T)/p.R75Q* 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.E528E* 1/660 (0.2%) 0/1758 NS e p.R117H (7T/7T)/p.S1235R 1/660 (0.2%) 0/1758 NS e p.I148T*/5T* 0/660 1/1758 (0.06%) NS e p.R347P/p.E528E* 1/660 (0.2%) 0/1758 NS e p.E528E*/5T* 1/660 (0.2%) 4/1758 (0.23%) NS e p.H667Y/5T* 1/660 (0.2%) 0/1758 NS e p.L997F/5T* 1/660 (0.2%) 0/1758 NS e p.L997F/p.E528E* 0/660 1/1758 (0.06%) NS e p.D1152Hy/5T* 1/660 (0.2%) 0/1758 NS e p.S1235R/5T* 2/660 (0.3%) 1/1758 (0.06%) NS e Total 17/660 (2.6%) 14/1758 (0.8%) 0.001 3.3 (1.6 to 6.7) CFTR Total (all, excluded)* 10/660 (1.5%) 1/1758 (0.06%) <0.0001 27 (3.5 to 211.7) SPINK1 p.N34S (hom) 17/660 (2.6%) 0/1758 <0.0001 95.6 (5.7 to 1594) p.N34S (het)/c.(1-215G>A;194+2T>C) 7/660 (1.1%) 0/1758 <0.0001 40.4 (2.3 to 708.2) Total 24/660 (3.6%) 0/1758 <0.0001 135.4 (8.2 to 2231) CTRC p.R254W (hom) 1/546 (0.2%) 0/1700 NS e p.R254W/p.V235I 1/546 (0.2%) 0/1700 NS e Total 2/546 (0.4%) 0/1700 NS e For CFTR compound heterozygous carriers, calculations were performed for patients and controls carrying a combination of one CF-causing severe or a CF-causing mild in addition with one CF-causing mild variant (upper section). Login to comment

[hide] CFTR mutation analysis and haplotype associations ... Mol Genet Metab. 2012 Feb;105(2):249-54. doi: 10.1016/j.ymgme.2011.10.013. Epub 2011 Oct 26. Cordovado SK, Hendrix M, Greene CN, Mochal S, Earley MC, Farrell PM, Kharrazi M, Hannon WH, Mueller PW
CFTR mutation analysis and haplotype associations in CF patients.
Mol Genet Metab. 2012 Feb;105(2):249-54. doi: 10.1016/j.ymgme.2011.10.013. Epub 2011 Oct 26., [PMID:22137130]

Abstract [show]
Most newborn screening (NBS) laboratories use second-tier molecular tests for cystic fibrosis (CF) using dried blood spots (DBS). The Centers for Disease Control and Prevention's NBS Quality Assurance Program offers proficiency testing (PT) in DBS for CF transmembrane conductance regulator (CFTR) gene mutation detection. Extensive molecular characterization on 76 CF patients, family members or screen positive newborns was performed for quality assurance. The coding, regulatory regions and portions of all introns were sequenced and large insertions/deletions were characterized as well as two intronic di-nucleotide microsatellites. For CF patient samples, at least two mutations were identified/verified and four specimens contained three likely CF-associated mutations. Thirty-four sequence variations in 152 chromosomes were identified, five of which were not previously reported. Twenty-seven of these variants were used to predict haplotypes from the major haplotype block defined by HapMap data that spans the promoter through intron 19. Chromosomes containing the F508del (p.Phe508del), G542X (p.Gly542X) and N1303K (p.Asn1303Lys) mutations shared a common haplotype subgroup, consistent with a common ancient European founder. Understanding the haplotype background of CF-associated mutations in the U.S. population provides a framework for future phenotype/genotype studies and will assist in determining a likely cis/trans phase of the mutations without need for parent studies.

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No. Sentence Comment
104 Mutation N alleles c.966T>G(5'flanking) c.234T>A(5'flanking)a c.-8G>C(5'UTR) c.-4G>C(Exon1) c.274-179G>A(Intron3) c.743+40A>G(Intron6) c.744-31TTGA(5_7)(Intron6) c.869+11C>T(Intron7) c.869+88T>A(Intron7) c.1209+43T>G(Intron9) IVS8CA(15-23)(Intron9) TG(10-13)_T(5-9)(Intron9) c.1393-61A>G(Intron10) M470V(Exon11) F508del(Exon11) c.1766+152T>A(Intron13) c.1767-231T>C(Intron13) c.1767-136T>C(Intron13) c.1767-132A>G(Intron13) c.2562T>G(Exon15) c.2604A>G(Exon15) c.2619+86_2619+87del(Intron15) c.2619+106T>A(Intron15) c.2909-92G>A(Intron17) IVS17bCA(11-17)(Intron20) c.3368-140A>C(Intron20) c.3469-65C>A(Intron21) F508del 32 TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- GA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- A5- 55- 55- 55- 66- 66- 66- 66- 66- 66- 66- 66- 66- 66- 55- 55- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TC- TT- TT- TT- TC- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TG- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- T17- 10_9- G- F508del- TA- 13C F508del 29 G23- 10_9- G- F508del- TA- 13C F508del 1 G21- 10_9- G- GG- G-F508del- TA- 13C F508del 1 G17- 10_9- G- F508del- A- G- delTA- 17- C- A N1303K 6 G542X 6 3849+10kbC→T 1 del Ex17a, b, Ex18 1 GG- GG- GG- 23- 10_9- GG-F508- T- TA- 13- C A455E 1 G22- 10_9- G- F508- T- TA- 13- C 621+1G→T 5 G21- 10_9- G- GG- GG- F508C- TA- 13- C 711+1G→T 3 3272-26A→G 2 3659delC 2 R347P 2 G16- 11_7- A- A-F508- TA- 13C del Ex 2, 3 2 del Ex 17a,17b 2 Normal 1 R334W 2 G17- 11_7- A- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA-AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- A-AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- AA- F508- TA- 13C 2183AA→G 2 G16- 10_7- F508- TATA- TATA- TATA- TATA- TATA- TATA- 13C del Ex 2 1 G16- 11_7- F508- 14C 1288insTA 1 G16- 12_7- F508- 13C Normal 1 G16- 12_7- F508- 13C R1162X 1 G17- 10_7- F508- 13C del Ex 2,3 1 G16- 11_7- F508- A17- C del Ex 17a,17b 1 GA- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT- TT-16- 11_7- F508- 14- C G85E 1 G16- 11_7- F508- 15C 1898+1G→A 1 G16- 11_7- F508- G13- C no mut detected 1 GT- TT- T16- 10_7- F508- 13C no mut detected 1 G16- 10_7- F508- 17A W1282X 2 G17- 10_7- F508- 17A W1282X 4 GC- CC- C17- 10_7- F508- delTA- 17- A Q39X 1 I507del 1 3849+10kbC→T 1 R560T 2 1717-1G→A 2 G551D 3 G16- 10_7- F508- delTA- 17- A G551D 2 1154insTC 1 G16- 10_7- F508- delTA- 17- 1717- 17A 1717-1G→A 1 2789+5G→A 1 GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- G17- 10_7- F508- AdelTA- A R1066C 1 GG- 17- 10_7- F508- delTA- A R1066H 1 GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- GG- G17- 9_7- F508- delTAC R553X 3 GG- GG- CA- AA- AA- AA- A17- 12_7- F508- delTA- 11- C 3121-1G→A 1 C17- 12_7- F508- delTA- 11- C R334W 1 G17- 12_7- F508- TA- 13- C (TG)13T5b 1 G17- 13_5- F508- delTA- 13- C CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- CC- R117H 1 CA- 6C- TT- 15- 12_5- AG- F508- T- TT- AT- ATA- TG- 13A- C R117H1 1 CA- 6C- TT- 16- 12_5- AG- F508- T- TT- AT- ATA- TG- 13A- C 1717-1G→A 1 R117Hb 1 GA- 6C- TT- 16- 10_7- AA- F508- A- TC- AG- AdelTA- TG- 13A- C 144c a Variation found in a sample where the haplotype could not be predicted. Login to comment

[hide] Lessons learned from 20 years of newborn screening... Med J Aust. 2012 Jan 16;196(1):67-70. Massie RJ, Curnow L, Glazner J, Armstrong DS, Francis I
Lessons learned from 20 years of newborn screening for cystic fibrosis.
Med J Aust. 2012 Jan 16;196(1):67-70., [PMID:22256939]

Abstract [show]
OBJECTIVE: To compare three cystic fibrosis (CF) newborn screening strategies used in Victoria since 1989. DESIGN, SETTING AND PARTICIPANTS: Retrospective review of newborn screening and clinical records for people with CF born in Victoria between 1989 and 2008 to compare screening strategies: repeat immunoreactive trypsinogen (IRT) testing (IRT/IRT, 1989-1990), IRT and p.F508del mutation analysis (IRT/p.F508del, 1991-2006) and IRT with analysis of 12 CFTR mutations (IRT/12 mutations, 2007-2008). MAIN OUTCOME MEASURES: Total number of infants screened, people identified with CF (by screening or clinical diagnosis), number of CF-affected terminations of pregnancy, and number of carriers detected. RESULTS: There were 420 people born with CF (live-birth prevalence, 1/3139; 95% CI, 1/2853-1/3462) and 78 CF-affected pregnancy terminations (overall prevalence, 1/2647; 95% CI, 1/2425-1/2896). Of the babies born with CF, 283 (67.4%) were detected by newborn screening alone, 61 (14.5%) had meconium ileus, 33 (7.9%) had a family history of CF, nine (2.1%) were diagnosed antenatally, and 34 (8.1%) were missed by screening (17 missed because IRT level was < 99th percentile, two with repeat IRT level not elevated, 14 without a screened CFTR mutation, and one with missing data). The sensitivities of the protocols were 86.6% for IRT/IRT, 89.9% for IRT/p.F508del, and 95.8% for IRT/12 mutations. Including 12 mutations in the analysis detected one patient who would otherwise have been missed and, had this protocol been implemented from 1989, it would have detected four others. CONCLUSION: Most babies with CF without meconium ileus, a family history or antenatal diagnosis are detected by newborn screening. Despite improved sensitivity with the 12-mutation analysis, most infants detected would have been diagnosed using the IRT/p.F508del protocol.

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30 Where possible, all patients with a diagnosis of CF had further CFTR mutation analysis performed in an attempt to clarify the genotype (p.A455E, p.S549N, p.R347H, p.R1162X, p.R347P, p.R334W, p.R117H). Login to comment

[hide] Frequency of the hyperactive W493R ENaC variant in... J Cyst Fibros. 2012 Jan;11(1):53-5. Epub 2011 Sep 13. Handschick M, Hedtfeld S, Tummler B
Frequency of the hyperactive W493R ENaC variant in carriers of a CFTR mutation.
J Cyst Fibros. 2012 Jan;11(1):53-5. Epub 2011 Sep 13., [PMID:21917531]

Abstract [show]
BACKGROUND: The basic defect of the autosomal recessive disorder cystic fibrosis (CF) manifests in chloride hyposecretion and sodium hyperabsorption. CF-like disease has been reported in a heterozygous carrier of F508del CFTR and the hyperactive variant p.W493R-SCNN1A of the epithelial sodium channel (ENaC). METHODS: The hypothesis that heterozygosity for p.W493R-SCNN1A and one loss-of-function CFTR mutation causes or predisposes to CF or CF-like disease was tested in 441 parents of a child with CF. RESULTS: p.W493R-SCNN1A was detected in three female carriers of F508del CFTR who did not show any symptoms of respiratory or intestinal disease that could be interpreted as the manifestation of CF or CFTR-related disorder. Frequency of p.W493R was lower in CF parents than in Caucasian control subjects. CONCLUSIONS: A hyperactive ENaC does not necessarily cause CF-like disease in a CF gene carrier, but its low frequency in CF parents suggests that it is a risk factor.

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53 A. Caucasians a F508del 378 2184delA 2 CFTRdele2,3(21 kb) 4 2789+5 G-A 1 R117H 1 I1005R 1 405+1 G-A 1 L1077P 1 H199Y 1 Y1092X 1 L206W 1 3601-111 G-C 1 R347P 3 3849+10 kb C-T 1 Q414X 1 3850-3 T-G 1 G551D 4 W1282X 1 R553X 8 N1303K 2 1717-1 G-A 1 4374+1 G-T 1 2143delT 1 Unknown 9 B. Turks K68N 1 1525-1 G-A 1 G85E 1 F508del 2 E92K 1 1677delTA 1 CFTRdele2(ins186) 2 2184delA 1 CFTRdele2,3(21 kb) 2 3601-2 A-G 1 435insA 1 Unknown 1 a The subjects were born in Austria (N=9 subjects), Belgium (2), France (4), Germany (374), Greece (4), Italy (12), The Netherlands (7), Poland (2), Spain (5), Sweden (2) and United Kingdom (5). Login to comment

[hide] Extensive molecular analysis of patients bearing C... J Mol Diagn. 2012 Jan;14(1):81-9. Epub 2011 Oct 20. Amato F, Bellia C, Cardillo G, Castaldo G, Ciaccio M, Elce A, Lembo F, Tomaiuolo R
Extensive molecular analysis of patients bearing CFTR-related disorders.
J Mol Diagn. 2012 Jan;14(1):81-9. Epub 2011 Oct 20., [PMID:22020151]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs) may present with pancreatic sufficiency, normal sweat test results, and better outcome. The detection rate of mutations is lower in CFTR-RD than in classic CF: mutations may be located in genes encoding proteins that interact with CFTR or support channel activity. We tested the whole CFTR coding regions in 99 CFTR-RD patients, looking for gene mutations in solute carrier (SLC) 26A and in epithelial Na channel (ENaC) in 33 patients who had unidentified mutations. CFTR analysis revealed 28 mutations, some of which are rare. Of these mutations, RT-PCR demonstrated that the novel 1525-1delG impairs exon 10 splicing; by using minigene analysis, we excluded the splicing effect of three other novel intronic variants. Analysis of SLC26A genes revealed several variants, some of which are novel, that did not affect mRNA expression. Other mutations occurred in the ENaC genes encoding the ENaC subunits, but their frequency did not significantly differ between patients and controls. Our data, although obtained on a preliminary cohort of CFTR-RD patients, exclude a role of mutations in SLC26A and in SCNN genes in the pathogenesis of such disease; we confirm that CFTR analysis has a relevant role in CFTR-RD patients; and it appears mandatory to use CFTR scanning techniques and approaches to reveal the effect of novel mutations.

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69 Allele Frequency and CFTR Mutations in Patients Bearing CFTR-RDs Mutation (traditional name) HGVS nomenclature15 CBAVD (118 alleles)* RP (42 alleles)* DB (38 alleles)* Total (198 alleles)* TG12-T5-470V 34 (28.8) 2 (4.8) 10 (26.3) 46 (23.2) F508del c.1521_1523del 19 (16.1) 7 (16.7) 4 (10.5) 30 (15.2) 3195del6 c.3063_3069del 9 (7.6) 0 0 9 (4.5) N1303K c.3909CϾG 3 (2.5) 1 (2.4) 4 (10.5) 8 (4.0) G542X c.1624GϾT 4 (3.4) 1 (2.4) 1 (2.6) 6 (3.0) D1152H c.3454GϾC 1 (0.8) 2 (4.8) 2 (5.3) 5 (2.5) G85E c.254GϾA 2 (1.7) 3 (7.1) 0 5 (2.5) 1525-1delG c.1394de 3 (2.5) 1 (2.4) 0 4 (3.0) 4016insT c.3885insT 2 (1.7) 1 (2.4) 0 3 (1.5) 2789ϩ5GϾA c.2657ϩ5GϾA 0 3 (7.1) 0 3 (1.5) Q1476X c.4426CϾT 3 (2.5) 0 0 3 (1.5) 2183AAϾG c.2051_2052delinsG 1 (0.8) 1 (2.4) 0 2 (1.0) R553X c.1657CϾT 1 (0.8) 1 (2.4) 0 2 (1.0) L568F c.1704GϾT 2 (1.7) 0 0 2 (1.0) R1158X c.3472CϾT 2 (1.7) 0 0 2 (1.0) V920M c.2758GϾA 1 (0.8) 0 1 (2.6) 2 (1.0) 711ϩ1GϾT c.579ϩ1GϾT 0 1 (2.4) 0 1 (0.5) D614G c.1841AϾG 1 (0.8) 0 0 1 (0.5) 2184insA c.2052del 0 1 (2.4) 0 1 (0.5) 621ϩ1GϾT c.489ϩ1GϾT 1 (0.8) 0 0 1 (0.5) R1438W c.4312CϾT 0 1 (2.4) 0 1 (0.5) E193X c.577GϾT 0 1 (2.4) 0 1 (0.5) G1244E c.3731GϾA 1 (0.8) 0 0 1 (0.5) K68E c.202AϾG 1 (0.8) 0 0 1 (0.5) R347P c.1040GϾC 1 (0.8) 0 0 1 (0.5) 621ϩ3AϾG c.489ϩ3AϾG 1 (0.8) 0 0 1 (0.5) L997F c.2991GϾC 0 1 (2.4) 0 1 (0.5) F508C c.1523TϾG 1 (0.8) 0 0 1 (0.5) Total 94 (79.7) 28 (66.7) 22 (57.9) 144 (72.7) Undetected 24 (20.3) 14 (33.3) 16 (42.1) 54 (27.3) *Data are given as number (percentage). Login to comment

[hide] CFTR mutation screening in an assisted reproductiv... Aust N Z J Obstet Gynaecol. 2011 Dec;51(6):536-9. doi: 10.1111/j.1479-828X.2011.01348.x. Epub 2011 Aug 22. Field PD, Martin NJ
CFTR mutation screening in an assisted reproductive clinic.
Aust N Z J Obstet Gynaecol. 2011 Dec;51(6):536-9. doi: 10.1111/j.1479-828X.2011.01348.x. Epub 2011 Aug 22., [PMID:21875427]

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INTRODUCTION: Cystic fibrosis (CF) is the most common deleterious single-gene recessive disorder in non-Hispanic Caucasians. Mutations within the CF transmembrane receptor (CFTR) gene produce a variable phenotype, including pulmonary disease, pancreatic insufficiency, meconium ileus and infertility. Screening of antenatal/preconception patients to identify CFTR mutation carriers has been shown to reduce the incidence of CF-affected babies at birth. The application of preconception screening to assisted reproductive technology (ART) patients enables carrier couples a choice between prenatal screening and preimplantation genetic diagnosis (PGD). AIM: To screen patients entering an infertility clinic, for 30 common CFTR mutations, and to detect carrier patients prior to initiating assisted reproductive treatment. METHOD: DNA from 5600 infertility patients was screened using a PCR/OLA kit for 30 CFTR mutations. All identified carriers and carrier couples were offered genetic counselling. Prenatal testing and PGD for CFTR mutations were offered to carrier couples where appropriate. RESULTS: A total of 5600 patients were screened for 30 CFTR mutations with 261 carriers being identified and at a significantly increased carrier rate of one in 21.5 (4.66% +/- 0.55%). R117H/c.350G>A was significantly increased in this infertile population and accounted for 13.8% of all mutations identified. Twelve carrier couples were identified, and nine carrier couples had at least one cycle of PGD for CFTR mutations. CONCLUSION: The carrier rate of CFTR mutations is elevated in patients presenting for infertility treatment, and preconception screening should be encouraged in all patients entering ART clinics.

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37 Table 1 A breakdown of the CFTR mutations identified in the infertile patient population, the percentage of those mutations identified, the percentage of the infertile population screened, the percentage of the same mutations identified in the antenatal population by Massie et al. and figures published by Bobadilla et al. for the corresponding CFTR mutations in a global population study 'Legacy Mutation Name` and HGVS convention nomenclature* Number of mutations identified in infertile population Percentage of mutations identified in infertile population (%) Percentage of mutations identified in antenatal population4 (%) Percentage of mutations identified in a global population5 (%) F508delCTT / c.1521_1523delCTT 185 70.9 88.89 75.48 R117H / c.350G>A 36 13.8 0.63 G551D / c.1652G>A 12 4.6 2.78 3.82 G542X / c.1624G>T 6 2.3 0.93 1.83 N1303K / c.3909C>G 4 1.5 0.93 0.95 621+1G>T / c.489+1G>T 5 1.9 0.93 0.96 I507del / c.1519-1521delATC 2 0.8 0.53 3659delC / c.3528delC 2 0.8 R1162X / c.3484C>T 1 0.4 0.20 3120+1G>A / c.2988+1G>A 1 0.4 2184-delA / c.2052delA 1 0.4 3849+10kbC>T / c.3717-2477C>T 1 0.4 4.63 2789+5G>A / c.2657+5G>A 1 0.4 0.93 R347P / c.1040G>A 1 0.4 0.16 1717-1G>A / c.1585-1G>A 1 0.4 0.81 R553X / c.1657C>T 1 0.4 S549R / c.1647T>G 1 0.4 Total CFTR mutations identified 261 Total patients screened 5600 Incidence of CF carriers at QFG 1 in 21.5 (4.66%) CF, cystic fibrosis; CFTR, CF transmembrane receptor. Login to comment

[hide] Cystic fibrosis mutations for p.F508del compound h... Clin Genet. 2012 Dec;82(6):546-551. doi: 10.1111/j.1399-0004.2011.01804.x. Epub 2011 Nov 29. Sebro R, Levy H, Schneck K, Dimmock D, Raby B, Cannon C, Broeckel U, Risch N
Cystic fibrosis mutations for p.F508del compound heterozygotes predict sweat chloride levels and pancreatic sufficiency.
Clin Genet. 2012 Dec;82(6):546-551. doi: 10.1111/j.1399-0004.2011.01804.x. Epub 2011 Nov 29., [PMID:22035343]

Abstract [show]
Sebro R, Levy H, Schneck K, Dimmock D, Raby BA, Cannon CL, Broeckel U, Risch NJ. Cystic fibrosis mutations for p.F508del compound heterozygotes predict sweat chloride levels and pancreatic sufficiency. Cystic fibrosis (CF) is a monogenetic disease with a complex phenotype. Over 1500 mutations in the CFTR gene have been identified; however, the p.F508del mutation is most common. There has been limited correlation between the CFTR mutation genotype and the disease phenotypes. We evaluated the non-p.F508del mutation of 108 p.F508del compound heterozygotes using the biological classification method, Grantham and Sorting Intolerant from Tolerant (SIFT) scores to assess whether these scoring systems correlated with sweat chloride levels, pancreatic sufficiency, predicted FEV(1) , and risk of infection with Pseudomonas aeruginosa in the last year. Mutations predicted to be 'mild' by the biological classification method are associated with more normal sweat chloride levels (p < 0.001), pancreatic sufficiency (p < 0.001) and decreased risk of infection with Pseudomonas in the last year (p = 0.014). Lower Grantham scores are associated with more normal sweat chloride levels (p < 0.001), and pancreatic sufficiency (p = 0.014). Higher SIFT scores are associated with more normal sweat chloride levels (p < 0.001) and pancreatic sufficiency (p = 0.011). There was no association between pulmonary function measured by predicted FEV(1) and the biological classification (p = 0.98), Grantham (p = 0.28) or SIFT scores (p = 0.62), which suggests the pulmonary disease related to CF may involve other modifier genes and environmental factors.

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64 CFTR mutation classification for compound heterozygotesa Mutations n (%) Biological classification Grantham score SIFT Q493X 3 (3) Ib - - G542X 21 (20) Ib,c,e - - R553X 4 (4) Ib,e - - Y1092X 2 (2) Ib - - R1158X 1 (1) NA - - W1282X 9 (9) Ib,e - - G85E 4 (4) IIIb 98 0.01 R117H 4 (4) IVb,c 29 0.60 R334W 1 (1) IVb 101 0.02 R347P 1 (1) IVb 103 0.05 R352Q 1 (1) NA 43 0.35 G551D 20 (19) IIIb,c 94 0.00 R560T 3 (3) IIIb 71 0.00 D1270N 1 (1) NA 23 0.01 N1303K 6 (6) IIg 94 0.00 I507del 3 (3) IId - - 394delTT 1 (1) NAc - - 621+1G>T 7 (7) Ib,f - - 711+1G>T 2 (2) Ib - - 1717-1G>A 5 (5) Ib,c,e,f - - 1898+1G>A 2 (2) NA - - 2789+5G>A 3 (3) Vb - - 3659delC 1 (1) Ib - - 3849+10kbC>T 2 (2) Vb,c,f - - 3905insT 1 (1) Ib - - NA, not applicable; SIFT, Sorting Intolerant from Tolerant. a The following mutations biological classification scores could not be verified: 1898+G-A, 394delTT, D1270N, R352Q, and R1158X. Login to comment

[hide] First study of the F508del mutation in Malaysian c... J Paediatr Child Health. 2011 Aug;47(8):573-5. doi: 10.1111/j.1440-1754.2011.02149.x. Nathan AM, Thong MK, deBruyne J, Ariffin H
First study of the F508del mutation in Malaysian children diagnosed with cystic fibrosis.
J Paediatr Child Health. 2011 Aug;47(8):573-5. doi: 10.1111/j.1440-1754.2011.02149.x., [PMID:21843195]

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48 Letters to the Editor Journal of Paediatrics and Child Health 47 (2011) 572-575 (c) 2011 The Authors Journal of Paediatrics and Child Health (c) 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians) Table1Summaryoftheclinicalcharacteristics,sweattestresultsandcysticfibrosistransmembraneconductanceregulatormutationstudiesofthepatientsdiagnosedwithcysticfibrosisinUniversity MalayaMedicalCenterfrom2000to2009 PatientAgeat presentation PresentingsymptomsOtherfindingsConsanguinityRaceSweatconductivity (mmol/l) KS score Mutations Rin3monthsRecurrentpneumoniaandFTTPseudo-Bartter`ssyndromeYesIndian13440†Nonedetected Nes8yearsSeverepersistentasthmaFTTNoIndian12450F508del/unknown Abd4monthsSeverepneumoniaandventilator dependent FTTYesYemeni11730F508del/F508del Ben7yearsCirrhosisoftheliverwithportal hypertension FTTUnknown(adopted)Unknown14080†Nonedetected(7T polymorphism) Sak3monthsRecurrentpneumoniaandFTTNDYesIndian11350F508del/F508del Ngan3yearsPseudo-Bartter`ssyndromeNDNoChinese13790Notdone(parentsrefused) LJH5monthsPseudo-Bartter`ssyndromeRecurrentpneumoniaNoChinese/Indonesian9465F508delnegative Josh5monthsPseudo-Bartter`ssyndromeandFTTNDNoIndian8585†Nonedetected Nur3monthsChronicdiarrhoeaandFTTPseudo-Bartter`ssyndromeNoMalay/Chinese13085‡†R553X/nonedetected Vin4monthsRecurrentpneumoniaandFTTNDNoChinese12260F508delnegative Muh5yearsPoorlycontrolledasthmaNDNoMalay10765F508delnegative Naz3monthsFTTandsteatorrhoeaRecurrentlunginfectionsand pseudo-Bartter`s NoMalay14675F508delnegative Additionalmutationsscreenedinthefourpatients:†F508del,I506/7del,G551D,G542X,R553X,R117C,R117H,621+1G>T,V520F,A455E,N1303K,3849+10kbC>T.‡R334W,R347P,A455E,S549N,R560T, 3659delC,W1282X.FTT,failuretothrive;KS,Schwachman-Kulczycki(KS)score;ND,nodata. Login to comment

[hide] Detecting Common CFTR Mutations by Reverse Dot Blo... Iran J Pediatr. 2011 Mar;21(1):51-7. Dooki MR, Akhavan-Niaki H, Juibary AG
Detecting Common CFTR Mutations by Reverse Dot Blot Hybridization Method in Cystic Fibrosis First Report from Northern Iran.
Iran J Pediatr. 2011 Mar;21(1):51-7., [PMID:23056764]

Abstract [show]
OBJECTIVE: Cystic fibrosis and its distribution vary widely in different countries and/or ethnic groups. Common cystic fibrosis transmembrane conductance regulator (CFTR) mutations were reported from Iran, but the northern population was not or underrepresented in those studies. The aim of this study was to determine the frequency of common CFTR mutations in children from northern Iran. METHODS: Thirty unrelated Iranian cystic fibrosis patients aged less than 11 years and living in Mazandaran province (in Iran) were screened for 5 common CFTR gene mutations. deltaF508, N1303K, G542X, R347H and W1282X using Reverse Dot Blot method. FINDINGS: Only one mutation, DeltaF508, was found in 7 patients accounting for 21.7% (13/60) of alleles. CONCLUSION: These findings can be used for planning future screening and appropriate genetic counseling programs in Iranian CF families.

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67 Table 1: Human cystic fibrosis transconductance regulator probes CFTR probe sequenceLocation in the CFTR geneProbe name 5'-NH2-GAAACACCAAAGATGATA-3'Exon10∆F508-N 5'-NH2-GGAAACACCAATGATATT-3'Exon10∆F508-MUT 5'-NH2-TATAGTTCTTGGAGAAGGTG3'Exon11G542X-N 5'-NH2-TATAGTTCTTTGAGAAGGTG-3'Exon11G542X-MUT 5'-NH2-GCTTTCCTCCACTGTTG-3'Exon20W1282X-N 5'-NH2-CAACAGTGAAGGAAAGC-3'Exon20W1282X-MUT 5'-NH2-AGAAAAAACTTGGATCC-3'Exon21N1303K-N 5'-NH2-GGGATCCAACTTTTTTCT-3'Exon21N1303K-MUT 5'-NH2-AATTGTTCTGCGCATGG-3'Exon7R347H-N 5'-NH2-CATTGTTCTGCCCATGGC-3'Exon7R347H-MUT Table 2: Human cystic fibrosis transmembrane conductance regulator primers Cystic fibrosis primer sequence Exon amplified Cystic fibrosis primer name Cystic fibrosis mutation tested 5'-Biotin-AGACCATGCTCAGATCTTCCAT-3' 5'-Biotin-GCAAAGTTCATTAGAACTGATC-3' 7 CF7-F CF7-R R347P 5'-Biotin-GCAGAGTACCTGAAACAGGA-3' 5'-Biotin-CATTCACAGTAGCTTACCCA-3' 10 CF10-F CF10-R ∆F508 5'-Biotin-CAACTGTGGTTAAAGCAATAGTGT-3' 5'-Biotin-GCACAGATTCTGAGTAACCATAAT-3' 11 CF11-F CF11-R G542X 5'-Biotin-TGGGCCTCTTGGGAAGAACT-3' 5'-Biotin-CTCACCTGTGGTATCACTCC-3' 20 CF20-F CF20-R W1282X 5'-Biotin-GGTAAGTACATGGGTGTTTC-3' 5'-Biotin-CAAAAGTACCCTGTTGCTCCA-3' 21 CF21-F CF21-R N1303K Genotype Analysis: Mutation screening of the CFTR gene in 60 alleles by reverse dot blot hybridization for five common mutations showed that 13 (21.6%) alleles were ∆F508. Login to comment

[hide] The use of DHPLC (Denaturing High Performance Liqu... J Prenat Med. 2010 Jul;4(3):45-8. Mesoraca A, Di Natale M, Cima A, Di Giacomo G, Sarti M, Barone MA, Bizzoco D, Cignini P, Mobili L, D'emidio L, Giorlandino C
The use of DHPLC (Denaturing High Performance Liquid Chromatography) in II level screening of the CFTR gene in Prenatal Diagnosis.
J Prenat Med. 2010 Jul;4(3):45-8., [PMID:22439061]

Abstract [show]
OBJECTIVE: The aim of the study is to evaluate the role of Denaturing High Performance Liquid Chromatography (DHPLC) in the second level screening of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. METHODS: A 9-month prospective study, between June 2008 and March 2009 at Artemisia Fetal Medical Centre, included 3829 samples of amniotic fluid collected from women undergoing mid-trimester amniocentesis.The genetic diagnosis of CF was based on research of the main mutations of the CFTR gene on fetal DNA extracted from the amniocytes, (first level screening) using different commercial diagnostic systems. A second level screening using DHPLC, on the amniotic fluid and on a blood sample from the couple, was offered in case of fetuses heterozygous at first level screening. RESULTS: Of 3829 fetuses, 134 were found to be positive, 129 heterozygous and 5 affected. Of the 129 couples, following appropriate genetic counselling, 53 requested a second level screening. Through the use of DHPLC, 44 couples were found to be negative, and in nine couples, nine rare mutations were identified. CONCLUSIONS: The first level screening can be useful to evidence up to 75% of the CF mutations. The second level screening can identify a further 10% of mutant alleles. DHPLC was found to be a reliable and specific method for the rapid identification of the rare CFTR mutations which were not revealed in initial first level screening.

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100 48 Journal of Prenatal Medicine 2010; 4 (3): 45-50 Table III Mutations found with II level screening through DHPLC Mutations of mutated alleles DF508 29 W1282X 3 N1303K 8 1717-1G®A 2 3659delC 1 G85E 1 2789 +5G®A 2 R553X 2 R1162X 1 R117H 1 G542X 3 Total 53Table I Mutations found through I level screeningMutations analysed with I level screening through OLA CFTR Mutations Position on the CFTR gene DF508 Exon 10 3849+10KbC®T Intron 19 R334W Exon 7 W1282X Exon 10 V520F Exon 10 3905insT Exon 20 N1303K Exon 21 3876delA Exon 20 1717-1G®A Exon 11 3659delC Exon 19 DI507 Exon 10 A455E Exon 9 G85E Exon 3 2789 +5G®A Exon 14 / Intron 14 2183AA®G Exon 13 1898+1G®A Exon 12 / Intron 12 R347P Exon 7 R347H Exon 7 R560T Exon 11 1078delT Exon 7 R553X Exon 11 711+1G®T Exon 5 / Intron 5 G551D Exon 11 R1162X Exon 19 S549R Exon 11 R117H Exon 4 S549N Exon 11 621+1G®T Exon 4 G542X Exon 11 394delTT Exon 3 3120+1G®ðA Exon 16/ Intron 16 2184delA Exon 13 Table II Mutations found through I level screening Mutations Positions on CFTR gene R1066C Exon 17 b L1065P Exon 17 b A1006E Exon 19 R75Q Exon 3 D537E Exon 11 W1134X Exon 18 W1145X Exon 18 L1077P Exon 17b C524X Exon 11 Total 9 The use of DHPLC (Denaturing High Performance Liquid Chromatography) in II level screening of the CFTR gene in Prenatal Diagnosis Journal of Prenatal Medicine 2010; 4 (3): 45-50 49 tion was to provide the couple with adequate counselling in order to better understand the genotype-phenotype correlation in the various associations of mutations. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Hepatol. 2009 Jan;50(1):150-7. Epub 2008 Oct 7. Henckaerts L, Jaspers M, Van Steenbergen W, Vliegen L, Fevery J, Nuytten H, Roskams T, Rutgeerts P, Cassiman JJ, Vermeire S, Cuppens H
Cystic fibrosis transmembrane conductance regulator gene polymorphisms in patients with primary sclerosing cholangitis.
J Hepatol. 2009 Jan;50(1):150-7. Epub 2008 Oct 7., [PMID:18992954]

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BACKGROUND/AIMS: Primary sclerosing cholangitis (PSC) is a progressive cholestatic disease commonly associated with inflammatory bowel disease (IBD) and characterized by fibrosing inflammatory destruction of bile ducts. The histological features in the liver of PSC patients are similar to those observed in cystic fibrosis (CF). Our aim was to study whether variants in the CFTR gene are associated with the occurrence and/or evolution of PSC. METHODS: PSC patients (n=140) were genotyped for F508del, the TGmTn variants, and four additional polymorphic loci (1001+11 C>T, M470V, T854T and Q1463Q), and compared to 136 matched healthy controls. RESULTS: The 1540G-allele, encoding V470, was less frequent in PSC (52%) than in controls (64%, p=0.003), and was associated with protection against PSC in individuals without IBD (OR 0.25, 95% CI 0.12-0.52, p=0.0002). Also TG11-T7 was less frequent in PSC (53%) than in controls (61%, p=0.04), this haplotype was associated with reduced risk for PSC (OR 0.34, 95% CI 0.17-0.70, p=0.003) in individuals without IBD. CONCLUSIONS: In this cohort of PSC patients, several CFTR-variants affecting the functional properties of the CFTR protein seem to offer protection against the development of PSC, confirming our hypothesis that CFTR might be implicated in the pathogenesis of PSC.

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91 There was Table 4 Summary of the 37 CFTR variants studied in the exploratory phase INNO-LiPA CFTR 19 INNO-LiPA CFTR17+Tn Update F508del 621+1GfiT G542X 3849+10kbCfiT N1303K 2183AAfiG W1282X 394delTT G551D 2789+5GfiA 1717-1GfiA R1162X R553X 3659delC CFTRdele2,3(21kb) R117H I507del R334W 711+1GfiT R347P 3272-26AfiG G85E 3905insT 1078delT R560T A455E 1898+1GfiA 2143delT S1251N E60X I148T 2184delA 3199del6 711+5GfiA 3120+1GfiA Tn Q552X Fig. 1. Login to comment

[hide] Improvement in clinical markers in CF patients usi... J Cyst Fibros. 2008 Sep;7(5):433-6. Epub 2008 May 21. Visca A, Bishop CT, Hilton SC, Hudson VM
Improvement in clinical markers in CF patients using a reduced glutathione regimen: an uncontrolled, observational study.
J Cyst Fibros. 2008 Sep;7(5):433-6. Epub 2008 May 21., [PMID:18499536]

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CFTR mutation, which causes cystic fibrosis (CF), has also recently been identified as causing glutathione system dysfunction and systemic deficiency of reduced glutathione (GSH). Such dysfunction and deficiency regarding GSH may contribute to the pathophysiology of CF. We followed 13 patients (age range 1-27 years) with cystic fibrosis who were using a regimen of reduced glutathione (GSH), including oral glutathione and inhaled buffered glutathione in an uncontrolled, observational study. Dosage ranged from 66-148 mg/kg/day in divided doses, and the term examined was the initial 5.5 months of GSH use (45 days of incrementally adjusted dose, plus 4 months of use at full dosage). Baseline and post-measurements of FEV1 percent predicted, BMI percentile, and weight percentile were noted, in addition to bacterial status and pulmonary exacerbations. Significant improvement in the following clinical parameters was observed: average improvement in FEV1 percent predicted (N=10) was 5.8 percentage points (p<0.0001), average weight percentile (N=13) increased 8.6 points (p<0.001), BMI percentile (N=11) improved on average 1.22 points (p<0.001). All patients improved in FEV1 and BMI, if measured in their case; 12 of 13 patients improved in weight percentile. Positive sputum cultures of bacteria in 11 patients declined from 13 to 5 (p<0.03) with sputum cultures of Pseudomonas aeruginosa becoming negative in 4 of 5 patients previously culturing PA, including two of three patients chronically infected with PA as determined by antibody status. Use of a daily GSH regimen appears to be associated in CF patients with significant improvement in lung function and weight, and a significant decline in bacteria cultured in this uncontrolled study. These findings bear further clinical investigation in larger, randomized, controlled studies.

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43 65 64 71 28.5 28 30 9 5 6 PA PA none 3, F, 19 DF508/G1244E 47 48 55 43 43 48 3 3 9 PA b PAb PA 4, M, 5 DF508/R347P NA NA NA 17 17.5 19 33 33 40 SA SA none 5, M, 24 W1282G/G542X 60 58 70 51 51.5 57 3 3 7 BC BC BC 6, F, 14 3659delC/? Login to comment
64 15.1 15.3 1 0 36 30 3, F, 19 DF508/G1244E 16.3 18.3 0 0 9 18 4, M, 5 DF508/R347P 14.7 15.4 0 1 11 11 5, M, 24 W1282G/G542X 17.8 19.7 1 0 16 20 6, F, 14 3659delC/? Login to comment

[hide] The study of cystic fibrosis transmembrane conduct... J Cyst Fibros. 2008 Sep;7(5):423-8. Epub 2008 May 7. Frentescu L, Brownsell E, Hinks J, Malone G, Shaw H, Budisan L, Bulman M, Schwarz M, Pop L, Filip M, Tomescu E, Mosescu S, Popa I, Benga G
The study of cystic fibrosis transmembrane conductance regulator gene mutations in a group of patients from Romania.
J Cyst Fibros. 2008 Sep;7(5):423-8. Epub 2008 May 7., [PMID:18467194]

Abstract [show]
BACKGROUND: Cystic fibrosis (CF) is produced by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator Gene (CFTR) gene. METHODS: One hundred twenty eight patients with CF were analysed for mutations in the CFTR gene in order to establish the frequency of CF mutations in the Romanian population. The chief methods of analysis were polymerase chain reaction (PCR) of DNA extracted from blood and electrophoresis of PCR products. RESULTS: The frequency of F508del in CF chromosomes from Romania is approximately 56.3%. Other frequent mutations noted are: G542X (3.9%), W1282X (2.3%), and CFTRdele2,3(21 kb)(1.6%); the remaining mutations have frequencies below 1%. CONCLUSIONS: We consider that the frequency of F508del in CF patients from Romania is higher than in previous reports, reaching 56.3%, probably owing to more rigorous selection of patients for genetic testing, allowing improved calculation of mutation frequencies.

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35 Nine patients were tested for 13 mutations [F508del, 1677delTA, I507del, R117H, R553X, 621+ 1GNT, R334W, R347P, G55D, G542X, W1282X, N1303K, CFTR dele2,3(21 kb)] in the Department of Human Genomics, Institute for Molecular Biology and Genetics, National Academy of Science, Kiev, Ukraine (Table 1). Login to comment
47 For other Table 1 PCR primers and references for the analysis of 13 common mutations in the CFTR gene Mutation Name of primers Restriction enzyme Reference R334W 7F MspI [10] R347P 7R Hin6I R117H 4A Hin6I [11] 621+1GNT 4B HincII N1303K N1303F DdeI [12] N1303R W1282X W1182F MnlI [13] W1282R [14] G551D 11i5 HincII [15] R553X 11i3 Sau3A G542X 11ex3` MvaI [11] G542X F508del CF2 [3] I507del CF3 [16] 1677delTA C16B [17] C16D [18] [19] CFTRdele2,3(21 kb) CFTRdel2,3F [20] CFTRdel2,3R [13] Control primers for exon 3: 3i-5 3i-3 common mutations, the CF-3 kit was used, and/or restriction enzyme digestions of PCR products were performed, followed by the analysis of restriction products by agarose gel electrophoresis (Table 1); alternatively, the kits from Belgium and UK mentioned above, were used for selected samples, especially for heterozygous patients with F508del and an unknown mutation. Login to comment

[hide] Cystic fibrosis carrier frequency and estimated pr... J Cyst Fibros. 2008 Sep;7(5):440-3. Epub 2008 Feb 1. Ratbi I, Genin E, Legendre M, Le Floch A, Costa C, Cherkaoui-Deqqaqi S, Goossens M, Sefiani A, Girodon E
Cystic fibrosis carrier frequency and estimated prevalence of the disease in Morocco.
J Cyst Fibros. 2008 Sep;7(5):440-3. Epub 2008 Feb 1., [PMID:18243066]

Abstract [show]
BACKGROUND: The epidemiology of cystic fibrosis (CF) is poorly known in North African populations, in particular in Morocco and the CF carrier frequency in the general Moroccan population has never been evaluated. METHODS: To estimate the prevalence of CF mutations in Morocco, blood samples from 150 healthy Moroccans were tested for frequent CFTR mutations and the intron 8 polyT variant. RESULTS: Two subjects were heterozygous for F508del and eight others for the (T)5 variant. CONCLUSION: These findings indicate that the Moroccan population is at risk for CF and CFTR-related disorders. CF prevalence could be in the range of that found in European populations. Wider studies are necessary to identify the clinical pattern and accurately determine the prevalence and molecular basis of CF in Morocco.

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27 We screened for 32 CFTR gene mutations (G85E, 394delTT, R117H, 621+1GNT, 711+1GNT, R334W, R347P, R347H, 1078delT, A455E, I507del, F508del, V520F, 1717-1GNA, G542X, G551D, R553X, R560T, S549R(TNG), S549N, 1898+1GNA, 2183AANG, 2184delA, 2789+5GNA, 3120 + 1G NA, R1162X, 3659delC, 3849 + 10kbC NT, W1282X, 3905insT, 3876delA, N1303K) and the (T)5 splicing variant of intron 8, using a commercial kit (CF v3 Genotyping Assay, Abbott, Rungis, France). Login to comment

[hide] Validation of high-resolution DNA melting analysis... J Mol Diagn. 2008 Sep;10(5):424-34. Epub 2008 Aug 7. Audrezet MP, Dabricot A, Le Marechal C, Ferec C
Validation of high-resolution DNA melting analysis for mutation scanning of the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
J Mol Diagn. 2008 Sep;10(5):424-34. Epub 2008 Aug 7., [PMID:18687795]

Abstract [show]
High-resolution melting analysis of polymerase chain reaction products for mutation scanning, which began in the early 2000s, is based on monitoring of the fluorescence released during the melting of double-stranded DNA labeled with specifically developed saturation dye, such as LC-Green. We report here the validation of this method to scan 98% of the coding sequence of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We designed 32 pairs of primers to amplify and analyze the 27 exons of the gene. Thanks to the addition of a small GC-clamp at the 5' ends of the primers, one single melting domain and one identical annealing temperature were obtained to co-amplify all of the fragments. A total of 307 DNA samples, extracted by the salt precipitation method, carrying 221 mutations and 21 polymorphisms, plus 20 control samples free from variations (confirmed by denaturing high-performance liquid chromatography analysis), was used. With the conditions described in this study, 100% of samples that carry heterozygous mutations and 60% of those with homozygous mutations were identified. The study of a cohort of 136 idiopathic chronic pancreatitis patients enabled us to prospectively evaluate this technique. Thus, high-resolution melting analysis is a robust and sensitive single-tube technique for screening mutations in a gene and promises to become the gold standard over denaturing high-performance liquid chromatography, particularly for highly mutated genes such as CFTR, and appears suitable for use in reference diagnostic laboratories.

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147 Analysis of exon 7 does not appear challenging, and the addition of a GC clamp secures one single melting domain, but the parameter of analysis [ie, intervals of temperature for the upper (100%) and the lower (0% baseline) fluorescence lines, and sensitivity level] defined by using the most common mutations within this exon, such as R347P, do not allow visualization of the 1078delT mutation. Login to comment

[hide] Consensus on the use and interpretation of cystic ... J Cyst Fibros. 2008 May;7(3):179-96. Castellani C, Cuppens H, Macek M Jr, Cassiman JJ, Kerem E, Durie P, Tullis E, Assael BM, Bombieri C, Brown A, Casals T, Claustres M, Cutting GR, Dequeker E, Dodge J, Doull I, Farrell P, Ferec C, Girodon E, Johannesson M, Kerem B, Knowles M, Munck A, Pignatti PF, Radojkovic D, Rizzotti P, Schwarz M, Stuhrmann M, Tzetis M, Zielenski J, Elborn JS
Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice.
J Cyst Fibros. 2008 May;7(3):179-96., [PMID:18456578]

Abstract [show]
It is often challenging for the clinician interested in cystic fibrosis (CF) to interpret molecular genetic results, and to integrate them in the diagnostic process. The limitations of genotyping technology, the choice of mutations to be tested, and the clinical context in which the test is administered can all influence how genetic information is interpreted. This paper describes the conclusions of a consensus conference to address the use and interpretation of CF mutation analysis in clinical settings. Although the diagnosis of CF is usually straightforward, care needs to be exercised in the use and interpretation of genetic tests: genotype information is not the final arbiter of a clinical diagnosis of CF or CF transmembrane conductance regulator (CFTR) protein related disorders. The diagnosis of these conditions is primarily based on the clinical presentation, and is supported by evaluation of CFTR function (sweat testing, nasal potential difference) and genetic analysis. None of these features are sufficient on their own to make a diagnosis of CF or CFTR-related disorders. Broad genotype/phenotype associations are useful in epidemiological studies, but CFTR genotype does not accurately predict individual outcome. The use of CFTR genotype for prediction of prognosis in people with CF at the time of their diagnosis is not recommended. The importance of communication between clinicians and medical genetic laboratories is emphasized. The results of testing and their implications should be reported in a manner understandable to the clinicians caring for CF patients.

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1236 Table 1 Geographical distribution of the most common mutations E60X Southern European S549N Indian CFTR Slavic - Eastern European G551D United Kingdom, Central Europe R75X Southern European, US-Hispanic Q552X Southern European, Italian 394delTT Nordic - Baltic sea region R553X Central European G85E Southern Europe A559T African-American 406-1GNA US-Hispanic R560T Northern Irish R117H European-derived populations 1811+1.6kbANG Spanish, US-Hispanic R117C Northern European 1898+1GNA United Kingdom, Central Europe 621+1GNT Southern European 1898+5GNT East Asian populations 711+1GNT French, French Canadian 2143delT Slavic - Eastern European 711+5GNA US-Hispanic 2183delAANG Southern Europe, Middle Eastern, Iranian, Latin American L206W Spanish and US-Hispanic 2184delA European-derived populations V232D Spanish and US-Hispanic 2789+5GNA European-derived populations 1078delT French Brittany Q890X Southern European R334W Southern European, Latin American 3120+1GNA African, Arabian, African-American, Southern Europe 1161delC Indian 3272-26ANG European-derived populations R347P European-derived, Latin America 3659delC Scandinavian R347H Turkish 3849+10kbCNT Ashkenazi-Jewish, Southern European, Middle Eastern, Iranian, Indian A455E Dutch R1066C Southern European 1609delCA Spanish, US-Hispanic Y1092X (CNA) Southern European I506T Southern European, Spanish M1101K US-Hutterite I507del European-derived populations 3905insT Swiss F508del European-derived populations D1152H European-derived populations 1677delTA Southern European, Middle Eastern R1158X Southern European 1717-GNA European-derived populations R1162X Italian, Amerindian, Latin America V520F Irish S1251N European-derived populations G542X Southern European, Mediterranean W1282X Ashkenazi-Jewish, Middle Eastern S549R(TNG) Middle Eastern N1303K Southern European, Middle Eastern Legend: these alleles occur with a frequency superior to 0.1% in selected populations. Login to comment
1239 Table 1 Geographical distribution of the most common mutations E60X Southern European S549N Indian CFTR Slavic - Eastern European G551D United Kingdom, Central Europe R75X Southern European, US-Hispanic Q552X Southern European, Italian 394delTT Nordic - Baltic sea region R553X Central European G85E Southern Europe A559T African-American 406-1GNA US-Hispanic R560T Northern Irish R117H European-derived populations 1811+1.6kbANG Spanish, US-Hispanic R117C Northern European 1898+1GNA United Kingdom, Central Europe 621+1GNT Southern European 1898+5GNT East Asian populations 711+1GNT French, French Canadian 2143delT Slavic - Eastern European 711+5GNA US-Hispanic 2183delAANG Southern Europe, Middle Eastern, Iranian, Latin American L206W Spanish and US-Hispanic 2184delA European-derived populations V232D Spanish and US-Hispanic 2789+5GNA European-derived populations 1078delT French Brittany Q890X Southern European R334W Southern European, Latin American 3120+1GNA African, Arabian, African-American, Southern Europe 1161delC Indian 3272-26ANG European-derived populations R347P European-derived, Latin America 3659delC Scandinavian R347H Turkish 3849+10kbCNT Ashkenazi-Jewish, Southern European, Middle Eastern, Iranian, Indian A455E Dutch R1066C Southern European 1609delCA Spanish, US-Hispanic Y1092X (CNA) Southern European I506T Southern European, Spanish M1101K US-Hutterite I507del European-derived populations 3905insT Swiss F508del European-derived populations D1152H European-derived populations 1677delTA Southern European, Middle Eastern R1158X Southern European 1717-GNA European-derived populations R1162X Italian, Amerindian, Latin America V520F Irish S1251N European-derived populations G542X Southern European, Mediterranean W1282X Ashkenazi-Jewish, Middle Eastern S549R(TNG) Middle Eastern N1303K Southern European, Middle Eastern Legend: these alleles occur with a frequency superior to 0.1% in selected populations. Login to comment

[hide] ENaCbeta and gamma genes as modifier genes in cyst... J Cyst Fibros. 2008 Jan;7(1):23-9. Epub 2007 Jun 7. Viel M, Leroy C, Hubert D, Fajac I, Bienvenu T
ENaCbeta and gamma genes as modifier genes in cystic fibrosis.
J Cyst Fibros. 2008 Jan;7(1):23-9. Epub 2007 Jun 7., [PMID:17560176]

Abstract [show]
BACKGROUND: Clinical phenotype varies among cystic fibrosis (CF) patients with identical CF transmembrane conductance regulator (CFTR)genotype, suggesting that genetic modifiers exist. Transgenic mice that overexpress SCNN1beta present CF-like lung disease symptoms. Mutations or variants in SCNN1beta may therefore potentially modulate the clinical phenotype in CF patients. METHODS: We analysed by DHPLC SCNN1beta and SCNN1gamma genes in 56 patients with classical CF. Patients were classified into two groups according to their CFTR genotype and their severity: 38 patients with severe genotype and an unexpectedly mild lung phenotype, and 18 patients with mild genotype and a severe lung phenotype. RESULTS: We found 3 patients out of 56 carrying at least one missense mutation. Two were novel (p.Thr313Met in SCNN1beta, p.Leu481Gln in SCNN1gamma) and two were previously described (p.Gly589Ser in SCNN1beta and p.Val546Ileu in SCNNgamma). p.Thr313Met has been identified in a CF patient with mild genotype and severe lung phenotype suggesting that it could act in increasing ENaC activity. The three other variants have been identified in CF patients with severe genotype and mild lung phenotype suggesting that they might decrease ENaC activity. However, the function of ENaC in the nasal epithelia of these patients, evaluated by nasal potential difference measurements, did not support the fact that these variants were functional, at least in nasal epithelium. CONCLUSION: Our results suggest that genetic variants in ENaCbeta and gamma genes do not modulate disease severity in the majority of CF patients.

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106 Lung transplant IV antibiotic courses/year Bronchial colonization 1 F508del: F508del p.G589S 36 PI 19.7 76 No 0 P. aeruginosa 2 F508del: F508del p.L481Q: p.V546IL 24 PI 25.6 74 No 1 P. aeruginosa 3 F508del: R347P p.T313M 27 PS 15.0 18 Awaiting 12 B. cepacia PI: pancreatic insufficient, PS: pancreatic sufficient, FEV1: forced expiratory flow in one second, BMI: body mass index. Login to comment
113 The new variant p.Thr313Met was present in a CF patient aged 27 years old, with mild CFTR genotype (Phe508del: R347P) but presenting a severe lung disease with Burkholderia cepacia colonization (FEV1 18%; continuous intravenous antibiotic treatment awaiting lung transplantation) (Table 3). Login to comment
135 Table 4 Nasal PD measurements and sweat test in CF patients bearing a missense mutation in ENaCβ or ENaCγ Patient number CFTR mutations ENaC mutations Basal NPD (mV) Δamil (mV) Δ0Cl-/amil (mV) Δ(iso/0Cl-) (mV) Cl- sweat mmol/L 1 F508del: F508del p.Gly589Ser -61 56 0 -5 114 2 F508del: F508del p.Leu481Gln: p.Val546Ileu -51 22 1 1 115 3 F508del: R347P p.Thr313Met Not done 64 NPD: nasal potential difference; amil: amiloride. Login to comment

[hide] High incidence of the CFTR mutations 3272-26A-->G ... J Cyst Fibros. 2007 Nov 30;6(6):371-5. Epub 2007 May 3. Storm K, Moens E, Vits L, De Vlieger H, Delaere G, D'Hollander M, Wuyts W, Biervliet M, Van Schil L, Desager K, Nothen MM
High incidence of the CFTR mutations 3272-26A-->G and L927P in Belgian cystic fibrosis patients, and identification of three new CFTR mutations (186-2A-->G, E588V, and 1671insTATCA).
J Cyst Fibros. 2007 Nov 30;6(6):371-5. Epub 2007 May 3., [PMID:17481968]

Abstract [show]
We have analyzed 143 unrelated Belgian patients with a positive diagnosis of cystic fibrosis (CF) for mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. An initial screening for 29 CFTR mutations led to mutation identification in 89.9% of the tested chromosomes. Subsequently an extensive analysis of the CFTR gene was performed by denaturating gradient gel electrophoresis (DGGE) in those patients with at least one unknown mutation after preliminary screening. In addition to 10 previously reported mutations we identified 2 new mutations 186-2A-->G and E588V. A third new mutation 1671insTATCA was identified during routine screening for DeltaF508. Two mutations were detected with a higher frequency than expected: 3272-26A-->G, which is the second most common mutation after DeltaF508 in our CF population with a frequency of 3.8%, and L927P (2.4%). The clinical data is presented for the mutations 186-2A-->G, E588V, 3272-26A-->G and L927P. The mutation data are useful for the Belgian population to supplement the initial screening set of mutations.

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32 The Inno Lipa™ CFTR17 assay contains normal and mutant probes for 17 other CFTR mutations (394delTT, G85E, 621+1G→T, R117H, 1078delT, R347P, R334W, E60X, 711+5G→A, 2789 + 5G→ A, R1162X, 3659delC, 3849 + 10kbC→ T, 2143delT, A455E, 2183AA→G, 2184delA) (Innogenetics). Login to comment

[hide] Highly preferential association of NonF508del CF m... J Cyst Fibros. 2007 Jan;6(1):15-22. Epub 2006 Jun 19. Ciminelli BM, Bonizzato A, Bombieri C, Pompei F, Gabaldo M, Ciccacci C, Begnini A, Holubova A, Zorzi P, Piskackova T, Macek M Jr, Castellani C, Modiano G, Pignatti PF
Highly preferential association of NonF508del CF mutations with the M470 allele.
J Cyst Fibros. 2007 Jan;6(1):15-22. Epub 2006 Jun 19., [PMID:16784904]

Abstract [show]
BACKGROUND: On the basis of previous findings on random individuals, we hypothesized a preferential association of CF causing mutations with the M allele of the M470V polymorphic site of the CFTR gene. METHODS: We have determined the M/V-CF mutation haplotype in a series of 201 North East Italian and 73 Czech CF patients who were not F508del homozygotes, as F508del was already known to be fully associated with the M allele. RESULTS: Out of 358 not F508del CF genes, 84 carried the V allele and 274 the less common M allele. In the N-E Italian population, MM subjects have a risk of carrying a CF causing mutation 6.9x greater than VV subjects when F508del is excluded and 15.4x when F508del is included. In the Czech population a similar, although less pronounced, association is observed. CONCLUSIONS: Besides the possible biological significance of this association, the possibility of exploiting it for a pilot screening program has been explored in a local North East Italian population for which CF patients were characterized for their CF mutation. General M470V genotyping followed by common CF mutation screening limited to couples in which each partner carries at least one M allele would need testing only 39% of the couples, which contribute 89% of the total risk, with a cost benefit.

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121 Table 5 shows the estimated residual Table 4 CF mutations found in the 53 CF patients of the Bolzano province CF mutation Absolute and relative (%) frequencies Associated with(1) F508del 56 (52.8) M 711+5 G>A 10 (9.4) M R347P 3 (2.8) V S466X 1 (0.9) M 1717-1 G>A 1 (0.9) M G542X 1 (0.9) M G551D 2 (1.9) V 1874insT 1 (0.9) V 2183AA>G 3 (2.8) M 2789+5G>A 1 (0.9) M R1162X 24 (22.6) M N1303K 2 (1.8) M (1) Based on data of Table 1. Login to comment

[hide] Mutational spectrum of cystic fibrosis patients fr... Mol Genet Metab. 2006 Apr;87(4):370-5. Epub 2006 Jan 19. Ramirez AM, Ramos MD, Jimenez J, Ghio A, de Botelli MM, Rezzonico CA, Marques I, Pereyro S, Casals T, de Kremer RD
Mutational spectrum of cystic fibrosis patients from Cordoba province and its zone of influence: implications of molecular diagnosis in Argentina.
Mol Genet Metab. 2006 Apr;87(4):370-5. Epub 2006 Jan 19., [PMID:16423550]

Abstract [show]
Cystic Fibrosis (CF) is an autosomal recessive disorder affecting 1/2000-4000 newborns in Caucasian populations. This lethal disease mainly affects respiratory and digestive organs as well as fertility in man. So far, the CF prevalence and mutational spectrum have showed specificity among populations and regions, making it necessary to establish them in each one. In this study, we present the spectrum and frequency of CFTR gene mutations in CF patients from Cordoba (a province with 3.1 millions inhabitants in the middle of Argentina) and its zone of influence, to offer an accurate genetic testing. The study includes 78 families in which 98 patients fulfilled clinical criteria to CF diagnosis. The strategy for the molecular diagnosis comprised analysis of 21 common mutations, microsatellite haplotypes and the complete CFTR gene analysis using scanning techniques followed by sequencing of the abnormal migration patterns. Our first step led us to the identification of 10 mutations that represented 76% of alleles. Another four mutations (p.R1066C, c.1811 + 1.6 kbA > G, c.711 + 1G > T, and p.G85E) were found based on the microsatellite haplotype-mutation association. Finally, 14 mutations were characterized after the CFTR gene scanning, three of them are not previously described (p.G27R, c.622-2A > G, and p.W277R). In summary, we have identified 27 mutations accounting for 94.23% of CF alleles. This characteristic mutational spectrum highlights the 14 most frequent mutations (>1%) in the Cordoba region.

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44 Mutations (p.F508del, p.N1303K, p.G542X, p.R334W, c.2789 + 5G > A, c.3659delC, p.R553X, c.3849 + 10kbC > T, p.R1162X, c.621 + 1G > T, p.W1282X, p.R117H, c.1078delT, p.E60X, p.R347P, p.A455E, p.I507del, c.1717-1G > A, p.G551D, [c.2183A > G; c.2184delA] and p.S1251N) were analyzed by heteroduplex analysis on polyacrylamide gel electrophoresis [11,12] and by ampliWcation refractory mutation system [13] in all 78 patients. Login to comment

[hide] Cytogenetic analysis of azoospermic patients: kary... Eur J Obstet Gynecol Reprod Biol. 2006 Feb 1;124(2):197-203. Epub 2005 Sep 12. Stipoljev F, Vujisic S, Parazajder J, Hafner D, Jezek D, Sertic J
Cytogenetic analysis of azoospermic patients: karyotype comparison of peripheral blood lymphocytes and testicular tissue.
Eur J Obstet Gynecol Reprod Biol. 2006 Feb 1;124(2):197-203. Epub 2005 Sep 12., [PMID:16157443]

Abstract [show]
OBJECTIVE: The objective was to compare the results of a complete chromosomal, genetic and histological investigation in 13 azoospermic men with the results of the intracytoplasmic sperm injection (ICSI) procedure. STUDY DESIGN: Peripheral blood samples were used for the measurement of follicle-stimulating hormone (FSH) levels, chromosomal analysis, microdeletions in the azoospermia factor (AZF) region of the Y chromosome and cystic fibrosis transmembrane conductance regulator (CFTR) mutation analysis. Testicular tissue was used for histological scoring and cytogenetic evaluation. RESULTS: Peripheral blood cytogenetic analysis revealed a normal male karyotype in all cases. Chromosomal analysis from testicular tissue revealed a mosaicism for the terminal deletion of chromosome 22 with a breakpoint site at 22q13 in one patient with congenital bilateral absence of the vas deferens (CBAVD). Deletions in the AZFa, ATFb, and AZFc regions were not detected. The CFTR mutational analysis showed normal results in all patients. CONCLUSIONS: Cytogenetic evaluation of testicular tissue should be performed in non-obstructive and obstructive azoospermic patients as well as in patients with multiple failed IVF and recurrent spontaneous abortion.

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61 T, R117H; exon 7: 1078delT, R347P, R334W; exon 13: 2143delT, 2183AA ! Login to comment

[hide] Increased frequency of cystic fibrosis transmembra... Fertil Steril. 2006 Jan;85(1):135-8. Schulz S, Jakubiczka S, Kropf S, Nickel I, Muschke P, Kleinstein J
Increased frequency of cystic fibrosis transmembrane conductance regulator gene mutations in infertile males.
Fertil Steril. 2006 Jan;85(1):135-8., [PMID:16412743]

Abstract [show]
OBJECTIVE: To investigate the frequency of mutations of the cystic fibrosis transmembrane regulator (CFTR) gene in males with reduced sperm quality before intracytoplasmic sperm injection (ICSI). DESIGN: The nine most frequent cystic-fibrosis-causing mutations in the German population and IVS8T alleles were analyzed. SETTING: University-based centers for reproductive medicine and clinical genetics. PATIENT(S): An unselected group of 597 males with oligo-, astheno-, terato-, crypto-, oligoasthenoteratozoospermia, or azoospermia, which underwent pre-ICSI genetic counseling over a 5-year period. INTERVENTION(S): Blood samples were collected from the patients during genetic counseling. MAIN OUTCOME MEASURE(S): Frequency of mutations of CFTR gene in infertile males. RESULT(S): A heterozygous CFTR mutation was observed in 34 of 597 patients (5.70%). None of the patients had two CFTR mutations. Given that our mutation panel recognizes about 82% of heterozygotes, it can be assumed that the frequency of CFTR heterozygotes in our cohort is about 6.94%. The frequency of CFTR mutations in our cohort did not correlate with a reduced sperm count. CONCLUSION(S): The frequency of cystic fibrosis in the German population is 1:3300. Thus, a CFTR heterozygosity of 3.42% can be estimated. This indicates that in our cohort of infertile males, the frequency of CFTR heterozygosity is twofold higher than in the general population (P<.0001).

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45 Mutations R117H, R347P, G542X, G551D, R553X, 3849ϩ10kbCϾT, and N1303K were analyzed by PCR and restriction enzyme cleavage. Login to comment
47 Among CFTR mutations detected in the German population, F508del, R117H, R347P, G542X, G551D, R553X, 3849ϩ10kbCϾT, N1303K, and CFTR2,3dele(21kb) occur with a frequency of 72%, 1%, 1.2%, 1.2%, 0.9%, 2%, 1%, 1.8%, and 1.2%, respectively (9-11). Login to comment

[hide] Cystic fibrosis mutations and genotype-pulmonary p... J Cyst Fibros. 2006 Jan;5(1):33-41. Epub 2005 Nov 4. Braun AT, Farrell PM, Ferec C, Audrezet MP, Laxova A, Li Z, Kosorok MR, Rosenberg MA, Gershan WM
Cystic fibrosis mutations and genotype-pulmonary phenotype analysis.
J Cyst Fibros. 2006 Jan;5(1):33-41. Epub 2005 Nov 4., [PMID:16275171]

Abstract [show]
BACKGROUND: Although there are more than 1000 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, most of them are uncommon and only limited information exists regarding genotype-pulmonary phenotype relationships. METHODS: We determined and classified the CFTR mutations using denaturing high-performance liquid chromatography and developed new, quantitative methods to categorize pulmonary phenotypes. RESULTS: Two novel alleles were discovered, namely G1047R and 1525-2A-->G, which were accompanied by F508del and G551D mutations, respectively. Assessment of numerous options revealed that CF pulmonary phenotype categorization in children cannot be accomplished with clinical or pulmonary function data but is facilitated by longitudinal quantitative chest radiology. It was most useful to categorize pulmonary disease status by evaluating the typical pattern of abnormalities in patients homozygous for the F508del mutation, and then compare patients with minor mutations to this typical CF pulmonary phenotype. By this method, both patients with novel mutations have pulmonary phenotypes typical of F508del homozygotes. However, patients with class IV mutations (e.g., R347P) or with pancreatic sufficiency showed serial chest radiographs that were atypically mild. CONCLUSIONS: Longitudinal quantitative chest radiography provides a new strategy for CF pulmonary phenotype categorization that should be useful for genotype-phenotype delineation in individual patients and in both epidemiologic studies and clinical trials involving groups of children with CF.

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6 However, patients with class IV mutations (e.g., R347P) or with pancreatic sufficiency showed serial chest radiographs that were atypically mild. Login to comment
80 Thereafter, the longitudinal patterns of WCXR and BCXR for the two patients with novel mutations (i.e., G1047R and 1525-2AYG) were superimposed on the Table 1 Summary of patient characteristics Characteristics F508del homozygote group (n =38) Pancreatic sufficiency groupa (n =19) Sex Male 25 8 Female 13 11 Center Madison 21 12 Milwaukee 17 7 Group Screened 38 3 Control 0 14 Other 0 2 Meconium ileus Yes 6 0 No 32 19 Mean age at diagnosis (weeks)TS.D. 7.15T2.4 193.1T192 Mean sweat Cl mEq/lTS.D. Login to comment
81 101.0T9.5 83.5T21.2 CXR scores at diagnosis WCXR 2.48T32b 4.68T71 BCXR 21.9T0.3 21.1T.48 Pulmonary function at 8 years FEV1 (%)c 97T4 104T2 FVC (%)c 103T3 103T2 FEV1/FVC% 0.92T0.03 0.98T.01 FEF25 - 75% 99T11 104T5 a Mild pancreatic phenotype mutations include: R117H occurring with F508del (n =5) and G542X (n =1); R117C with F508del (n =2); R347P with F508del (n =1), R1066H (n =1) and 2184insA (n À1), 2789+5G>A with F508del (n =3); 3272À26A>G with F508del (n =1); 3849+10kbC>T with F508del (n =1); L138ins with 3272À26A>G (n =1); R352Q with F508del (n =1); and 1336K with F508del (n =1). Login to comment
150 In contrast to patients #1 and #2, the longitudinal chest radiography data on patients with PS are different from the F508del homozygotes (e.g., R347P or 2789+5GYA as shown in Fig. 4). Login to comment
151 In comparison with the longitudinal progression of the F508del homozygote group, the F508del/ R347P child obviously shows an atypical pattern of progression although she had slightly abnormal WCXR and BCXR scores when diagnosed at 6 weeks with sweat chloride values of 100 and 102 mEq/L. Login to comment
167 A variety WCXRscore 0 5 10 15 20 25 30 F508del/F508del Pancreatic sufficiency F508del/R347P Patient WCXRscore 0 5 10 15 20 25 30 F508del/F508del Pancreatic sufficiency F508del/2789+5G->A Patient 0 1 2 3 4 5 6 7 8 9 10 11 12 Age in years Fig. 4. Login to comment
149 In contrast to patients #1 and #2, the longitudinal chest radiography data on patients with PS are different from the F508del homozygotes (e.g., R347P or 2789+5GYA as shown in Fig. 4). Login to comment
166 A variety WCXR score 0 5 10 15 20 25 30 F508del/F508del Pancreatic sufficiency F508del/R347P Patient WCXR score 0 5 10 15 20 25 30 F508del/F508del Pancreatic sufficiency F508del/2789+5G->A Patient 0 1 2 3 4 5 6 7 8 9 10 11 12 Age in years Fig. 4. Login to comment

[hide] Spectrum of mutations in CFTR in Finland: 18 years... J Cyst Fibros. 2005 Dec;4(4):233-7. Epub 2005 Jul 26. Kinnunen S, Bonache S, Casals T, Monto S, Savilahti E, Kere J, Jarvela I
Spectrum of mutations in CFTR in Finland: 18 years follow-up study and identification of two novel mutations.
J Cyst Fibros. 2005 Dec;4(4):233-7. Epub 2005 Jul 26., [PMID:16051530]

Abstract [show]
BACKGROUND: The incidence of cystic fibrosis (CF) is low in the isolated Finnish population and the Finnish CF mutation spectrum has differed from many European countries. METHODS: We have analyzed the mutation spectrum and the geographical distribution of CF mutations in Finland covering the last 18 years (1987-2004). RESULTS: A total of 14 mutations were identified; two of them new, 774insT and S589T (G>C at 1,898). The overall coverage of mutations was 97% (99/102 chromosomes). The most frequent mutations were F508del and 394delTT, found in 36% (37/102) and 35% (36/102) of the CF chromosomes respectively. Of the rare mutations, a mutation of presumable Slavic origin, CFTRdele2.3 (21 kb), was enriched in a rural isolate with a frequency of 5,9% (6/102), and a mutation that possibly indicates Swedish influence, 3659delC, was scattered throughout the country with a similar frequency of 5,9% (6/102). G542X, R1162X, R117H, 3732delA, 1,898 + 3A >C, S1196X, S945L, W57R, 774insT and S589T were each identified in a number of chromosomes from one to three. CONCLUSIONS: Our observations of the Finnish CF mutation spectrum fit well with the characteristics of Finland as a population of multiple local founder effects.

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36 The InnoLipa assay recognizes 36 mutations: E60X (c.178G>T, p.Glu60X), G85E (c.254G>A, p.Gly85- Glu), 394delTT, R117H (c.350G>A, p.Arg117His), I148T (c.443T>C, p.Ile148Thr), 621+1G>T (c.489+1G>T), 711+1G>T (c.579+1G>T), 711+5G>A (c.579+5G>A), 1078delT (c.948delT, p.Phe316fs), R334W (c.1000C>T, p.Arg334Trp), R347P (c.1040G>C, p.Arg347Pro), A455E (c.1364C>A, p.Ala455Glu), I507del (c.1519_1521delATC, p.Ile507del), F508del, 1717À1G>A (c.1585À1G>A), G542X, G551D (c.1652G >A, p.Gly551Asp), Q552X (c.1654C > T, p.Gln552X), R553X (c.1657C > T, p.Arg553X), R560T (1679G>vC, p.Arg560Thr), 1898+ 1G > A (c.1766 + 1G > A), 2143delT (c.2012delT, p.Leu671fs), 2183AA > G (c.2051_2052delAAinsG, p.Lys684fs), 2184delA (c.2052delA, p.Lys684fs), 2789+ 5G>A (c.2657+5G>A), 3120+1G>A (c.2988+1G>A), 3199del6 (c.3067_3072del, p.Ile1023_Val1024del), 3272À 26A > G (c.3140 À26A > G), R1162X (c.3484C > T, p.Arg1162X), 3849+10kbCYT, 3659delC (c.3528delC, p.Lys1177fs), S1251N (c.3752G > A, p.Ser1251Asn), 3905insT (c.3773dupT, p.Leu1258fs), W1282X (c.3846G> A, p.Trp1282X), N1303K (c.3909C>G, p.Asn1303Lys), CFTRdele2,3(21kb) and Tn-polymorphism on intron 8. Login to comment
37 The InnoLipa assay recognizes 36 mutations: E60X (c.178G>T, p.Glu60X), G85E (c.254G>A, p.Gly85Glu), 394delTT, R117H (c.350G>A, p.Arg117His), I148T (c.443T>C, p.Ile148Thr), 621+1G>T (c.489+1G>T), 711+1G>T (c.579+1G>T), 711+5G>A (c.579+5G>A), 1078delT (c.948delT, p.Phe316fs), R334W (c.1000C>T, p.Arg334Trp), R347P (c.1040G>C, p.Arg347Pro), A455E (c.1364C>A, p.Ala455Glu), I507del (c.1519_1521delATC, p.Ile507del), F508del, 1717 1G>A (c.1585 1G>A), G542X, G551D (c.1652G >A, p.Gly551Asp), Q552X (c.1654C > T, p.Gln552X), R553X (c.1657C > T, p.Arg553X), R560T (1679G>vC, p.Arg560Thr), 1898+ 1G > A (c.1766 + 1G > A), 2143delT (c.2012delT, p.Leu671fs), 2183AA > G (c.2051_2052delAAinsG, p.Lys684fs), 2184delA (c.2052delA, p.Lys684fs), 2789+ 5G>A (c.2657+5G>A), 3120+1G>A (c.2988+1G>A), 3199del6 (c.3067_3072del, p.Ile1023_Val1024del), 3272 26A > G (c.3140 26A > G), R1162X (c.3484C > T, p.Arg1162X), 3849+10kbCYT, 3659delC (c.3528delC, p.Lys1177fs), S1251N (c.3752G > A, p.Ser1251Asn), 3905insT (c.3773dupT, p.Leu1258fs), W1282X (c.3846G> A, p.Trp1282X), N1303K (c.3909C>G, p.Asn1303Lys), CFTRdele2,3(21kb) and Tn-polymorphism on intron 8. Login to comment

[hide] Hyperechogenic fetal bowel: counseling difficultie... Eur J Med Genet. 2005 Oct-Dec;48(4):421-5. Marcus-Soekarman D, Offermans J, Van den Ouweland AM, Mulder AL, Muntjewerff N, Vossen M, Kleijer W, Schrander-Stumpel C, Dooijes D
Hyperechogenic fetal bowel: counseling difficulties.
Eur J Med Genet. 2005 Oct-Dec;48(4):421-5., [PMID:16378926]

Abstract [show]
The detection of echodense fetal bowel on ultrasound examination in the second trimester of pregnancy justifies invasive procedures such as amniocentesis to detect an underlying cause. We present a case in which initial tests identified only one mutation in the cystic fibrosis transmembrane regulator (CFTR)-gene of the fetus, the family history being negative for CF. Strongly reduced intestinal enzyme activities suggested intestinal obstruction and further increased the estimated risk for CF. After the 24th gestational week, a second mutation was found, confirming cystic fibrosis in this child. Problems in counseling in this particular case are discussed.

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67 Routine CFTR-mutation analysis, using Table 1 CFTR-mutations screened for in the first step E60X 2143delT G542X G85E 2183AA-G G551D 394delTT 2184delA Q552X 621 + 1G-T 2789 + 5G-A R553X R117H 3849 + 10kbC-T R560T 711 + 5G-A R1162X S1251N 1078delT 3659delC 390insT R334W delta I507 W1282X R347P delta F508 N1303K A455E 1717-1G-A a panel of 29 CFTR-mutations, detects only 41.6% of CFTR-mutations in the Turkish population [1]. Login to comment

[hide] Genotyping microarray for the detection of more th... J Mol Diagn. 2005 Aug;7(3):375-87. Schrijver I, Oitmaa E, Metspalu A, Gardner P
Genotyping microarray for the detection of more than 200 CFTR mutations in ethnically diverse populations.
J Mol Diagn. 2005 Aug;7(3):375-87., [PMID:16049310]

Abstract [show]
Cystic fibrosis (CF), which is due to mutations in the cystic fibrosis transmembrane conductance regulator gene, is a common life-shortening disease. Although CF occurs with the highest incidence in Caucasians, it also occurs in other ethnicities with variable frequency. Recent national guidelines suggest that all couples contemplating pregnancy should be informed of molecular screening for CF carrier status for purposes of genetic counseling. Commercially available CF carrier screening panels offer a limited panel of mutations, however, making them insufficiently sensitive for certain groups within an ethnically diverse population. This discrepancy is even more pronounced when such carrier screening panels are used for diagnostic purposes. By means of arrayed primer extension technology, we have designed a genotyping microarray with 204 probe sites for CF transmembrane conductance regulator gene mutation detection. The arrayed primer extension array, based on a platform technology for disease detection with multiple applications, is a robust, cost-effective, and easily modifiable assay suitable for CF carrier screening and disease detection.

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51 Complete List of Mutations Detectable with the CF APEX Assay CFTR location Amino acid change Nucleotide change 1 E 1 Frameshift 175delC 2 E 2,3 Frameshift del E2, E3 3 E 2 W19C 189 GϾT 4 E 2 Q39X 247 CϾT 5 IVS 2 Possible splicing defect 296 ϩ 12 TϾC 6 E 3 Frameshift 359insT 7 E 3 Frameshift 394delTT 8 E 3 W57X (TAG) 302GϾA 9 E 3 W57X (TGA) 303GϾA 10 E 3 E60X 310GϾT 11 E 3 P67L 332CϾT 12 E 3 R74Q 353GϾA 13 E 3 R75X 355CϾT 14 E 3 G85E 386GϾA 15 E 3 G91R 403GϾA 16 IVS 3 Splicing defect 405 ϩ 1GϾA 17 IVS 3 Possible splicing defect 405 ϩ 3AϾC 18 IVS 3 Splicing defect 406 - 1GϾA 19 E 4 E92X 406GϾT 20 E 4 E92K 406GϾA 21 E 4 Q98R 425AϾG 22 E 4 Q98P 425AϾC 23 E 4 Frameshift 444delA 24 E 4 Frameshift 457TATϾG 25 E 4 R117C 481CϾT 26 E 4 R117H 482GϾA 27 E 4 R117P 482GϾC 28 E 4 R117L 482GϾT 29 E 4 Y122X 498TϾA 30 E 4 Frameshift 574delA 31 E 4 I148T 575TϾC 32 E 4 Splicing defect 621GϾA 33 IVS 4 Splicing defect 621 ϩ 1GϾT 34 IVS 4 Splicing defect 621 ϩ 3AϾG 35 E 5 Frameshift 624delT 36 E 5 Frameshift 663delT 37 E 5 G178R 664GϾA 38 E 5 Q179K 667CϾA 39 IVS 5 Splicing defect 711 ϩ 1GϾT 40 IVS 5 Splicing defect 711 ϩ 1GϾA 41 IVS 5 Splicing defect 712 - 1GϾT 42 E 6a H199Y 727CϾT 43 E 6a P205S 745CϾT 44 E 6a L206W 749TϾG 45 E 6a Q220X 790CϾT 46 E 6b Frameshift 935delA 47 E 6b Frameshift 936delTA 48 E 6b N287Y 991AϾT 49 IVS 6b Splicing defect 1002 - 3TϾG 50 E 7 ⌬F311 3-bp del between nucleotides 1059 and 1069 51 E 7 Frameshift 1078delT 52 E 7 Frameshift 1119delA 53 E 7 G330X 1120GϾT 54 E 7 R334W 1132CϾT 55 E 7 I336K 1139TϾA 56 E 7 T338I 1145CϾT 57 E 7 Frameshift 1154insTC 58 E 7 Frameshift 1161delC 59 E 7 L346P 1169TϾC 60 E 7 R347H 1172GϾA 61 E 7 R347P 1172GϾC 62 E 7 R347L 1172GϾT 63 E 7 R352Q 1187GϾA 64 E 7 Q359K/T360K 1207CϾA and 1211CϾA 65 E 7 S364P 1222TϾC 66 E 8 Frameshift 1259insA 67 E 8 W401X (TAG) 1334GϾA 68 E 8 W401X (TGA) 1335GϾA 69 IVS 8 Splicing changes 1342 - 6 poly(T) variants 5T/7T/9T 70 IVS 8 Splicing defect 1342 - 2AϾC Table 1. Continued CFTR location Amino acid change Nucleotide change 71 E 9 A455E 1496CϾA 72 E 9 Frameshift 1504delG 73 E 10 G480C 1570GϾT 74 E 10 Q493X 1609CϾT 75 E 10 Frameshift 1609delCA 76 E 10 ⌬I507 3-bp del between nucleotides 1648 and 1653 77 E 10 ⌬F508 3-bp del between nucleotides 1652 and 1655 78 E 10 Frameshift 1677delTA 79 E 10 V520F 1690GϾT 80 E 10 C524X 1704CϾA 81 IVS 10 Possible splicing defect 1717 - 8GϾA 82 IVS 10 Splicing defect 1717 - 1GϾA 83 E 11 G542X 1756GϾT 84 E 11 G551D 1784GϾA 85 E 11 Frameshift 1784delG 86 E 11 S549R (AϾC) 1777AϾC 87 E 11 S549I 1778GϾT 88 E 11 S549N 1778GϾA 89 E 11 S549R (TϾG) 1779TϾG 90 E 11 Q552X 1786CϾT 91 E 11 R553X 1789CϾT 92 E 11 R553G 1789CϾG 93 E 11 R553Q 1790GϾA 94 E 11 L558S 1805TϾC 95 E 11 A559T 1807GϾA 96 E 11 R560T 1811GϾC 97 E 11 R560K 1811GϾA 98 IVS 11 Splicing defect 1811 ϩ 1.6 kb AϾG 99 IVS 11 Splicing defect 1812 - 1GϾA 100 E 12 Y563D 1819TϾG 101 E 12 Y563N 1819TϾA 102 E 12 Frameshift 1833delT 103 E 12 D572N 1846GϾA 104 E 12 P574H 1853CϾA 105 E 12 T582R 1877CϾG 106 E 12 E585X 1885GϾT 107 IVS 12 Splicing defect 1898 ϩ 5GϾT 108 IVS 12 Splicing defect 1898 ϩ 1GϾA 109 IVS 12 Splicing defect 1898 ϩ 1GϾC 110 IVS 12 Splicing defect 1898 ϩ 1GϾT 111 E 13 Frameshift 1924del7 112 E 13 del of 28 amino acids 1949del84 113 E 13 I618T 1985TϾC 114 E 13 Frameshift 2183AAϾG 115 E 13 Frameshift 2043delG 116 E 13 Frameshift 2055del9ϾA 117 E 13 D648V 2075TϾA 118 E 13 Frameshift 2105-2117 del13insAGAA 119 E 13 Frameshift 2108delA 120 E 13 R668C 2134CϾT 121 E 13 Frameshift 2143delT 122 E 13 Frameshift 2176insC 123 E 13 Frameshift 2184delA 124 E 13 Frameshift 2184insA 125 E 13 Q685X 2185CϾT 126 E 13 R709X 2257CϾT 127 E 13 K710X 2260AϾT 128 E 13 Frameshift 2307insA 129 E 13 V754M 2392GϾA 130 E 13 R764X 2422CϾT 131 E 14a W846X 2670GϾA 132 E 14a Frameshift 2734delGinsAT 133 E 14b Frameshift 2766del8 134 IVS 14b Splicing defect 2789 ϩ 5GϾA 135 IVS 14b Splicing defect 2790 - 2AϾG 136 E 15 Q890X 2800CϾT 137 E 15 Frameshift 2869insG 138 E 15 S945L 2966CϾT 139 E 15 Frameshift 2991del32 140 E 16 Splicing defect 3120GϾA interrogation: ACCAACATGTTTTCTTTGATCTTAC 3121-2A3G,T S; 5Ј-ACCAACATGTTTTCTTTGATCTTAC A GTTGTTATTAATTGTGATTGGAGCTATAG-3Ј; CAACAA- TAATTAACACTAACCTCGA 3121-2A3G,T AS. Login to comment
73 Genomic DNA Samples Used for Mutation Evaluation on the APEX Array Mutations validated with native DNA CFTRdel 2,3 (21 kb) 394delTT G85E R75X 574delA Y122X R117C R117H 621 ϩ 1GϾT 621 ϩ 3AϾG 711 ϩ 1GϾT I336K R334W R347P IVS8-5T IVS8-7T IVS8-9T A455E ⌬F508 ⌬I507 1677delTA 1717 - 1GϾA G542X G551D R553X R560T S549N 1898 ϩ 1GϾA 1898 ϩ 1GϾC 2183AAϾG 2043delG R668C 2143delT 2184delA 2184insA 2789 ϩ 5GϾA S945L 3120 ϩ 1GϾA I1005R 3272 - 26AϾG R1066C G1069R Y1092X (CϾA) 3500 - 2AϾT R1158X R1162X 3659delC S1235R 3849 ϩ 10 kb CϾT W1282X primer. Login to comment

[hide] Complete gene scanning by temperature gradient cap... J Mol Diagn. 2005 Feb;7(1):111-20. Chou LS, Gedge F, Lyon E
Complete gene scanning by temperature gradient capillary electrophoresis using the cystic fibrosis transmembrane conductance regulator gene as a model.
J Mol Diagn. 2005 Feb;7(1):111-20., [PMID:15681482]

Abstract [show]
Many inherited diseases involve large genes with many different mutations. Identifying a wide spectrum of mutations requires an efficient gene-scanning method. By differentiating thermodynamic stability and mobility of heteroduplexes from heterozygous samples, temperature gradient capillary electrophoresis (TGCE) was used to scan the entire coding region of the cystic fibrosis transmembrane conductance regulator gene. An initial panel (29 different mutations) showed 100% agreement between TGCE scanning and previously genotyped results for heterozygous samples. Different peak patterns were observed for single base substitutions and base insertions/deletions. Subsequently, 12 deidentified clinical samples genotyped as wild type for 32 mutations were scanned for the entire 27 exons. Results were 100% concordance with the bidirectional sequence analysis. Ten samples had nucleotide variations including a reported base insertion in intron 14b (2789 + 2insA) resulting in a possible mRNA splicing defect, and an unreported missense mutation in exon 20 (3991 G/A) with unknown clinical significance. This methodology does not require labeled primers or probes for detection and separation through a temperature gradient eliminates laborious temperature optimization required for other technologies. TGCE automation and high-throughput capability can be implemented in a clinical environment for mutation scanning with high sensitivity, thus reducing sequencing cost and effort.

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75 Mutation Samples with Known Genotypes Scanned by TGCE* Exon Mutation† Amplicon size (bp) Location of mutation from 5Ј end (bp) Base change Detection‡ 3 G85E 234 124 G to A 1/1 3 394delTT 234 132 del TT 1/1 4 R117H 270 83 G to T 2/2 4 I148T 270 176 T to C 3/3 Intron 4 621 ϩ 1 G/T 270 233 G to T 1/1 5 663delT/663delT 186 75 del T 0/1 Intron 5 711 ϩ 1 G/T 186 124 G to T 1/1 7 R334W 345 208 C to T 1/1 7 R347P 345 248 G to C 1/1 9 A455E 263 155 C to A 2/2 10 I506V 292 168 A to G 1/1 10 ⌬I507 292 171 del ATC 2/2 10 ⌬F508 292 174 del TTT 2/2 10 ⌬F508/⌬F508 292 174 del TTT 0/1 10 F508C 292 175 T to G 1/1 10 V520F 292 210 G to T 1/1 Intron 10 1717-1 G/A 175 50 G to A 1/1 11 G542X 175 90 G to T 2/2 11 G542X/G542X 175 90 G to T 0/1 11 G551D 175 118 G to A 3/3 11 R553X 175 123 C to T 3/3 11 R560T 175 145 G to C 2/2 13 2184delA 834 356 del A 1/1 Intron 14b 2789 ϩ 5G/A 192 102 G to A 1/1 Intron 16 3120 ϩ 1G/A 216 111 G to A 1/1 19 R1162X 322 68 C to T 1/1 19 3659delC 322 111 del C 1/1 20 W1282X 206 154 G to A 1/1 21 N1303K 250 175 C to G 2/2 Total exon/intron Overall accuracy 17 93% *Samples were compared with their respective wild-type control (confirmed by sequencing). Login to comment

[hide] Rapid screening for 31 mutations and polymorphisms... Methods Mol Med. 2005;114:147-71. Dunbar SA, Jacobson JW
Rapid screening for 31 mutations and polymorphisms in the cystic fibrosis transmembrane conductance regulator gene by Lminex xMAP suspension array.
Methods Mol Med. 2005;114:147-71., [PMID:16156102]

Abstract [show]
A suspension array hybridization assay is described for the detection of 31 mutations and polymorphisms in the cystic fibrosis transmembrane conductance regulator (CFTR) gene using Luminex xMAP technology. The Luminex xMAP system allows simultaneous detection of up to 100 different targets in a single multiplexed reaction. Included in the method are the procedures for design of oligonucleotide capture probes and PCR amplification primers, coupling oligonucleotide capture probes to carboxylated microspheres, hybridization of coupled microspheres to oligonucleotide targets, production of targets from DNA samples by multiplexed PCR amplification, and detection of PCR-amplified targets by direct hybridization to probe-coupled microspheres. Mutation screening with the system is rapid, requires relatively few sample manipulations, and provides adequate resolution to reliably genotype the 25 CFTR mutations and 6 CFTR polymorphisms contained in the ACMG/ACOG/NIH-recommended core mutation panel for general population CF carrier screening.

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25 A 635-nm 10-mW red diode laser excites the two fluo- 148 Dunbar and Jacobson xMAP™ 149 Table 1 Recommended Core Mutation Panel for General Population Cystic Fibrosis (CF) Carrier Screening Standard mutation panel ΔF508 ΔI507 G542X G551D W1282X N1303K R553X 621+1G→T R117H 1717-1G→A A455E R560T R1162X G85E R334W R347P 711+1G→T 1898+1G→A 2184delA 1078delT 3849+10kbC→T 2789+5G→A 3659delC 1148T 3120+1G→A Reflex tests I506Va I507Va F508Ca 5T/7T/9Tb a Benign variants. Login to comment
94 Methods The methods described below include: (1) design of oligonucleotide capture probes, (2) design of PCR amplification primers and multiplexed PCR reactions, (3) preparation of the probe-conjugated microsphere sets, (4) verification 150 Dunbar and Jacobson xMAPTM Table 2 Oligonucleotide Capture Probesa Target Microsphere Probe sequence Modificationb Sequence 5' → 3' set Standard mutation panel 1c I507 & F508 5'-AmMC12 AACACCAAAGATGATATTTT 006 2B DI507 5'-AmMC12 ACACCAAAGATATTTTCTT 008 3B DF508 5'-AmMC12 AAACACCAATGATATTTTC 015 4B W1282 5'-AmMC12 CAACAGTGGAGGAAAGCC 012 5B W1282X 5'-AmMC12 CAACAGTGAAGGAAAGCC 020 6 1717-1G 5'-AmMC12 TTGGTAATAGGACATCTCCA 017 7 1717-1GÆA 5'-AmMC12 TTGGTAATAAGACATCTCCA 019 8B G542 5'-AmMC12 TATAGTTCTTGGAGAAGGTGGA 026 9B G542X 5'-AmMC12 TATAGTTCTTTGAGAAGGTGGA 028 10C G551 & R553 5'-AmMC12 AGTGGAGGTCAACGAGCAA 038 11B G551D 5'-AmMC12 GTGGAGATCAACGAGCAA 030 12C R553X 5'-AmMC12 GTGGAGGTCAATGAGCAA 032 13 R560 5'-AmMC12 CTTTAGCAAGGTGAATAACT 035 14 R560T 5'-AmMC12 CTTTAGCAACGTGAATAACT 039 15 R117 5'-AmMC12 AGGAGGAACGCTCTATCGCG 042 16 R117H 5'-AmMC12 AGGAGGAACACTCTATCGCG 025 17B I148 5'-AmMC12 CTTCATCACATTGGAATGCAGA 034 18B I148T 5'-AmMC12 CTTCATCACACTGGAATGCAGA 045 19C 621+1G 5'-AmMC12 TTTATAAGAAGGTAATACTTCCT 046 20E 621+1G→T 5'-AmMC12 ATTTATAAGAAGTTAATACTTCCTT 048 21 N1303 5'-AmMC12 GGGATCCAAGTTTTTTCTAA 051 22 N1303K 5'-AmMC12 GGGATCCAACTTTTTTCTAA 052 23B 1078T 5'-AmMC12 CACCACAAAGAACCCTGA 054 24C 1078delT 5'-AmMC12 ACACCACAAGAACCCTGA 061 25 R334 5'-AmMC12 ATATTTTCCGGAGGATGATT 063 26 R334W 5'-AmMC12 ATATTTTCCAGAGGATGATT 064 27B R347 5'-AmMC12 ACCGCCATGCGCAGAACAA 067 28B R347P 5'-AmMC12 ACCGCCATGGGCAGAACAA 053 29C 711+1G 5'-AmMC12 ATTTGATGAAGTATGTACCTAT 059 30C 711+1G→T 5'-AmMC12 ATTTGATGAATTATGTACCTAT 071 31 G85 5'-AmMC12 TGTTCTATGGAATCTTTTTA 066 32B G85E 5'-AmMC12 ATGTTCTATGAAATCTTTTTA 073 33 3849+10kbC 5'-AmMC12 GTCTTACTCGCCATTTTAAT 077 34 3849+10kbC→T 5'-AmMC12 GTCTTACTCACCATTTTAAT 075 35 A455 5'-AmMC12 CCAGCAACCGCCAACAACTG 011 36D A455E 5'-AmMC12 TCCAGCAACCTCCAACAACTG 036 37 R1162 5'-AmMC12 TAAAGACTCGGCTCACAGAT 060 38 R1162X 5'-AmMC12 TAAAGACTCAGCTCACAGAT 068 39B 3659C 5'-AmMC12 TTGACTTGGTAGGTTTAC 022 40C 3659delC 5'-AmMC12 TTGACTTGTAGGTTTACC 079 41B 2789+5G 5'-AmMC12 TGGAAAGTGAGTATTCCATGTC 074 42D 2789+5G→A 5'-AmMC12 TTGGAAAGTGAATATTCCATGTC 014 43E 2184A 5'-AmMC12 GAAACAAAAAAACAATC 007 44E 2184delA 5'-AmMC12 AGAAACAAAAAACAATC 018 45B 1898+1G 5'-AmMC12 TATTTGAAAGGTATGTTCTTTG 013 (Continued) of microsphere coupling, (5) direct hybridization of biotinylated PCR amplification products to the multiplexed probe-coupled microsphere sets, and (6) results and data analysis. Login to comment
106 Table 3 Reverse Complementary Oligonucleotide Targetsa Target Target sequence Modification Sequence 5' → 3' Standard mutation panel C1b I507 & F508 5'-Biotin AAAATATCATCTTTGGTGTT C2 ΔI507 5'-Biotin AAAGAAAATATCTTTGGTGT C3 ΔF508 5'-Biotin AGAAAATATCATTGGTGTTT C4 W1282 5'-Biotin GGCTTTCCTCCACTGTTGC C5 W1282X 5'-Biotin GGCTTTCCTTCACTGTTGC C6 1717-1G 5'-Biotin TGGAGATGTCCTATTACCAA C7 1717-1G→A 5'-Biotin TGGAGATGTCTTATTACCAA C8 G542 5'-Biotin CCACCTTCTCCAAGAACTAT C9 G542X 5'-Biotin CCACCTTCTCAAAGAACTAT C10 G551 & R553 5'-Biotin CTTGCTCGTTGACCTCCACT C11 G551D 5'-Biotin CTTGCTCGTTGATCTCCACT C12 R553X 5'-Biotin CTTGCTCATTGACCTCCACT C13 R560 5'-Biotin AGTTATTCACCTTGATAAAG C14 R560T 5'-Biotin AGTTATTCACGTTGCTAAAG C15 R117 5'-Biotin CGCGATAGAGCGTTCCTCCT C16 R117H 5'-Biotin CGCGATAGAGTGTTCCTCCT C17 I148 5'-Biotin CTGCATTCCAATGTGATGAA C18 I148T 5'-Biotin CTGCATTCCAGTGTGATGAA C19 621+1G 5'-Biotin GGAAGTATTACCTTCTTATA C20 621+1G→T 5'-Biotin GGAAGTATTAACTTCTTATA C21 N1303 5'-Biotin TTAGAAAAAACTTGGATCCC C22 N1303K 5'-Biotin TTAGAAAAAAGTTGGATCCC C23 1078T 5'-Biotin CTCAGGGTTCTTTGTGGTGT C24 1078delT 5'-Biotin TCTCAGGGTTCTTGTGGTGT C25 R334 5'-Biotin AATCATCCTCCGGAAAATAT C26 R334W 5'-Biotin AATCATCCTCTGGAAAATAT C27 R347 5'-Biotin ATTGTTCTGCGCATGGCGGT C28 R347P 5'-Biotin ATTGTTCTGCCCATGGCGGT C29 711+1G 5'-Biotin TAGGTACATACTTCATCAAA C30 711+1G→T 5'-Biotin TAGGTACATAATTCATCAAA C31 G85 5'-Biotin TAAAAAGATTCCATAGAACA C32 G85E 5'-Biotin TAAAAAGATTTCATAGAACA C33 3849+10kbC 5'-Biotin ATTAAAATGGCGAGTAAGAC C34 3849+10kbC→T 5'-Biotin ATTAAAATGGTGAGTAAGAC C35 A455 5'-Biotin CAGTTGTTGGCGGTTGCTGG C36 A455E 5'-Biotin CAGTTGTTGGAGGTTGCTGG C37 R1162 5'-Biotin ATCTGTGAGCCGAGTCTTTA C38 R1162X 5'-Biotin ATCTGTGAGCTGAGTCTTTA (Continued) Rapid CF Screening by xMAPTM 153 Table 3 (Continued) Target Target sequence Modification Sequence 5' → 3' C39 3659C 5'-Biotin GGTAAACCTACCAAGTCAAC C40 3659delC 5'-Biotin AGGTAAACCTACAAGTCAAC C41 2789+5G 5'-Biotin ACATGGAATACTCACTTTCC C42 2789+5G→A 5'-Biotin ACATGGAATATTCACTTTCC C43 2184A 5'-Biotin AAGATTGTTTTTTTGTTTCT C44 2184delA 5'-Biotin AAGATTGTTTTTTGTTTCTG C45 1898+1G 5'-Biotin AAAGAACATACCTTTCAAAT C46 1898+1G→A 5'-Biotin AAAGAACATATCTTTCAAAT C47 3120+1G 5'-Biotin TTTTTACATACCTGGATGAA C48 3120+1G→A 5'-Biotin TTTTTACATATCTGGATGAA Reflex panel CR2 I506V 5'-Biotin GAAAATGTCATCTTTGGTGT CR3 I507V 5'-Biotin GAAAATATCGTCTTTGGTGT CR4 F508C 5'-Biotin AAAATATCATCTGTGGTGTT CR5 5T 5'-Biotin TCCCTGTTAAAAACACACAC CR6 7T 5'-Biotin CCCTGTTAAAAAAACACACA CR7 9T 5'-Biotin CCTGTTAAAAAAAAACACAC a The position and sequence of the mutation or variation is indicated in bold type. b Target C1 (I507 & F508) is also used in the reflex panel. Login to comment
114 Using a small target DNA (approx 100-300 bp) minimizes the potential for steric hindrance to affect the xMAPTM Table 4 PCR Amplification Primers Size CFTR target Mutation(s) Primer 5' Modification Sequence 5' → 3' (bp) Exon 10 ΔI507, ΔF508, BE10U 5'-Biotin TTCTGTTCTCAGTTTTCCTGG 107 I506V, I507V, E10D None TTGGCATGCTTTGATGACG F508C Exon 20 W1282X E20U None TTGAGACTACTGAACACTGAAGG 126 BE20D 5'-Biotin TTCTGGCTAAGTCCTTTTGC Intron 10 1717-1G→A E11U None TCAGATTGAGCATACTAAAAGTGAC 89 BE11D2 5'-Biotin GAACTATATTGTCTTTCTCTGCAAAC Exon 11 G542X, G551D, E11U2 None AAGTTTGCAGAGAAAGACAATATAG 135 R553X, R560T BE11D 5'-Biotin GAATGACATTTACAGCAAATGC Exon 4 R117H E4U None TTTGTAGGAAGTCACCAAAGC 145 BE4D2 5'-Biotin GAGCAGTGTCCTCACAATAAAGAG Exon 4/intron 4 I148T, E4U2 None CTTCTCTTTATTGTGAGGACACTGC 169 621+1G→T BE4D 5'-Biotin ATGACATTAAAACATGTACGATACAG Exon 21 N1303K BE21U 5'-Biotin TGCTATAGAAAGTATTTATTTTTTCTGG 106 E21D None AGCCTTACCTCATCTGCAAC Exon 7 1078delT, BE7U 5'-Biotin GAACAGAACTGAAACTGACTCG 199 R334W, R347P E7D3 None CAGGGAAATTGCCGAGTG Intron 5 711+1G→T I5U None CAACTTGTTAGTCTCCTTTCC 99 BI5D2 5'-Biotin AGTTGTATAATTTATAACAATAGTGC Exon 3 G85E E3U None CTGGCTTCAAAGAAAAATCC 117 BE3D2 5'-Biotin TGAATGTACAAATGAGATCCTTACC Chromosome 7 3849+10kbC→T BC7U 5'-Biotin GACTTGTCATCTTGATTTCTGG 148 C7D None TTTGGTGCTAGCTGTAATTGC Exon 9 A455E BE9U 5'-Biotin TCACTTCTTGGTACTCCTGTCC 105 E9D None CAAAAGAACTACCTTGCCTGC Exon 19-I R1162X BE19U 5'-Biotin ATTGTGAAATTGTCTGCCATTC 167 E19Da None CAATAATCATAACTTTCGAGAGTTG Exon 19-II 3659delC BE19U2 5'-Biotin TTTAAGTTCATTGACATGCCAAC 91 E19Da None CAATAATCATAACTTTCGAGAGTTG Intron 14B 2789+5G→A I14BU None GTGTCTTGTTCCATTCCAGG 147 BI14BD 5'-Biotin TGGATTACAATACATACAAACATAGTGG Exon 13 2184delA E13U None AGATGCTCCTGTCTCCTGG 126 BE13D 5'-Biotin TGCACAATGGAAAATTTTCGTATAG Intron 12 1898+1G→A I12U None TTAGACTCTCCTTTTGGATACC 110 BI12D 5'-Biotin GTCTTTCTTTTATTTTAGCATGAGC Intron 16 3120+1G→A I16U None ATGACCTTCTGCCTCTTACC 118 BI16D 5'-Biotin ATGAAAACAAAATCACATTTGC Intron 8 5T/7T/9T I8U None TAATGGATCATGGGCCATGTGC 212 BI8D 5'-Biotin ACTGAAGAAGAGGCTGTCATCACC CFTR, cystic fibrosis transmembrane conductance regulator gene. Login to comment
119 Coriell Cell Repositories, NA12960 ΔI507/R347P Patient sample G551D/R347P Coriell Cell Repositories, NA12785 621+1G→T/711+1G→T Coriell Cell Repositories, NA11280 621+1G→T/G85E Coriell Cell Repositories, NA11282 3849+10kbC→T/3849+10kbC→T Coriell Cell Repositories, NA11860 A455E/normal Patient sample 621+1G→T/A455E Coriell Cell Repositories, NA11290 R1162X/normal Coriell Cell Repositories, NA12585 ΔF508/3659delC Coriell Cell Repositories, NA11275 2789+5G→A/2789+5G→A Coriell Cell Repositories, NA11859 2184delA/normal Patient sample 1898+1G→A/normal Patient sample 621+1G→T/3120+1G→A Coriell Cell Repositories, NA07441 3120+1G→A/3120+1G→A Patient sample F508C/normal Coriell Cell Repositories, NA13033 I506V/normal Coriell Cell Repositories, NA13032 R347H/normal Patient sample ΔF508/3120G→A Patient sample S549N/normal Patient sample S549R/normal Patient sample CFTR, cystic fibrosis transmembrane conductance regulator gene. Login to comment

[hide] High heterogeneity of CFTR mutations and unexpecte... J Cyst Fibros. 2004 Dec;3(4):265-72. des Georges M, Guittard C, Altieri JP, Templin C, Sarles J, Sarda P, Claustres M
High heterogeneity of CFTR mutations and unexpected low incidence of cystic fibrosis in the Mediterranean France.
J Cyst Fibros. 2004 Dec;3(4):265-72., [PMID:15698946]

Abstract [show]
In this report, we present updated spectrum and frequency of mutations of the CFTR gene that are responsible for cystic fibrosis (CF) in Languedoc-Roussillon (L-R), the southwestern part of France. A total of 75 different mutations were identified by DGGE in 215 families, accounting for 97.6% of CF genes and generating 88 different mutational genotypes. The frequency of p.F508del was 60.23% in L-R versus 67.18% in the whole country and only five other mutations (p.G542X, p.N1303K, p.R334W, c.1717-1G>A, c.711+1G>T) had a frequency higher than 1%. The mutations were scattered over 20 exons or their border. This sample representing only 5.7% of French CF patients contributed to 24% of CFTR mutations reported in France. This is one of the highest molecular allelic heterogeneity reported so far in CF. We also present the result of a neonatal screening program based on a two-tiered approach "IRT/20 mutations/IRT" analysis on blood spots, implemented in France with the aim to improve survival and quality of life of patients diagnosed before clinical onset. This 18-month pilot project showed an unexpected low incidence of CF (1/8885) in South of France, with only six CF children detected among 43,489 neonates born in L-R, and 13 among 125,339 neonates born in Provence-Alpes-Cote-d'Azur (PACA).

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38 The 20 most common mutations responsible for CF worldwide were investigated by amplification refractory mutation system (ARMS) and migration on agarose gel (Kit Elucigene CF20, including mutations c.1717-1GNA, p.G542X, p.W1282X, p.N1303K, p.F508del, c.3849+10kbCNT, c.621+1GNT, p.R553X, p.G551D, p.R117H, p.R1162X, p.R334W, p.A455E, c.2183AANG, c.3659delC, c.1078delT, p.I507del, p.R347P, p.S1251N, p.E60X). Login to comment
68 of chromosomes (frequency %) p.M1V 1 1 (0.23) p.M1K 1 1 (0.23) c.300delA 3 1 (0.23) p.P67L 3 1 (0.23) c.359insT 3 1 (0.23) p.G85E 3 3 (0.70) c.394delTT 3 1 (0.23) p.Q98R 4 1 (0.23) p.R117H 4 2 (0.47) p.Y122X 4 2 (0.47) p.Y161N 4 1 (0.23) c.621+1GNT intron 4 1 (0.23) c.621+2TNG intron 4 1 (0.23) p.I175V 5 2 (0.47) c.711+1GNT intron 5 5 (1.16) p.L206W 6 3 (0.70) p.Q220X 6 1 (0.23) p.L227R 6 1 (0.23) c.1078delT 7 2 (0.47) p.R334W 7 7 (1.63) p.R347P 7 2 (0.47) c.1215delG 7 1 (0.23) c.T5 intron 8 1 (0.23) p.D443Y 9 1 (0.23) p.I506T 10 1 (0.23) p.I507del 10 4 (0.93) p.F508del 10 259 (60.23) p.F508C 10 1 (0.23) c.1677delTA 10 1 (0.23) c.1717-8GNA intron 10 1 (0.23) c.1717-1GNA intron 10 6 (1.40) p.G542X 11 23 (5.35) p.S549R 11 1 (0.23) p.G551D 11 2 (0.47) p.R553X 11 1 (0.23) c1811+1.6kbANG intron 11 4 (0.93) c.1812-1GNA intron 11 1 (0.23) p.T582I 12 1 (0.23) p.E585X 12 2 (0,47) c.1898+1GNA intron 12 1 (0.23) [c.1898+5GNA ;p.E725K] intron 12 1 (0.23) c.1898+73TNG intron 12 1 (0.23) c.2183AANG 13 4 (0.93) c.2184insA 13 1 (0.23) p.K710X 13 4 (0.93) c.2423delG 13 1 (0.23) p.S776X 13 1 (0.23) c.2493ins8 13 1 (0.23) p.R792X 13 1 (0.23) p.K830X 13 1 (0.23) p.D836Y 14a 1 (0.23) p.W846X1 14a 1 (0.23) c.2711delT 14a 1 (0.23) c.2789+5GNA intron 14b 3 (0.70) p.S945L 15 3 (0.70) p.D993Y 16 1 (0.23) c.3129del4 17a 1 (0.23) c.3195del6 17a 1 (0.23) c.3272-26ANG intron 17a 1 (0.23) [c.3395insA ;pI148T] 17b/4 1 (0,23) p.Y1092X 17b 3 (0.70) Table 1 (continued) Mutation Location exon/intron No. Login to comment
131 The panel of 30 mutations (c.1717-1GNA, p.G542X, p.W1282X, p.N1303K, p.F508del, c.3849+10kbCNT, c.621+1GNT, p.R553X, p.G551D, p.R117H, p.R1162X, p.R334W, p.A455E, c.2183AANG, c.3659delC, c.1078delT, p.I507del, p.R347P, p.S1251N, p.E60X, p.Y1092X, c.394delTT, c.1811+1.6kbANG, c.3272-26ANG, c.2789+5GNA, c.3120+1GNA, c.711+ 1GNT, p.G85E, p.Y122X, p.W846X) should account for 83.32% of the CF alleles in L-R and 84.25% in the whole country. Login to comment

[hide] Microsphere bead arrays and sequence validation of... J Mol Diagn. 2004 Nov;6(4):348-55. Hadd AG, Laosinchai-Wolf W, Novak CR, Badgett MR, Isgur LA, Goldrick M, Walkerpeach CR
Microsphere bead arrays and sequence validation of 5/7/9T genotypes for multiplex screening of cystic fibrosis polymorphisms.
J Mol Diagn. 2004 Nov;6(4):348-55., [PMID:15507674]

Abstract [show]
The development of simple and rapid methods for the detection of the common genetic mutations associated with cystic fibrosis (CF) requires access to positive-control samples including the 5/7/9T variants of intron 8. We used PCR and a simple multiplex bead-array assay to identify 5/7/9T control samples from 29 commercially available DNA samples. Unpurified PCR products were directly hybridized to color-coded beads containing allele-specific capture probes for 5/7/9T detection. The performance of the assay was investigated using reverse-complement oligonucleotides, individual PCR products, and multiplex PCR products for 5/7/9T detection within a complex CFTR screening assay. Samples were genotyped by grouping the relative signal intensities from each capture probe. Of 29 commercially available DNA samples analyzed, 2 5T/7T, 2 5T/9T, 9 7T/9T, 11 7T/7T, and 5 9T/9T genotypes were identified. The genotype within each sample group was confirmed by DNA sequencing. The assay was compatible with the analysis of 10 to 1000 ng of genomic DNA isolated from whole blood and allowed for the separate identification of primary CFTR mutations from reflex variants. The correct identification of positive controls demonstrated the utility of a simple bead-array assay and provided accessible samples for assay optimization and for routine quality control in the clinical laboratory.

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197 Intron 8 Genotype by Coriell Number, Characterized CF Mutation and Allele Fraction for 5/7/9T Intron 8 genotype Coriell sample Characterized mutation Allele fraction by probe 5T 7T 9T 7T/7T NA09947 Normal 0.04 0.93 0.03 NA11277 ⌬I507/normal 0.06 0.90 0.04 NA11761 G551D/R553X 0.06 0.92 0.02 NA11859 2789ϩ5GϾA/2789ϩ5GϾA 0.02 0.96 0.02 NA11860 3849ϩ10kbCϾT/3849ϩ10kbCϾT 0.03 0.94 0.03 NA12444 1717-1GϾT/normal 0.06 0.87 0.07 NA12585 R1162X/normal 0.07 0.86 0.08 NA12785 R347P/G551D 0.04 0.92 0.05 NA12960 R334W/normal 0.06 0.92 0.02 NA12961 V520F/normal 0.06 0.89 0.05 NA13033 F508C/normal 0.03 0.93 0.04 9T/9T NA01531 ⌬F508/⌬F508 0.14 0.04 0.82 NA11281 621ϩ1GϾT/⌬F508 0.14 0.04 0.82 NA11283 A455E/⌬F508 0.13 0.05 0.82 NA11290 A455E/621ϩ1GϾT 0.12 0.01 0.87 NA11496 G542X/G542X 0.14 0.05 0.81 5T/7T NA11723 W1282X/normal 0.53 0.44 0.03 NA13032 I506V/normal 0.58 0.39 0.03 5T/9T NA11279 129GϾC/⌬F508 0.51 0.00 0.49 NA13591 R117H/⌬F508 0.52 0.00 0.48 7T/9T NA07441 3120ϩ1GϾA/621ϩ1GϾA 0.08 0.41 0.51 NA07552 R553X/⌬F508 0.09 0.36 0.55 NA07830 556dA/⌬F508 0.11 0.37 0.52 NA11275 3659dC/⌬F508 0.10 0.37 0.53 NA11278 Q493X/⌬F508 0.09 0.38 0.53 NA11280 711ϩ1GϾT/621ϩ1GϾA 0.09 0.37 0.54 NA11282 G85E/621ϩ1GϾA 0.07 0.39 0.53 NA11284 R560T/⌬F508 0.08 0.39 0.52 NA11472 N1303K/G1349D 0.08 0.39 0.54 Figure 3. Login to comment

[hide] Long-range (17.7 kb) allele-specific polymerase ch... J Mol Diagn. 2004 Aug;6(3):264-70. Pont-Kingdon G, Jama M, Miller C, Millson A, Lyon E
Long-range (17.7 kb) allele-specific polymerase chain reaction method for direct haplotyping of R117H and IVS-8 mutations of the cystic fibrosis transmembrane regulator gene.
J Mol Diagn. 2004 Aug;6(3):264-70., [PMID:15269305]

Abstract [show]
Genotyping of genetic polymorphisms is widely used in clinical molecular laboratories to confirm or predict diseases due to single locus mutations. In contrast, very few molecular methods determine the phase or haplotype of two or more mutations that are kilobases apart. In this report, we describe a new method for haplotyping based on long-range allele-specific PCR. Reaction conditions were established to circumvent the incompatibility of using allele-specific primers and a polymerase with proofreading activity. Haplotypes are determined by post-PCR analysis using different detection methods. The clinical application presented here directly determines the phase of two mutations separated by 17.7 kilobases in the cystic fibrosis transmembrane conductance regulator gene. Each mutation, the missense mutation R117H in exon 4 and the 5T polymorphism in intron 8 (IVS-8), have mild phenotypic effect unless they are present on the same chromosome (in cis). If an individual is heterozygous for both R117H and the IVS-8 5T variant, cis/trans testing is required to completely interpret results. The molecular method presented here bypasses the need to perform family studies to establish haplotypes. We propose use of this assay as a reflex clinical test for R117H- 5T-positive samples.

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110 Mutations at these positions (621 ϩ 1G Ͼ T, 711 ϩ 1G Ͼ T, R347P, I148T, R334W, and 1078delT) could be detected and associated with one of the haplotypes. Login to comment

[hide] Pancreatitis in hispanic patients with cystic fibr... Clin Gastroenterol Hepatol. 2004 Jun;2(6):504-9. Maisonneuve P, Campbell P 3rd, Durie P, Lowenfels AB
Pancreatitis in hispanic patients with cystic fibrosis carrying the R334W mutation.
Clin Gastroenterol Hepatol. 2004 Jun;2(6):504-9., [PMID:15181620]

Abstract [show]
BACKGROUND & AIMS: Cystic fibrosis (CF) results from abnormal production of sticky mucus, which obstructs many organs. In most cases, the pancreas is severely compromised, but 10%-15% of patients with CF have pancreas sufficiency (PS) and are subject to develop pancreatitis. The aim of this study is to determine which specific genotypes lead to the development of pancreatitis in patients with CF. METHODS: We used prospective data collected by the Cystic Fibrosis Foundation and performed a nested case-control study with all patients who reported at least 1 episode of pancreatitis constituting the cases. We used logistic regression to assess the association between pancreatitis and genotype and the Kaplan-Meier method to estimate the cumulative incidence of pancreatitis for selected genotypes. RESULTS: Three hundred sixty-four of 17,871 genotyped patients with CF (2.0%) reported at least 1 episode of pancreatitis. Only 0.9% of 12,997 patients with genotypes generally associated with pancreas insufficiency reported pancreatitis against 11.9% of 868 patients carrying at least 1 mild CF mutation generally associated with PS. The greatest rate of pancreatitis (19.0%) was observed for patients carrying an R334W mutation: 48% of these 79 patients were Hispanic and 13 patients were living in Puerto Rico. CONCLUSIONS: Of all patients with CF, those carrying an R334W mutation have the greatest risk for developing pancreatitis. This mutation is found mostly in Hispanic patients with CF living in Puerto Rico. There are no current data to determine whether asymptomatic carriers of the R334W mutation are at greater risk for developing pancreatitis or whether this mutation is frequent in Hispanics with idiopathic pancreatitis.

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26 Of Ͼ1000 identified mutations in the CFTR gene, only 25 proven disease-causing mutant alleles (⌬F508, G551D, G542X, R553X, W1282X, R347P, NI303K, R560T, ⌬I507, 1717-1GϾA, A455E, 3120ϩ1GϾA, 621ϩ1GϾT, R117H, 711ϩ1GϾT, R1162X, 3849ϩ10kbCϾT, 2789ϩ5GϾT, R334W, G85E, 1078delT, 1898ϩ1GϾT, 2184delA, 3659delC, and I148T) are recommended by the American College of Medical Genetics for routine diagnostic and carrier testing.16 Most of these are routinely recorded in the CFF registry, but rarer mutations can be recorded if identified by more comprehensive testing. Login to comment
28 Patients were classified according to their genotype: those carrying 2 severe mutations (⌬F508, ⌬I507, G542X, G551D, N1303K, R553X, R560T, R1162X, W1282X, 621ϩ1GϾT, 711ϩ1GϾT, 1717-1GϾA, 2184delA, and 3659delC), which generally are associated with pancreas insufficiency (PI); and those carrying at least 1 mild mutation (3849ϩ10kbCϾT, R117H, 2789ϩ5GϾA, R347P, R334W, and A455E), which are generally associated with PS. Login to comment
42 The greatest frequency of pancreatitis was reported in patients carrying at least 1 R334W mutation (19.0%), followed by patients with a 2789ϩ5GϾA mutation (14.9%), R117H mutation (11.7%), R347P mutation (11.6%), 3849ϩ10kbCϾT mutation (9.0%), A455E mutation (8.3%), or G85E mutation (8.0%; Table 1). Login to comment
47 This sex difference was unique for R334W and was not apparent for patients with other pancreatitis-related genotypes (R347P, R117H, G85E, 2789ϩ5GϾA, or 3849ϩ10kbCϾT) or for patients with pancreatitis in the PI group. Login to comment
59 Other mutants, such as R117H, R334W, and R347P, which are correctly processed and retain some residual apical chloride channel function, are associated with a milder form of the disease.20,21 However, the vast majority of CF centers in Europe and the United States do not formally assess pancreatic function at diagnosis, and many assume that a patient with a diagnosis of CF has PI and requires enzyme supplements. Login to comment
64 of patients Patients with pancreatitis At least 1 attack of pancreatitis Ն2 attacks of pancreatitis All genotyped patients with CF 17,871 364 (2.0) - - Pancreas insufficienta 12,997 114 (0.9) 1.0 (reference) 1.0 (reference) Pancreas sufficientb 868 103 (11.9) 9.3 (6.7-12.8) 14.8 (8.2-26.8) 3849ϩ10kbCϾT/anyc 256 23 (9.0) 5.3 (3.1-9.0) 7.1 (2.8-18.3) R117H/anyc 249 29 (11.7) 8.9 (5.5-14.5) 14.1 (6.1-32.7) 2789ϩ5GϾA/anyc 134 20 (14.9) 13.2 (7.3-23.8) 10.4 (3.1-35.5) R347P/anyc 95 11 (11.6) 11.1 (5.3-23.1) 26.6 (9.1-77.4) R334W/anyc,d 79 15 (19.0) 25.8 (13.2-50.5) 43.6 (15.3-124) A455E/anyc 60 5 (8.3) 3.4 (2.6-4.4) 18.3 (5.0-67.9) Genotype incompletely determinede 4006 147 (3.7) 3.4 (2.6-4.4) 6.3 (3.8-10.5) NOTE. Values expressed as number (percent) or odds ratio (95% confidence interval). Login to comment
68 bPatients with pancreas sufficiency (PS) carrying at least 1 PS mutation (3849ϩ10kbCϾT, R117H, 2789ϩ5GϾA, R347P, R334W, A455E). Login to comment

[hide] Therapeutic approaches to repair defects in deltaF... Adv Drug Deliv Rev. 2002 Dec 5;54(11):1395-408. Powell K, Zeitlin PL
Therapeutic approaches to repair defects in deltaF508 CFTR folding and cellular targeting.
Adv Drug Deliv Rev. 2002 Dec 5;54(11):1395-408., [PMID:12458151]

Abstract [show]
The deltaF508 mutation in the cystic fibrosis transmembrane regulator (CFTR) gene is the most common mutation in CF. The mutant CFTR protein is defective with respect to multiple functions including cAMP-regulated chloride conductance, nucleotide transport, and regulatory actions on other ion channels. Since the deltaF508 protein is also temperature-sensitive and unstable during translation and folding in the endoplasmic reticulum (ER), most of the nascent chains are targeted for premature proteolysis from the ER. This paper focuses on the events that occur in the ER during folding and reviews potential targets for therapeutic intervention.

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95 Cyclic R334W, R347P) result in a CFTR that reaches the AMP activated chloride conductance was present for plasma membrane but has reduced chloride conduct- cells grown at 30 8C but not at 37 8C. Login to comment
96 Cyclic R334W, R347P) result in a CFTR that reaches the AMP activated chloride conductance was present for plasma membrane but has reduced chloride conduct- cells grown at 30 8C but not at 37 8C. Login to comment

[hide] Genotype and phenotype correlations in patients wi... Gastroenterology. 2002 Dec;123(6):1857-64. Durno C, Corey M, Zielenski J, Tullis E, Tsui LC, Durie P
Genotype and phenotype correlations in patients with cystic fibrosis and pancreatitis.
Gastroenterology. 2002 Dec;123(6):1857-64., [PMID:12454843]

Abstract [show]
BACKGROUND & AIMS: Pancreatitis is known to occur in some patients with cystic fibrosis (CF), but the prevalence, natural history, and genotypic basis are unclear. We examined a well-defined cohort of patients with CF to answer these questions. METHODS: Patients with CF were identified from a computerized database (1966-1996). Chart audit identified all patients with CF and pancreatitis. RESULTS: Among 1075 patients with CF, 937 (87%) were pancreatic insufficient at diagnosis, 28 (3%) were pancreatic sufficient but developed pancreatic insufficiency after diagnosis, and 110 (10%) have remained pancreatic sufficient. No patients with pancreatic insufficiency developed pancreatitis. Nineteen patients (17.3%) with pancreatic sufficiency experienced one or more attacks of pancreatitis. The mean age at diagnosis of pancreatitis was 22.7 +/- 10.3 years (range, 10-35 years), and pancreatitis was recognized before the diagnosis of CF in 6 patients (32%). The diagnosis of CF in pancreatic-sufficient patients, with and without pancreatitis, was established at a significantly older age than in those with pancreatic insufficiency (P < 0.0001). Genotyped patients with pancreatic insufficiency carried 2 severe mutant alleles. All genotyped patients with pancreatic sufficiency and pancreatitis carried at least one mild mutation. No specific genotype was predictive of pancreatitis. CONCLUSIONS: Patients with CF with pancreatic sufficiency carry at least one mild mutant allele and are at a significant risk of developing pancreatitis. Symptoms of pancreatitis may precede the diagnosis of CF. Pancreatitis is associated with an otherwise mild CF phenotype.

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105 CFTR Genotypes Among CF Patients With PS With and Without Pancreatitis Two mutations (n) ⌬F508/R117H (9) ⌬F508/(5T) (6) ⌬F508/3272-26A 3 G (4) ⌬F508/R347H (2) ⌬F508/P574H (2) ⌬F508/875 ϩ 1G Ͼ C (2) ⌬F508/3849 ϩ 10kb C 3 T (1) ⌬F508/A455E (1) ⌬F508/D614G (1) ⌬F508/G85E (1) ⌬F508/R347P (1) ⌬F508/S1251N (1) ⌬F508/⌬F508a (1) ⌬F508/3120G Ͼ A (1) ⌬F508/G551Da (1) G542X/R117H (1) R560T/L206W (1) R117H/R117H (1) R31L/P67L (1) 1461ins4 (AGAT)/G85E (1) G551D/(5T) (1) R1066C/3849 ϩ 10kb C Ͼ T (1) G551D/3849 ϩ 10kb C Ͼ T (1) R334W/R334W (1) R334W/681delC (1) W1282X/3489 ϩ 10kb C Ͼ T (1) One mutation (n) ⌬F508/- (18) L1077P/- (1) W1282X/- (1) M1137V/- (1) G551D/- (1) R347H/- (1) Q30X1/- (1) G1244E/- (1) R117H/- (1) 621 ϩ 2G621 ϩ 1G 3 T/- (1) NOTE. Login to comment
124 of episodes of pancreatitis Genotype 1 0.3 12 21.7 2 ⌬F508/S1251N 2 0.3 34 30.0 1 ⌬F508/R347H 3 4.4 13 42.5 3 / 4 4.4 21 36.5 1 ⌬F508/ 5 7.3 26 40.8 10 ⌬F508/P67L 6 9.6 29 29.9 (D) 1 ⌬F508/ 7 12.0 18 39.9 1 ⌬F508/R347P 8 12.9 37 40.9 2 G542X/D1152H 9 13.0 30 50.3 1 ⌬F508/3849 ϩ 10Kbc Ͼ T 10 14.7 13 21.5 1 DF508/R117H 11 15.6 34 40.8 1 ⌬F508/2789ϩ5G Ͼ T 12 15.6 10 26.0 10 ⌬F508/R117H 13 16.0 10 22.0 14 ⌬F/508/3849 ϩ 10kbC Ͼ T 14 16.0 18 21.2 (D) 1 R1066C/3849 ϩ 10kbC Ͼ T 15 19.9 15 40.8 5 No DNA 16 23.2 19 23.2 15 ⌬F508/11234V 17 24.1 40 47.6 (D) 1 No DNA 18 26.9 25 43.3 12 No DNA 19 27.4 35 50.3 (D) 2 ⌬F508/A455E NOTE. Login to comment

[hide] Cystic fibrosis and related diseases of the pancre... Best Pract Res Clin Gastroenterol. 2002 Jun;16(3):511-26. Naruse S, Kitagawa M, Ishiguro H, Fujiki K, Hayakawa T
Cystic fibrosis and related diseases of the pancreas.
Best Pract Res Clin Gastroenterol. 2002 Jun;16(3):511-26., [PMID:12079272]

Abstract [show]
The discovery of the gene for cystic fibrosis (CF), the cystic fibrosis transmembrane conductance regulator (CFTR), brought about a new era in the study of this disease. Identification of the molecular target has yielded a flood of data that add to our understanding of the pathogenesis, diagnosis and treatment of CF. The CFTR protein is a cAMP-regulated Cl(-) channel with multiple functions in epithelial cells. In the exocrine pancreas the CFTR plays a key role in the apical Cl(-), HCO(3)(-), and water transport in duct cells. The severe loss of functions, caused by mutations of the CFTR gene, leads to pathological lesions of the pancreas. Over 1200 CFTR mutations and polymorphisms have been identified and their diversity may explain the high level of heterogeneity in the CF phenotype. Mutation analyses of the CFTR gene have revealed a spectrum of CFTR-related diseases that do not fit the classical CF picture but are associated with dysfunction of CFTR, such as chronic pancreatitis.

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62 is observed only when normal CFTR function is less than 1%.13 In general, patients with pancreatic insuciency are homozygous or compound heterozygous for two severe mutations (class I, II or III in Figure 3), such as DF508, DI507, Q493X, G542X, R553X, W1282X, 621 1G 4 T, 1717-1G 4 A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T, whereas the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H (class IV or V).5,20 EXOCRINE PANCREAS IN CYSTIC FIBROSIS Pathology of the pancreas in CF There is a spectrum of pancreatic abnormalities in CF irrespective of age.21,22 Pancreatic lesions may be absent in an individual case, but in long-standing CF the pancreas is small, hard and nodular with increased fat and multiple cysts; hence the name `cystic ®brosis of the pancreas'. Login to comment
64 is observed only when normal CFTR function is less than 1%.13 In general, patients with pancreatic insuQciency are homozygous or compound heterozygous for two severe mutations (class I, II or III in Figure 3), such as DF508, DI507, Q493X, G542X, R553X, W1282X, 621 W 1G 4 T, 1717-1G 4 A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T, whereas the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H (class IV or V).5,20 EXOCRINE PANCREAS IN CYSTIC FIBROSIS Pathology of the pancreas in CF There is a spectrum of pancreatic abnormalities in CF irrespective of age.21,22 Pancreatic lesions may be absent in an individual case, but in long-standing CF the pancreas is small, hard and nodular with increased fat and multiple cysts; hence the name `cystic &#ae;brosis of the pancreas'. Login to comment

[hide] CFTR mutations in three Latin American countries. Am J Med Genet. 2000 Apr 10;91(4):277-9. Restrepo CM, Pineda L, Rojas-Martinez A, Gutierrez CA, Morales A, Gomez Y, Villalobos MC, Borjas L, Delgado W, Myers A, Barrera-Saldana HA
CFTR mutations in three Latin American countries.
Am J Med Genet. 2000 Apr 10;91(4):277-9., [PMID:10766983]

Abstract [show]
We analyzed 192 cystic fibrosis (CF) alleles in three Latin American countries: Mexico, Colombia, and Venezuela. Mutation screening was performed by polymerase chain reaction (PCR) and a reverse dot blot detection kit that enables determination of 16 of the most common CF mutations worldwide. Mutations were detected in 47.9% of the screened CF alleles. The most prevalent CF allele was DeltaF508 (39. 6%). The remaining 16 non-DeltaF508 detectable mutations represented 8.3% of the CF alleles. Among them, the G542X, N1303K, and 3849+10kb C>T were the most common. Although the frequency of DeltaF508 described here is lower than that reported for Caucasian populations, including in Spain, it is remarkable that mutation prevalences found in this study resemble those observed in Spain. Two of these mutations, G542X and 3849+10kb C>T, that were relevant in this analysis, have a particularly high incidence in Spanish communities. The low frequency of DeltaF508 described here may be explained by the Amerindian, Caucasian, and Black admixture that occurred in Latin America after the discovery of the New World, and also by the probable occurrence of mutations contributed by the original natives, which were undetectable in this analysis.

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34 The isolated DNA from each patient was amplified by polymerase chain reaction (PCR) using a kit for reverse dot blot detection of 16 common CF mutations: ⌬F508, R553X, G542X, G551D, N1303K, W1282X, R117H, R334W, R347P, A455E, ⌬I507, 1717-1 G>A, R560T, 3849+10kb C>T, 621+1 G>T, S549N [Villalobos-Torres et al., 1997]. Login to comment

[hide] Spectrum of CFTR mutations in cystic fibrosis and ... Hum Mutat. 2000;16(2):143-56. Claustres M, Guittard C, Bozon D, Chevalier F, Verlingue C, Ferec C, Girodon E, Cazeneuve C, Bienvenu T, Lalau G, Dumur V, Feldmann D, Bieth E, Blayau M, Clavel C, Creveaux I, Malinge MC, Monnier N, Malzac P, Mittre H, Chomel JC, Bonnefont JP, Iron A, Chery M, Georges MD
Spectrum of CFTR mutations in cystic fibrosis and in congenital absence of the vas deferens in France.
Hum Mutat. 2000;16(2):143-56., [PMID:10923036]

Abstract [show]
We have collated the results of cystic fibrosis (CF) mutation analysis conducted in 19 laboratories in France. We have analyzed 7, 420 CF alleles, demonstrating a total of 310 different mutations including 24 not reported previously, accounting for 93.56% of CF genes. The most common were F508del (67.18%; range 61-80), G542X (2.86%; range 1-6.7%), N1303K (2.10%; range 0.75-4.6%), and 1717-1G>A (1.31%; range 0-2.8%). Only 11 mutations had relative frequencies >0. 4%, 140 mutations were found on a small number of CF alleles (from 29 to two), and 154 were unique. These data show a clear geographical and/or ethnic variation in the distribution of the most common CF mutations. This spectrum of CF mutations, the largest ever reported in one country, has generated 481 different genotypes. We also investigated a cohort of 800 French men with congenital bilateral absence of the vas deferens (CBAVD) and identified a total of 137 different CFTR mutations. Screening for the most common CF defects in addition to assessment for IVS8-5T allowed us to detect two mutations in 47.63% and one in 24.63% of CBAVD patients. In a subset of 327 CBAVD men who were more extensively investigated through the scanning of coding/flanking sequences, 516 of 654 (78. 90%) alleles were identified, with 15.90% and 70.95% of patients carrying one or two mutations, respectively, and only 13.15% without any detectable CFTR abnormality. The distribution of genotypes, classified according to the expected effect of their mutations on CFTR protein, clearly differed between both populations. CF patients had two severe mutations (87.77%) or one severe and one mild/variable mutation (11.33%), whereas CBAVD men had either a severe and a mild/variable (87.89%) or two mild/variable (11.57%) mutations.

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102 Distribution of 310 CF Mutations in France With Respect to Relative Frequencies (Total Number of CF Chromosomes = 7,420) Group Mutations Number of alleles % Cum. % A F508del 4,985 67.18 G542X 212 2.86 N1303K 156 2.10 73.45 1717-1G>A 97 1.31 B G551D 73 0.98 2789+5G>A 72 0.97 W1282X 68 0.91 R553X 66 0.89 I507del 52 0.70 1078delT 49 0.66 7.47 2183AA>G 48 0.64 711+1G>T 33 0.44 R1162X 33 0.44 Y1092X 30 0.40 3849+10kbC>T 30 0.40 C 12 mutationsa 29 to 15 (239) 0.39-0.20 19 mutationsb 14 to 8 (190) 0.19-0.10 11 mutationsc 7 to 6 (71) 0.09-0.08 11 mutationsd 5 (55) 0.06 10.57 15 mutationse 4 (60) 0.05 23 mutationsf 3 (69) 0.04 50 mutationsg 2 (100) 0.02 D 154 mutationsh 1 (154) 0.01 2.07 6,942 93.56 a 3659delC, R347P, 3272-26A>G, R334W, W846X, 621+1G>T, G85E, R1066C, L206W, 394delTT, 4055+1G>A, R347H. Login to comment
140 Non-F508del Mutations Found as Homozygous in a Sample of 3,710 Patients With Cystic Fibrosis Mutation n 711+1G>T 8 G542X 7 N1303K 7 2183delAA>G 5 W1282X 4 G551D 3 3905insT 3 R334W 2 R347P 2 1078delT 2 1811+1.6kbA>G 2 2113delA 2 Y1092X 2 R1162X 2 306insA 1 E92K 1 G178R 1 L227R 1 1677delTA 1 1717-1G>A 1 1717-8G>A 1 R553X 1 S549R(T>G) 1 R560S 1 V562I 1 Y569D 1 2711delT 1 S945L 1 R1158X 1 I1234V 1 3849+10kbC>T 1 Q1313X 1 del25kb 1 E831X 1 I175V 1 G314V 1 L1077P 1 produce a small quantity of functional protein as a result of a variable proportion of normal CFTR mRNA transcripts in addition to the abnormal ones (class V); 3) they are located in sites known to generate less severe mutants (external loops, residues lining the pore); and/or 4) they have been observed in CF with pancreatic sufficiency, CBAVD, and/or CF-related attenuated phenotypes only. Login to comment

[hide] A comparison of fluorescent SSCP and denaturing HP... Hum Mutat. 2000;15(6):556-64. Ellis LA, Taylor CF, Taylor GR
A comparison of fluorescent SSCP and denaturing HPLC for high throughput mutation scanning.
Hum Mutat. 2000;15(6):556-64., [PMID:10862085]

Abstract [show]
We examined 67 different mutations in 16 different amplicons in a comparison of mutation detection by fluorescent single strand conformation polymorphism (F-SSCP) and by denaturing HPLC (DHPLC). F-SSCP was used to analyze fluorescent amplicons with internal size standards and automated fragment analysis (GeneScan, PE Applied Biosystems, Foster City, CA). In DHPLC, unlabelled amplicons were analyzed by reverse phase HPLC with fragment detection by absorbance at 260nm. Both methods had high sensitivity (95-100%) and specificity (100%). Overall, F-SSCP with external temperature control was the more sensitive method, but DHPLC was particularly useful for the rapid analysis of novel fragments.

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97 Comparison of F-SSCP and DHPLC Using a Panel of ABCC7 Mutations Gel condition Location Location 49:1 49:1 49:1 49:1 MDE MDE MDE Capillary DHPLC °C from 5' (bp) from 3' (bp) 15 20 25 35 20 25 35 35 N/A Exon 3 (320bp) E60X 128 192 + + + + + + + + - P67L 150 170 + + + - + + + - + R75X 173 147 + + + + + + + + + R75Q 174 146 + + + - + + + + + G85E 204 116 + + + - + + + + + L88S 213 107 + + + + + + + + + Exon 4 (400bp) 441delA 135 265 + + + + + + + + + D110H 154 246 + + + + + + - + + R117H/H 176 224 + + + + + + + + N/A R117R/H 176 224 + + + + + + + + + L137H 236 164 + + + + + + + + + I148T 261 139 + + + + + + + + + 621+1 (G>T) 309 91 + + + + + + + + + Exon 7 (360bp) R334W 180 180 + + + + + + + - + 1058delC 105 255 + + + + + + + + + 1078delT 125 235 + + + - + + + + + 1138insG 226 134 - + + - + + + + + 1154insTC 202 158 + + + + + + + + + 1161delC 209 151 + + + + + + + + + R347H 220 140 + + + + + + - + + R347P 220 140 + + + - + + + - + A349V 226 134 + + + + + + + + + W356X 248 112 + + + + + + + + + Exon 10 (365bp) M470V 143 222 + + + + + + + + + Q493X 212 153 + + + + + + - + - DelF508 255 110 + + + + + + + + - Del I507 253 112 + + + + + + + + + V520F 293 72 + + - + + - + - + Exon 11 (190bp) 1717-1 (G>A) 54 136 + + + - + + - + + G542X 94 96 + + + - + + - + + S549N 116 74 + + + + + + + + - S549R 117 73 + + + + - - - + + G551D 122 68 + - - - + + + - + R553X 127 63 + + + + + + + + + G551D/R553X + + + + + + + + + R560T 149 41 + + + - - - - - + R560K 149 41 + + + - + + + - + 1811+1 (G>C) 150 40 + + + + + + + + + Exon 12 (250bp) 1898+1(G>A) 167 83 + + + + + + - + + Exon 13a (290bp) C590W 87 203 + + - - + - - + + Exon 13b (405bp) 2184insA 148 257 + + + + + + + - + R709X 220 185 - + - - - - - - + V754M 453 52 + + + + + + + - - Exon 13c (345bp) V754M 65 280 + + + + + + - - + R785X 158 187 + + - - + + - - + Exon 19 (370bp) 3601-17 (T>C) 29 341 - + + - + + + - + R1162X 61 309 + + - - + - - + + 3659delC 105 265 - - - + + + + + + Y1182X 123 247 - + + - + + + - + Exon 20 (370bp) W1282X 186 184 + + + + + + + + + % detected 90 96 86 66 94 88 74 72 90 remainder were detected using DGGE. Login to comment

[hide] Cystic fibrosis: a multiple exocrinopathy caused b... Am J Med. 1998 Jun;104(6):576-90. Schwiebert EM, Benos DJ, Fuller CM
Cystic fibrosis: a multiple exocrinopathy caused by dysfunctions in a multifunctional transport protein.
Am J Med. 1998 Jun;104(6):576-90., [PMID:9674722]

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243 Other mutations in TMD1 which affect function and cause disease include other arginines in predicted ␣-helix 6, R334W, R347P, and R347E (97,98) and a glycine, G314E, in ␣-helix 5 (99). Login to comment

[hide] Topological model of membrane domain of the cystic... J Mol Graph Model. 1998 Apr;16(2):72-82, 97-8. Gallet X, Festy F, Ducarme P, Brasseur R, Thomas-Soumarmon A
Topological model of membrane domain of the cystic fibrosis transmembrane conductance regulator.
J Mol Graph Model. 1998 Apr;16(2):72-82, 97-8., [PMID:9879057]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator is a cAMP-regulated chloride channel. We used molecular modelling to predict 3-D models for the CFTR membrane domain. Hydropathy and residue conservation in all CFTRs as well as in other proteins suggested that the membrane domain is a 12-helix bundle. If the domain is enclosing a channel for chloride, it could be made of five helices. We propose two structural models in which both lumenal and cytoplasmic entrances to the chloride pore have a ring of positively charged residues. The inner surface of the channel is covered with neutral polar plus one or two charged residues. Helices that are not directly involved in the chloride channel could organise to form a second channel; a dimeric symmetrical structure is proposed. Analysis raised interest for helix 5: this hydrophobic fragment is conserved in all CFTRs and aligns with segments present in several different ion channels and transporters. The existence of an FFXXFFXXF motif is proposed. Helix 5 could be an important domain of CFTRs. The models agree with available data from pathological mutations but does not account for the membrane insertion of a hydrophilic fragment of NBDI.

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232 Mutations associated with mild forms of cystic fibrosis (R117H, R334W, and R347P) implicate three of our inner pore residues in the chloride conductance.50 In other studies, basic amino acids of membrane helices were replaced by acidic residues (K95D, K335E, R347E, and R1030E). Login to comment
236 Mutations associated with mild forms of cystic fibrosis (R117H, R334W, and R347P) implicate three of our inner pore residues in the chloride conductance.50 In other studies, basic amino acids of membrane helices were replaced by acidic residues (K95D, K335E, R347E, and R1030E). Login to comment

[hide] Chloride channel and chloride conductance regulato... Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2674-9. Schwiebert EM, Morales MM, Devidas S, Egan ME, Guggino WB
Chloride channel and chloride conductance regulator domains of CFTR, the cystic fibrosis transmembrane conductance regulator.
Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2674-9., [PMID:9482946]

Abstract [show]
CFTR is a cyclic AMP (cAMP)-activated chloride (Cl-) channel and a regulator of outwardly rectifying Cl- channels (ORCCs) in airway epithelia. CFTR regulates ORCCs by facilitating the release of ATP out of cells. Once released from cells, ATP stimulates ORCCs by means of a purinergic receptor. To define the domains of CFTR important for Cl- channel function and/or ORCC regulator function, mutant CFTRs with N- and C-terminal truncations and selected individual amino acid substitutions were created and studied by transfection into a line of human airway epithelial cells from a cystic fibrosis patient (IB3-1) or by injection of in vitro transcribed complementary RNAs (cRNAs) into Xenopus oocytes. Two-electrode voltage clamp recordings, 36Cl- efflux assays, and whole cell patch-clamp recordings were used to assay for the Cl- channel function of CFTR and for its ability to regulate ORCCs. The data showed that the first transmembrane domain (TMD-1) of CFTR, especially predicted alpha-helices 5 and 6, forms an essential part of the Cl- channel pore, whereas the first nucleotide-binding and regulatory domains (NBD1/R domain) are essential for its ability to regulate ORCCs. Finally, the data show that the ability of CFTR to function as a Cl- channel and a conductance regulator are not mutually exclusive; one function could be eliminated while the other was preserved.

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41 For null the construct, R334W͞R347P in the transmembrane domain (TMD)-1 background (R334W͞ R347P-TMD-1), the identical mutations were introduced along with a silent NcoI site (as above) as well as a stop codon and an EcoRV site slightly downstream with a longer mutagenic oligonucleotide, 5Ј-GGA ATC ATC CTC TGG AAA ATA TTC ACC ACC ATC TCA TTC TGC ATT GTT CTG CCC ATG GCG GTC ACT CGG CAA TTT CCA TGG GCT GTA CAA ACA TGG TAT GAC TCT CTT GGA GCA ATA AAC TAA ATA CAG GAT ATC TTA C-3Ј. Login to comment
115 Finally, dual Cl- conduction mutations, R334W and R347P (referred to as dual arginine CFTR) were made. Login to comment
123 Cl- currents in CFTR cRNA-injected Xenopus oocytes cRNA injected Current, nA n P valueBasal cAMP-stimulated None -89.3 Ϯ 13.7 -82.7 ee; 13.5 9 NS Wild-type CFTR -117.2 Ϯ 27.7 -828.1 Ϯ 295.7 16 Ͻ0.001 ⌬259-M265 -133.4 Ϯ 27.6 -509.9 Ϯ 159.9 8 Ͻ0.01 ⌬259-M265V -106.2 Ϯ 32.1 -103.7 Ϯ 29. Login to comment
124 9 NS TMD-1 -321.5 Ϯ 75.6* -587.7 Ϯ 145.5 10 Ͻ0.05 T-N-R -110.7 Ϯ 27.6 -316.3 Ϯ 35.7 8 Ͻ0.05 R334W-R347P 107.4 Ϯ 16.1 -104.7 Ϯ 17.3 6 NS R334W-R347P- TMD-1 -75.9 Ϯ 20.1 -117.3 Ϯ 22.4 6 NS Current values are shown for all mutants immediately before and 5 min after stimulation with cAMP agonists [forskolin, 10 ␮M; 3-isobutyl-1-methylxanthine (IBMX), 1 mM] at the -90-mV clamped voltage. Login to comment
159 Consistent with oocyte expression and the Cl- efflux studies, these results showed that elimination of the first four ␣-helices of CFTR and mutation of methionine-265 to a valine eliminated CFTR`s ability to generate Cl- currents in both oocytes and IB3-1 cells. Login to comment
161 Likewise, cAMP-stimulated whole cell Cl- currents generated by R334W-R347P (dual arginine) CFTR in transfected IB3-1 cells were strongly outwardly rectified and blocked fully by DIDS. Login to comment
170 Insertion of both R334W and R347P mutations into a TMD-1 background eliminated its ability to generate Cl- currents, as shown in Table 1, and its ability to activate ORCCs, as demonstrated by the complete lack of any currents when this construct was expressed in IB3-1 cells (Fig. 3). Login to comment
172 More importantly, results with T-N-R CFTR suggest that the region of CFTR important for regulatory interaction with ORCCs lies Table 2. cAMP-stimulated Cl- efflux in CFTR cDNA-transfected IB3-1 CF cells cDNA transfected n Cl- efflux, % lost per min Paired P valueBefore agonists After agonists Mock 42 33.01 Ϯ 3.12 29.53 Ϯ 2.22 NS Wild-type 37 22.99 Ϯ 1.47 46.51 Ϯ 6.53* Ͻ0.005 ⌬259-M265 30 21.85 Ϯ 1.43 47.67 Ϯ 5.95* Ͻ0.005 ⌬259-M265V 18 24.55 Ϯ 1.17 29.25 Ϯ 2.23** Ͻ0.05 TMD-1 (K370X) 24 16.63 Ϯ 1.80 53.51 Ϯ 9.50* Ͻ0.005 TMD-1 (K370EcoRV) 24 19.54 Ϯ 1.67 41.27 Ϯ 5.22* Ͻ0.005 T-N-R 18 19.21 Ϯ 1.89 28.05 Ϯ 3.35** Ͻ0.05 R334W-R347P 18 19.85 Ϯ 3.20 31.16 Ϯ 6.79** Ͻ0.05 R334W-R347P-TMD-1 18 23.12 Ϯ 2.60 26.26 Ϯ 3.42 NS The Before agonists value is the rate of 36Cl- efflux immediately prior to stimulation with cAMP agonists (2.5 ␮M forskolin, 250 ␮M CPT-cAMP, and 250 ␮M 8-bromo-cAMP). Login to comment
174 For mutants ⌬259-M265V, T-N-R, and R334W-R347P, the magnitude of cAMP stimulation is significantly less (P Ͻ 0.05, versus paired control value as denoted by two asterisks) than that for the wild type and other responding mutants [⌬259-M265, TMD-1 (K370X), TMD-1 (K370EcoRV), P Ͻ 0.005 as denoted by one asterisk], as determined by ANOVA followed by the Bonferroni ad hoc test. Login to comment
114 Finally, dual Cl2 conduction mutations, R334W and R347P (referred to as dual arginine CFTR) were made. Login to comment
169 Insertion of both R334W and R347P mutations into a TMD-1 background eliminated its ability to generate Cl2 currents, as shown in Table 1, and its ability to activate ORCCs, as demonstrated by the complete lack of any currents when this construct was expressed in IB3-1 cells (Fig. 3). Login to comment
171 More importantly, results with T-N-R CFTR suggest that the region of CFTR important for regulatory interaction with ORCCs lies Table 2. cAMP-stimulated Cl2 efflux in CFTR cDNA-transfected IB3-1 CF cells cDNA transfected n Cl2 efflux, % lost per min Paired P value Before agonists After agonists Mock 42 33.01 6 3.12 29.53 6 2.22 NS Wild-type 37 22.99 6 1.47 46.51 6 6.53* ,0.005 D259-M265 30 21.85 6 1.43 47.67 6 5.95* ,0.005 D259-M265V 18 24.55 6 1.17 29.25 6 2.23** ,0.05 TMD-1 (K370X) 24 16.63 6 1.80 53.51 6 9.50* ,0.005 TMD-1 (K370EcoRV) 24 19.54 6 1.67 41.27 6 5.22* ,0.005 T-N-R 18 19.21 6 1.89 28.05 6 3.35** ,0.05 R334W-R347P 18 19.85 6 3.20 31.16 6 6.79** ,0.05 R334W-R347P-TMD-1 18 23.12 6 2.60 26.26 6 3.42 NS The Before agonists value is the rate of 36Cl2 efflux immediately prior to stimulation with cAMP agonists (2.5 mM forskolin, 250 mM CPT-cAMP, and 250 mM 8-bromo-cAMP). Login to comment
173 For mutants D259-M265V, T-N-R, and R334W-R347P, the magnitude of cAMP stimulation is significantly less (P , 0.05, versus paired control value as denoted by two asterisks) than that for the wild type and other responding mutants [D259-M265, TMD-1 (K370X), TMD-1 (K370EcoRV), P , 0.005 as denoted by one asterisk], as determined by ANOVA followed by the Bonferroni ad hoc test. Login to comment

[hide] Cystic fibrosis clinical trials. Adv Drug Deliv Rev. 1998 Mar 2;30(1-3):205-217. Alton E, Geddes D
Cystic fibrosis clinical trials.
Adv Drug Deliv Rev. 1998 Mar 2;30(1-3):205-217., [PMID:10837612]

Abstract [show]
The ion transport abnormalities in cystic fibrosis are becoming increasingly well defined, although how these lead to lung pathology is still speculation. Correction of these defects could theoretically be achieved either through pharmacological means or via gene therapy. Pharmacological approaches include increasing the amount of CFTR protein that reaches its correct localisation in epithelial cells. Secondly, approaches have been suggested which could increase the function of the protein already present at this correct localisation. Finally, it may be possible to identify alternative channels which could subserve the function of CFTR. Gene therapy is theoretically an attractive proposition as it should circumvent each of the identified abnormalities in cystic fibrosis. The principal difficulty at present relates to delivering sufficient copies of the normal CFTR gene into the appropriate cell population in vivo. A number of clinical trials have now been undertaken and steady and encouraging progress has been made in moving this approach from theory to practice.

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77 The chloride conductance of R347P and ments include the cDNA with appropriate promoter, R117H mutant CFTR has been assessed in vitro, and linked to a gene transfer agent (GTA). Login to comment
79 Thus patients promoters such as SV40, CMV and RSV, although who are R347P/delta F508 or R117H/delta F508 whether these function with equal efficiency in compound heterozygotes should demonstrate approx- differing cell types is far from clear. Login to comment

[hide] Correlation of sweat chloride concentration with g... Clin Biochem. 1998 Feb;31(1):33-6. De Braekeleer M, Allard C, Leblanc JP, Aubin G, Simard F
Correlation of sweat chloride concentration with genotypes in cystic fibrosis patients in Saguenay Lac-Saint-Jean, Quebec, Canada.
Clin Biochem. 1998 Feb;31(1):33-6., [PMID:9559222]

Abstract [show]
OBJECTIVES: Saguenay Lac-Saint-Jean, a geographically isolated region of northeastern Quebec has a high incidence of cystic fibrosis (CF) and three mutations only account for 94% of the CF chromosomes. The objective of the present study was to determine whether different mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene had different effects upon the sweat chloride concentration. DESIGN AND METHODS: The sweat chloride concentration of 114 patients was measured by quantitative pilocarpine iontophoresis. RESULTS: CF patients carrying the A455E mutation, usually associated with pancreatic sufficiency, had lower sweat chloride concentrations than those carrying mutations associated with pancreatic insufficiency (delta F508 and 621 + 1G-->T). CONCLUSIONS: Our results confirm that mutations resulting in a reduction of the chloride current at the apical membrane of epithelial cells induce lower sweat chloride values. However, there are differences in the chloride current between genotypes, even if they are composed of mutations apparently having the same functional effect.

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58 Class IV mutations result in a reduction in the amount of chloride current (e.g., R117H, R347P, S1251N mutations) while class V mutations result in a reduction in the amount of a normally functioning CFTR protein (e.g., A455E, 3849ϩ10kbC3T mutations). Login to comment
69 Simone Aubin, Claudette La- rochelle and Suzanne Mignault from the Clinique de TABLE 2 Distribution of the Mean Sweat Chloride Concentration by Genotype Genotype No. of CF Patients Mean Chloride Concentration (mmol/L) (SD) Pancreatic Status References G542X/⌬F508 128 109 (23) Pl 18 R553X/⌬F508 46 105 (18) Pl 18 N1303K/⌬F508 56 104 (24) Pl 18 W1282X/⌬F508 13 110 (18) Pl 18 1717-1G3A/⌬F508 26 107 (36) Pl 18 621ϩ1G3T/⌬F508 22 100 (20) Pl 18 R117H/⌬F508 20 82 (19) PS 18 ⌬F508/⌬F508 328 106 (22) Pl 18 3849ϩ10kb C3T/⌬F508 6 61 (11) PS 19 3849ϩ10kb C3T/⌬F508 9 41 (12) PS (6) 20 R347P/⌬F508 5 100 (26) Pl 21 R334W/⌬F508 10 108 (19) Pl (6) 22 1811ϩ1.6kb A3C/⌬F508a 17 98 (12) Pl 23 3905insT/⌬F508 7 124 Pl 24 W1282X/W1282X 16 113 (12) Pl 25 W1282X/⌬F508 22 109 (11) Pl 25 G551D/⌬F508 58 101 (16) Pl 26 R1162X/R1162X 9 99 (13) Pl 27 1949del84/⌬F508 4 105 (20) Pl 28 ⌬F508/⌬F508 47 103 (8) Pl This study 621ϩ1G3T/⌬F508 28 103 (7) Pl This study 621ϩ1G3T/A455E 6 94 (11) Pl/PS This study A455E/⌬F508 12 77 (18) Pl/PS This study a Or other 'severe` mutations. Login to comment
60 Class IV mutations result in a reduction in the amount of chloride current (e.g., R117H, R347P, S1251N mutations) while class V mutations result in a reduction in the amount of a normally functioning CFTR protein (e.g., A455E, 3849110kbC3T mutations). Login to comment
71 Simone Aubin, Claudette Larochelle and Suzanne Mignault from the Clinique de TABLE 2 Distribution of the Mean Sweat Chloride Concentration by Genotype Genotype No. of CF Patients Mean Chloride Concentration (mmol/L) (SD) Pancreatic Status References G542X/DF508 128 109 (23) Pl 18 R553X/DF508 46 105 (18) Pl 18 N1303K/DF508 56 104 (24) Pl 18 W1282X/DF508 13 110 (18) Pl 18 1717-1G3A/DF508 26 107 (36) Pl 18 62111G3T/DF508 22 100 (20) Pl 18 R117H/DF508 20 82 (19) PS 18 DF508/DF508 328 106 (22) Pl 18 3849110kb C3T/DF508 6 61 (11) PS 19 3849110kb C3T/DF508 9 41 (12) PS (6) 20 R347P/DF508 5 100 (26) Pl 21 R334W/DF508 10 108 (19) Pl (6) 22 181111.6kb A3C/DF508a 17 98 (12) Pl 23 3905insT/DF508 7 124 Pl 24 W1282X/W1282X 16 113 (12) Pl 25 W1282X/DF508 22 109 (11) Pl 25 G551D/DF508 58 101 (16) Pl 26 R1162X/R1162X 9 99 (13) Pl 27 1949del84/DF508 4 105 (20) Pl 28 DF508/DF508 47 103 (8) Pl This study 62111G3T/DF508 28 103 (7) Pl This study 62111G3T/A455E 6 94 (11) Pl/PS This study A455E/DF508 12 77 (18) Pl/PS This study a Or other 'severe` mutations. Login to comment

[hide] Genetic diseases of the seminal ducts. Biomed Pharmacother. 1998;52(5):197-203. Meschede D, Dworniczak B, Nieschlag E, Horst J
Genetic diseases of the seminal ducts.
Biomed Pharmacother. 1998;52(5):197-203., [PMID:9755815]

Abstract [show]
Azoospermia due to an obstruction of the genital tract is one of numerous possible pathophysiologic mechanisms underlying male infertility. The blockage of the seminal ducts may be acquired or congenital. Only recently has the strong association between mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and various subtypes of obstructive azoospermia been elucidated. Most patients with congenital bilateral absence of the vas deferens or bilateral ejaculatory duct obstruction are carriers of such mutations. The relationship between abnormal CFTR alleles and unilateral absence of the vas deferens, isolated seminal vesicle anomalies, and Young syndrome is less well characterized and awaits further investigation.

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91 The seventh patient from this group is heterozygous for R347P, and it is likely that he harbors another mutation that went undetected. Login to comment
92 Another group recently reported a single case of BED0 with compound heterozygosity for the CFTR mutations R347H and N1303K [18]. Login to comment

[hide] Severe cystic fibrosis associated with a deltaF508... Clin Genet. 1998 Jan;53(1):50-3. Hojo S, Fujita J, Miyawaki H, Obayashi Y, Takahara J, Bartholomew DW
Severe cystic fibrosis associated with a deltaF508/R347H + D979A compound heterozygous genotype.
Clin Genet. 1998 Jan;53(1):50-3., [PMID:9550362]

Abstract [show]
This report is concerned with twins with cystic fibrosis (CF). They are of mixed parentage: Japanese mother and German father. One case is presented with meconium ileus as a neonate. The other patient did relatively well until the age of 6 years when she was first hospitalized and diagnosed with pulmonary aspergillosis. They have been receiving standard therapies for CF including digestive enzymes, vitamins and periodic antibiotic therapy in the US. At 19 years of age, they were tested for common mutations and one AF508 cystic fibrosis transmembrane conductance regulator (CFTR) allele was found. Further testing of their CFTR gene as well as those of their Japanese mother and grandmother revealed missense mutations in exon 7 (R347H) and exon 16 (D979A). Although the D979A mutant is very rare, this mutation combination seemed to be responsible for severe CF phenotypes.

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70 R347P, first described by Dean et al. (lo), results in a mild pulmonary manifestation of CF and pancreatic sufficiency. Login to comment
72 Mutations R347P and R347L change an arginine- codon to proline and leucine respectively, i.e. a basic amino acid to amino acids bearing nonpolar side chains in CFTR. Login to comment
73 Kosztolanyi et al. (5) suggested that the unusually mild nature of CF in patient AF508/R347H genotype is associated with the fact that a missense mutation resulting in an exchange between similarly charged (basic) amino acids, histidine for arginine, produces even less significant change in ion flow through the chloride channel than the transition in R347P and R347L. Login to comment

[hide] High heterogeneity for cystic fibrosis in Spanish ... Hum Genet. 1997 Dec;101(3):365-70. Casals T, Ramos MD, Gimenez J, Larriba S, Nunes V, Estivill X
High heterogeneity for cystic fibrosis in Spanish families: 75 mutations account for 90% of chromosomes.
Hum Genet. 1997 Dec;101(3):365-70., [PMID:9439669]

Abstract [show]
We have analyzed 640 Spanish cystic fibrosis (CF) families for mutations in the CFTR gene by direct mutation analysis, microsatellite haplotypes, denaturing gradient gel electrophoresis, single-strand conformation analysis and direct sequencing. Seventy-five mutations account for 90.2% of CF chromosomes. Among these we have detected seven novel CFTR mutations, including four missense (G85V, T582R, R851L and F1074L), two nonsense (E692X and Q1281X) and one splice site mutation (711+3A-->T). Three variants, two in intronic regions (406-112A/T and 3850-129T/C) and one in the coding region (741C/T) were also identified. Mutations G85V, T582R, R851L, E692X and Q1281X are severe, with lung and pancreatic involvement; 711+3A-->T could be responsible for a pancreatic sufficiency/insufficiency variable phenotype; and F1074L was associated with a mild phenotype. These data demonstrate the highest molecular heterogeneity reported so far in CF, indicating that a wide mutation screening is necessary to characterize 90% of the Spanish CF alleles.

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33 Eight mutations have frequencies 366 Table 1 Seventy-five CFTR mutations identified in 640 Spanish families with cystic fibrosis (CF) Mutation Exon/intron CF alleles % ∆F508 E.10 681 53.20 G542X E.11 108 8.43 N1303K E.21 34 2.65 1811+1.6kbA→Ga I.11 24 1.87 711+1G→T I.5 22 1.71 R1162Xa E.19 21 1.64 R334Wa E.7 21 1.64 R1066C E.17b 14 1.09 1609delCAa E.10 13 1.01 Q890X E.15 13 1.01 G85E E.3 12 0.94 712-1G→Ta I.5 11 0.86 2789+5G→A I.14b 11 0.86 ∆I507 E.10 10 0.78 W1282X E.20 10 0.78 2869insGa E.15 9 0.70 L206W E.6a 7 0.54 R709X E.13 7 0.54 621+1G→T I.4 6 0.47 3272-26A→G I.17a 6 0.47 R347H E.7 5 0.39 2183AA→G E.13 5 0.39 K710X E.13 5 0.39 2176insC E.13 5 0.39 3849+10kbC→T I.19 5 0.39 P205Sa E.6a 4 0.31 1078delT E.7 4 0.31 R553X E.11 4 0.31 G551D E.11 4 0.31 1812-1G→Aa I.11 4 0.31 CFdel#1a E.4-7/11-18 4 0.31 V232D E.6a 3 0.23 936delTAa E.6b 3 0.23 1717-8G→A I.10 3 0.23 1949del84 E.13 3 0.23 W1089X E.17b 3 0.23 R347P E.7 3 0.23 del E.3a E.3 2 0.16 R117H E.4 2 0.16 L558S E.11 2 0.16 A561E E.12 2 0.16 2603delT E.13 2 0.16 Y1092X E.17b 2 0.16 Q1100Pa E.17b 2 0.16 M1101K E.17b 2 0.16 delE.19a E.19 2 0.16 G1244E E.20 2 0.16 P5La E.1 1 0.08 Q30Xa E.2 1 0.08 G85Va E.3 1 0.08 E92Ka E.4 1 0.08 A120Ta E.4 1 0.08 I148T E.4 1 0.08 711+3A→Ta I.5 1 0.08 H199Y E.6a 1 0.08 875+1G→A I.6a 1 0.08 Table 1 (continued) Mutation Exon/intron CF alleles % 1717-1G→A I.10 1 0.08 L571S E.12 1 0.08 T582Ra E.12 1 0.08 E585X E.12 1 0.08 1898+3A→G I.12 1 0.08 G673X E.13 1 0.08 E692Xa E.13 1 0.08 R851X E.14a 1 0.08 R851La E.14a 1 0.08 A1006E E.17a 1 0.08 L1065Ra E.17b 1 0.08 F1074La E.17b 1 0.08 R1158X E.19 1 0.08 3667del4a E.19 1 0.08 3860ins31a E.20 1 0.08 3905insT E.20 1 0.08 4005+1G→A I.20 1 0.08 Q1281Xa E.20 1 0.08 Q1313X E.21 1 0.08 Known mutations (75) 1155 90.23 Unknown mutations 125 9.77 a Mutations discovered by the CF group of the Medical and Molecular Genetics Centre - IRO, Barcelona, Spain that range between 0.5% and 0.9%, representing 6.0% of the CF chromosomes. Login to comment

[hide] Novel and characteristic CFTR mutations in Saudi A... J Med Genet. 1997 Dec;34(12):996-9. el-Harith EA, Dork T, Stuhrmann M, Abu-Srair H, al-Shahri A, Keller KM, Lentze MJ, Schmidtke J
Novel and characteristic CFTR mutations in Saudi Arab children with severe cystic fibrosis.
J Med Genet. 1997 Dec;34(12):996-9., [PMID:9429141]

Abstract [show]
More than 600 different CFTR (cystic fibrosis transmembrane conductance regulator) gene mutations have been identified so far that are considered to cause the fatal genetic disorder cystic fibrosis (CF). We have investigated 15 Arab children from 12 families, who were diagnosed as having CF, for mutations in the coding region and in the flanking intron sequences of the CFTR gene. Six different CFTR mutations were identified including two novel mutations, 1548delG in exon 10 and 406-2A-->G in intron 3. Prominent mutations were the splice mutation 3120 + 1G-->A (intron 16) followed by N1303K (exon 21) and 1548delG (exon 10). Most CF children were homozygotes who presented with a severe form of the disease including failure to thrive, recurrent chest infections, particularly with Pseudomonas aeruginosa, and frequent hospital admissions. Identification of the CFTR mutations facilitates molecular investigation of the disease and better understanding of its pathophysiology in Arab children, among whom CF is probably an underdiagnosed disease.

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26 Deletions of two or more base pairs were screened for by electrophoresis using a native 12% polyacrylamide gel. The 20 common CFTR mutations that were screened for were AF508, AI507, 1677delTA, R347P, R347H, R553X, G551D, G542X, N1303K, 3849+1OKbC-8'T, R334W, I336K, 2789+5G-A, 1717-1G-A, 3272- 26A- G, Y1092X, 2143delT, W1282X, RI 17H, and the 5T allele. Login to comment

[hide] Cystic fibrosis phenotype associated with pancreat... J Biol Chem. 1997 Nov 28;272(48):30563-6. Fanen P, Labarthe R, Garnier F, Benharouga M, Goossens M, Edelman A
Cystic fibrosis phenotype associated with pancreatic insufficiency does not always reflect the cAMP-dependent chloride conductive pathway defect. Analysis of C225R-CFTR and R1066C-CFTR.
J Biol Chem. 1997 Nov 28;272(48):30563-6., [PMID:9374552]

Abstract [show]
We have previously screened the cystic fibrosis transmembrane conductance regulator (CFTR) gene and identified new disease-causing mutations. C225R and R1066C are both associated with pancreatic insufficiency, but the former mutation is associated with mild and unusual lung disease, whereas the latter is associated with severe lung disease. In the present study, we expressed these mutants heterologously in HeLa cells, and we analyzed protein synthesis by immunoprecipitation and chloride channel function by using a halide-sensitive fluorescent dye, 6-methoxy-N-ethylquinolinium. Immunoprecipitation and functional studies showed that cells transfected with C225R-CFTR exhibit cAMP-dependent chloride fluxes; C225R-CFTR protein is poorly expressed but fully glycosylated and can be compared with R117H-CFTR. R1066C-CFTR protein is not correctly processed and, unlike DeltaF508-CFTR, this defect cannot be corrected by reduced temperature or overexpression in butyrate-treated cells; defective processing may occur at a different step in the biosynthetic pathway. These results point to two different mechanisms underlying the same pancreatic status and suggest that it is unwise to use pancreatic sufficiency and insufficiency to define mild and severe cystic fibrosis (CF) disease, respectively. Finally, the experimental model described here may be helpful to predict the pulmonary status of CF patients bearing mutations located in putative membrane-spanning domains of the CFTR protein.

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101 Six CF-associated mutations (P99L, R117H, P205S, R334W, R347P, and R347H) located in putative membrane-spanning domains that have already been analyzed for their functional properties (2-5) were all associated with a mild phenotype (pancreatic sufficiency, PS). Login to comment

[hide] CFTR gene mutations in men with bilateral ejaculat... Am J Hum Genet. 1997 Nov;61(5):1200-2. Meschede D, Dworniczak B, Behre HM, Kliesch S, Claustres M, Nieschlag E, Horst J
CFTR gene mutations in men with bilateral ejaculatory-duct obstruction and anomalies of the seminal vesicles.
Am J Hum Genet. 1997 Nov;61(5):1200-2., [PMID:9345100]

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23 Direct testing by allele-specific amplification, heteroduplex analysis, or by restriction analysis was performed in all patients, for detection of the following CFTR gene mutations: R117H, R347P, DI507, DF508, 1717-1 GrA, G542X, G551D, R553X, 3849ϩ10 kB, W1282X, and N1303K. Login to comment
26 It is common among men with CBAVD (De Braekeleer and Fe´rec 1996) and may here, Letters to the Editor Table 1 Summary of Mutation Analysis in CFTR Gene in 16 Men with IASV and in 7 Men with BEDO Diagnosis CFTR Genotypea T5/T7/T9 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/9 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 5/7 IASV ϩ/ϩ 7/7 IASV ϩ/ϩ 7/7 IASV I1139V/ϩ 7/9 IASV ϩ/ϩ 7/7 BEDO DF508/ϩ 9/5 BEDO DF508/R117H 9/7 BEDO ϩ/ϩ 7/9 BEDO DF508/R117H 9/7 BEDO R553X/ϩ 7/5 BEDO R347P/ϩ 7/7 BEDO DF508/ϩ 9/5 a A plus sign (ϩ) denotes the wild-type allele (i.e., no mutation was detected). Login to comment
33 Compound heterozygosity for DF508/R117H was detected in two patients, for DF508/T5 in another two, and for R553X/ T5 in one. Login to comment
34 One man was heterozygous for R347P. Login to comment
22 DNA was isolated from peripheral lymphocytes, and target sequences were amplified by PCR. Direct testing by allele-specific amplification, heteroduplex analysis, or by restriction analysis was performed in all patients, for detection of the following CFTR gene mutations: R117H, R347P, DI507, DF508, 1717-1 GrA, G542X, G551D, R553X, 3849af9;10 kB, W1282X, and N1303K. Login to comment
25 It is common among men with CBAVD (De Braekeleer and Fe &#b4;rec 1996) and may here, Letters to the Editor Table 1 Summary of Mutation Analysis in CFTR Gene in 16 Men with IASV and in 7 Men with BEDO Diagnosis CFTR Genotypea T5/T7/T9 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/9 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV af9;/af9; 5/7 IASV af9;/af9; 7/7 IASV af9;/af9; 7/7 IASV I1139V/af9; 7/9 IASV af9;/af9; 7/7 BEDO DF508/af9; 9/5 BEDO DF508/R117H 9/7 BEDO af9;/af9; 7/9 BEDO DF508/R117H 9/7 BEDO R553X/af9; 7/5 BEDO R347P/af9; 7/7 BEDO DF508/af9; 9/5 a A plus sign (af9;) denotes the wild-type allele (i.e., no mutation was detected). Login to comment

[hide] Permeability of wild-type and mutant cystic fibros... J Gen Physiol. 1997 Oct;110(4):355-64. Linsdell P, Tabcharani JA, Rommens JM, Hou YX, Chang XB, Tsui LC, Riordan JR, Hanrahan JW
Permeability of wild-type and mutant cystic fibrosis transmembrane conductance regulator chloride channels to polyatomic anions.
J Gen Physiol. 1997 Oct;110(4):355-64., [PMID:9379168]

Abstract [show]
Permeability of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel to polyatomic anions of known dimensions was studied in stably transfected Chinese hamster ovary cells by using the patch clamp technique. Biionic reversal potentials measured with external polyatomic anions gave the permeability ratio (P/P) sequence NO > Cl > HCO > formate > acetate. The same selectivity sequence but somewhat higher permeability ratios were obtained when anions were tested from the cytoplasmic side. Pyruvate, propanoate, methane sulfonate, ethane sulfonate, and gluconate were not measurably permeant (P/P < 0.06) from either side of the membrane. The relationship between permeability ratios from the outside and ionic diameters suggests a minimum functional pore diameter of approximately 5.3 A. Permeability ratios also followed a lyotropic sequence, suggesting that permeability is dependent on ionic hydration energies. Site-directed mutagenesis of two adjacent threonines in TM6 to smaller, less polar alanines led to a significant (24%) increase in single channel conductance and elevated permeability to several large anions, suggesting that these residues do not strongly bind permeating anions, but may contribute to the narrowest part of the pore.

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13 Some of these low conductance mutations (R334W, R347P, and R347H) occur in cystic fibrosis patients and have been associated with relatively mild disease symptoms. Login to comment
17 Some of these low conductance mutations (R334W, R347P, and R347H) occur in cystic fibrosis patients and have been associated with relatively mild disease symptoms. Login to comment

[hide] Halide permeation in wild-type and mutant cystic f... J Gen Physiol. 1997 Oct;110(4):341-54. Tabcharani JA, Linsdell P, Hanrahan JW
Halide permeation in wild-type and mutant cystic fibrosis transmembrane conductance regulator chloride channels.
J Gen Physiol. 1997 Oct;110(4):341-54., [PMID:9379167]

Abstract [show]
Permeation of cystic fibrosis transmembrane conductance regulator (CFTR) Cl channels by halide ions was studied in stably transfected Chinese hamster ovary cells by using the patch clamp technique. In cell-attached patches with a high Cl pipette solution, the CFTR channel displayed outwardly rectifying currents and had a conductance near the membrane potential of 6.0 pS at 22 degrees C or 8.7 pS at 37 degrees C. The current-voltage relationship became linear when patches were excised into symmetrical, -tris(hydroxymethyl)methyl-2-aminomethane sulfonate (TES)-buffered solutions. Under these conditions, conductance increased from 7.0 pS at 22 degrees C to 10.9 pS at 37 degrees C. The conductance at 22 degrees C was approximately 1.0 pS higher when TES and HEPES were omitted from the solution, suggesting weak, voltage-independent block by pH buffers. The relationship between conductance and Cl activity was hyperbolic and well fitted by a Michaelis-Menten-type function having a of approximately 38 mM and maximum conductance of 10 pS at 22 degrees C. Dilution potentials measured with NaCl gradients indicated high anion selectivity (P/P = 0.003-0.028). Biionic reversal potentials measured immediately after exposure of the cytoplasmic side to various test anions indicated P(1.8) > P(1. 3) > P(1.0) > P(0.17), consistent with a "weak field strength" selectivity site. The same sequence was obtained for external halides, although inward F flow was not observed. Iodide currents were protocol dependent and became blocked after 1-2 min. This coincided with a large shift in the (extrapolated) reversal potential to values indicating a greatly reduced I/Cl permeability ratio (P/P< 0.4). The switch to low I permeability was enhanced at potentials that favored Cl entry into the pore and was not observed in the R347D mutant, which is thought to lack an anion binding site involved in multi-ion pore behavior. Interactions between Cl and I ions may influence I permeation and be responsible for the wide range of P/P ratios that have been reported for the CFTR channel. The low P/P ratio usually reported for CFTR only occurred after entry into an altered permeability state and thus may not be comparable with permeability ratios for other anions, which are obtained in the absence of iodide. We propose that CFTR displays a "weak field strength" anion selectivity sequence.

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21 Mutations in CFTR that cause it to be mislocalized (i.e., ⌬F508) or unresponsive (i.e., G551D) are associated with severe forms of cystic fibrosis, whereas mutations that only partially reduce CFTR conductance (R347P,H, Sheppard et al., 1993; Tabcharani et al., 1993), open probability (R117H, Sheppard et al., 1993; Becq et al., 1994; intracellular loop IV mutants, Seibert et al., 1996), or processing (A455E, Sheppard et al., 1995) are associated with milder symptoms. Login to comment
24 Mutations in CFTR that cause it to be mislocalized (i.e., DF508) or unresponsive (i.e., G551D) are associated with severe forms of cystic fibrosis, whereas mutations that only partially reduce CFTR conductance (R347P,H, Sheppard et al., 1993; Tabcharani et al., 1993), open probability (R117H, Sheppard et al., 1993; Becq et al., 1994; intracellular loop IV mutants, Seibert et al., 1996), or processing (A455E, Sheppard et al., 1995) are associated with milder symptoms. Login to comment

[hide] Distinct spectrum of CFTR gene mutations in congen... Hum Genet. 1997 Sep;100(3-4):365-77. Dork T, Dworniczak B, Aulehla-Scholz C, Wieczorek D, Bohm I, Mayerova A, Seydewitz HH, Nieschlag E, Meschede D, Horst J, Pander HJ, Sperling H, Ratjen F, Passarge E, Schmidtke J, Stuhrmann M
Distinct spectrum of CFTR gene mutations in congenital absence of vas deferens.
Hum Genet. 1997 Sep;100(3-4):365-77., [PMID:9272157]

Abstract [show]
Congenital absence of the vas deferens (CAVD) is a frequent cause for obstructive azoospermia and accounts for 1%-2% of male infertility. A high incidence of mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has recently been reported in males with CAVD. We have investigated a cohort of 106 German patients with congenital bilateral or unilateral absence of the vas deferens for mutations in the coding region, flanking intron regions and promotor sequences of the CFTR gene. Of the CAVD patients, 75% carried CFTR mutations or disease-associated CFTR variants, such as the "5T" allele, on both chromosomes. The distribution of mutation genotypes clearly differed from that observed in cystic fibrosis. None of the CAVD patients was homozygous for delta F508 and none was compound heterozygous for delta F508 and a nonsense or frameshift mutation. Instead, homozygosity was found for a few mild missense or splicing mutations, and the majority of CAVD mutations were missense substitutions. Twenty-one German CAVD patients were compound heterozygous for delta F508 and R117H, which was the most frequent CAVD genotype in our study group. Haplotype analysis indicated a common origin for R117H in our population, whereas another frequent CAVD mutation, viz. the "5T allele" was a recurrent mutation on different intragenic haplotypes and multiple ethnic backgrounds. We identified a total of 46 different mutations and variants, of which 15 mutations have not previously been reported. Thirteen novel missense mutations and one unique amino-acid insertion may be confined to the CAVD phenotype. A few splice or missense variants, such as F508C or 1716 G-->A, are proposed here as possible candidate CAVD mutations with an apparently reduced penetrance. Clinical examination of patients with CFTR mutations on both chromosomes revealed elevated sweat chloride concentrations and discrete symptoms of respiratory disease in a subset of patients. Thus, our collaborative study shows that CAVD without renal malformation is a primary genital form of cystic fibrosis in the vast majority of German patients and links the particular expression of clinical symptoms in CAVD with a distinct subset of CFTR mutation genotypes.

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43 This initial screening included the mutations ∆F508, G542X, R553X, G551D, N1303K, 1717-1 G→A, 3272-26 A→G, Y1092X, 2143delT, R347P, R347H, R334W, I336K, R117H, R117C, 2789+5 G→A, 3849+10kB C→T and the "5T" allele, the latter two splice variants being tested according to the instructions of Highsmith et al. (1994) and Chillón et al. (1995). Login to comment

[hide] Relevance of genetic counselling in couples prior ... Hum Reprod. 1997 Sep;12(9):1909-12. Pauer HU, Hinney B, Michelmann HW, Krasemann EW, Zoll B, Engel W
Relevance of genetic counselling in couples prior to intracytoplasmic sperm injection.
Hum Reprod. 1997 Sep;12(9):1909-12., [PMID:9363704]

Abstract [show]
Since the first reports of successful pregnancies after treatment with intracytoplasmic sperm injection (ICSI) in humans numerous attempts have been made to assess the genetic risks of this highly invasive technique. During the study period (February 1995-November 96), 142 couples were referred to our genetic counselling unit prior to ICSI. In three couples, genetic counselling revealed a high recurrence risk for a monogenic disease (myotonic dystrophy, hereditary ataxia and polycystic kidney disease). In nine out of 128 men (7%) an abnormal karyotype was identified, including three Robertsonian translocations, two reciprocal translocations, three sex chromosome aberrations and one case with centric fission of chromosome no. 7. A total of 14 men refused chromosomal analysis. Only one of the 122 women examined had an abnormal karyotype (47, XXX). Five out of six men with congenital bilateral absence of the vas deferens (CBAVD) had at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Three had mutations in both CFTR alleles, including one case in which the second mutation was the 5T allele. One patient with CBAVD and a single Delta F508 CFTR mutation also had left renal agenesis. In conclusion, we strongly recommend that genetic counselling, chromosomal analysis and, in the case of CBAVD, screening for CFTR mutations should be offered to all couples with a diagnosis of male or idiopathic infertility.

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25 Patients whose history or physical examination showed a possible diagnosis of CBAVD were typed for 19 additional CFTR mutations (e.g. R117H, Introduction R347P, 1717-1, G542X, G551D, R553X, W1282X and N1303K), including an intronic polymorphism (5T allele) which leads to reducedThe development of intracytoplasmic sperm injection (ICSI) for splicing efficiency of the CFTR mRNA (Chillo´n et al., 1995). Login to comment
24 Patients whose history or physical examination showed a possible diagnosis of CBAVD were typed for 19 additional CFTR mutations (e.g. R117H, Introduction R347P, 1717-1, G542X, G551D, R553X, W1282X and N1303K), including an intronic polymorphism (5T allele) which leads to reduced The development of intracytoplasmic sperm injection (ICSI) for splicing efficiency of the CFTR mRNA (Chillo &#b4;n et al., 1995). Login to comment

[hide] A new mutation, 3905insT, accounts for 4.8% of 117... Hum Genet. 1997 Aug;100(2):220-3. Hergersberg M, Balakrishnan J, Bettecken T, Chevalier-Porst F, Bragger C, Burger R, Einschenk I, Liechti-Gallati S, Morris M, Schorderet D, Thonney F, Moser H, Malik N
A new mutation, 3905insT, accounts for 4.8% of 1173 CF chromosomes in Switzerland and causes a severe phenotype.
Hum Genet. 1997 Aug;100(2):220-3., [PMID:9254853]

Abstract [show]
We have analysed 1173 cystic fibrosis (CF) chromosomes from Switzerland for eight mutations in the CF transmembrane conductance regulator (CFTR) gene. This permitted the identification of 88.5% of all mutations present. A novel insertion mutation in exon 20 of the CFTR gene, 3905insT, was discovered. This mutation accounted for 4.8% of CFTR gene mutations in Switzerland and has since been identified in other populations of probable Swiss descent. It is associated with a highly variable clinical phenotype but always with pancreatic insufficiency. Haplotype analysis with three intragenic microsatellites in the CFTR gene showed that the mutation is associated with a haplotype rarely identified on other CFTR alleles and, therefore, that the frequency of the mutation in Switzerland is explained by a founder effect of a relatively recent mutation event.

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17 Martin Hergersberg · Jaya Balakrishnan · Thomas Bettecken · Francoise Chevalier-Porst · Christian Brägger · René Burger · Inge Einschenk · Sabina Liechti-Gallati · Michael Morris · Daniel Schorderet · Francine Thonney · Hans Moser · Naseem Malik A new mutation, 3905insT, accounts for 4.8% of 1173 CF chromosomes in Switzerland and causes a severe phenotype Hum Genet (1997) 100:220-223 (c) Springer-Verlag 1997 Received: 17 February 1997 / Accepted: 26 March 1977 ORIGINAL INVESTIGATION M. Hergersberg (౧) · J. Balakrishnan · I. Einschenk Institut für Medizinische Genetik, Universität Zürich, Rämistrasse 74, CH-8001 Zurich, Switzerland Tel.: +411 257 25 35; Fax: +411 262 04 70; e-mail hergie@medgen.unizh.ch T. Bettecken · S. Liechti-Gallati · H. Moser Universitäts-Kinderklinik, Bern, Switzerland F. Chevalier-Porst Hôpital Debrousse, Lyon, France C. Brägger · R. Burger Universitäts-Kinderklinik, Zurich, Switzerland M. Morris Division de Génétique Médicale, Gèneve, Switzerland D. Schorderet · F. Thonney Division Autonome de Génétique Médicale, Lausanne, Switzerland N. Malik Abteilung für Medizinische Genetik, Universitätskinderklinik, Basel, Switzerland Materials and methods Patients and families All blood samples received by the five Swiss University Centres of medical genetics for mutation analysis in the CFTR gene were screened for the eight mutations ∆F508, R553X, 1717-1G→A, G542X, N1303K, W1282X, R347P and 3905insT (Table 1). Login to comment
42 Using this method, the 3905insT mutation was found on 56 (4.8%) of "Swiss" CF chromosomes, but was not detected in more than 400 normal chromosomes, in more than 200 CF chromosomes with the ∆F508 mutation and in numerous CF chromosomes 221 Table 1 The frequency of eight common cystic fibrosis (CF) mutations among 1173 CF mutations in Switzerland Mutation Number of CF Frequency chromosomes (%) ∆F508 841 71.7 3905insT 56 4.8 R553X 43 3.7 1717-1G→A 39 3.3 G542X 23 2.0 N1303K 17 1.4 W1282X 13 1.1 R347P 7 0.6 Other mutations 21 1.9 Total 1060 90.4 Unidentified mutations 113 9. Login to comment

[hide] CFTR gene transfer reduces the binding of Pseudomo... Am J Respir Cell Mol Biol. 1997 Jun;16(6):657-63. Davies JC, Stern M, Dewar A, Caplen NJ, Munkonge FM, Pitt T, Sorgi F, Huang L, Bush A, Geddes DM, Alton EW
CFTR gene transfer reduces the binding of Pseudomonas aeruginosa to cystic fibrosis respiratory epithelium.
Am J Respir Cell Mol Biol. 1997 Jun;16(6):657-63., [PMID:9191467]

Abstract [show]
Much of the morbidity and mortality seen in cystic fibrosis (CF) is related to chronic infection of the respiratory tract with Pseudomonas aeruginosa. Some studies have attributed the strong relationship between CF and Pseudomonas colonization to the presence of increased numbers of specific cell-surface receptors, although other work suggests that this relates to the presence of mucus. Several groups are now assessing the use of gene transfer as a novel form of treatment for CF. We have examined whether P. aeruginosa binding to freshly obtained CF respiratory epithelial cells is increased, and have studied the effects of transfer of the CF transmembrane conductance regulator (CFTR) gene on this attachment. Binding of P. aeruginosa to noncultured nasal epithelial cells from both CF patients (n = 31) and healthy controls (n = 15) was studied with scanning electron microscopy. Binding was also assessed for CF cells following transfection with CFTR/liposome complexes. Epifluorescence microscopy was used to assess the effects of gene transfer on chloride fluxes. Adherence of P. aeruginosa directly to the cell surface of CF airway epithelium was significantly (P < 0.001) increased over that in non-CF controls. Liposome-mediated CFTR gene transfer resulted in a significant (P < 0.01) reduction in the numbers of bacteria bound to ciliated epithelial cells. Fluorescence microscopy confirmed correction of the basic chloride defect. Thus, in CF, the absence of normal CFTR results in increased binding of P. aeruginosa to respiratory epithelial cells. This abnormality can be corrected in vitro by restoration of CFTR function. This has important implications both for the pathogenesis of CF and for the future application and assessment of gene therapy for this disease.

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95 Twelve patients were homozygous for the dF508 mutation, six were compound heterozygotes with two identified mutations (d/G542X X 3, d/R347P, d/R117H, d/1717), 11 were heterozygous for dF508 with an unknown mutation, and in 3, the genotype was unknown. Login to comment

[hide] Newborn screening for cystic fibrosis in Wisconsin... Pediatrics. 1997 Jun;99(6):819-24. Gregg RG, Simantel A, Farrell PM, Koscik R, Kosorok MR, Laxova A, Laessig R, Hoffman G, Hassemer D, Mischler EH, Splaingard M
Newborn screening for cystic fibrosis in Wisconsin: comparison of biochemical and molecular methods.
Pediatrics. 1997 Jun;99(6):819-24., [PMID:9164776]

Abstract [show]
OBJECTIVES: To evaluate neonatal screening for cystic fibrosis (CF), including study of the screening procedures and characteristics of false-positive infants, over the past 10 years in Wisconsin. An important objective evolving from the original design has been to compare use of a single-tier immunoreactive trypsinogen (IRT) screening method with that of a two-tier method using IRT and analyses of samples for the most common cystic fibrosis transmembrane regulator (CFTR) (DeltaF508) mutation. We also examined the benefit of including up to 10 additional CFTR mutations in the screening protocol. METHODS: From 1985 to 1994, using either the IRT or IRT/DNA protocol, 220 862 and 104 308 neonates, respectively, were screened for CF. For the IRT protocol, neonates with an IRT >/=180 ng/mL were considered positive, and the standard sweat chloride test was administered to determine CF status. For the IRT/DNA protocol, samples from the original dried-blood specimen on the Guthrie card of neonates with an IRT >/=110 ng/mL were tested for the presence of the DeltaF508 CFTR allele, and if the DNA test revealed one or two DeltaF508 alleles, a sweat test was obtained. RESULTS: Both screening procedures had very high specificity. The sensitivity tended to be higher with the IRT/DNA protocol, but the differences were not statistically significant. The positive predictive value of the IRT/DNA screening protocol was 15.2% compared with 6.4% if the same samples had been screened by the IRT method. Assessment of the false-positive IRT/DNA population revealed that the two-tier method eliminates the disproportionate number of infants with low Apgar scores and also the high prevalence of African-Americans identified previously in our study of newborns with high IRT levels. We found that 55% of DNA-positive CF infants were homozygous for DeltaF508 and 40% had one DeltaF508 allele. Adding analyses for 10 more CFTR mutations has only a small effect on the sensitivity but is likely to add significantly to the cost of screening. CONCLUSIONS: Advantages of the IRT/DNA protocol over IRT analysis include improved positive predictive value, reduction of false-positive infants, and more rapid diagnosis with elimination of recall specimens.

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152 DNA Analysis of Genotyped CF Patients in the US* n Percent ⌬F508 12701 67.7 G542X 403 2.2 G551D 357 1.9 W1282X 240 1.3 N1303K 223 1.2 R553X 157 0.8 3849 ϩ 10kbC 3 T 102 0.5 621 ϩ 1G 3 T 147 0.8 1717 - 1G 3 A 101 0.5 R117H 101 0.5 R334W 36 0.2 ⌬I507 42 0.2 R347P 37 0.2 R560T 23 0.1 R1162X 44 0.2 2789 ϩ 5G 3 A 25 0.1 A455E 16 0.1 3120 ϩ IG 3 A 14 0.0 S549N 12 0.0 711 ϩ IG 3 T 9 0.0 Other 178 0.9 Unidentified 3814 20.3 Total 18782 99.7† Patient Genotypes Allele 1/Allele 2 n % of Genotype ⌬F508/⌬F508 4573 48.7 ⌬F508/Known 1511 16.1 ⌬F508/Unknown 2044 21.8 Known/unknown 310 3.3 Known/known 223 2.4 Unknown/unknown 730 7.8 Total 9391 100.0 *Data from Cystic Fibrosis Registry, 1995; Annual Report. Login to comment
147 DNA Analysis of Genotyped CF Patients in the US* n Percent DF508 12701 67.7 G542X 403 2.2 G551D 357 1.9 W1282X 240 1.3 N1303K 223 1.2 R553X 157 0.8 3849 1 10kbC 3 T 102 0.5 621 1 1G 3 T 147 0.8 1717 2 1G 3 A 101 0.5 R117H 101 0.5 R334W 36 0.2 DI507 42 0.2 R347P 37 0.2 R560T 23 0.1 R1162X 44 0.2 2789 1 5G 3 A 25 0.1 A455E 16 0.1 3120 1 IG 3 A 14 0.0 S549N 12 0.0 711 1 IG 3 T 9 0.0 Other 178 0.9 Unidentified 3814 20.3 Total 18782 99.7ߤ Patient Genotypes Allele 1/Allele 2 n % of Genotype DF508/DF508 4573 48.7 DF508/Known 1511 16.1 DF508/Unknown 2044 21.8 Known/unknown 310 3.3 Known/known 223 2.4 Unknown/unknown 730 7.8 Total 9391 100.0 *Data from Cystic Fibrosis Registry, 1995; Annual Report. Login to comment

[hide] Identification of common cystic fibrosis mutations... Am J Hum Genet. 1997 May;60(5):1122-7. Macek M Jr, Mackova A, Hamosh A, Hilman BC, Selden RF, Lucotte G, Friedman KJ, Knowles MR, Rosenstein BJ, Cutting GR
Identification of common cystic fibrosis mutations in African-Americans with cystic fibrosis increases the detection rate to 75%.
Am J Hum Genet. 1997 May;60(5):1122-7., [PMID:9150159]

Abstract [show]
Cystic fibrosis (CF)--an autosomal recessive disorder caused by mutations in CF transmembrane conductance regulator (CFTR) and characterized by abnormal chloride conduction across epithelial membranes, leading to chronic lung and exocrine pancreatic disease--is less common in African-Americans than in Caucasians. No large-scale studies of mutation identification and screening in African-American CF patients have been reported, to date. In this study, the entire coding and flanking intronic sequence of the CFTR gene was analyzed by denaturing gradient-gel electrophoresis and sequencing in an index group of 82 African-American CF chromosomes to identify mutations. One novel mutation, 3120+1G-->A, occurred with a frequency of 12.3% and was also detected in a native African patient. To establish frequencies, an additional group of 66 African-American CF chromosomes were screened for mutations identified in two or more African-American patients. Screening for 16 "common Caucasian" mutations identified 52% of CF alleles in African-Americans, while screening for 8 "common African" mutations accounted for an additional 23%. The combined detection rate of 75% was comparable to the sensitivity of mutation analysis in Caucasian CF patients. These results indicate that African-Americans have their own set of "common" CF mutations that originate from the native African population. Inclusion of these "common" mutations substantially improves CF mutation detection rates in African-Americans.

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39 Mutation Analysis All patients were screened for the AF508 mutation and 15 common Caucasian CF mutations using a reverse dot strip hybridization system (Kawasaki et al. 1993) (R117H, 621+1G--T, R334W, R347P, A455E, A1507, 1717-1G-+A, G542X, S549N, GSS1D, R553X, R560T, 3849+10kbC-+T, W1282X, and N1303K) (Welsh et al. 1995) and a deep intron 11 splice-site mutation, 1811+1.6kbA-+G (Chillon et al. 1995). Login to comment
86 The most common muta- Table 2 Distribution of CF Mutations in African-American and U.S.-Caucasian CF Patients African-American U.S. Caucasiana Mutation (n= 148) % (n = 8,714) % Caucasian mutations: AF508 71 48 5,769 66.2 R117H 0 0 47 .5 621+1 G--T 0 0 68 .8 R334W 1 .7 7 .1 R347P 0 0 24 .3 A455E 0 0 5 .1 AI507 1 .7 10 .1 1717-1 G-IA 1 .7 39 .5 G542X 1 .7 204 2.3 S549N 1 .7 4 .1 GS51D 1 .7 173 2.0 R553X (Caucasian)b 0 0 87 1.0 R560T 0 0 16 .2 3849+10kb C-T 0 0 51 .6 W1282X 0 0 235 2.7 N1303K 0 0 116 1.3 Subtotal 77 52 6,855 78.7 African-American mutations: 405+3 A-C 2 1.4 ... ... 444delA 1 .7 ... ... G480C 2 1.4 ... ... R553X (African)b 3 2.0 ... ... A559T 3 2.0 ... ... 2307insA 3 2.0 ... ... 3120+1 GC-A 18 12.2 ... ... S1255X 2 1.4 ... ... Subtotal 34 23 ... ... Total 111 75.0 6,855 78.7 NOTE.-Percentages are rounded. Login to comment
40 Mutation Analysis All patients were screened for the AF508 mutation and 15 common Caucasian CF mutations using a reverse dot strip hybridization system (Kawasaki et al. 1993) (R117H, 621+1G--T, R334W, R347P, A455E, A1507, 1717-1G-+A, G542X, S549N, GSS1D, R553X, R560T, 3849+10kbC-+T, W1282X, and N1303K) (Welsh et al. 1995) and a deep intron 11 splice-site mutation, 1811+1.6kbA-+G (Chillon et al. 1995). Login to comment
87 The most common muta- Table 2 Distribution of CF Mutations in African-American and U.S.-Caucasian CF Patients African-American U.S. Caucasiana Mutation (n= 148) % (n = 8,714) % Caucasian mutations: AF508 71 48 5,769 66.2 R117H 0 0 47 .5 621+1 G--T 0 0 68 .8 R334W 1 .7 7 .1 R347P 0 0 24 .3 A455E 0 0 5 .1 AI507 1 .7 10 .1 1717-1 G-IA 1 .7 39 .5 G542X 1 .7 204 2.3 S549N 1 .7 4 .1 GS51D 1 .7 173 2.0 R553X (Caucasian)b 0 0 87 1.0 R560T 0 0 16 .2 3849+10kb C-T 0 0 51 .6 W1282X 0 0 235 2.7 N1303K 0 0 116 1.3 Subtotal 77 52 6,855 78.7 African-American mutations: 405+3 A-C 2 1.4 ... ... 444delA 1 .7 ... ... G480C 2 1.4 ... ... R553X (African)b 3 2.0 ... ... A559T 3 2.0 ... ... 2307insA 3 2.0 ... ... 3120+1 GC-A 18 12.2 ... ... S1255X 2 1.4 ... ... Subtotal 34 23 ... ... Total 111 75.0 6,855 78.7 NOTE.-Percentages are rounded. Login to comment

[hide] Chromosomal findings in 150 couples referred for g... Hum Reprod. 1997 May;12(5):930-7. Mau UA, Backert IT, Kaiser P, Kiesel L
Chromosomal findings in 150 couples referred for genetic counselling prior to intracytoplasmic sperm injection.
Hum Reprod. 1997 May;12(5):930-7., [PMID:9194642]

Abstract [show]
A total of 150 infertile couples underwent chromosome analysis and genetic counselling before intracytoplasmic sperm injection (ICSI). Chromosomal abnormalities, including low-level sex chromosome mosaicism, were detected in 12% of the men and an unexpectedly high 6% of the women. Chromosomal abnormalities included gonosomal mosaicism in 13 cases, Robertsonian translocations in four males, autosomal reciprocal translocations in five cases, reciprocal translocation involving a sex chromosome in one case, inversions in three cases and a marker chromosome in one male. Chromosomal variants found in 11 women and 13 men were not included in the above percentages. Couples with a chromosomal aberration in one partner received a second counselling. The different aspects of genetic counselling in these couples are discussed. In conclusion, we recommend genetic counselling and chromosomal analysis of men and women prior to ICSI therapy.

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21 Mutation screening included δI507, δF508, in combination with other abnormalities of the semen 1717-1(G→A), G542X, G551D, R553X, W1282X, N1303K, R347P, (Bourrouillou et al., 1992). Login to comment

[hide] Analysis of 16 cystic fibrosis mutations in Mexica... Am J Med Genet. 1997 Apr 14;69(4):380-2. Villalobos-Torres C, Rojas-Martinez A, Villareal-Castellanos E, Cantu JM, Sanchez-Anzaldo FJ, Saiki RK, Barrera-Saldana HA
Analysis of 16 cystic fibrosis mutations in Mexican patients.
Am J Med Genet. 1997 Apr 14;69(4):380-2., [PMID:9098486]

Abstract [show]
We carried out molecular analysis of 80 chromosomes from 40 unrelated Mexican patients with a diagnosis of cystic fibrosis. The study was performed in two PCR steps: a preliminary one to identify mutation delta F508, the most frequent cause of cystic fibrosis worldwide, and the second a reverse dot-blot with allele-specific oligonucleotide probes to detect 15 additional common mutations in the Caucasian population. A frequency of 45% for delta F508 was found, making it the most common in our sample of Mexican patients. Another five mutations (G542X, 3,849 + 10 kb C-->T, N1303K, SN549N, and 621 + 1 G-->T) were detected, and those accounted for 11.25%. The remaining mutations (43.75%) were undetectable with the methodology used.

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14 According to data from the Cystic Fibrosis Genetic Analysis Consortium [1994] (CFGAC), the most frequent non-⌬F508 mutations are the following: G542X (2.4%), G551D (1.6%), N1303K (1.3%), W1282X (1.2%), R553X (0.7%), 621 + 1 G→T (0.7%), 1717 - 1 G→T (0.6%), R117H (0.3%), R1162X (0.3%), G85E (0.2%), R347P (0.2%), ⌬I507 (0.2%), and 3849 + 10 kb C→T (0.2%). Login to comment
60 Mutation Frequency Data and Geographic Distribution of the Mutations Found in 80 Chromosomes From Mexican CF Patients Mutation Northeast n ‫ס‬ 54 Central n ‫ס‬ 16 Western n ‫ס‬ 10 Total n ‫ס‬ 80 CFGAC [1994] (%)n (%) n (%) n (%) n (%) ⌬F508 27 (50) 2 (12.5) 7 (70) 36 (45) 66 G542X 2 (3.7) 2 (12.5) 0 4 (5) 2.4 3849 + 10 kb C→T 1 (1.9) 0 1 (10) 2 (2.5) 0.2 N1303K 0 1 (6.25) 0 1 (1.25) 1.3 S549N 0 1 (6.25) 0 1 (1.25) 0.1 621 + 1 G→T 0 0 1 (10) 1 (1.25) 0.7 Othera 24 (44.4) 10 (62.5) 1 (10) 35 (43.7) Detected 30 (55.6) 6 (37.5) 9 (90) 45 (56.3) a Different from W1282X, R117H, R334W, R347P, A455E, ⌬I507, 1717 - 1 G→T, G551D, R553X, and R560T. Login to comment

[hide] Detection of mutations in human genes by a new rap... Mol Cell Probes. 1997 Apr;11(2):155-60. Rossetti S, Englisch S, Bresin E, Pignatti PF, Turco AE
Detection of mutations in human genes by a new rapid method: cleavage fragment length polymorphism analysis (CFLPA).
Mol Cell Probes. 1997 Apr;11(2):155-60., [PMID:9160331]

Abstract [show]
Cleavage fragment length polymorphism analysis with silver staining visualization (CFLPA-SS) was used for the detection of mutations previously detected by single strand conformation (SSCA) or heteroduplex analyses (HA); in order to assess this new method for mutation screening. The analysed mutations include single nucleotide transitions, transversions, a deletion and a duplication in the following genes: CFTR (cystic fibrosis transmembrane conductance regulator), COL4A5 (collagen type 4 alpha 5 chain), PKD1 (polycystic kidney disease 1), and FGFR3 (fibroblast growth factor receptor 3). Peripheral blood leukocyte genomic DNA was isolated, amplified by polymerase chain reaction (PCR), and then cleaved by Cleavase I enzyme at different temperatures. Electrophoresis of the fragments on denaturing polyacrylamide gel was followed by silver staining for 1 min. All 13 mutations investigated were reproducibly detected. CFLPA-SS proved to be a reliable method for mutation detection and more rapid than SSCA and HA.

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39 Mutations analysed by CFLPA-SSa Gene Mutation Sequence PCR CFLP temperature (°C) (reference) modification size (bp) 40 55 65 70 COL4A5 GI77R G→C 121 y n n y (7) COL4A5 1272delC DeltaC 181 y y nd n (9) COL4A5 G174R G→C 121 y n n y (7) COL4A5 G54D G→A 230 y n nd y (10) PKD1 11549dupl10 duplication 535 n n y y (12) PKD1 Q4041X C→T 418 y n n n (11) PKD1 Y4126X C→G 379 y n nd n (12) PKD1 M3677T T→C 268 y nd nd n (12) PKD1 12838C/T C→T 552 y nd nd n (14) PKD1 R4020X C→T 418 y nd nd n (13) FGFR3 R380G G→A 164 y nd nd n (15) CFTR R334W C→T 230 y nd nd n (17) CFTR R347P G→C 230 y nd nd n (18) a y=appearance of a mutation-specific DNA fragment after Cleavase I digestion. Login to comment
55 The CFTR mutation R347P, and age, irrespective of the PCR-fragment size. Login to comment
64 a: CFTR, R347P; b: COL4A5, G54D; c: PKD1, Q4041X; d: PKD1, 11549dup10; e: COL4A5, G174R. Login to comment
130 American Journal of Medicalgene mutations R334W and R347P and Dr Maria Giovanna Genetics 65, 155-9.Benetazzo for helpful discussions about silver staining. Login to comment
41 Mutations analysed by CFLPA-SSa Gene Mutation Sequence PCR CFLP temperature (&#b0;C) (reference) modification size (bp) 40 55 65 70 COL4A5 GI77R G࢐C 121 y n n y (7) COL4A5 1272delC DeltaC 181 y y nd n (9) COL4A5 G174R G࢐C 121 y n n y (7) COL4A5 G54D G࢐A 230 y n nd y (10) PKD1 11549dupl10 duplication 535 n n y y (12) PKD1 Q4041X C࢐T 418 y n n n (11) PKD1 Y4126X C࢐G 379 y n nd n (12) PKD1 M3677T T࢐C 268 y nd nd n (12) PKD1 12838C/T C࢐T 552 y nd nd n (14) PKD1 R4020X C࢐T 418 y nd nd n (13) FGFR3 R380G G࢐A 164 y nd nd n (15) CFTR R334W C࢐T 230 y nd nd n (17) CFTR R347P G࢐C 230 y nd nd n (18) a y=appearance of a mutation-specific DNA fragment after Cleavase I digestion. Login to comment
58 The CFTR mutation R347P, and age, irrespective of the PCR-fragment size. Login to comment
67 a: CFTR, R347P; b: COL4A5, G54D; c: PKD1, Q4041X; d: PKD1, 11549dup10; e: COL4A5, G174R. Login to comment
135 American Journal of Medical gene mutations R334W and R347P and Dr Maria Giovanna Genetics 65, 155-9. Login to comment

[hide] Diagnosing cystic fibrosis: blood, sweat, and tear... Arch Dis Child. 1997 Feb;76(2):85-8. Wallis C
Diagnosing cystic fibrosis: blood, sweat, and tears.
Arch Dis Child. 1997 Feb;76(2):85-8., [PMID:9068292]

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29 Pancreatic insuYciency appears to correlate with diVerent gene mutations at the CFTR locus21 (for example R117H, R334W, R347P, P574H), but to date there has not been a satisfactory correlation between a high chloride conduction (that is a high sweat test result )22 or severe pulmonary disease and genotyping.23 The most surprising finding to emanate from the numerous phenotype-genotype correlation studies that festoon the cystic fibrosis literature, is a new understanding of the wide phenotypic range that an individual, homozygous for a mutation in the CFTR gene, can present. Login to comment

[hide] Genotype-phenotype relationship in 12 patients car... J Med Genet. 1997 Feb;34(2):89-91. Antinolo G, Borrego S, Gili M, Dapena J, Alfageme I, Reina F
Genotype-phenotype relationship in 12 patients carrying cystic fibrosis mutation R334W.
J Med Genet. 1997 Feb;34(2):89-91., [PMID:9039981]

Abstract [show]
We present a phenotype-genotype correlation analysis in 12 patients with cystic fibrosis (CF) carrying the mutation R334W in the CFTR gene. The clinical data obtained for this group were compared with the clinical data of deltaF508/deltaF508 patients. Current age and age at diagnosis were significantly higher in the R334W mutation group (p=0.028 and p=0.0001). We found a lower rate of Pseudomonas aeruginosa colonisation in patients carrying the R334W mutation, although the difference was not found to be statistically significant. However, we found a statistically significant higher age of onset of Pseudomonas aeruginosa colonisation (p=0.0036) in the group of patients with the R334W mutation. Thirty three percent of R334W patients were pancreatic insufficient, significantly lower than the deltaF508/deltaF508 patients (p=0.004). We also found that the weight expressed as a percentage of ideal weight for height was significantly higher in patients with the R334W mutation (p=0.0028).

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36 '2 Class IV mutations (for example, RI 17H, R334W, and R347P) occur in the membrane spanning domains and are predicted to cause a mild CF phenotype. Login to comment
80 13 Morral N, Llevadot R, Casals T, et al. Independent origins of cystic fibrosis mutations R334W, R347P, Ri 162X, and 3849+1OkbCT provide evidence ofmutation recurrence in the CFTR gene. Login to comment
79 Independent origins of cystic fibrosis mutations R334W, R347P, Ri 162X, and 3849+1OkbCT provide evidence ofmutation recurrence in the CFTR gene. Login to comment

[hide] Rapid characterization of the variable length poly... Hum Mutat. 1997;10(2):108-15. Friedman KJ, Heim RA, Knowles MR, Silverman LM
Rapid characterization of the variable length polythymidine tract in the cystic fibrosis (CFTR) gene: association of the 5T allele with selected CFTR mutations and its incidence in atypical sinopulmonary disease.
Hum Mutat. 1997;10(2):108-15., [PMID:9259194]

Abstract [show]
The CFTR intron 8 variable length polythymidine tract modulates the cystic fibrosis (CF) phenotype associated with the mutation R117H. To explore whether other mutations reside on multiple intron 8 backgrounds with discernible impacts on phenotype, we developed an allele-specific PCR assay to characterize this locus. Our approach types samples rapidly without the use or radioisotopes. Polythymidine alleles were identified for mutations either associated with a wide range of clinical phenotypes (R117H, R347P, G85E, D1152H, R334W, 2789 + 5 G > A, 3849 + 10kb C > T), and/or located at hypermutable CpG loci (R117H, 3845 + 10kb C > T, R553X, R334W, S945L and R75Q). R117H was detected in cis with each of three alleles (5T, 7T, 9T) at the intron 8 locus. The novel R117H-9T association was detected in a 10-month African-American male with borderline-to-mildly elevated sweat chloride values (approximately 50-66 mEq/L). All other mutations studied were associated with 7T except 3849 + 10kb C > T, which was detected on both 7T and 9T backgrounds, but not 5T. Three individuals with a delta F508/3849 + 10kb C > T genotype were 9T,9T and had pancreatic sufficiency and normal sweat chloride values, whereas 15 others who carried 3849 + 10kb C > T on a 7T background had variable pancreatic function (sufficient, n = 12, insufficient, n = 3), and variable sweat chloride values (normal, n = 12, elevated, n = 3). Surprisingly, when not associated with known CFTR mutations, 5T was detected with elevated frequency among individuals with sinopulmonary disease of ill-defined etiology, but with some characteristics of variant CF. In summary, the 5T allele was not found in cis with CF-causing mutations besides R117H, but an elevated 5T allele frequency in variant CF patients suggests 5T may be associated with disease in some situations.

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3 Polythymidine alleles were identified for mutations either associated with a wide range of clinical phenotypes (R117H, R347P, G85E, D1152H, R334W, 2789+5 G>A, 3849+10kb C>T), and/or located at hypermutable CpG loci (R117H, 3849+10kb C>T, R553X, R334W, S945L and R75Q). Login to comment
37 We report the development of a rapid, nonisotopic assay that facilitates typing of this locus and utilize it to explore the role of the polythymidine tract alleles in thepathogenesisofCF.Mutationsassociatedwithclini- calheterogeneity(R347P,G85E,D1152H,R334W,and 3849 + 10kb C>T) and/or occurring at hypermutable loci (3849 + 10kb C>T, R334W, S945L, R553X, and R75Q) were analyzed for their association with different intron 8 alleles in CF and atypical patients. Login to comment
39 Mutation screening was performed for R553X (Cutting et al., 1990), R334W (Gasparini et al., 1991), G85E (Zielenski et al., 1991a), S945L (Claustres et al., 1993), 3849 + 10kb C>T (Highsmith et al., 1994), R117H and R347P (Dean et al., 1990), 2789+5G>A (Highsmith et al., 1997), D1152H (Highsmith, per. Login to comment
44 R117H, R347P, D1152H, and R75Q required electrophoresis at 230 V for 5 hr in a 10% polyacrylamide gel. Login to comment
94 Association of Selected CFTR Mutations with Intron 8 Polythymidine Alleles Chromosomes In cis with In cis with In cis with Mutation Site CpG locus 5T 7T 9T R75Qa EXON 3 Y 0 8 0 G85E EXON 3 N 0 5 0 R117H EXON 4 Y 8 5 1 R334W EXON 7 Y 0 4 0 R347P EXON 7 N 0 7 0 R553X EXON 11 Y 0 7 0 2789+5 G>A INTRON 14B N 0 5 0 S945L EXON 15 Y 0 3 0 D1152H EXON 18 N 0 7 0 3849+10kb C>T INTRON 19 Y 0 15 2 a Sequence variant. Login to comment

[hide] Sensitivity of the denaturing gradient gel electro... Hum Mutat. 1997;9(2):136-47. Macek M Jr, Mercier B, Mackova A, Miller PW, Hamosh A, Ferec C, Cutting GR
Sensitivity of the denaturing gradient gel electrophoresis technique in detection of known mutations and novel Asian mutations in the CFTR gene.
Hum Mutat. 1997;9(2):136-47., [PMID:9067754]

Abstract [show]
More than 500 mutations have been identified in the CFTR gene, making it an excellent system for testing mutation scanning techniques. To assess the sensitivity of denaturing gradient gel electrophoresis (DGGE), we collected a representative group of 202 CFTR mutations. All mutations analyzed were detected by scanning methods other than the DGGE approach evaluated in this study. DGGE analysis was performed on 24 of the 27 exons and their flanking splice site sequences. After optimization, 201 of the 202 control samples produced an altered migration pattern in the region in which an alteration occurred. The remaining sample was sequenced and found not to have the reported mutation. The ability of DGGE to identify novel mutations was evaluated in three Asian CF patients with four unknown CF alleles. Three novel Asian mutations were detected-K166E, L568X, and 3121-2 A-->G (in homozygosity)-accounting for all CF alleles. These results indicate that an optimized DGGE scanning strategy is highly sensitive and specific and can detect 100% of mutations.

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42 621 + 1 GÃT, R334W, R347P, A455E, aI507, aF508, 1717-1 GÃA, G542X, S549N, G551D, R553X, R560T, 3849 + 10kb CÃT, W1282X, and N1303K) was performed using the rapid multiplex reverse dot hybridization system, under conditions provided by Roche Molecular Systems (Alameda, CA) (Kawasaki et al., 1993; Welsh et al., 1995). Login to comment

[hide] Description of a symptomless cystic fibrosis L346P... Mol Cell Probes. 1996 Aug;10(4):315-8. Deltas CC, Boteva K, Georgiou A, Papageorgiou E, Georgiou C
Description of a symptomless cystic fibrosis L346P/M348K compound heterozygous Cypriot individual.
Mol Cell Probes. 1996 Aug;10(4):315-8., [PMID:8865181]

Abstract [show]
During the past few years we have been testing the hypothesis that Cyprus may have been spared many severe cystic fibrosis (CF) cases but not cystic fibrosis transmembrane conductance regulator (CFTR) mutations. We have been analysing by molecular methods patients with atypical mild phenotypes where CF enters the differential diagnosis. With this approach we identified a mutation, L346P, which in association with the severe mutation delta F508 or 1677delTA, confers a mild and atypical presentation. Recently, we identified another entirely symptomless 48-year-old individual, with genotype L346P/M348K. The fact that M348K was initially identified in a severely affected Italian patient strengthens the hypothesis that L346P, a putative mild mutation, is dominant over severe ones. One other explanation is that M348K is not a causative defect but a rare polymorphism. These findings have important implications for genetic counselling, especially when the counselling is sought by concerned couples for prenatal diagnostic purposes.

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38 Mutation R347P,14 which is right next toa carrier of another mutation, L346P, that she inherited from her mother. Login to comment

[hide] cAMP- and Ca2+-independent activation of cystic fi... J Biol Chem. 1996 Jul 5;271(27):16171-9. Becq F, Verrier B, Chang XB, Riordan JR, Hanrahan JW
cAMP- and Ca2+-independent activation of cystic fibrosis transmembrane conductance regulator channels by phenylimidazothiazole drugs.
J Biol Chem. 1996 Jul 5;271(27):16171-9., [PMID:8663098]

Abstract [show]
Patch-clamp, iodide efflux, and biochemical techniques were used to evaluate the ability of phenylimidazothiazoles to open normal and mutated cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels and to investigate the mechanism of activation. As reported previously for bromotetramisole, levamisole activated wild-type CFTR channels stably expressed in Chinese hamster ovary cells in the absence of other secretagogues and without elevating intracellular cAMP or calcium. The protein kinase A (PKA) inhibitor N - (2-(p-bromocinnamylamino)ethyl)-5-isoquinolinesul-fonamid e abolished activation by forskolin but only partially inhibited stimulation by levamisole, suggesting the involvement of other kinases. CFTR channels bearing mutations at multiple phosphorylation sites, in the membrane domains, and in the first nucleotide binding domain (including the disease-causing mutations G551D and DeltaF508) all responded to phenylimidazothiazoles. Moreover, levamisole and bromotetramisole increased the activity of wild-type and mutant channels already exposed to PKA + MgATP, consistent with the inhibition of a constitutive, membrane-associated phosphatase activity. We conclude that phenylimidazothiazole drugs can open normal and mutated CFTR channels by stabilization of phosphoforms of CFTR that are produced by basal activity of PKA and alternative protein kinases. If similar stimulation is observed in humans in vivo, phenylimidazothiazoles may be useful in the development of pharmacological therapies for cystic fibrosis.

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153 We also examined a CFTR mutation (R347D) that is at a residue where disease-causing mutations have been identified (R347P and R347H). Login to comment
152 We also examined a CFTR mutation (R347D) that is at a residue where disease-causing mutations have been identified (R347P and R347H). Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Am J Hum Genet. 1996 Jul;59(1):45-51. Miller PW, Hamosh A, Macek M Jr, Greenberger PA, MacLean J, Walden SM, Slavin RG, Cutting GR
Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in allergic bronchopulmonary aspergillosis.
Am J Hum Genet. 1996 Jul;59(1):45-51., [PMID:8659542]

Abstract [show]
The etiology of allergic bronchopulmonary aspergillosis (ABPA) is not well understood. A clinical phenotype resembling the pulmonary disease seen in cystic fibrosis (CF) patients can occur in some individuals with ABPA. Reports of familial occurrence of ABPA and increased incidence in CF patients suggest a possible genetic basis for the disease. To test this possibility, the entire coding region of the cystic fibrosis transmembrane regulator (CFTR) gene was analyzed in 11 individuals who met strict criteria for the diagnosis of ABPA and had normal sweat electrolytes (< or = 40 mmol/liter). One patient carried two CF mutations (deltaF508/R347H), and five were found to carry one CF mutation (four deltaF508; one R117H). The frequency of the deltaF508 mutation in patients with ABPA was significantly higher than in 53 Caucasian patients with chronic bronchitis (P < .0003) and the general population (P < .003). These results suggest that CFTR plays an etiologic role in a subset of ABPA patients.

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63 DNA samples from ABPA patients were screened for nine additional mutations associated with pancreatic sufficient and atypical CF: R117H (ASO), R347P (NcoI digest) and R347H (HhaI digest), R334W (MspI digest), A455E (ASO and BamHI digest), G551S (ASO) (Strong et al. 1991), 2789+5G-*A (ASO), D1152H (ASO) (Tsui 1992), and 3849+10kbC-*T (ASO and HphI digest) (Highsmith et al. 1994). Login to comment

[hide] Contribution of proline residues in the membrane-s... J Biol Chem. 1996 Jun 21;271(25):14995-5001. Sheppard DN, Travis SM, Ishihara H, Welsh MJ
Contribution of proline residues in the membrane-spanning domains of cystic fibrosis transmembrane conductance regulator to chloride channel function.
J Biol Chem. 1996 Jun 21;271(25):14995-5001., [PMID:8663008]

Abstract [show]
Proline residues located in membrane-spanning domains of transport proteins are thought to play an important structural role. In the cystic fibrosis transmembrane conductance regulator (CFTR), the predicted transmembrane segments contain four prolines: Pro99, Pro205, Pro324, and Pro1021. These residues are conserved across species, and mutations of two (P99L and P205S) are associated with cystic fibrosis. To evaluate the contribution of these prolines to CFTR Cl- channel function, we mutated each residue individually to either alanine or glycine or mutated all four simultaneously to alanine (P-Quad-A). We also constructed the two cystic fibrosis-associated mutations. cAMP agonists stimulated whole cell Cl- currents in HeLa cells expressing the individual constructs that resembled those produced by wild-type CFTR. However, the amount of current was decreased in the rank order: wild-type CFTR = Pro324 > Pro1021 > Pro99 >/= Pro205 mutants. The anion selectivity sequence of the mutants (Br- >/= Cl- > I-) resembled wild-type except for P99L (Br- >/= Cl- = I-). Although the Pro99, Pro324, and Pro1021 mutants produced mature protein, the amount of mature protein was much reduced with the Pro205 mutants, and the P-Quad-A made none. Because the Pro99 constructs produced mature protein but had altered whole cell currents, we investigated their single-channel properties. Mutant channels were regulated like wild-type CFTR; however, single-channel conductance was decreased in the rank order: wild-type CFTR >/= P99G > P99L >/= P99A. These results suggest that proline residues in the transmembrane segments are important for CFTR function, Pro205 is critical for correct protein processing, and Pro99 may contribute either directly or indirectly to the Cl- channel pore.

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215 The present results complement and extend our previous study of mild CF mutants located in MSD1 (R117H, R334W, and R347P). Login to comment
223 The present results complement and extend our previous study of mild CF mutants located in MSD1 (R117H, R334W, and R347P). Login to comment

[hide] Disease-associated mutations in the fourth cytopla... J Biol Chem. 1996 Jun 21;271(25):15139-45. Seibert FS, Linsdell P, Loo TW, Hanrahan JW, Clarke DM, Riordan JR
Disease-associated mutations in the fourth cytoplasmic loop of cystic fibrosis transmembrane conductance regulator compromise biosynthetic processing and chloride channel activity.
J Biol Chem. 1996 Jun 21;271(25):15139-45., [PMID:8662892]

Abstract [show]
A cluster of 18 point mutations in exon 17b of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has been detected in patients with cystic fibrosis. These mutations cause single amino acid substitutions in the most C-terminal cytoplasmic loop (CL4, residues 1035-1102) of the CFTR chloride channel. Heterologous expression of the mutants showed that 12 produced only core-glycosylated CFTR, which was retained in the endoplasmic reticulum; the other six mutants matured and reached the cell surface. In some cases substitution of one member of pairs of adjacent residues resulted in misprocessing, whereas the other did not. Thus, the secondary structure of CL4 may contribute crucially to the proper folding of the entire CFTR molecule. Cyclic AMP-stimulated iodide efflux was not detected from cells expressing the misprocessed variants but was from the other six, indicating that their mutations cause relatively subtle channel defects. Consistent with this, these latter mutations generally are present in patients who are pancreatic-sufficient, while the processing mutants are mostly from patients who are pancreatic-insufficient. Single-channel patch-clamp analysis demonstrated that the processed mutants had the same ohmic conductance as wild-type CFTR, but a lower open probability, generally due to an increase in channel mean closed time and a reduction in mean open time. This suggests that mutations in CL4 do not affect pore properties of CFTR, but disrupt the mechanism of channel gating.

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88 Other disease-causing CFTR mutants, which are appropriately processed and trafficked to the plasma membrane, show defective ion conduction properties (e.g. R334W, R347H, and R347P; Sheppard et al., 1993; Tabcharani et al., 1993) or defective regulation of channel activity (e.g. G551S, G1244E, S1255P, and G1349D; Anderson and Welsh, 1992). Login to comment
95 Other disease-causing CFTR mutants, which are appropriately processed and trafficked to the plasma membrane, show defective ion conduction properties (e.g. R334W, R347H, and R347P; Sheppard et al., 1993; Tabcharani et al., 1993) or defective regulation of channel activity (e.g. G551S, G1244E, S1255P, and G1349D; Anderson and Welsh, 1992). Login to comment

[hide] Identification of cystic fibrosis transmembrane co... Biophys J. 1996 Jun;70(6):2688-95. Cheung M, Akabas MH
Identification of cystic fibrosis transmembrane conductance regulator channel-lining residues in and flanking the M6 membrane-spanning segment.
Biophys J. 1996 Jun;70(6):2688-95., [PMID:8744306]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) forms a chloride channel that is regulated by phosphorylation and ATP binding. Work by others suggested that some residues in the sixth transmembrane segment (M6) might be exposed in the channel and play a role in ion conduction and selectivity. To identify the residues in M6 that are exposed in the channel and the secondary structure of M6, we used the substituted cysteine accessibility method. We mutated to cysteine, one at a time, 24 consecutive residues in and flanking the M6 segment and expressed these mutants in Xenopus oocytes. We determined the accessibility of the engineered cysteines to charged, lipophobic, sulfhydryl-specific methanethiosulfonate (MTS) reagents applied extracellularly. The cysteines substituted for Ile331, Leu333, Arg334, Lys335, Phe337, Ser341, Ile344, Arg347, Thr351, Arg352, and Gln353 reacted with the MTS reagents, and we infer that they are exposed on the water-accessible surface of the protein. From the pattern of the exposed residues we infer that the secondary structure of the M6 segment includes both alpha-helical and extended regions. The diameter of the channel from the extracellular end to the level of Gln353 must be at least 6 A to allow the MTS reagents to reach these residues.

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198 The mutations R334W and R347P have been shown to reduce single-channel conductance and open probability (Sheppard et al., 1993). Login to comment
196 The mutations R334W and R347P have been shown to reduce single-channel conductance and open probability (Sheppard et al., 1993). Login to comment

[hide] CFTR channels expressed in CHO cells do not have d... J Membr Biol. 1996 May;151(2):139-48. Grygorczyk R, Tabcharani JA, Hanrahan JW
CFTR channels expressed in CHO cells do not have detectable ATP conductance.
J Membr Biol. 1996 May;151(2):139-48., [PMID:8661502]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated, ATP-dependent chloride channel which may have additional functions. Recent reports that CFTR mediates substantial electrodiffusion of ATP from epithelial cells have led to the proposal that CFTR regulates other ion channels through an autocrine mechanism involving ATP. The aim of this study was to determine the ATP conductance of wild-type CFTR channels stably expressed in Chinese hamster ovary cells using patch clamp techniques. In the cell-attached configuration with 100 mM Mg middle dot ATP or Tris middle dot ATP solution in the pipette and 140 mM NaCl in the bath, exposing cells to forskolin caused the activation of a low-conductance channel having kinetics resembling those of CFTR. Single channel currents were negative at the resting membrane potential (Vm), consistent with net diffusion of Cl from the cell into the pipette. The transitions decreased in amplitude, but did not reverse direction, as Vm was clamped at increasingly positive potentials to enhance the driving force for inward ATP flow (>+80 mV). In excised patches, single channel currents did not reverse under essentially biionic conditions (Clin/ATPout or ATPin/Clout), although PKA-activated currents were clearly visible in the same patches at voltages where they would be carried by chloride ions. Moreover, with NaCl solution in the bath and a mixture of ATP and Cl in the pipette, the single channel I/V curve reversed at the predicted equilibrium potential for chloride. CFTR channel currents disappeared when patches were exposed to symmetrical ATP solutions and were restored by reexposure to Cl solution. Finally, in the whole-cell configuration with NaCl in the bath and 100 mM MgATP or TrisATP in the pipette, cAMP-stimulated cells had time-independent, outwardly rectifying currents consistent with CFTR selectivity for external Cl over internal ATP. Whole-cell currents reversed near Vm = -55 mV under these conditions, however the whole cell resistance measured at -100 mV was comparable to that of the gigaohm seal between the plasma membrane and glass pipette (7 Gomega). We conclude that CFTR does not mediate detectable electrodiffusion of ATP.

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15 Thus, mutations that cause mislocalization (⌬F508; [11]) or inhibit responsiveness to secretagogues (G551D; [13]) are usually associated with severe disease symptoms, whereas mutations that only partially reduce open probability (R117H; [26, 5]), single channel conductance (R347P/H; [25, 26]), or targeting to the plasma membrane (A445E; [25]) correlate with milder disease symptoms [31]. Login to comment

[hide] Survey of cystic fibrosis transmembrane conductanc... Dig Dis Sci. 1996 Mar;41(3):540-2. McGill JM, Williams DM, Hunt CM
Survey of cystic fibrosis transmembrane conductance regulator genotypes in primary sclerosing cholangitis.
Dig Dis Sci. 1996 Mar;41(3):540-2., [PMID:8617131]

Abstract [show]
A variety of cholestatic liver diseases appear to primarily affect the biliary epithelium, including cystic fibrosis (CF). CF results from a defect in the chloride channel protein, cystic fibrosis transmembrane conductance regulator (CFTR). Although the majority of CF patients have a genomic deletion in deltaF508, other mutations of CFTR may result in less severe clinical presentations and outcomes. Recently, CFTR has been shown to be involved in secretin-stimulated choleresis in intrahepatic bile duct epithelial cells. Cholestasis in cystic fibrosis appears to result from defective chloride transport across the biliary epithelium and is the only cholestatic disease of bile ducts for which a cellular defect has been identified. Primary sclerosing cholangitis (PSC) is a cholestatic disease with histological and cholangiographic features similar to CF. The purpose of this pilot study was to explore whether there is an increased prevalence of CFTR mutations. Two patients exhibited mutations in one allele, yielding a carrier rate of 10.6%, not statistically different from the general U.S. population carrier rate of 4%.

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33 In total, 32 mutations were evaluated, which represent 90% of the most common mutations (t4): AF508 G542X G551D W1282X 3905insT NI303K 3849+ 10kbC--~T R553X 621+ IG--*T 1717- IG--,A lt)78delT 2789+5G---~A 3849+4A--~G 711+ IG---oT R1162X 1898+IG----~A R117H 3659delC G85E 2184delA A1507 R347P Y1092X R560T A455E R334W Y122X S549R(T---~G) Q493X V520F $549N R347H Patient Selection. Login to comment

[hide] Mutation characterization of CFTR gene in 206 Nort... Hum Mutat. 1996;8(4):340-7. Hughes DJ, Hill AJ, Macek M Jr, Redmond AO, Nevin NC, Graham CA
Mutation characterization of CFTR gene in 206 Northern Irish CF families: thirty mutations, including two novel, account for approximately 94% of CF chromosomes.
Hum Mutat. 1996;8(4):340-7., [PMID:8956039]

Abstract [show]
A variety of mutation detection techniques, including restriction endonuclease digestion, allele specific oligonucleotides, and automated fluorescent sequencing, were used in the identification of 15 CFTR mutations representing 86.7% of CF chromosomes in 206 Northern Irish cystic fibrosis (CF) families. A systematic analysis of the 27 exons and intron/exon boundaries of the CFTR gene was performed using denaturing gradient gel electrophoresis (DGGE) in an attempt to characterise the 55 unknown CF mutations in 51 patients. Twenty different mutations were detected by DGGE on 30 chromosomes accounting for a further 7.3% of CF alleles. Fifteen of these mutations had not previously been found in Northern Ireland, and two are novel, M1I(G > T) and V562L. In total, 30 CFTR mutations account for 93.9% of the 412 Northern Irish CF chromosomes tested. The three major CF mutations in Northern Ireland are delta F508, G551D, and R117H with respective frequencies of 68.0%, 5.1%, and 4.1%. The efficacy of the DGGE technique was proven by the detection of 77 out of 77 control variants from all the CFTR exons. DGGE is a highly efficient and sensitive method for mutation screening especially in large genes where the mutation spectrum is known to be heterogeneous.

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74 441delA, 557delT 711+1G>T, 711+3A>G H199Y, L206W 977insA R297Q 1078delT,R334W, 1154insTC, R347P W401X l46linsAGAT 1525- 1G>A, A1507, AI5071AF508. Login to comment

[hide] Fluorescent multiplex microsatellites used to defi... Hum Mutat. 1996;8(3):229-35. Hughes D, Wallace A, Taylor J, Tassabehji M, McMahon R, Hill A, Nevin N, Graham C
Fluorescent multiplex microsatellites used to define haplotypes associated with 75 CFTR mutations from the UK on 437 CF chromosomes.
Hum Mutat. 1996;8(3):229-35., [PMID:8889582]

Abstract [show]
The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene contains three highly informative microsatellites: IVS8CA, IVS17bTA, and IVS17bCA. Their analysis improves prenatal/ carrier diagnosis and generates haplotypes from CF chromosomes that are strongly associated with specific mutations. Microsatellite haplotypes were defined for 75 CFTR mutations carried on 437 CF chromosomes (220 for delta F508, 217 for other mutations) from Northern Ireland and three English regions: the North-West, East Anglia, and the South. Fluorescently labelled microsatellites were amplified in a triplex PCR reaction and typed using an ABI 373A fluorescent fragment analyser. These mutations cover all the common and most of the rare CF defects found in the UK, and their corresponding haplotypes and geographic region are tabulated here. Ancient mutations, delta F508, G542X, N1303K, were associated with several related haplotypes due to slippage during replication, whereas other common mutations were associated with the one respective haplotype (e.g., G551D and R560T with 16-7-17, R117H with 16-30-13, 621 + 1G > T with 21-31-13, 3659delC with 16-35-13). This simple, fast, and automated method for fluorescent typing of these haplotypes will help to direct mutation screening for uncharacterised CF chromosomes.

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74 CF 8CA-17bTA-17bCA Mutation chromosomes % Normal Laboratoryb Reference' HaplotVpe 1)15-29-13 557delT Nl Graham et al.. 1992 21 16-07-17 MU (G>T) 3) 16-24-13 4) 16-25-13 5) 16-29-13 6) 16-30-13 7) 16-30-14 8) 16-31-13 9) 16-31-14 10) 16-32-13 12) 16-33-13 13) 16-34-13 14) 16-35-13 11)16-32-17 15)1645-13 16) 1646-13 17) 1646-14 19) 17-07-17 18)16-53-13 20)17-29-14 21) 17-31-13 22) 17-32-13 23) 17-35-13 24) 17-51-11 25) 17-55-13 27) 17-58-13 28) 21-31-13 29) 22-31-13 31)23-22-17 26) 17-56-13 30) 22-33-13 32) 23-29-13 33)23-31-13 34)23-32-13 35)23-33-13 36)23-34-13 37) 23-36-13 38)24-22-17 39) 24-31-13 182delT P67L R75X L206W 1154insTC 146linsAGAT Q493x V520F 1717-1G>A G551D R560T V562L R709X S1196X L1254X R1283M G85E 2184insA 711+lG>T 3495delA 4279insA SlOR L88S R117C R117H G178R 1717-1G>A Y563N W1098R G1123R 3850- 1G>A E6OX %%deIT 1138insG R34P 2183AA>G 2184delA R1158X 1078delT R1162X 3849G>A Q141W R347P Y917C G2iX 711+3A>G 441delA 3130de115 3659delC 1898+1G>A R709X 2711delT R1158X E92K 3849+lOkbC>T 2118delAACT 4048insCC 296+1 2 T S Q22OX R297Q A1507 2789+5G>A 3120+1G>A W128W 1811+lG>C AF508 E831X R116W AF508 W846X1 3120G>A R785X R553X R553X R553X 621+1G>T G542X G542X Y1182X N1303K AF508 G54W 3041delG 1525-1G>A N1303K G542X G542X G542X 394delTT R709X N1303K 1 1 1 2 1 1 4 2 3 4 2 26 8 1 1 1 1 1 8 1 1 1 1 1 1 1 19 1 2 1 1 1 1 7 1 1 2 1 1 2 1 1 1 1 1 1 1 1 2 1 1 7 4 1 2 1 1 2 1 1 4 Asian 1 2 1Asian 5 4 i Afro-Caribbean 5 1 42 (19%) 1 1 57 (26%) 1 2 1 1 1 2 12 2 11.4 0.4 4.9 16.3 1.1 3.8 1.9 10.6 2.3 1.5 2.3 1.5 2.7 4.5 0.4 0.8 0.8 0.4 0.8 0.4 1 2 1 7 1 1 1Asian 1 1.5 0.8 0.8 NI G NI, M M NI NI. Login to comment

[hide] Haplotype analysis of 94 cystic fibrosis mutations... Hum Mutat. 1996;8(2):149-59. Morral N, Dork T, Llevadot R, Dziadek V, Mercier B, Ferec C, Costes B, Girodon E, Zielenski J, Tsui LC, Tummler B, Estivill X
Haplotype analysis of 94 cystic fibrosis mutations with seven polymorphic CFTR DNA markers.
Hum Mutat. 1996;8(2):149-59., [PMID:8844213]

Abstract [show]
We have analyzed 416 normal and 467 chromosomes carrying 94 different cystic fibrosis (CF) mutations with polymorphic genetic markers J44, IVS6aGATT, IVS8CA, T854, IVS17BTA, IVS17BCA, and TUB20. The number of mutations found with each haplotype is proportional to its frequency among normal chromosomes, suggesting that there is no preferential haplotype in which mutations arise and thus excluding possible selection for specific haplotypes. While many common mutations in the worldwide CF population showed absence of haplotype variation, indicating their recent origins, some mutations were associated with more than one haplotype. The most common CF mutations, delta F508, G542X, and N1303K, showed the highest number of slippage events at microsatellites, suggesting that they are the most ancient CF mutations. Recurrence was probably the case for 9 CF mutations (R117H, H199Y, R347YH, R347P, L558S, 2184insA, 3272-26A-->G, R1162X, and 3849 + 10kbC-->T). This analysis of 94 CF mutations should facilitate mutation screening and provides useful data for studies on population genetics of CF.

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91 Other mutations appeared in varioushaplotypes that were different at both microsatelliteand diallelic markers: R117H, H199Y, R347H, R347P, L558S, 2184insA, 3272-26A+G, R1162X, and 3849+10kbC-T (Table 4). Login to comment
96 One example is mutation R347P, which was found associatedwith two haplotypes, only differing at microsatellites IVS8CA and IVS17BTA (Table 4); as one haplotype was associatedwith haplotype A (XV-Zc/TaqI allele 1, KM.l9/PstI allele 1) and the other with haplotype C (XV-ZdTaqIallele 2, KM.19lPstI allele l) (5` to CFTR and not shown in Table 4), an independent origin for this mutation or a double recombination can be postulated. Login to comment
105 CFTR Haplotypes for Diallelic and Multiallelic DNA Markers for 94 CF Mutations" J44-GATT- 8CA-17BTA- No. of T854-TUB20 17BCA Mutation chromosomes % Normal Laboratory Reference 2-7-1-2 17-47-13 (55.4%) 17-46-13 17-45-13 17-34-13 17-32-13 17-31-14 17-31-13 17-29-14 17-28-13 16-48-13 16-46-14 16-46-13 16-45-13 16-44-13 16-35-13 16-33-13 16-32-13 16-31-14 16-31-13 16-30-13 16-29-13 16-26-13 16-25-13 16-24-13 14-31-13 1-7-2-1 17-7-17 (16.8%) R334W R334W 3860ins31 G1244E R1162X R1162X R1162X G91R MllOlK R347P R334W R117C E92K 3849+lOkbC+T 3293delA 1811+1.6kb A-tG 1811+1.6kb A-tG 2184insA P205S 3659delC G673X 11005R I336K W58S R347P W846X 405+1-A G178R 3905insT R1162X R347H 3100insA E60X 1078delT 4005+1-A K710X 1677delTA H199Y 3601-2AjG 3850-3T+G 3272-26A-tG 3850-1-A 1812-1-A R117H L1059X S492F Y1092X Y569H 3732delA C866Y 711+1G+T 711+1-T G85E 1949del84 2789+5-A H1085R W1282X R1066C 2043delG V456F 2 1 1 1 2 1 6 2 2 1 2 1 1 2 1 1 4 1 1 1 3 2 1 1 1 1 1 1 2 7 1 1 1 1 2 1 1 3 19 3 3 1 1 2 1 1 5 1 1 1 1 3 6 3 5 1 13 2 1 1 - 0.48 0.48 - - - 0.24 - - - 2.65 2.40 1.93 2.65 1.68 2.65 0.72 13.94 13.46 1.93 - 0.72 0.24 3.37 - b b fP fP fP t b,fb.fP h fb t h t h h fP fP b.h b h h b h h h h h fb fb,fP.t fP fP fP9t fP b t fPh b h fb b.fb,h fb*fP b,fP h h t h fb fb,fp,h.t fP fP fb t b.fP,t b,fb,h,t b f b h h fb b,fb.fP,h fP h h Gasparini et al. (1991b) Chilldn et al. (1993a) Devoto et al. (1991) Gasparini et al. (1991b) Dork et al. (1993a) Guillermit et al. (1993) Zielenski et al. (1993) Dean et al. (1990) Dork et al. (1994a) Nunes et al. (1993) Highsmith et al. (1994) Ghanem et al. (1994) Chilldn et al. (1995) Dork et al. (1994a) Dork et al. (1993a) Chilldn et al. (1993b) Kerem et al. (1990) Dork et al. (1994a) Dork et al. (1994a) Cuppenset al. (1993) Fanen et al. (1992) Maggio et al. (personal communication) Audrezet et al. (1993) Vidaud et al. (1990) Dork et al. (1993b) Zielenski et al. (1991a) Chilldn et al. (1994b) Malik et al. (personal communication) Cremonesi et at. Login to comment
138 Nine mutations (R117H, H199Y, R347H, R347P, L558S, 2184insA, 3272-26A+G, R1162X, and 3849+10kbC+T) have been found associated with more than one haplotype for both diallelic and microsatellite markers. Login to comment
141 In addition, fiveof them (R177H, R347H, R347P, R1162X, and 3849+1OkbC-T) have occurredat CpG dinucleotides.Although it is difficult to prove recurrence for these mutations, this has already been postulated for severalCFmu- tations (Reisset al., 1991;Kiesewetteret al., 1993; Dork et al., 1994a; Morral et al., 1994b). Login to comment

[hide] Cystic fibrosis mutation detection by hybridizatio... Hum Mutat. 1996;7(3):244-55. Cronin MT, Fucini RV, Kim SM, Masino RS, Wespi RM, Miyada CG
Cystic fibrosis mutation detection by hybridization to light-generated DNA probe arrays.
Hum Mutat. 1996;7(3):244-55., [PMID:8829658]

Abstract [show]
We have combined photochemistry and photolithography with solid-phase DNA synthesis chemistry to form a new technology that makes high density oligonucleotide probe array synthesis possible. Hybridization to these two-dimensional arrays containing hundreds or thousands of oligonucleotide probes provides a powerful DNA sequence analysis tool. Two types of light-generated DNA probe arrays have been used to test for a variety of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. One array, made up of 428 probes, was designed to scan through the length of CFTR exon 11 and identify differences from the wild type reference sequence. The second type of array contained 1480 probes chosen to detect known deletions, insertions, or base substitution mutations. The validity of the probe arrays was established by hybridizing them with fluorescently labeled control oligonucleotide targets. Characterized mutant CFTR genomic DNA samples were then used to further test probe array hybridization specificity. Finally, ten unknown patient samples were genotyped using the CFTR probe array assay. The genotype assignments were identical to those obtained by PCR product restriction fragment analysis. Our results show that light-generated DNA probe arrays are highly effective in analyzing complex mutation and polymorphism patterns in a relatively large gene such as CFTR.

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238 Cystic Fibrosis Mutation-Specific DNA Probe Array" Mutation Exon and column Tested Subarrayhow G85E R117H I148T 621 -+ l(G+T) 711 + 1(G+T) R334W R347H R347P 1078 delT A455E G480C Q493X A1507 F508C AF508 V520F G542X S549R(T-+ G) G551D Q552X R553X A559T R560T 1898 + l(G-,A) 2184 del A 2789 + 5(G+ A) R1066C L1077P Y1092X R1162X 3659 del C 1717-1(& A) 3272 - 26(A+ G) 3 4 4 in 4 in 5 7 7 7 7 9 10 10 10 10 10 10 in 10 11 11 11 11 11 11 11 in 12 13 in 14b in 17a 17b 17b 17b 19 19 * * * * * * * * * * * * * * * * * * * * * * * * * * * * 3849 + lOkb C-, T in 19 9,3 W1282X 20 994 3905insT 20 10.1 * N1303K 21 10,2 * * * "Row and column locations for each of the mutation specific,40 probe sets included in the specialized probe array design. Login to comment

[hide] Methods for screening in cystic fibrosis. Methods Mol Med. 1996;5:99-119. Schwarz M, Malone G
Methods for screening in cystic fibrosis.
Methods Mol Med. 1996;5:99-119., [PMID:21374513]

Abstract [show]
Cystic fibrosis (CF) is the most common lethal autosomal recessive disorder in Whites, with an incidence of approx 1 m 2500 live births and a carrier frequency of approx 1 in 25. Since the discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene m 1989 (1-3), molecular genetics laboratories throughout the world have endeavored to identify the mutations present in their population of CF-bearing chromosomes. Since the entire CFTR gene and its intron-exon boundaries have been sequenced, mutation analysis in CF has become relatively simple, although time consuming. Generally, a number of different methods are applied to mutation analysis, but all involve an imtial step of amplification of part of the gene by polymerase chain reaction (PCR) (4), or a derivative of it, such as amplification refractory mutation system (ARMS) (5).

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42 Screening in Cystic Fibrosis 107 Table 5 CF Mutations Detectable by Restriction Endonuclease (RE) Digestion of PCR Products Mutation PCR primers0 RE RE digestion product sizes, bpbJ Normal Mutant G85E 621+ 1 (G`V 1154insTC R334W R347P G551D R553X R560T S549N 3849+ IOkb CC ` T) W1282X 3i5 and 313 4i5 and 4i3 Hinff MseI 105 + 204 33,35,71, 118, 181 7i5 and 7i3 MspI, RsaI 50,68,74 + 21V 715 and 7i3 MspI 192 + 218 7i5 and 7i3 CfoI 151+ 259 1li5 and 1113 Mb01 425 1115 and lli3 HzncII 186 + 239 lli5 and lli3 Mae11 425 lli5 and lli3 DdeI 13, 174 + 238 i19F and i19R HphI 88 + 349 2Oi5 and 2Oi3 Mnfl 185 + 288 309 33,35,54,71, 118, 127 50,68,76 + 21gc 410 410 182+243 425 215 + 210 13 + 412 88,127 + 222 473 'See Table 2 bThe expected digestion product sizes for both normal and mutant sequences are shown CTheseproducts may be d1stmgmshedby PAGE 1.2.3. Login to comment

[hide] Chloride channels and cystic fibrosis of the pancr... Biosci Rep. 1995 Dec;15(6):531-41. Gray MA, Winpenny JP, Verdon B, McAlroy H, Argent BE
Chloride channels and cystic fibrosis of the pancreas.
Biosci Rep. 1995 Dec;15(6):531-41., [PMID:9156582]

Abstract [show]
Cystic fibrosis (CF) affects approximately 1 in 2000 people making it one of the commonest fatal, inherited diseases in the Caucasian population. CF is caused by mutations in a cyclic AMP-regulated chloride channel known as CFTR, which is found on the apical plasma membrane of many exocrine epithelial cells. In the CF pancreas, dysfunction of the CFTR reduces the secretory activity of the tubular duct cells, which leads to blockage of the ductal system and eventual fibrosis of the whole gland. One possible approach to treating the disease would be to activate an alternative chloride channel capable of bypassing defective CFTR. A strong candidate for this is a chloride channel regulated by intracellular calcium, which has recently been shown to protect the pancreas in transgenic CF mice. Pharmacological intervention directed at activating this calcium-activated Cl- conductance might provide a possible therapy to treat the problems of pancreatic dysfunction in CF.

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116 The first group involve missense mutations of arginine residues within the pore-forming domain MSD1 (R117H, R334W and R347P), which collectively account for approximatley 2% of CF patients. Login to comment
117 The second group involves residues within NBD1 (A455E and P574H) which are located close to the walker A (residues 458-464) and B (residues 568-572) motifs, crucial for ATP binding. Login to comment

[hide] Correlation of sweat chloride concentration with c... J Pediatr. 1995 Nov;127(5):705-10. Wilschanski M, Zielenski J, Markiewicz D, Tsui LC, Corey M, Levison H, Durie PR
Correlation of sweat chloride concentration with classes of the cystic fibrosis transmembrane conductance regulator gene mutations.
J Pediatr. 1995 Nov;127(5):705-10., [PMID:7472820]

Abstract [show]
OBJECTIVE: To compare differences in epithelial chloride conductance according to class of mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. METHODS: We evaluated the relationship between the functional classes of CFTR mutations and chloride conductance using the first diagnostic sweat chloride concentration in a large cystic fibrosis (CF) population. RESULTS: There was no difference in sweat chloride value value between classes of CFTR mutations that produce no protein (class I), fail to reach the apical membrane because of defective processing (class II), or produce protein that fails to respond to cyclic adenosine monophosphate (class III). Those mutations that produce a cyclic adenosine monophosphate-responsive channel with reduced conductance (class IV) were associated with a significantly lower, intermediate sweat chloride value. However, patients with the mutations that cause reduced synthesis or partially defective processing of normal CFTR (class V) had sweat chloride concentrations similar to those in classes I to III. CONCLUSION: Studies of differences in chloride conductance between functional classes of CFTR mutations provide insight into phenotypic expression of the disease.

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43 Defined mutations (each mutation cited in references 8, 23, and 24; numerals in parentheses indicate number of patients): Nonsense mutations-----class I: Frameshift mutations---class I: Splice site mutations-class I: Missense mutations---class HI: Missense mutations---class IV: Partially defective processing---class V: Alternative spficing-----classV: R1162X (3), Y1092X (3), G542X (21), Q552X (2), Q493X (2), w1282x (2), E1104X (1), R553X (6), E585X (l), (all PI) 3659delC (5), 2184delA (4), 4010de14 (1), 556delA (1), 3002delG (1) 3905insT (1), 4016insT (3), 1154insTC (l), 441delA (1), 2184insA (2), 1078delT (1), 4326delTC (3) (all PI) I717-1G--~A (4), 621+lG--*T (10), 711+IG--~T (3), 875+1G-+C (2), 3120+IG-~A (1) (18 PI, 2 PS) G551D (25), N1303K (7), R560T (8), I148T (1), G85E (3), A559T (1), L1077P (2), T1234V (1), (47 PI, 1 PS) R117H (10), R347H (3), R347P (1), D614G (1), S1251N (2), (all PS) P574H (2), A455E (2), (all PS) 3272-26A-+G (4), 3849+10KbC---~T (2), 3120G-+A (1), (all PS) analysis, we further grouped the patients according to the molecular consequences conferred by the CFTR alleles. Login to comment
79 When channel function was examined by patch clamp studies, three missense CFFR gene mutations (Rll7H, R334W, R347P) were correctly processed and transported to the apical membrane. Login to comment

[hide] Severity of disease in cystic fibrosis. Lancet. 1995 Oct 14;346(8981):1036-7. Dork T, Stuhrmann M
Severity of disease in cystic fibrosis.
Lancet. 1995 Oct 14;346(8981):1036-7., [PMID:7475569]

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56 Pediatr Pulmonol 1994; 10 (suppl): 215. 4 Morral N, Llevadot R, Casals T, et al. Independent origins of cystic fibrosis mutations R334W, R347P, R1162X, and 3849+10 kb C→T provide evidence of mutation recurrence in the CFTR gene. Login to comment
55 Independent origins of cystic fibrosis mutations R334W, R347P, R1162X, and 3849+10 kb C→T provide evidence of mutation recurrence in the CFTR gene. Login to comment

[hide] Screening Young syndrome patients for CFTR mutatio... Am J Respir Crit Care Med. 1995 Oct;152(4 Pt 1):1353-7. Friedman KJ, Teichtahl H, De Kretser DM, Temple-Smith P, Southwick GJ, Silverman LM, Highsmith WE Jr, Boucher RC, Knowles MR
Screening Young syndrome patients for CFTR mutations.
Am J Respir Crit Care Med. 1995 Oct;152(4 Pt 1):1353-7., [PMID:7551394]

Abstract [show]
Young syndrome is characterized by obstructive azoospermia associated with chronic sinobronchial disease of an infectious nature, but normal sweat-gland and pancreatic function as well as normal nasal potential differences. Congenital bilateral absence of the vas deferens (CBAVD) in some patients arises from mutations within the cystic fibrosis (CF) transmembrane regulator (CFTR) gene. Because of some similarities between Young syndrome, CF, and CBAVD, we evaluated 13 patients with Young syndrome, including screening for more than 30 different mutations within the CFTR gene. The mean age of the patients was 43 yr (range, 32 to 50 yr), and all were of northern European extraction. The sweat chloride concentration was normal in all patients (mean = 29 mEq/L; range, 8 to 43 mEq/L). Most had intermittent bronchial and sinus infections, but none was chronically colonized with Staphylococcus aureus or Pseudomonas aeruginosa. The FEV1 was normal or only mildly reduced in most patients (mean = 74%; range, 48 to 100% predicted). Of 26 Young syndrome chromosomes, we identified one with the recognized CF mutation delta F508. The incidence of CFTR mutations (1 in 26) did not differ significantly from the expected carrier frequency in this population. In summary, it is unlikely that the typical Young syndrome patient has a clinical disease associated with CFTR mutation on both alleles.

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78 Of the 13 Young syndrome patients, we identified one (Patient 5) who was het- CBAVD Dl152H D1270N G576A* R75Q* P67L Rl17H 3849 + 10 KB C > T G551S Rl17H Pancreatic Sufficient, Moderate Pulmonary Symptoms, Normal Sweat Chloride Concentrations Pancreatic Sufficient, Moderate Pulmonary Symptoms R347P 2789 + 5 G > A R334W G85E R347H R347L Rl17H G91R A455E S945L Y563N Q1291H R297Q R352Q L1065P 3850-3 T > G F1286S 3849 + 10 KB C > T TABLE 1 CFTR MUTATION SCREENING PANEL Severe M508 G551D R553X N1303K W1282X G542X 1717-1 G > A ~1507 R560T 3659deiC 621 + 1 G > T S549N TABLE 2 CLINICAL FEATURES OF YOUNG SYNDROME PATIENTS Patient Age Sweat CI- FEV, Paranasal Sputum No. Login to comment

[hide] A controlled study of adenoviral-vector-mediated g... N Engl J Med. 1995 Sep 28;333(13):823-31. Knowles MR, Hohneker KW, Zhou Z, Olsen JC, Noah TL, Hu PC, Leigh MW, Engelhardt JF, Edwards LJ, Jones KR, et al.
A controlled study of adenoviral-vector-mediated gene transfer in the nasal epithelium of patients with cystic fibrosis.
N Engl J Med. 1995 Sep 28;333(13):823-31., [PMID:7544439]

Abstract [show]
BACKGROUND: Cystic fibrosis is a monogenic disease that deranges multiple systems of ion transport in the airways, culminating in chronic infection and destruction of the lung. The introduction of a normal copy of the cystic fibrosis transmembrane conductance regulator (CFTR) gene into the airway epithelium through gene transfer is an attractive approach to correcting the underlying defects in patients with cystic fibrosis. We tested the feasibility of gene therapy using adenoviral vectors in the nasal epithelium of such patients. METHODS: An adenoviral vector containing the normal CFTR complementary DNA in four logarithmically increasing doses (estimated multiplicity of infection, 1, 10, 100, and 1000), or vehicle alone, was administered in a randomized, blinded fashion to the nasal epithelium of 12 patients with cystic fibrosis. Gene transfer was quantitated by molecular techniques that detected the expression of CFTR messenger RNA and by functional measurements of transepithelial potential differences (PDs) to assess abnormalities of ion transport specific to cystic fibrosis. The safety of this treatment was monitored by nasal lavage and biopsy to assess inflammation and vector replication. RESULTS: The adenoviral vector was detected in nasal-lavage fluid by culture, the polymerase chain reaction (PCR), or both in a dose-dependent fashion for up to eight days after vector administration. There was molecular evidence of gene transfer by reverse-transcriptase PCR assays or in situ hybridization in five of six patients treated at the two highest doses. However, the percentage of epithelial cells transfected by the vector was very low (< 1 percent), and measurement of PD across the epithelium revealed no significant restoration of chloride transport or normalization of sodium transport. At the lower doses of vector, there were no toxic effects. However, at the highest dose there was mucosal inflammation in two of three patients. CONCLUSIONS: In patients with cystic fibrosis, adenoviral-vector-mediated transfer of the CFTR gene did not correct functional defects in nasal epithelium, and local inflammatory responses limited the dose of adenovirus that could be administered to overcome the inefficiency of gene transfer.

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51 *N1303K indicates a substitution of lysine for asparagine at amino acid position 1303, and R347P a substitution of proline for arginine at position 347. Login to comment
55 SEX/AGE (YR) GENOTYPE* ADENOVIRAL VECTOR CONCENTRATION (pfu/ml) VOLUME (ml) DOSE (pfu) ESTIMATED MULTIPLICITY OF INFECTION Cohort 1 1 2 3 F/25 F/39 M/44 ⌬F508 /⌬F508 ⌬F508 /⌬F508 ⌬F508/N1303K 107 2 2ϫ107 1 Cohort 2 4 5 6 M/23 F/32 M/21 ⌬F508 /⌬F508 ⌬F508/⌬F508 ⌬F508/Unknown 108 2 2ϫ108 10 Cohort 3 7 8 9 F/24 F/34 F/40 ⌬F508/R347P ⌬F508/⌬F508 ⌬F508/⌬F508 109 2 2ϫ109 100 Cohort 4 10 11 12 F/19 M/19 M/29 ⌬F508/⌬F508 ⌬F508 /R347P ⌬F508/⌬F508 1010 2 2ϫ1010 1000 enoviral vector by paired t-tests. Login to comment

[hide] Search for mutations in pancreatic sufficient cyst... Hum Genet. 1995 Sep;96(3):312-8. Brancolini V, Cremonesi L, Belloni E, Pappalardo E, Bordoni R, Seia M, Russo S, Padoan R, Giunta A, Ferrari M
Search for mutations in pancreatic sufficient cystic fibrosis Italian patients: detection of 90% of molecular defects and identification of three novel mutations.
Hum Genet. 1995 Sep;96(3):312-8., [PMID:7544319]

Abstract [show]
A cohort of 31 cystic fibrosis patients showing pancreatic sufficiency and bearing an unidentified mutation on at least one chromosome was analyzed through denaturing gradient gel electrophoresis of the whole coding region of the cystic fibrosis transmembrane conductance regulator gene, including intron-exon boundaries. Three new and 19 previously described mutations were detected. The combination of these with known mutations detected by other methods, allowed the characterization of mutations on 56/62 (90.3%) chromosomes. Among those identified, 17 can be considered responsible for pancreatic sufficiency, since they were found in patients carrying a severe mutation on the other chromosome. Among these presumed mild mutations, eight were detected more than once, R352Q being the most frequent in this sample (4.83%). Intragenic microsatellite analysis revealed that the six chromosomes still bearing unidentified mutations are associated with five different haplotypes. This may indicate that these chromosomes bear different mutations, rarely occurring among cystic fibrosis patients, further underlying the molecular heterogeneity of the genetic defects present in patients having pancreatic sufficiency.

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42 The remaining 19 included R352Q (Cremonesi et al. 1992) (three chromosomes), G85E (Zielenski et al. 1991a), Dl152H (High- Fig. 1 A-C Direct sequencing of PCR products from three cystic fibrosis patients (CF) carrying the W57G (A), E193K (B) and D579G (C) mutations, in parallel with control samples (C) displaying normal sequences (N/N) smith et al., personal communication to the CF Genetic Analysis Consortium), R1066H (Ferec et al. 1992), T338I (Saba et al. 1993), 711 +5G--+A (Gasparini et al., personal communication to the CF Genetic Analysis Consortium), M1V (Cheadle et al. 1993), R334W (Gasparini et al. 1991) (two chromosomes each), 4382delA (Claustres et al. 1993), R1158X (Ronchetto et al. 1992), F1052V (Mercier et al. 1993), G1349D (Beaudet et al. 1991), 1898+3A-+G (Cremonesi et al. 1992), $549N (Cutting et al. 1990), 711+ 3A-->G (Petreska et al. 1994), R347P (Dean et al. 1990), 2789+5G--+A (Highsmith et al. 1990), R1066C (Fanen et al. 1992) and S1251N (K~ilin et al. 1992) (one chromosome each). Login to comment
70 (UN yet unidentified mutation) Patient Genotype after Genotype at the end number preliminary screening of the analysis UN/UN M1V/4382delA 1717-1G---~A/UN 1717-1G---~A/R1066H AF508/UN AF508/D579G UN/UN M1V/UN AF508/UN AF508/UN UN/UN T338I/R1158X UN/UN G85E/71 I+5G---~A UN/UN D1152H/UN AF508/UN AF508/UN AF508/UN AF508/3849+ 10kbC---~T UN/UN 711+3A---~G/UN AF508/UN AF508/F1052V UN/UN R352Q/W57G UN/UN 1898+3A----~G/UN AF508/UN AF508/711+5G--~A G542X/UN G542X/DI 152H AF508/UN AF508/E193K 1717-1G---~A/UN 1717-1G---~A/2789+5A---)G AF508/UN AF508/G1349D AF508/UN AF508/G85E AF508/UN AF508/R347P AF508/UN AF508/R352Q AF508/UN AF508/R352Q AF508/UN AF508/S549N G542X/UN G542X/R1066H AF508/UN AF508/T338I AF508/UN AF508/R334W AF508/UN AF508/R334W AF508/UN AF508/S1251N AF508/UN AF508/R1066C AF508/UN AF508/D579G results) while the remaining three haplotypes had been found in association with other rare mutations, which were excluded by DGGE analysis in these patients (Table 3). Login to comment
86 Of these mutations, seven (G85E, EI93K, 711+5G--qA, R347P, R334W, R352Q, T338|) are located in the first transmembrane (I TM) domain, five (2789+ 5A---~G, RI066H, F1052V, D1152H, R1066C) in the second transmembrane (II TM) domain, four in the nucleo- R334W R347P R352Q T338I E193K 711+.E G85E 1 2 3 4 D579G G->A I S 549N 5 6a 6b 7 8 9 10 11 12 13 3849+11 !11 ! Login to comment
90 Moreover, some classical mild mutations, which have been frequently detected in other PS sample populations, are absent (R117H) (Dean et al. 1990) or infrequent (R347P) in our patients. Login to comment

[hide] Recurrent nasal polyps as a monosymptomatic form o... Hum Mol Genet. 1995 Aug;4(8):1463-4. Varon R, Magdorf K, Staab D, Wahn HU, Krawczak M, Sperling K, Reis A
Recurrent nasal polyps as a monosymptomatic form of cystic fibrosis associated with a novel in-frame deletion (591del18) in the CFTR gene.
Hum Mol Genet. 1995 Aug;4(8):1463-4., [PMID:7581390]

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38 In vitro studies have shown that some missense mutations located in the MSD1 retain a significant Cl" channel function and might therefore be responsible for the mild clinical phenotype, although the R347P mutation seems to be an exception (18). Login to comment

[hide] A cystic fibrosis mutation associated with mild lu... N Engl J Med. 1995 Jul 13;333(2):95-9. Gan KH, Veeze HJ, van den Ouweland AM, Halley DJ, Scheffer H, van der Hout A, Overbeek SE, de Jongste JC, Bakker W, Heijerman HG
A cystic fibrosis mutation associated with mild lung disease.
N Engl J Med. 1995 Jul 13;333(2):95-9., [PMID:7539891]

Abstract [show]
BACKGROUND: Cystic fibrosis is the most common lethal autosomal recessive disorder among whites. Among Dutch patients with cystic fibrosis, delta F508 is the most common mutation and A455E the second most common mutation of the cystic fibrosis transmembrane conductance regulator gene on chromosome 7. A455E is associated with preserved pancreatic function and residual secretion of chloride across membranes. We investigated whether it is also associated with less severe pulmonary disease in patients with cystic fibrosis. METHODS: A total of 33 patients with compound heterozygosity for the A455E mutation were matched according to age and sex with patients who were homozygous for the delta F508 mutation. The pairs were analyzed with respect to the following outcome variables: age at diagnosis, pulmonary-function values, and the frequency of pseudomonas colonization, pancreatic sufficiency, and diabetes mellitus. RESULTS: Cystic fibrosis was diagnosed at a later age in the patients with the A455E mutation than in the delta F508 homozygotes (mean age at diagnosis, 15.0 vs. 3.1 years; P < 0.001). Fewer patients with the A455E mutation had pancreatic insufficiency (21.2 percent vs. 93.9 percent, P < 0.001), and none had diabetes mellitus (0 percent vs. 27.3 percent, P = 0.004). Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were significantly higher in the patients with the A455E mutation (mean FEV1, 73.9 percent of the predicted value vs. 54.3 percent of the predicted value; P = 0.002; mean FVC, 88.7 percent of the predicted value vs. 76.3 percent of the predicted value; P = 0.04). Fewer patients with the A455E mutation were colonized with Pseudomonas aeruginosa (33.3 percent vs. 60.6 percent, P = 0.02). CONCLUSIONS: A455E is a common mutation causing cystic fibrosis in the Netherlands. Although several mutations are known to be associated with less severe pancreatic disease, our findings demonstrate a correlation between the A455E mutation and mild pulmonary disease. Because mortality in this disease depends primarily on the progression of pulmonary disease, patients with the A455E mutation have a better prognosis than patients who are homozygous for the delta F508 mutation.

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29 Since the gene for cystic fibrosis was cloned, there have been several studies on associations between the genotype and the phenotype in cystic fibrosis.5-8 A number of mutations (R117H, R334W, R347P, A455E, and P574H) appear to be associated with pancreatic sufficiency9 and residual transmembrane transport of chloride.10,11 The most common mutation, ⌬F508, is associated with pancreatic insufficiency and severe pulmonary disease.5,6 There is great variation in the severity of lung disease, but until now no mutation associated with mild pulmonary disease has been found. Login to comment
28 Since the gene for cystic fibrosis was cloned, there have been several studies on associations between the genotype and the phenotype in cystic fibrosis.5-8 A number of mutations (R117H, R334W, R347P , A455E, and P574H) appear to be associated with pancreatic sufficiency9 and residual transmembrane transport of chloride.10,11 The most common mutation, F508, is associated with pancreatic insufficiency and severe pulmonary disease.5,6 There is great variation in the severity of lung disease, but until now no mutation associated with mild pulmonary disease has been found. Login to comment

[hide] A change in gating mode leading to increased intri... EMBO J. 1995 Jun 1;14(11):2417-23. Champigny G, Imler JL, Puchelle E, Dalemans W, Gribkoff V, Hinnrasky J, Dott K, Barbry P, Pavirani A, Lazdunski M
A change in gating mode leading to increased intrinsic Cl- channel activity compensates for defective processing in a cystic fibrosis mutant corresponding to a mild form of the disease.
EMBO J. 1995 Jun 1;14(11):2417-23., [PMID:7540133]

Abstract [show]
The effects of the mild cystic fibrosis (CF) mutation P574H were analysed and compared with those of three severe ones (delta I507, delta F508 and R560T). Immunochemical and functional analyses indicate that the rank order of CFTR expression at the cell surface is: wild type CFTR > P574H >> delta F508 >> R560T approximately 0. Patch-clamp analysis indicates that the open probability of P574H Cl- channels is almost twice as high as that of the wild type CFTR-Cl- channel. This increased intrinsic activity of individual P574H CFTR-Cl- channels compensates for the lower number of P574H CFTR-Cl- channels reaching the cell surface, and probably explains the milder form of CF associated with the P574H mutation. NS004, a recently described activator, restores near normal CFTR activity in cells expressing the P574H-CFTR channel. The P574H mutation modifies the gating mode of the channel with a large increase (approximately x 7) in the mean channel open time. Proline 574 might play an important role in the process connecting ATP hydrolysis at the nucleotide binding domain and opening and closing events of the CFTR-Cl- channel.

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129 An initial conclusion from these observations is that mutations associated with mild CF: (i) can lead to partial defective processing, less severe than previously observed for severe mutations, and (ii) are not necessarily associated with a decrease in intrinsic channel activity as previously reported for R 117H, R334W and R347P. Login to comment
130 These three mutations, identified in mildly affected patients, are located at the extemal end of the second (R 117H) and the sixth (R334W, R347P) putative membrane-spanning sequences. Login to comment
132 A second conclusion is that the 'quality control' which prevents the trafficking of mutated CFTR-Cl- channels to the plasma membrane does not only eliminate mutants with reduced or abolished Cl- channel activity, since the intrinsic activity of the P574H mutant protein is higher than normal. Login to comment
133 These three mutations, identified in mildly affected patients, are located at the extemal end of the second (R 117H) and the sixth (R334W, R347P) putative membrane-spanning sequences. Login to comment

[hide] Comparison of heteroduplex and single-strand confo... Mol Cell Probes. 1995 Jun;9(3):195-200. Rossetti S, Corra S, Biasi MO, Turco AE, Pignatti PF
Comparison of heteroduplex and single-strand conformation analyses, followed by ethidium fluorescence visualization, for the detection of mutations in four human genes.
Mol Cell Probes. 1995 Jun;9(3):195-200., [PMID:7477013]

Abstract [show]
Non-isotopic DNA single-strand conformation analysis and heteroduplex analysis by ethidium bromide fluorescence visualization (SSCAE and HAE, respectively) were compared for the detection of 15 different naturally occurring mutations in 15 different DNA samples. The mutations included single nucleotide transitions, transversions and deletions, in CFTR (cystic fibrosis transmembrane conductance regulator), COL4A5 (collagen type IV alpha 5 chain), HEXB (hexosaminidase B), and COL1A2 (collagen type 1 alpha 2 chain) genes, responsible for diseases of medical interest. Genomic DNA from peripheral blood leukocytes or cDNA from reverse-transcribed fibroblast mRNA were amplified by polymerase chain reaction (PCR), and then analysed by two SSCAE and one HAE protocol. Fourteen out of 15 mutations (93%) were detected with one or the other method. HAE was more sensitive than SSCAE for the larger products (257-426 bp). The only undetected mutation was then identified with the use of a different primer, located farther from the mutation was then identified with the use of a different primer, located farther from the mutation site, thus increasing the combined efficiency of the two methods to 100%. We believe that combined use of SSCAE and HAE is a good, cheap and safe approach for mutation screening in a human gene.

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41 9 and 10: normal control and R347P (CFTR)carrier, respectively. Molecular weight marker: 1 kb ladder (Gibco BRL).Arrowhead: double stranded (ds) DNA (230 bp), 7-10. Login to comment
57 1: 1271delC (COL4A5), male, 2: R344W (CFTR), carrier, 3:G177R (COL4A5), male, 4: 2940/ 2943delA (COL4A5), male, 5: R75Q (CFTR),carrier, 6: R347P (CFTR),carrier. Login to comment
61 Mutations analysed by SSCAEand HAE: reproducibility scores Gene Mutation Exon PCR Sequence SSCAE SSCAE HAE (reference) size modification +4°C +20°C (A) Amplified fragment size range: 68-230 bp CFTR R334W 7 230 C~T + + + + + + (1) CFTR R347P 7 230 G--*C + + + + + + (2) CFTR R75Q 3 176 G~A - - - (UP-1) (3) CFTR R75Q 3 213 G~A + + + (UP-40) CFTR 2183AAJG 13 145 AA~C + + + - + + (4) COL4A5 2940/2943 34 146 Delta A + + + + + delA (5) COL4A5 1272delC 42 181 Delta C + + + + + (6) COL4A5 G325E 17 68 G~A + + + (7) COL4A5 G17R* 9 121 G~C + + + + - COL4A5 G177R* 9 121 G-,C + + + + - COL4A5 G54D* 3 230 G~A + + + - + + (B) Amplified fragment size range: 257-426 bp HEX B P405L 11 426 C~T - - (8) HEX B 929delT* 8 426 Delta T - - HEX B C317Y* 8 270 G~A - - COL1 A2 G586V 33-37 257 G~T - + (9) COL1A2 G640C 33-37 257 G--.T - - (10) + + ++ + + + + =very good (515repeats); + =good (4•5 repeats); +- =sufficient (315repeats); - =not sufficient(0, or 2/5 repeats). Login to comment

[hide] Analysis of the complete coding region of the CFTR... Hum Genet. 1995 Apr;95(4):397-402. Bonizzato A, Bisceglia L, Marigo C, Nicolis E, Bombieri C, Castellani C, Borgo G, Zelante L, Mastella G, Cabrini G, et al.
Analysis of the complete coding region of the CFTR gene in a cohort of CF patients from north-eastern Italy: identification of 90% of the mutations.
Hum Genet. 1995 Apr;95(4):397-402., [PMID:7535742]

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A complete coding-region analysis on 225 cystic fibrosis (CF) chromosomes from a cohort that includes all the affected subjects born in two North-Eastern Italian regions over eight years was performed. In a previous study, we identified mutations on 166/225 (73.8%) CF chromosomes after screening for 62 mutations. To characterise the remaining 59 CF chromosomes, we carried out automated direct DNA sequencing (exons 9 and 13), RNA single-strand conformation polymorphism (exons 1-8 and 10-12) and denaturing gradient gel electrophoresis (exons 14a-24) of the 27 exons and flanking regions of the CF transmembrane conductance regulator gene. We identified 22 mutations, four of which are novel, viz. 711 + 5G-->A, R709X, 3132delTG and 2790-2A-->G, and we characterised 90.2% (203/225) of the CF chromosomes. Taking advantage of the homogeneity of the sample, an evaluation of the most important clinical parameters, assessed at the age of 12 years, is presented. We confirm some previously reported genotype-phenotype correlations and we report a new nonsense mutation (R709X) associated with a pancreatic sufficient phenotype.

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35 Table 1 CF mutations identified in this cohort study (225 chromosomes from Veneto and Trentino Alto-Adige) n Number of CF chromosomes, Cum fi cumulative fraction, wnovel mutation identified during this study " Cystic Fibrosis Genetic Analysis Consortium, personal comunication Table 2 DNA sequence variations identified in this cohort study (w Novel sequence variation identified during this study a Cystic Fibrosis Genetic Analysis Consortium, personal comunication Mutation Exon n % Cure fr References AF508 l0 107 47.56 47.56 Kerem et al. 1989 R1162X 19 22 9.78 57.33 Gasparini et al. 1991 2183AA----~G 13 21 9.33 66.67 Bozon et al. 1994 N1303K 21 9 4.00 70.67 Osborne et al. t991 G542X 11 6 2.67 73.33 Kerem et al. 1990 711+5G--~A intron 5 6 2.67 76.00 w 1717 1G--~A intron 10 5 2.22 78.22 Kerem et al. 1990 G85E 3 3 1.33 79.56 Zielenski et al. 1991~' R553X 11 3 1.33 80.89 Cutting et al. 1990 2789+5G--~A intron 14b 3 1.33 82.22 Highsmith* Q552X 11 3 1.33 83.56 Devoto et al. 1991 621+lG---~T intron 4 2 0.89 84.44 Zielenski et al. 1991b W1282X 20 2 0.89 85.33 Vidaud et al. 1990 3132delTG 17a 2 0.89 86.22 w 2790-2A---~G intron 14b 2 0.89 87.11 w 457TAT--)G 4 1 0.44 87.56 Ravnik-Glavac et al. 1993 R347P 7 1 0.44 88.00 Dean et al. 1990 G551D 11 .1 0.44 88.44 Cutting et al. 1990 1717-8G-+A intron 10 1 0.44 88.89 Savov et al. 1994 3849+ 10KbC--)T intron 19 1 0.44 89.33 Highsmith* R709X 13 1 0.44 89.78 w 1898+3A---~G intron 12 1 0.44 90.22 Cremonesi et al. 1992 Identified 203 90.22 Unidentified 22 9.78 Variatioh Exon References 1540 A orG Met or Val at 470 10 Kerem et al. 1990 1898+152 T or A intron 12 Chillon et al. 1991 2134 C or T Arg or Cys at 668 13 Fanen et al. 1992 2694 T or G No change Thr at 854 14a Zielenski et al. 199 lb 2752-22 A or G intron 14a w 3601-65 C or A intron 18 Dork et al. 199l 4029 A or G No change Thr at 1299 21 Fanen et al. 1992 4404 C or T No change Tyr at 1424 24 ShoshanP 711 +5G--+A This mutation was found in the splice donor site flanking the 3' end of exon 5. Login to comment
53 In reference to the previously suggested classification of the phenotypes, whereby PS is attributable to the presence of at least one mild dominant CF allele (Kerem et al. 1989), we confirm that mutations R347P, 2789 + 5G--~A, 1898 + 3A--~G and 3849 + 10KbC--~T are all associated with a PS phenotype. Login to comment

[hide] Increased incidence of cystic fibrosis gene mutati... Hum Mol Genet. 1995 Apr;4(4):635-9. Pignatti PF, Bombieri C, Marigo C, Benetazzo M, Luisetti M
Increased incidence of cystic fibrosis gene mutations in adults with disseminated bronchiectasis.
Hum Mol Genet. 1995 Apr;4(4):635-9., [PMID:7543317]

Abstract [show]
In order to identify a possible hereditary predisposition to the development of obstructive pulmonary disease of unknown origin, we have looked for the presence of Cystic Fibrosis Transmembrane Regulator (CFTR) gene mutations in unrelated patients with no signs of Cystic Fibrosis (CF). We screened for 70 common mutations, and also for rare mutations by denaturing gradient gel electrophoresis analysis. In this search, different CFTR gene mutations (R75Q, delta F508, R1066C, M1137V and 3667ins4) were found in five out of 16 adult Italian patients with disseminated bronchiectasis, a significant increase over the expected frequency of carriers. Moreover, three rare CFTR gene DNA polymorphisms (G576A, R668C, and 2736 A-->G), not deemed to be the cause of CF, were found in two patients, one of which was a compound heterozygote with R1066C. These results indicate that CFTR gene mutations, and perhaps also DNA polymorphisms, may be involved in the etiopathogenesis of at least some cases of bronchiectasis.

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25 RESULTS Common CF mutations All the study subjects were initially typed with respect to some CFTR mutations known to be present in CF patients in the North East Italian population: AF508, R1162X, 2183AA->G, NI303K, G542X, 711 + 5G->A, 1717-1 G^>A, 1717-8G->A, G85E, R553X, 2789 + 5 G->A, Q552X, 621 + 1 G->T, W1282X, 3132delTG, 2790-2A->G, 457 TAT->G, R347P, G551D, 1898 + 3A->G and 3849 + 10 kbC^T. Login to comment
120 Several mutations were searched by restriction analysis: 457 TAT-»G, R334W, R347P/H/L, A455E, Q552X, 3849 + 10 kbC->T, D1270N. Login to comment

[hide] Mechanism of dysfunction of two nucleotide binding... EMBO J. 1995 Mar 1;14(5):876-83. Sheppard DN, Ostedgaard LS, Winter MC, Welsh MJ
Mechanism of dysfunction of two nucleotide binding domain mutations in cystic fibrosis transmembrane conductance regulator that are associated with pancreatic sufficiency.
EMBO J. 1995 Mar 1;14(5):876-83., [PMID:7534226]

Abstract [show]
Variability in the severity of cystic fibrosis (CF) is in part due to specific mutations in the CF transmembrane conductance regulator (CFTR) gene. To understand better how mutations in CFTR disrupt Cl- channel function and to learn about the relationship between genotype and phenotype, we studied two CF mutants, A455E and P574H, that are associated with pancreatic sufficiency. A455E and P574H are located close to conserved ATP binding motifs in CFTR. Both mutants generated cAMP-stimulated apical membrane Cl- currents in heterologous epithelial cells, but current magnitudes were reduced compared with wild-type. Patch-clamp analysis revealed that both mutants had normal conductive properties and regulation by phosphorylation and nucleotides. These mutants had normal or increased Cl- channel activity: A455E had an open-state probability (Po) similar to wild-type, and P574H had an increased Po because bursts of activity were prolonged. However, both mutants produced less mature glycosylated protein, although levels were greater than observed with the delta F508 mutant. These changes in channel activity and processing provide a quantitative explanation for the reduced apical Cl- current. These data also dissociate structural requirements for channel function from features that determine processing. Finally, the results suggest that the residual function associated with these two mutants is sufficient to confer a milder clinical phenotype and infer approaches to developing treatments.

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22 In contrast, three mutations (RI 17H, R334W and R347P) in the first membrane-spanning domain (MSD1) are associated with the PS phenotype (Kristidis et al., 1992; The Cystic Fibrosis Genotype-Phenotype Consortium, 1993). Login to comment
218 It is interesting to compare our present results with those from our study of mild CF mutations that occur in MSD1 (R117H, R334W and R347P). Login to comment

[hide] Cystic fibrosis: genotypic and phenotypic variatio... Annu Rev Genet. 1995;29:777-807. Zielenski J, Tsui LC
Cystic fibrosis: genotypic and phenotypic variations.
Annu Rev Genet. 1995;29:777-807., [PMID:8825494]

Abstract [show]
Cystic fibrosis (CF) is a common genetic disorder in the Caucasian population. The gene was identified in 1989 on the basis of its map location on chromosome 7. The encoded gene product, named cystic fibrosis transmembrane conductance regulator (CFTR), corresponds to a cAMP-regulated chloride channel found almost exclusively in the secretory epithelial cells. Although the major mutation that results in a single amino acid deletion (F508) accounts for 70% of the disease alleles, more than 550 additional mutant alleles of different forms have been detected. Many of these mutations can be divided into five general classes in terms of their demonstrated or presumed molecular consequences. In addition, a good correlation has been found between CFTR genotype and one of the clinical variables--pancreatic function status. An unexpected finding, however, is the documentation of CFTR mutations in patients with atypical CF disease presentations, including congenital absence of vas deferens and several pulmonary diseases. Thus, the implication of CFTR mutation is more profound than CF alone.

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551 FIBROSIS Table 1 Most common CFTR mutations in the world Name of Mutation �F508 0542X 0551D NI303K WI282X R553X 621 + 10 � T 1717-10 � A RI17H R1162X R347P 3849 + IOkbC � T �1507 394delTT 085E R560T A455E 1078deiT 2789 + SO � A 3659deiC R334W 1898 + 10 � T 711 + 10 --. Login to comment
574 On the other hand, many mutations (R117H, H199Y, R334W, R347P, R553X; L558S, 3272-26A�G, 3849+lOkbC�T, R1162X) are found associated with two or three haplotypes that cannot be possibly derived from each other by simple molecular mechanisms (58, 124). Login to comment
628 This strategy may also be applied to patients with other Normal II III IV V No synthesis Block in Block in Altered Reduced processing regulation conductance synthesis Nonsense Missense G542X Missense Missense Missense A455E Frameshift N1303K G551D R117H 394deiTT AA deletion Alternative L1F508 R347P splicing Splice junction 1717-1G-->A 3849+1OkbC-->T Figure 3 Molecular consequence of different classes ofCF mutations. Login to comment
634 Examples of this group include R l 17H near TM2, G314E in TM5, and R334W and R347P in TM6. Login to comment
1127 Independent origins of cystic fibrosis mutations R334W, R347P, R I I 62X, and 3849+10kb CT provide evidence of mutation recurrence in the CFTR gene. Login to comment

[hide] The CFTR chloride channel of mammalian heart. Annu Rev Physiol. 1995;57:387-416. Gadsby DC, Nagel G, Hwang TC
The CFTR chloride channel of mammalian heart.
Annu Rev Physiol. 1995;57:387-416., [PMID:7539989]

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19 Also, three missense mutations associated with relatively mild CF disease, two (R334W and R347P) neutralizing positively charged arginines in M6 and one (Rl19H) substituting histidine for an arginine near the extracellular end of M2, all diminish open-channel conductance (120). Login to comment

[hide] Development of mouse models for cystic fibrosis. J Inherit Metab Dis. 1995;18(4):495-500. Dorin JR
Development of mouse models for cystic fibrosis.
J Inherit Metab Dis. 1995;18(4):495-500., [PMID:7494407]

Abstract [show]
Using gene targeting in embryonal stem cells it is now possible to create accurate genetic models of inherited human disease in the mouse. The value of an animal model of cystic fibrosis is in providing clarification of disease pathogenesis, genotype-phenotype correlation, the identification of other relevant genetic factors, and as the optimal test system for novel therapeutic intervention. Correction of the basic defect by a somatic gene therapy approach is an attractive approach to disease treatment. CF mouse models have been described which display the characteristic electrophysiological defect and thus both safety and efficacy can be monitored in these animals. Modulation of Cftr levels in transgenic animals and the results on disease phenotype give some indication of the level of gene expression necessary to give clinical effect.

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81 Sheppard and colleagues (1993) report that the cAMP-mediated chloride conductance of R347P and R117H mutant constructs in the vaccinia virus T7 hybrid expression system are approximately 30% and 15% of wild type values, respectively. Login to comment
82 Individuals who are R347P/AF508 or Rll7H/AF508 compound heterozygotes are therefore predicted to retain approximately 15% or 7.5% of normal CFTR function, respectively. Login to comment

[hide] Independent origins of cystic fibrosis mutations R... Am J Hum Genet. 1994 Nov;55(5):890-8. Morral N, Llevadot R, Casals T, Gasparini P, Macek M Jr, Dork T, Estivill X
Independent origins of cystic fibrosis mutations R334W, R347P, R1162X, and 3849 + 10kbC-->T provide evidence of mutation recurrence in the CFTR gene.
Am J Hum Genet. 1994 Nov;55(5):890-8., [PMID:7526685]

Abstract [show]
Microsatellite analysis of chromosomes carrying particular cystic fibrosis mutations has shown different haplotypes in four cases: R334W, R347P, R1162X, and 3849 + 10kbC-->T. To investigate the possibility of recurrence of these mutations, analysis of intra- and extragenic markers flanking these mutations has been performed. Recurrence is the most plausible explanation, as it becomes necessary to postulate either double recombinations or single recombinations in conjunction with slippage at one or more microsatellite loci, to explain the combination of mutations and microsatellites if the mutations arose only once. Also in support of recurrence, mutations R334W, R347P, R1162X, and 3849 + 10kbC-->T involve CpG dinucleotides, which are known to have an increased mutation rate. Although only 15.7% of point mutations in the coding sequence of CFTR have occurred at CpG dinucleotides, approximately half of these CpG sites have mutated at least once. Specific nucleotide positions of the coding region of CFTR, distinct from CpG sequences, also seem to have a higher mutation rate, and so it is possible that the mutations observed are recurrent. G-->A transitions are the most common change found in those positions involved in more than one mutational event in CFTR.

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2 55:890-898, 1994 Independent Origins of Cystic Fibrosis Mutations R334W, R347P, R I 1 62X, and 3849+ 1 OkbC--*T Provide Evidence of Mutation Recurrence in the CFTR Gene Nuria Morral,' Roser Llevadot,' Teresa Casals,' Paolo Gasparini,2 Milan Macek, Jr.,3'4 Thilo Dork,s and Xavier Estivill' 'Molecular Genetics Department, Institut de Recerca Oncol6gica, Hospital Duran Reynals, Barcelona; 2Servizio di Genetica Medica, IRCCS-Ospedale "CSS," San Giovanni Rotondo, Foggia, Italy; 3Center for Medical Genetics, Johns Hopkins Medical Institutions, Baltimore; 4First Medical Faculty of Charles University, Prague; and 5Medizinische Hochschule Hannover, Zentrum Biochemie, Hannover Summary Microsatellite analysis of chromosomes carrying particular cystic fibrosis mutations has shown different haplotypes in four cases: R334W, R347P, R1162X, and 3849+10kbC-).T. Login to comment
5 Also in support of recurrence, mutations R334W, R347P, R1162X, and 3849+10kbC--T involve CpG dinucleotides, which are known to have an increased mutation rate. Login to comment
19 While analyzing microsatellites IVS8CA (Morral et al. 1991), and IVS17BTA,IVS17BCA (Zielenski et al. 1991b; Morral et al. 1992) in CF chromosomes carrying mutations R334W (Gasparini et al. 1991b), R347P (Dean et al. 1990), R1162X (Gasparini et al. 1991b), and 3849+10kbC--T (Highsmith et al., in press), several haplotypes were observed associated with each of these mutations. Login to comment
21 Analysis with markers flanking mutations R334W, R347P, R1162X, and 3849+10kbC- T indicated that recurrence was the most probable mechanism. Login to comment
22 All these mutations involve nucleotide sequences that are prone to mutation; mutations R334W, R1162X, and 3849+10kbC- T result from C--T transitions at 5-methylcytosine (SmC), and mutation R347P results from a G--C change in a CpG dinucleotide. Login to comment
24 Table I CFTR Microsatellite Haplotypes of Mutations R334W, R347P, R I 162X, and 3849+ 1 OkbC--T Mutation and % No. of Haplotype Normala Chromosomes Origin R334W: 17-46-13 .3 6 Spanish 17-47-13 .2 3 Spanish 16-32-13 7.9 1 Czech 17-7-17b 5.3 2 Russian 17/24-31/35-13c 2 German R347P: 16-45-13 1.5 1 Slovak 16-32-13b 7.9 2 Czech 17-28-13 .07 1 Czech 16-45-13 1.5 1 Czech 17-28-13 .07 2 German 16-32-13 7.9 1 German R1162X: 17-31-13 1.1 37 Italian 17-30-13 .3 2 Italian 16-46-13 . Login to comment
32 Fifty-eight chromosomes carried mutation R1162X, 14 carried R334W, 8 carried R347P, and 6 carried 3849+10kbC- oT. Login to comment
35 R334W, R347P, and R1162X were analyzed as described elsewhere, by PCR amplification and digestion with the appropriate restriction enzyme (Dean et al. 1990; Gasparini et al. 1991b). Login to comment
36 In addition, mutations R334W, R347P, and R1162X were confirmed by sequencing (fmol DNA Sequencing System; Promega). Login to comment
70 Table 2 Haplotypes for Mutation R334W and R347P in Exon 7 of CFTR in Several Populations CHROMOSOME ORIGINa Czech Russian German Spanish Czech/Slovak Czech/German Czech/German MARKER (n=-) (n=2) (n=2) (n=9) (n=2) (n=3) (n=3) MetH/Mspl 1 1/2 1 1 XV-2c/TaqI 1/2 1 1 1 1 1 2 KM.19/PstI 2 2 2 1 1 1 1 IVS6aGATT 7 7 6 7 7 7 7 Mutation .R334W R334W R334W R334W R347P R347P R347P IVS8CA .16 17 17/24 17 16 16 17 IVS12/Bc.. 2 2 1 1 1 1 1 T854/AvaII 2 2 1 1 1 1 1 IVS15/NsiI 1 2 1 1 1 1 1 IVS17BTA 32 7 35/31 46-47 45 32 28 IVS17BCA 13 17 13 13 13 13 13 TUB18/Hinfl 1 1 1 1 1 1 Q1463/Hinfl 1/2 1/2 2 2 2 J3.11/Msp. Login to comment
82 Mutation R347P This mutation was first reported on a chromosome of North American origin (Dean et al. 1990), but its highest frequency has been detected in Germany, where it accounts for 1.2%-1.4% of CF chromosomes. Login to comment
84 Analysis of microsatellites on R347P chromosomes from several populations has revealed three different haplotypes among German, Czech, and Slovak chromosomes, suggesting recurrence (table 1). Login to comment
87 Alternatively, mutation R347P could have arisen at least three times. Login to comment
108 )-.T R347L Audrezet et al. 1993 G--S-C R347P Dean et al. 1990 1789 ......... C--.G R553G C. Ferec, personal communication CI-T R553X Cutting et al. 1990 1790 ......... G---A R553Q Dork et al.1991a 3328 ......... C-OT R1066C Fanen et al. 1992 3329 ......... G-.A R1066H Ferec et al. 1992 GT R1066L Mercier et al. 1993 3340 ......... CT R1070W M. Macek, Jr., unpublished data 3341 ......... G-A R1070Q Mercier et al. 1993 a This change is a polymorphism, not a disease mutation. Login to comment
116 Mutations R334W, R347P, R1162X, and 3849+10kbC- T have been found associated with more than one haplotype. Login to comment
123 In addition, mutation R347P consists of a G- >C substitution in a CpG dinucleotide (positions 1171 and 1172 of the CFTR cDNA). Login to comment
144 A collaborative study involving the analysis of 94 mutations in the CFTR gene has shown that mutations R117H, H199Y, R347H, R347P, L558S, 2184insA, R1162X, 3272-26A--G, and 3849+10kbC-)T have arisen more than once in different genetic backgrounds (authors' unpublished data). Login to comment
145 A collaborative study involving the analysis of 94 mutations in the CFTR gene has shown that mutations R117H, H199Y, R347H, R347P, L558S, 2184insA, R1162X, 3272-26A--G, and 3849+10kbC-)T have arisen more than once in different genetic backgrounds (authors' unpublished data). Login to comment

[hide] Detection of more than 50 different CFTR mutations... Hum Genet. 1994 Nov;94(5):533-42. Dork T, Mekus F, Schmidt K, Bosshammer J, Fislage R, Heuer T, Dziadek V, Neumann T, Kalin N, Wulbrand U, et al.
Detection of more than 50 different CFTR mutations in a large group of German cystic fibrosis patients.
Hum Genet. 1994 Nov;94(5):533-42., [PMID:7525450]

Abstract [show]
We have conducted a comprehensive study of the molecular basis of cystic fibrosis (CF) in 350 German CF patients. A screening approach based on single-strand conformation analysis and direct sequencing of genomic polymerase chain reaction products has allowed us to detect the molecular defects on 95.4% of the CF chromosomes within the coding region and splice sites of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The spectrum of sequence changes comprises 54 different mutations, including 17 missense mutations, 14 nonsense mutations, 11 frameshift mutations, 10 splice site variants and two amino acid deletions. Eleven of these mutations have not previously been described. Our results reflect the marked mutational heterogeneity of CF in a large sample of patients from a non-isolated population.

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77 Table 1 Frequency distribution and haplotypes of CFTR mutations in 700 German CF chromosomes Mutation~ Nucleotide changesb Locationc Frequencyd Haplotype~ Referencef Q39x C--~T at 247 Exon 2 1 (0.1%) D3 Cutting et al. (1992) E60X G-+T at 310 Exon 3 1 (0.1%) A2 Malone et al. (*) R75X C--+T at 355 Exon 3 1 (0.1%) C2 This study 405+1 G---~A G-+A at 405+1 Intron 3 1 (0.1%) C2 D6rk et al. (1993c) E92X G--~T at 406 Exon 4 2 (0.3%) B2 Will et al. (1994) R117C C---~Tat 481 Exon 4 1 (0.1%) C2 This study R117H G--+A at 482 Exon 4 2 (0.3%) B6 Dean et al. (1990) 621+1 G--+T G--+T at 621+1 Intron 4 1 (0.1%) B1 Zielenski et al. (1991b) H199Y C--+T at 727 Exon 6a 1 (0.1%) A2 This study (*) 1078delT Deletion of T at 1078 Exon 7 4 (0.6%) C2 Claustres et al. (1992) R334W C-~T at 1132 Exon 7 2 (0.3%) BI Gasparini et al. (1991) 1336K T-->A at 1139 Exon 7 3 (0.4%) A2 Cuppens et al. (1993) R347P G--+C at 1172 Exon 7 11 (1.6%) A2, C2 Dean et al. (1990) 1342-2 A--+C A--+C at 1342-2 Intron 8 3 (0.4%) A4 D/3rk et al. (1993b) Q414X C--+T at 1372 Exon 9 1 (0.1%) D3 D6rk et al. (1994a) A455E C-+A at 1496 Exon 9 1 (0.1%) BI Kerem et al. (1990) V456F G--~T at 1498 Exon 9 1 (0.1%) B3 D6rk et al. (1994a) A1507 Deletion of 3 bp between 1648-1653 Exon 10 1 (0.1%) D5 Kerem et al. (1990) AF508 Deletion of 3 bp between 1652-1655 Exon 10 504 (72.0%) B1, DI, B7 Kerem et al. (1989) 1717-1 G--+A G--+A at 1717-1 lntron 10 6 (0.9%) B3 Kerem et al. (1990) G542X G--+T at 1756 Exon 11 10 (1.4%) B1 Kerem et al. (1990) G551D G--+A at 1784 Exon 11 7 (l.0%) B3 Cutting et al. (1990) Q552X C-+T at 1786 Exon 11 1 (0.1%) A4 Devoto et al. (1991) R553X C--+T at 1789 Exon 11 16 (2.3%) A4, B4, D3 Cutting et al. (1990) L558S T--+C at 1805 Exon 11 1 (0.1%) C2 Maggio et al. (*) 1811+I.6kBA-+G A--+Gat 1811+l.6kB lntron 11 1 (0.1%) A2 Chillonetal. Login to comment
120 There are, however, only six additional CFTR mutations with a frequency of approximately 1% or more of the CF chromosomes; two nonsense mutations, G542X and R553X, and the missense mutations G551D and NI303K were predominantly seen in severely affected patients, whereas the transmembrane missense mutation R347P and the splice mutation 3849 + 10 kB C---~T Table 2 Rare sequence variants in the CFTR promoter and coding region Sequence variant Nucleotide change Location Frequency Associated mutatiow' Reference 125 G--+C G--~C at 125 Promoter 1 (0.1%) R75X F508C T--~G at 1655 Exon 10 2 (0.3%) S1251N 1716 G---)A G---~Aat 1716 Exon 10 1 (0.1%) L619S R553Q G-~A at 1790 Exon I 1 I (0.1%) * R668C C--~T at 2134 Exon 13 1 (0.1%) 3849+10 kB C--eT 3030 G---~A G--+A at 3030 Exon 15 1 (0.1%) 405+1 G--~A I1027 T T--~C at 3212 Exon 17a 2 (0.3%) * 3417 A-+T A--->Tat 3417 Exon 17b 1 (0.1%) Unknown 4002 A--eG A--~G at 4002 Exon 20 2 (0.3%) Unknown Cutting et al. (1992) Kobayashi et al. (1990) Kerem et al. (1990) D6rk et al. ( 1991) Fanen et al. (1992) Chillon et al. (1992) Fanen et al. (1992) This study Ferec et al. (1992) ~'Marked (*) sequence variations were present on AF508 chromosomes were the most frequent in pancreas-sufficient patients. Login to comment

[hide] Association of pancreatic adenocarcinoma, mild lun... Clin Chem. 1994 Oct;40(10):1972-4. Tsongalis GJ, Faber G, Dalldorf FG, Friedman KJ, Silverman LM, Yankaskas JR
Association of pancreatic adenocarcinoma, mild lung disease, and delta F508 mutation in a cystic fibrosis patient.
Clin Chem. 1994 Oct;40(10):1972-4., [PMID:7522998]

Abstract [show]
A case of adenocarcinoma of the pancreas and mild lung disease in a 39-year-old man homozygous for the delta F508 cystic fibrosis mutation is presented. Cystic fibrosis is the most common lethal genetic disease in Caucasians, and is most commonly associated with severe obstructive lung disease. To our knowledge, this is only the fifth case of adenocarcinoma of the pancreas in a CF patient to be reported and the first case for which molecular data are available. The rare incidence of this type of malignancy in the general population suggests a possible association of CF with this malignant disease.

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44 CorrelatIon of phenotype and genotype of CFTR mutations Key phenotypic Lung disease SweatC1 Exocnne pancreas function Vasdeferens Associated CFTR mutations Pancreatic InsuffIcIent Pancreatic sufficient Normalsweat C1 Severe Less severe Relatively mild Elevated Elevated Normal Insufficient Sufficient Sufficient Absent Absent Absent SF508, G542X, R553X, G5510, Ni 303K, Wi 282X, RI 17H, and others 2789 + 5G>A, R117H, R334W, R347P, A455E, P574H, S945L, G85E, and others G551S, R117H, 3849 + 10kb C>T, and others Congenitalabsence of the vas deferens None Normal or elevated Sufficient Absent F508C, Ri 17H, Di D1152H, and others FIg. 2. Login to comment

[hide] Novel pore-lining residues in CFTR that govern per... Neuron. 1994 Sep;13(3):623-34. McDonough S, Davidson N, Lester HA, McCarty NA
Novel pore-lining residues in CFTR that govern permeation and open-channel block.
Neuron. 1994 Sep;13(3):623-34., [PMID:7522483]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is both a member of the ATP-binding cassette superfamily and a Cl(-)-selective ion channel. We investigated the permeation pathway of human CFTR with measurements on conduction and open-channel blockade by diphenylamine-2-carboxylic acid (DPC). We used site-directed mutagenesis and oocyte expression to locate residues in transmembrane domain (TM) 6 and TM 12 that contact DPC and control rectification and single-channel conductances. Thus, TM 12 and the previously investigated TM 6 line the CFTR pore. In each TM, residues in contact with DPC are separated by two turns of an alpha helix. The contributions of TM 6 and TM 12 to DPC block and Cl- permeation, however, are not equivalent. The resulting structural model for the conduction pathway may guide future studies of permeation in other Cl- channels and ATP-binding cassette transporters.

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173 Previous studies of CFTR have found that mutations of positively charged residues in TM 1 and TM 6 (including K335E) give small changes in ionic selectivity (Anderson et al., 1991b) and that naturally occurring mutations of positively charged residues just extracellular to TM 2, or within TM 6 (R347P and R334W), reduce single-channel conductance and alter kinetics (Sheppard et al., 1993). Login to comment
178 Mutations R334W, R347P, and S341A may reduce single-channel conductance by removing a Cl--binding site. Login to comment

[hide] Identification of three novel mutations in the CFT... Hum Genet. 1994 Aug;94(2):154-8. Grade K, Grunewald I, Graupner I, Behrens F, Coutelle C
Identification of three novel mutations in the CFTR gene using temperature-optimized non-radioactive conditions for SSCP analysis.
Hum Genet. 1994 Aug;94(2):154-8., [PMID:7519167]

Abstract [show]
Optimal temperature conditions for the detection of 28 known mutations on 15 exons of the human cystic fibrosis transmembrane conductance regulator gene by single strand conformation polymorphism analysis using the Diagen TGGE Apparatus were established. This procedure was applied to the detection of unknown mutations in 58 non-deltaF508 chromosomes. Three novel mutations, -471del3 (5' flanking region), 3171insC (exon 17a) and 4700(T)8/9 (3' non-translated region) of the CFTR gene were found. Mutation 3171insC occurred in conjunction with the delta F508 mutation on the other allele of a child presenting with severe pathology. Mutation -471del3 has so far only been found in one healthy individual and her father, and 4700(T)8/9 is a DNA sequence polymorphism.

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7 A further 10% (approximately) are attributable to the presence of the mutations R347P, G542X, G551D and R553X (Coutelle et al. 1992). Login to comment
23 Frameshi~ R347P DF508 9 417 15 227 9 and 20 98 No banding 9 and 20 20 No banding 491 2 4 20 3 2~ 498 3 5 4 4 b 3 5 426 3 5 426 1 2 511 2 2b 3 400 3 8 5 390 2 4 399 3 4-5 240 3 4 4 4 477 3 30 3 4 2 3b 569 2-3 2 delTCT1652-1654 A 1540G Wild type 1717-1G-~A G1756T GI784A C1789T Wild type G1859C Wild type 1898+lG--~A Wild type T2694G Wild type 2991de132 G3030A Wild type 3171insC Wild type C3408A Wild type T3895C G3978A 3905insT Wild type C4041G Wild type 4006-200G--~A C4041G Wild type 4521G/A 4700T8/9 DF508 M470V Splice rout. Login to comment

[hide] Long-term survival of the exon 10 insertional cyst... Mamm Genome. 1994 Aug;5(8):465-72. Dorin JR, Stevenson BJ, Fleming S, Alton EW, Dickinson P, Porteous DJ
Long-term survival of the exon 10 insertional cystic fibrosis mutant mouse is a consequence of low level residual wild-type Cftr gene expression.
Mamm Genome. 1994 Aug;5(8):465-72., [PMID:7949729]

Abstract [show]
Recently we have created a mouse model of cystic fibrosis (CF) by insertional gene targeting to exon 10. In common with CF subjects, this model displays a low incidence of meconium ileus. This contrasts strikingly with the very high level of fatal intestinal obstruction in the three other CF mouse models so far described. We investigate here the molecular basis of this difference in phenotype. We show that the partial duplication consequent upon insertional gene targeting allows exon skipping and aberrant splicing to produce normal Cftr mRNA, but at levels greatly reduced compared with wild-type mice. Furthermore, instead of the predicted mutant Cftr transcript, a novel mRNA is produced that utilizes cryptic splice sites in the disrupting plasmid sequence. However, we have previously shown that these mice display the ion transport defect characteristic of CF, and mutant animals can be distinguished from their normal littermates on this basis. Consistent with this, residual CFTR function has recently been observed for several "mild" mutations in CF individuals who display pancreatic sufficiency but still develop lung disease. We conclude that (i) residual wild-type mRNA in the exon 10 insertional mutant mouse ameliorates the severity of the intestinal phenotype observed in the absolute "null" CF mice, (ii) the presence of low-level residual wild-type Cftr mRNA does not correct the CF ion transport defect, and (iii) the long-term survival of this insertional mutant mouse provides the opportunity to address the factors important in development of lung disease.

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174 Sheppard and associates (1993) report that the chloride conductance of R347P and R117H mutant constructs in the vaccinia virus T7 hybrid expression system are approximately 30% and 15% of wild-type values respectively. Login to comment
175 Individuals who are R347P/AF508 or R117H/AF508 compound heterozygotes are therefore predicted to retain approximately 15% or 7.5% of normal CFTR function. Login to comment

[hide] Amino acid residues lining the chloride channel of... J Biol Chem. 1994 May 27;269(21):14865-8. Akabas MH, Kaufmann C, Cook TA, Archdeacon P
Amino acid residues lining the chloride channel of the cystic fibrosis transmembrane conductance regulator.
J Biol Chem. 1994 May 27;269(21):14865-8., [PMID:7515047]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator forms a chloride channel that is regulated by phosphorylation and intracellular ATP levels. The structure of the channel-forming domains is undetermined. To identify the residues lining this channel we substituted cysteine, one at a time, for 9 consecutive residues (91-99) in the M1 membrane-spanning segment. The cysteine substitution mutants were expressed in Xenopus oocytes. We determined the accessibility of the engineered cysteine to charged, sulfhydryl-specific methanethiosulfonate reagents added extracellularly. We assume that, among residues in membrane-spanning segments, only those lining the channel will be accessible to react with these hydrophilic reagents and that such a reaction would irreversibly alter conduction through the channel. Only the cysteines substituted for Gly-91, Lys-95, and Gln-98 were accessible to the reagents. We conclude that these residues are in the channel lining. The periodicity of these residues is consistent with an alpha-helical secondary structure.

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16 Three mutationsassociated with mild clinical disease, R117H, R334W, and R347P,displayed altered single-channel properties (ll), but the structural basisof the functional changes is unknown. Login to comment

[hide] Novel cystic fibrosis mutation associated with mil... Hum Genet. 1994 May;93(5):529-32. Boteva K, Papageorgiou E, Georgiou C, Angastiniotis M, Middleton LT, Constantinou-Deltas CD
Novel cystic fibrosis mutation associated with mild disease in Cypriot patients.
Hum Genet. 1994 May;93(5):529-32., [PMID:7513296]

Abstract [show]
Cyprus is an island in the eastern Mediterranean basin inhabited by people of Caucasian extraction, mostly Greek-Cypriots. The most common inherited disease among Caucasians is cystic fibrosis (CF). Although no careful scientific study had ever been done the impression was that CF was extremely rare among the Greek-Cypriots, with an incidence estimated at around 1:30,000. About 2 years ago, we introduced molecular diagnostic methodology in an effort to assist clinicians in safer diagnosis of patients presenting with atypical CF symptomatology, and also for testing the hypothesis that mutations that cause milder phenotypes might be responsible for misdiagnosis or for missing entirely some cases of CF. Initial screening for delta F508 revealed that it is indeed rare in the general population. Further screening of suspected CF patients revealed a novel mutation that converted leucine at position 346 to proline (L346P) in two unrelated families. The second CF mutation was delta F508 and 1677delTA in the two families respectively, both reportedly associated with severe phenotypes. Yet our patients did not present with typical CF pictures possibly because of the dominant nature of this novel mild mutation in exon 7. Symptoms included failure to thrive, chest infections and electrolyte disturbances. These findings raise the possibility that Cyprus might have been spared very severe CF phenotypes but not cystic fibrosis transmembrane conductance regulator (CFTR) mutations.

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86 These milder phenotypes are more easily explained by the possible mildness of the second mutation, L346E This is in exon 7, which is part of the membrane-spanning region, and next to another previously reported mutation, R347P, which is also known to be associated with less severely impaired pancreatic function (Dean et al. 1990). Login to comment

[hide] Sensitivity of single-strand conformation polymorp... Hum Mol Genet. 1994 May;3(5):801-7. Ravnik-Glavac M, Glavac D, Dean M
Sensitivity of single-strand conformation polymorphism and heteroduplex method for mutation detection in the cystic fibrosis gene.
Hum Mol Genet. 1994 May;3(5):801-7., [PMID:7521710]

Abstract [show]
The gene responsible for cystic fibrosis (CF) contains 27 coding exons and more than 300 independent mutations have been identified. An efficient and optimized strategy is required to identify additional mutations and/or to screen patient samples for the presence of known mutations. We have tested several different conditions for performing single-stranded conformation polymorphism (SSCP) analysis in order to determine the efficiency of the method and to identify the optimum conditions for mutation detection. Each exon and corresponding exon boundaries were amplified. A panel of 134 known CF mutations were used to test the efficiency of detection of mutations. The SSCP conditions were varied by altering the percentage and cross-linking of the acrylamide, employing MDE (an acrylamide substitute), and by adding sucrose and glycerol. The presence of heteroduplexes could be detected on most gels and in some cases contributed to the ability to distinguish certain mutations. Each analysis condition detected 75-98% of the mutations, and all of the mutations could be detected by at least one condition. Therefore, an optimized SSCP analysis can be used to efficiently screen for mutations in a large gene.

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48 As seen in Fig. 3a, on an MDE/sucrose gel of eight exon 7 mutations, DNAs containing two different mutations (R347P and R352Q) produced SSCPs almost identical to the wild type DNA. Login to comment
77 Mutations L327R, R347P and R352Q were better distinguished from wild type on gel with higher acrylamide concentration. Login to comment
121 1078delT (35), L327R (Ravnik-Glavac a al., unpublished), R334W (36), D36K (31), R347L (26), R347P (14), A349V (26), R352Q (30), 1221delCT (34); Exon 8: W401X (31), 1342-1G-C (25); Exon 9: G458V (37), 1525 -1G-A (38); Exon 10: S492F (34), Q493X (39), 1609delCA (40,17), deltaI507 (39,41), deltaF5O8 (3), 1717-1G-A (39,42); Exon 11: G542X (39), S549N, G551D, R553X (43), R553Q (44), A559T (43), R560K (Fine et al., pers. comm.), R560T (39); Exon 12: Y563N (39), 1833delT (Schwartz et al., pers. comm.), P574H (39), 1898 + 1G-C (31), 1898+3A-G (Ferrari et al., pers. comm.); Exon 13: G628R(G-C) (31), Q685X (Firec et al., pers. comm.), K716X (26), L719X (Dork etal., pers. comm.), 2522insC (15), 2556insAT (45), E827X (34); Exon 14a: E831X (Ffrec et al., pers. comm.), R851X (29), 2721delll (31), C866Y (Audrezet et al., pers. comm.); Exon 14b: 2789+5G-A (Highsmith et al., pers. comm.); Exon 15: 2907denT (21), 2991del32 (Dark and TQmmler, pers. comm.), G970R (31); Exon 16: S977P, 3100insA (D6rk et al., pers. comm.); Exon 17a: I1005R (Dork and TQmmler, pers. comm.), 3272-1G-A (46); Exon 17b: H1054D (F6rec et al., pers. comm.), G1061R (Fdrec et al., pers. comm.), 332Oins5, R1066H, A1067T (34), R1066L (Fe"rec etal., pers. comm.), R1070Q (46), E1104X (Zielenski el al., pers. comm.), 3359delCT (46), L1077P (Bozon « a/., pers. comm.), H1085R (46), Y1092X (Bozon etal., pers. comm.), W1098R, M1101K (Zielenski et al., pers. comm.); Exon 18: D1152H (Highsmith et al., pers. comm.); Exon 19:R1162X (36), 3659delC (39), 3662delA (25), 3667del4 (Chillon et al., pers. comm.), 3737ddA (35), 3821ddT (15), I1234V (35), S1235R (31), Q1238X (26), 3849G-A (25), 385O-3T-G (38); Exon20:3860ins31 (Chillon etal., pers. comm.), S1255X (47), 3898insC (26), 3905insT (Malik et al., pers. comm.), D127ON (48), W1282X (49), Q1291R (Dork et al., pers. comm.), Exon 21: N1303H (35), N13O3K (50), W1316X (43); Exon 22: 11328L/4116delA (Dork and TQmmler, pers. comm.), E1371X (25); Exon 23: 4374+ 1G-T (38); Exon 24: 4382delA (Claustres et al., pers. comm.). Login to comment

[hide] Expression of cystic fibrosis transmembrane conduc... Am J Physiol. 1994 Apr;266(4 Pt 1):L405-13. Sheppard DN, Carson MR, Ostedgaard LS, Denning GM, Welsh MJ
Expression of cystic fibrosis transmembrane conductance regulator in a model epithelium.
Am J Physiol. 1994 Apr;266(4 Pt 1):L405-13., [PMID:7513963]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR) is a Cl- channel regulated by adenosine 3',5'-cyclic monophosphate (cAMP)-dependent phosphorylation and by intracellular nucleotides. The function of CFTR, like other recombinant ion channels, has generally been studied in single cells using voltage-clamp techniques. However, because CFTR is normally located in the apical membrane of epithelia we wanted to develop a system to study the function of recombinant CFTR expressed in an epithelium. We chose Fischer rat thyroid (FRT) epithelia for two reasons. First, when grown on permeable filter supports, FRT cells form polarized epithelia with a high transepithelial resistance. Second, they have no endogenous cAMP-regulated Cl- channels in their apical membrane. We expressed CFTR in FRT epithelia either transiently, using recombinant vaccinia virus, or stably, using a retrovirus. To measure apical membrane Cl- currents, we permeabilized the basolateral membrane to monovalent ions with nystatin and imposed a large transepithelial Cl- concentration gradient. cAMP agonists stimulated apical membrane Cl- currents in FRT epithelia infected with wild-type CFTR (vTF-CFTR) but not in FRT epithelia infected with either control virus (vTF7-3) or CFTR containing the delta F508 mutation (vTF-delta F508). These Cl- currents had properties similar to those of cAMP-activated Cl- currents in cells expressing endogenous or recombinant CFTR.(ABSTRACT TRUNCATED AT 250 WORDS)

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267 We have recently exploited FRT epithelia to characterize the dysfunction of CFTR Cl- channels caused by three mutations that are associated with a milder clinical CF phenotype 1O ` (R117H, R334W, and R347P) (31). Login to comment

[hide] Analysis of the CFTR gene confirms the high geneti... Hum Genet. 1994 Apr;93(4):447-51. Chillon M, Casals T, Gimenez J, Ramos MD, Palacio A, Morral N, Estivill X, Nunes V
Analysis of the CFTR gene confirms the high genetic heterogeneity of the Spanish population: 43 mutations account for only 78% of CF chromosomes.
Hum Genet. 1994 Apr;93(4):447-51., [PMID:7513293]

Abstract [show]
We have analysed 972 unrelated Spanish cystic fibrosis patients for 70 known mutations. Analysis was performed on exons 1, 2, 3, 4, 5, 6a, 6b, 7, 10, 11, 12, 13, 14a, 14b, 15, 16, 17b, 18, 19, 20 and 21 of the cystic fibrosis transmembrane regulator gene using single strand conformation polymorphism analysis and denaturing gradient gel electrophoresis. The major mutation delta F508 accounts for 50.6% of CF chromosomes, whereas another 42 mutations account for 27.6% of CF chromosomes, with 21.8% of Spanish CF chromosomes remaining uncharacterized. At present, we have identified 36 mutations that have frequency of less than 1% and that are spread over 15 different exons. This indicates that, in the Spanish population, with the exception of delta F508 (50.6%) and G542X (8%), the mutations are not concentrated in a few exons of the gene nor are there any predominating mutations. This high degree of genetic heterogeneity is mainly a result of the different ethnic groups that have populated Spain and of the maintenance of separated population sets (Basques, Arab-Andalusian, Mediterranean, Canarian and Gallician). The high proportion of CF chromosomes still unidentified (21.8%) together with association analysis with intragenic markers suggest that at least 100 different mutations causing CF are present in our population.

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31 At present, we have not detected any Spanish CF chromosomes bearing any of the following mutations: 394delTA, Y122X, 556delA, 852de122, R347P, $492F, 1677delTA, V520F, Q552X, R553X, L559S, R560K, R560T, Y563N, P564H, 2043delG, 3320ins5, R1066H, A1067T, H1085R, 3732delA, 3737delA, I1234V, S1255P, 3898insC, Q1291H or 4005+ 1G---~A. Login to comment

[hide] Genetic analysis of Hispanic individuals with cyst... Am J Hum Genet. 1994 Mar;54(3):443-6. Grebe TA, Seltzer WK, DeMarchi J, Silva DK, Doane WW, Gozal D, Richter SF, Bowman CM, Norman RA, Rhodes SN, et al.
Genetic analysis of Hispanic individuals with cystic fibrosis.
Am J Hum Genet. 1994 Mar;54(3):443-6., [PMID:7509564]

Abstract [show]
We have performed molecular genetic analyses of Hispanic individuals with cystic fibrosis (CF) in the southwestern United States. Of 129 CF chromosomes analyzed, only 46% (59/129) carry delta F508. The G542X mutation was found on 5% (7/129) of CF chromosomes. The 3849 + 10kbC-->T mutation, detected primarily in Ashkenazi Jews, was present on 2% (3/129). R1162X and R334W, mutations identified in Spain and Italy, each occurred on 1.6% (2/129) of CF chromosomes. W1282X and R553X were each detected once. G551D and N1303K were not found. Overall, screening for 22 or more mutations resulted in detection of only 58% of CF transmembrane conductance regulator gene mutations among Hispanic individuals. Analysis of KM19/XV2c haplotypes revealed an unusual distribution. Although the majority of delta F508 mutations are on chromosomes of B haplotypes, the other CF mutations are on A and C haplotypes at higher-than-expected frequencies. These genetic analyses demonstrate significant differences between Hispanic individuals with CF and those of the general North American population. Assessment of carrier/affected risk in Hispanic CF individuals cannot, therefore, be based on the mutation frequencies found through studies of the general population but must be adjusted to better reflect the genetic makeup of this ethnic group. Further studies are necessary to identify the causative mutation(s) in this population and to better delineate genotype/phenotype correlations. These will enable counselors to provide more accurate genetic counseling.

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45 The following CFTR gene mutations were identified by published methods: AF508 (Rommens et al. 1990); G542X (Kerem et al. 1990); GS51D and R553X (Cutting et al. 1990); R1162X (Gasparini et al. 1991); W1282X (Vidaud et al. 1990); N1303K (Osborne et al. 1991); 3849 +lOkbC- T (Highsmith et al., submitted); and R117H, Y122X, 1148T, 621+1G-*oT, 711+1G- T, G314E, 1078AT, R334W, R347P, Q493X, A1507, V520F, 1717 -1G-oA, R560T, and 3569AC (J. DeMarchi et al., submitted). Login to comment
54 COther = A1507, 621+1G- T, R117H, N1303K, 711+1G-*.T, 1717-1G-.A, R560T, Y122X, 1148T, G314E, 1078AT, R347P, Q493X, V520F, and 3659AC. Login to comment
56 The G542X mutation was found in 5.4% of Hispanic CF chromosomes, similar to the 3% frequency in the general population. Login to comment
47 The following CFTR gene mutations were identified by published methods: AF508 (Rommens et al. 1990); G542X (Kerem et al. 1990); GS51D and R553X (Cutting et al. 1990); R1162X (Gasparini et al. 1991); W1282X (Vidaud et al. 1990); N1303K (Osborne et al. 1991); 3849 +lOkbC-T (Highsmith et al., submitted); and R117H, Y122X, 1148T, 621+1G-*oT, 711+1G-T, G314E, 1078AT, R334W, R347P, Q493X, A1507, V520F, 1717 -1G-oA, R560T, and 3569AC (J. DeMarchi et al., submitted). Login to comment

[hide] A new missense mutation (G27E) in exon 2 of the CF... Hum Mol Genet. 1994 Feb;3(2):365-6. Bienvenu T, Cazeneuve C, Beldjord C, Dusser D, Kaplan JC, Hubert D
A new missense mutation (G27E) in exon 2 of the CFTR gene in a mildly affected cystic fibrosis patient.
Hum Mol Genet. 1994 Feb;3(2):365-6., [PMID:7516232]

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36 Other missense mutations (i.e. E92K, R117H, R334W, R347P, R347L) especially located in the first transmembrane domain are associated with pancreatic sufficiency (15-17). Login to comment

[hide] CFTR and calcium-activated chloride currents in pa... Am J Physiol. 1994 Jan;266(1 Pt 1):C213-21. Gray MA, Winpenny JP, Porteous DJ, Dorin JR, Argent BE
CFTR and calcium-activated chloride currents in pancreatic duct cells of a transgenic CF mouse.
Am J Physiol. 1994 Jan;266(1 Pt 1):C213-21., [PMID:7508188]

Abstract [show]
We have studied the cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride currents in pancreatic duct cells isolated from a transgenic cf/cf mouse created by targeted insertional mutagenesis. Adenosine 3',5'-cyclic monophosphate (cAMP)-activated CFTR chloride currents were detected in 78% (29/37) of wild-type cells, in 81% (35/43) of heterozygote cells, and in 61% (29/47) of homozygous cf/cf duct cells (P > 0.05, cf/cf vs. wild-type and heterozygote). The CFTR current density measured at membrane potentials of +/- 60 mV averaged 22-26 pA/pF in wild-type and heterozygote groups but only 13 pA/pF in cells derived from cf/cf animals (P < 0.05, cf/cf vs. wild-type and cf/cf vs. heterozygotes). In contrast, duct cells from animals of all three genotypic groups exhibited calcium-activated chloride currents that were of similar magnitude and up to 11-fold larger than the CFTR currents. We speculate that these transgenic insertional null mice do not develop the pancreatic pathology that occurs in cystic fibrosis patients because their duct cells contain 1) some wild-type CFTR generated by exon skipping and aberrant splicing and 2) a separate anion secretory pathway mediated by calcium-activated chloride channels.

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191 Interestingly, CFTR containing missense mutations that are associated with pancreatic sufficiency (e.g., Rll7H, R334W, and R347P, see Ref. 24) can generate 530% of the wild-type chloride current density in transfected cells (31). Login to comment

[hide] Exon 9 of the CFTR gene: splice site haplotypes an... Hum Genet. 1994 Jan;93(1):67-73. Dork T, Fislage R, Neumann T, Wulf B, Tummler B
Exon 9 of the CFTR gene: splice site haplotypes and cystic fibrosis mutations.
Hum Genet. 1994 Jan;93(1):67-73., [PMID:7505767]

Abstract [show]
The alternatively spliced exon 9 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene codes for the initial part of the amino-terminal nucleotide-binding fold of CFTR. A unique feature of the acceptor splice site preceding this exon is a variable length polymorphism within the polypyrimidine tract influencing the extent of exon 9 skipping in CFTR mRNA. We investigated this repeat for its relationship to CFTR mutations and intragenic markers on 200 chromosomes from German patients with cystic fibrosis (CF). Four frequent length variations were strongly associated with the four predominant haplotypes previously defined by intragenic marker dimorphisms. One of these alleles displayed absolute linkage disequilibrium to the major CF mutation delta F508. Other frequent CFTR mutations were linked to one particular splice site haplotype indicating that differential exon 9 skipping contributes little to the clinical heterogeneity among CF patients with an identical mutation. We also identified a novel missense mutation (V456F) and a novel nonsense mutation (Q414X) within the coding region of exon 9. The missense mutation V456F adjacent to Walker motif A was present in a pancreas-sufficient CF patient. In contrast, the pancreas-insufficient Q414X/delta F508 compound heterozygote suffered from a severe form of the disease, indicating that alternative splicing of exon 9 does not overcome the deleterious effect of a stop codon with this exon.

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61 Association of (TG),Tm alleles with CFTR mutations (TG),Tm CFTR mutationsa (TG)llT7 E60X, E92X, R117C, 1078delT, R347P, R553X, 2184delA, 2184insA, I1005R, 3272-26A--~G, L1059X, Y1092X, R1162X, 3659delC, 3850-3T-oG, S1251N Q39X, R117H, Q414X, V456F, AI507, 1717-1G--~A, G551D, 2043delG, 2183AA---~G, 2184insA, 2789 + 5 G---~A,3272-26A---~G, R1066C, L1077P, 3849 + l0 kB C---~T,4374 + 1 G---~T 621 + 1 G---~T,R334W, A455E, AF508, G542X, 2143delT, 3849 + 10 kB C---~T,NI303K 405 + 1 G----~A,1342-2 A---~C,R553X (TG)IoT7 (TG)10T9 (TG)12T7 a References are compiled in Tsui (1992), except for 2143delT (Dtrk et al. 1992b), 3850-3 T---~G,4374 + 1 G---~T,1342-2 A---~C (Dtrk et al. 1993a, b), Q414X, V456F (this work), 405 + 1 G---~A, E92X, R117C, 2184delA, 2184insA, I1005R, L1059X (T. Login to comment

[hide] Identification of six novel mutations in the CFTR ... Hum Mol Genet. 1994 Jan;3(1):57-60. Savov A, Mercier B, Kalaydjieva L, Ferec C
Identification of six novel mutations in the CFTR gene of patients from Bulgaria by screening the twenty seven exons and exon/intron boundaries using DGGE and direct DNA sequencing.
Hum Mol Genet. 1994 Jan;3(1):57-60., [PMID:7512860]

Abstract [show]
The CFTR gene, in which more than 300 mutations have been described, displays a spectrum of mutations which varies according to ethnic and geographic origin of patients. In this paper we report an exhaustive study of the 27 exons and exon/intron boundaries of a sample of 35 CF patients from Bulgaria which is situated in the south east of Europe. We have used denaturing gradient gel electrophoresis assay followed by DNA sequencing and we report the identification of six previously undescribed CFTR alleles.

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22 Preliminary studies on the molecular basis of CF in Bulgaria have shown that AF5O8 accounts for about 55% of the mutant alleles (9) with the N13O3K accounting for 6% (10), the G542X for 5% and three additional mutations including 1677 del TA, R1070Q and R347P for about 8%. Login to comment
74 The most common mutations of the CFTR gene (AF508, N1303K, G542X, 1677 del TA, R347P, R1070Q) have been in a first step identified and in our ongoing effort to identify the other mutations, we have fully scanned the entire coding sequence of 35 CF patients. Login to comment

[hide] Nasal epithelial ion transport and genetic analysi... Hum Mol Genet. 1993 Oct;2(10):1605-9. Osborne LR, Lynch M, Middleton PG, Alton EW, Geddes DM, Pryor JP, Hodson ME, Santis GK
Nasal epithelial ion transport and genetic analysis of infertile men with congenital bilateral absence of the vas deferens.
Hum Mol Genet. 1993 Oct;2(10):1605-9., [PMID:7505692]

Abstract [show]
It has been suggested that congenital bilateral absence of the vas deferens (CBAVD), an important cause of male infertility, is a variant of cystic fibrosis (CF). This study describes a defect in chloride conductance across the nasal epithelium of subjects with CBAVD which is dissimilar to that found in patients with CF. It also demonstrates normal sodium transport across the nasal epithelium in these men, in contrast to patients with CF who exhibit increased sodium absorption. The increased frequency of CFTR mutations in these men implicates the CFTR gene in the pathogenesis of this disorder. Genetic analysis of men with CBAVD who were heterozygous for a known CFTR mutation failed to identify a second mutation within any of the exons or introns of the CFTR gene. These results demonstrate that most men presenting with CBAVD are not compound heterozygotes for mutations within the CFTR gene and can be distinguished from individuals with atypical or asymptomatic CF on the basis of the bioelectric properties of their nasal epithelium. We postulate that mutations in the promoter region or at other regulatory sites of the CFTR gene may be responsible for the CBAVD phenotype in a proportion of cases.

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25 Nasal potential difference, sweat sodium concentration and CF genotype in subjects with CBAVD, CF patients and controls CF genotype Control cohort CBAVD cohort CF cohort N/N« AF5O8/R347H SM9N/R1070Q AF508/Other R553X/N*> Unknown/Unknowtf AF 5«/AF5O8 AFjQj/Other AF508/R347P AF50e/G542X AFjQg/RllTH AF5O8/G85E AF5Q8/R553X AFJO8/G551D AF5O8A^520F AFJO8/S549N AF^/DIjQ, N1303K/Other G542X/R117H AFJ08/R334W Other/Other Subjects 50 1 1 1 6 1 16 25 18 3 2 1 1 1 2 1 1 1 3 1 1 3 Mean (range) sweat Na+ concentration (mmol/1) 50 (27-78) 88 N/A 94 57 (47-70) 36 49 (32-76) 126(80-162) 99 (80-128) 108 (99-115) 128 (118-137) 95 107 130 122 (116-128) 90 80 118 96 (92-99) 84 123 108(83-130) Mean (range) nasal potential difference (-mV) 21 (8-30) 31 N/A 34 23 (13-29) -15 20 (-13-28) 45 (32-58) 41 (33-61) 50 (36-77) 43 (33-52) 51 42 39 60 (50-71) 32 37 41 38 (36-40) 32 34 44(31-57) N = non-CF chromosome Other = uncharacterised CF chromosome N/A not available • with CF carrier frequency of 1/20-1/25, it is likely that 2 or 3 of these individuals will be carriers. Login to comment

[hide] Analysis of the 27 exons and flanking regions of t... Hum Mol Genet. 1993 Aug;2(8):1209-13. Claustres M, Laussel M, Desgeorges M, Giansily M, Culard JF, Razakatsara G, Demaille J
Analysis of the 27 exons and flanking regions of the cystic fibrosis gene: 40 different mutations account for 91.2% of the mutant alleles in southern France.
Hum Mol Genet. 1993 Aug;2(8):1209-13., [PMID:7691344]

Abstract [show]
In order to characterize the non-delta F508 mutations that account for 36% of cystic fibrosis (CF) chromosomes in Southern France in a sample of 137 patients, we have systematically screened the entire coding region and adjacent sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by the single strand conformation polymorphism (SSCP) technique followed by direct sequencing of the mutant DNAs. We identified 13 novel mutations (9 reported in this paper) and 4 novel rare nucleotide sequence variations. Forty different mutations including delta F508, located in 15 exons, account for only 91.2% of mutants in a population originating from Southern France, in contrast with a recent report on the Celtic population of Brittany demonstrating that 90% of mutations can be detected with only three mutations. We present a very large spectrum of different CF mutations identified in a small geographical area.

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26 Mutations identified in a Southern french population mutation AF5O8 M1K 300delA P67L R74W G85E 394detTT 406-6 (T-C) Y122X I148T 621 + 1G-T 62/+2T-G L206W 1078deIT R334W R347H R347P AI507 1717-1G-A G542X R553X S549N G551D E585X 2184delA K710X R792X S945L Y1092X 3272-26A-G R1158X R1162X 3737delA 3659delC 11234V D1270N W1282X N13O3H N13O3K 4382delA Exon 10 1 3 3 3 3 3 intron 3 4 4 intron 4 intron 4 6a 7 7 7 7 10 intron 10 11 11 11 11 , 12 13 13 13 15 17b intron 17a 19 19 19 19 19 20 20 21 21 24 Amino acid change 3 bp deletion start-Lys at 1 frameshift Pro-Leu at67 Arg-Trp at 74 Gly-Glu at 85 frameshift splice mutation? Login to comment

[hide] Molecular mechanisms of CFTR chloride channel dysf... Cell. 1993 Jul 2;73(7):1251-4. Welsh MJ, Smith AE
Molecular mechanisms of CFTR chloride channel dysfunction in cystic fibrosis.
Cell. 1993 Jul 2;73(7):1251-4., [PMID:7686820]

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17 Classes of CFTR Mutations That Cause CF Class Defect Examples Do- Fre- Clin- main quency ical Protein production Nonsense mutations Frameshift Splice Processing Conduction 6542X NBDI 3.4 3905 insT NBD2 2.1 621 + G-T MSDl 1.3 Al507 NBDl AF506 NBDl s5491 NBDl S549R NED1 A559T NED1 N1303K NBDP G551 D NBDl G551S NBDl G1244E NBDP S1255P NBDP G1349D NBDP RI 17H MSDI R334W MSDl R347P MSDl 0.5 67.2 Rare 0.3 Rare 1.a 2.4 Rare Rare Rare Rare 0.6 0.4 0.5 PI PI PI PI PI PI PI PI PS PI PI PI PS PS PS NED, nucleotide-binding domain; MSD, membrane-spanning domain; PI, pancreatic insufficiency; PS, pancreatic sufficiency. Login to comment
66 Three mutations in the first membrane-spanning domain (R117H, R334W, and R347P) affect arginine residues located in putative membrane-spanning sequences. Login to comment
69 Nevertheless, the amount of current is reduced, with wild-type CFTR > R347P > R117H > R334W. Login to comment

[hide] A comprehensive CFTR mutation analysis of German c... Hum Mol Genet. 1993 Jun;2(6):809-11. Reiss J, Ellermeyer U, Rininsland F, Ballhausen P, Lenz U, Wagner S, Schlosser M
A comprehensive CFTR mutation analysis of German cystic fibrosis patients.
Hum Mol Genet. 1993 Jun;2(6):809-11., [PMID:7689013]

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56 Frequency of CFTR mutations checked routinely in German CF patients Mutation AF508 AI507 R553X G542X G551D R347P N1303K 1717 -lg-a S549R others in exon total Exon 10 10 11 11 11 7 21 llfb) 11 ll(c) Frequency 375/500 1/500 17/124(a) 13/124 7/124 6/124 6/124 5/124 2/124 0/124 % of total CF chromosomes 75.1 0.2 3.4 2.6 1.4 1.2 1.2 1.0 0.4 0.0 86.5 Reference (3) (17) (18) (17) (18) (10) (19) (17) (17) (20) (a) Non-AF508 chromosomes. Login to comment

[hide] A novel mutation in exon 3 of the CFTR gene. Hum Genet. 1993 Apr;91(3):233-5. Guillermit H, Jehanne M, Quere I, Audrezet MP, Mercier B, Ferec C
A novel mutation in exon 3 of the CFTR gene.
Hum Genet. 1993 Apr;91(3):233-5., [PMID:7682984]

Abstract [show]
We have screened the 27 exons of the cystic fibrosis transmembrane conductance regulator gene in 87 non-delta F508 chromosomes of Breton origin using the combined techniques of denaturing gradient gel electrophoresis and direct sequencing. By this process, we have detected a new missense mutation, G91R, which results in an arginine for glycine at codon 91. Three affected patients with a delta F508/G91R genotype are pancreatic sufficient. Such observations could facilitate a better understanding of the functional importance of different regions of the encoded product and of the pathogenesis of the disease.

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63 Other missense mutations reported by Kristidis et al. (1991) as being located in the transmembrane domain, i.e. R117H (exon 4), R334W (exon 7), R347P (exon 7), A455E (exon 9) and P574H (exon 12), are associated with pancreatic sufficiency; these observations are consistent with the genetic hypothesis that pancreatic sufficiency is a 235 dominant phenotypic trait associated with about 10% of the CF alleles. Login to comment

[hide] Genetic determinants of airways' colonisation with... Lancet. 1993 Jan 23;341(8839):189-93. Kubesch P, Dork T, Wulbrand U, Kalin N, Neumann T, Wulf B, Geerlings H, Weissbrodt H, von der Hardt H, Tummler B
Genetic determinants of airways' colonisation with Pseudomonas aeruginosa in cystic fibrosis.
Lancet. 1993 Jan 23;341(8839):189-93., [PMID:7678316]

Abstract [show]
Exocrine pancreatic insufficiency and lung infection with Pseudomonas aeruginosa are major features of cystic fibrosis (CF). This monogenic disease is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. 267 children and adolescents with CF who were regularly seen at the same centre were assessed for an association of the CFTR mutation genotype with exocrine pancreatic function and the age of onset of chronic colonisation with P aeruginosa. The major mutation delta F508 accounted for 74% of CF alleles; 33 further CFTR mutations had been detected on the CF chromosomes of the study population by June, 1992. With the exception of delta F508/R347P compound heterozygotes, patients of the same mutation genotype were either pancreas insufficient (PI) or pancreas sufficient (PS). The age-specific colonisation rates with P aeruginosa were significantly lower in PS than in PI patients. The missense and splice site mutations that are "mild" CF alleles with respect to exocrine pancreatic function were also "low risk" alleles for the acquisition of P aeruginosa. On the other hand, the proportion of P aeruginosa-positive patients increased most rapidly in the PI delta F508 compound heterozygotes who were carrying a termination mutation in the nucleotide binding fold-encoding exons. Pancreatic status and the risk of chronic airways' colonisation with P aeruginosa are predisposed by the CFTR mutation genotype and can be differentiated by the type and location of the mutations in the CFTR gene.

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4 With the exception of DgrF508/R347P compound heterozygotes, patients of the same mutation genotype were either pancreas insufficient (PI) or pancreas sufficient (PS). Login to comment
53 Patients of the same genotype were either all PI or all PS at diagnosis, the exception being the AF508/R347P compound heterozygotes (3 PI, 2 PS). Login to comment

[hide] Identification of 12 novel mutations in the CFTR g... Hum Mol Genet. 1993 Jan;2(1):51-4. Audrezet MP, Mercier B, Guillermit H, Quere I, Verlingue C, Rault G, Ferec C
Identification of 12 novel mutations in the CFTR gene.
Hum Mol Genet. 1993 Jan;2(1):51-4., [PMID:7683952]

Abstract [show]
Over 200 mutations, besides the deletion delta F508, have been identified in the CFTR gene and are known to cause CF. In order to characterize the molecular defects of non delta F508 CF chromosomes of various French origin, we have combined the techniques of denaturing gradient gel electrophoresis (DGGE) and direct sequencing to screen for mutations in the whole coding sequence of the CFTR gene corresponding to the 27 exons and their exon-intron boundaries. This approach enabled us to identify 12 novel mutations which are described here. We have systematically tested a large number of other nucleotide changes distributed in the 27 exons, each of them was clearly detected. These data support the notion that the DGGE conditions we have defined for screening coding sequence of the CFTR gene allows the identification of most of, if not all, the CFTR gene mutations.

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40 It appears that codon 347 could be a hot spot for mutations since two other nucleotide changes have been reported at nucleotide 1172 leading to R347P (12) or R347H which is associated with pancreatic sufficiency (Devoto, personal comm.). Login to comment

[hide] The spectrum of cystic fibrosis mutations. Trends Genet. 1992 Nov;8(11):392-8. Tsui LC
The spectrum of cystic fibrosis mutations.
Trends Genet. 1992 Nov;8(11):392-8., [PMID:1279852]

Abstract [show]
Although the major mutation causing cystic fibrosis accounts for almost 70% of mutant chromosomes screened, almost 300 sequence alterations have been identified in the gene during the past two and a half years. At least 230 of these mutations are probably associated with disease. This rapid accumulation of data is in part due to the highly coordinated effort by members of the Cystic Fibrosis Genetic Analysis Consortium. The information is not only essential to genetic diagnosis, but also will aid in understanding the structure and function of the protein, and possibly in correlating genotype with phenotype.

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64 Frequent cystic fibrosis mutations Name Relative freqeenc~ Mutation Con~,~'~luence Ref. Z~508 67.2 G542X 3.4 G551D 2.4 W1282X 2.1 3905insT 2.1 N1303K 1.8 3849+10kbC-+T 1.4 1717-1G-+A 1078delT 2789+5G--+A Deletion of 3 bp between nt 1652 and t655 in exon 10 G-+T at nt 1756 in exon 11 G-+A at nt 1784 in exon 1I G-+A at nt 3978 in exon 20 Insertion of T after nt 3905 in exon 20 C-+G at nt 4041 in exon 21 C-->T in a 6.2 kb EcoRI fragment 10 kb from 5' junction of intron 19 3849+4A-+G 1.0 7tt÷IG--+T 0.9 Rl162X 0.9 1898+lG-+A 0.9 Rll7H 0.8 3659delc 0.8 G85E 0.7 2184delA 0.7 AI5W 0.5 R347P 0.5 R~ 0.4 1,3 C-+T at nt 1"789in exon 11 1.3 G-+T at nt 1 from 5' junction of intron 4 1.1 G--+A at nt 1 from 3' junction of intron 10 1.1 Deletion of T at nt 1078 in exon 7 1.1 G-cA at 5 nt from 5' end of intron 14b A-->G at 4 nt from 5' end of intron 19 G-+T at nt 1 from 5' junction of intron 5 C-+T at nt 3616 in exon 19 G-+A at nt 1 from 5' junction of intron 12 G--)A at nt 482 in exon Deletion of C at nt 3659 in exon 19 G-+A at nt 386 in exon 3 A-->G at nt 2183 and deletion of A at nt 2184 in exon 13 Deletion of 3 bp between nt 1648 and 1653 in exon 10 G-+C at nt 1172 in exon 7 G-~C at nt 1811 in exon 11 A455E 0.4 R334W 0.4 Y122X 0.3 S549R(T-+G) 0.3 Q493X 0.3 V520F 0.2 S549N 0.2 C-+A at nt 1496 in exon 9 C-+T at nt 1132 in exon 7 T-cA at nt ~i98 in exon 4 T--+G at nt 1779 in exon 11 C-+T at nt 1609 in exon 10 G-+T at nt 1690 in exon 10 G-->A at nt I778 in exon !1 Deletion of Phe at codon 508 Gly-+Stop at codon 542 12 Gly-~Asp at codon 551 10 l"rp-->Stop at codon t282 35 Frameshift -~ Asn-+Lys at codon 1303 36 Aberrant splicing -~ Arg~Stop ~ codon 553 Splice mutation 10 37 Splice mutation 12 Frameshift 38 Splice mutation _c Splice mutation? Login to comment
103 Moreover, any charge alteration near the presumptive pore of the channel formed by the transmembrane segments may also be expected to cause a CFphen0type.Indeed, many mutations affecting the transmembranedomains and their neighboring sequences areaminoacidsub- stitutions involving a polar residue/Fig.5).Itis interesting that some of these mutati0ns- Rll7H(Ref.20), R334W (Ref. 21) and R347P (Ref.20)-areassociated with less severely impaired pancreaticfunction(see below). Login to comment
114 Although no specific example can be cited for the third class, it is reasonable to believe that some of the amino acid substitutions in the transmembrane domains [such as R334W (Ref. 21) and R347P (Ref. 20)] and neighboring regions [such as R117H (Ref. 20)] will belong to this class. Login to comment
122 This hypothesis has been well supported by analysis of patients, which shows that individuals with one or two copies of the missense alleles such as Rll7H, R334W, R347P, A455E (Ref. 12) or P574H (Ref. 12) are found to be PS, whereas those with two copies of nonsense, frameshift, splice-site or a subset of the missense mutations are invariably PI TIGNOVEMBER1992 VOt. Login to comment

[hide] Milestones in cystic fibrosis. Br Med Bull. 1992 Oct;48(4):717-37. Super M
Milestones in cystic fibrosis.
Br Med Bull. 1992 Oct;48(4):717-37., [PMID:1281032]

Abstract [show]
The study of cystic fibrosis (CF) provides a fascinating insight into developments in medicine in the 20th century. Milestones include the first clear clinical descriptions in the 1930s, discovery of a sweat electrolyte abnormality, establishing the autosomal recessive mode of inheritance and improvements in treatment. Microdissection experiments on sweat glands allowed the main defect to be delineated as one of chloride transport. Location of the gene to chromosome 7 made prenatal diagnosis feasible and carrier detection in siblings. The CF gene--its product being the cystic fibrosis transmembrane conductance regulator (CFTR), and its major mutation Delta F508 was discovered in 1989. World-wide collaboration has resulted in discovery of more than 150 further mutations. Incorporation of CFTR into non-chloride transporting insect cells by conferring chloride transport, proved it a chloride channel. CFTR incorporated into adenovirus results in correction of the chloride transport defect in airway cells, bringing gene therapy closer.

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164 Mutations encountered elsewhere in UK but not yet m N-W 1154insTC R347P A455E G458V Q493X C524X S549N R1283M Q1291H 199 (in the north-west group) 199 199 0 0 0 199 199 0 icant alteration in function appears to be worse than no CFTR being formed at all. Login to comment

[hide] Mutation analysis of 184 cystic fibrosis families ... J Med Genet. 1992 Sep;29(9):642-6. Cheadle J, Myring J, al-Jader L, Meredith L
Mutation analysis of 184 cystic fibrosis families in Wales.
J Med Genet. 1992 Sep;29(9):642-6., [PMID:1357180]

Abstract [show]
We describe a molecular analysis of 184 cystic fibrosis (CF) families in Wales. To determine accurate frequency data for the CF mutations in the Welsh population, families with at least three Welsh grandparents were strictly regarded as Welsh. Of these 74 families, we have identified approximately 90% of mutations causing CF, with delta F508 accounting for 71.8% and 621 + 1G greater than T 6.7%. We observed a significant difference between the Welsh and Scottish frequencies of 621 + 1G greater than T. To allow the rapid and efficient screening for the more common mutations we modified a multiplex used by Watson et al enabling the detection of delta F508, G551D, and R553X simultaneously with 621 + 1G greater than T. In parallel to this system we ran the Cellmark Diagnostics ARMS multiplex kit, which detects delta F508, 621 + 1G greater than T, G551D, and G542X. RFLP analysis of the 184 families shows that the delta F508 chromosomes are almost exclusively found on the B haplotype (XV2c 1, KM19 2); the other CF mutations have more heterogeneous backgrounds. Strong haplotype correlations exist between the markers XV2c, KM19, D9, and G2 and the other CF mutations. Haplotype data suggest that there are at least seven mutations that remain to be identified in these families.

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61 Welsh Mixed Undefined Total Mutation No % No % No % No % AF508 107/149 71-8 92/126 73 0 69/94 73 4 268/369 72-6 621 + 1G>T 10/42* 6-7 5/34* 4-0 4/25* 4-3 19/101* 51 G551D 2/42* 1-3 6/34* 4-8 3/25* 3-2 11/101* 3 0 G542X 4/42* 2-7 4/34* 3-2 1/25* 1.1 9/101* 2-4 G85E 0/41* 0-0 2/34* 1 6 3/24* 3*4 5/99* 1-4 R553X 2/42* 1-3 2/34* 16 0/25* 00 4/101* 1-1 R1283M 3/42* 2.0 0/34* 0.0 0/25* 0.0 3/101* 0-8 N1303K 1/42* 0 7 1/34* 0-8 0/24* 0.0 2/100* 0-6 AI507 2/149 1-3 0/126 0.0 0/94 0.0 2/369 0-5 R117H 1/42* 0 7 1/34* 0-8 0/25* 0.0 2/101* 0-5 1717- 1G>A 2/42* 1-3 0/34* 0 0 0/25* 0 0 2/101* 0-5 R560T 0/42* 00 0/34* 00 1/25* 1 1 1/101* 03 1154InsTC 0/40* 0 0 1/33* 0 9 0/24* 0.0 1/97* 0-3 V520F 0/42* 0 0 0/34* 0 0 0/25* 0.0 0/101* 0 0 W1282X 0/42* 0 0 0/34* 0.0 0/25* 0.0 0/101* 0 0 R347P 0/42* 0 0 0/34* 0 0 0/24* 0.0 0/100* 0 0 Q493X 0/42* 0 0 0/34* 0 0 0/24* 0 0 0/100* 00 Total (%) 89-8 90 7 86-5 891 * Non-AF508 chromosomes. Login to comment

[hide] Nine cystic fibrosis patients homozygous for the C... J Med Genet. 1992 Aug;29(8):558-62. Gasparini P, Borgo G, Mastella G, Bonizzato A, Dognini M, Pignatti PF
Nine cystic fibrosis patients homozygous for the CFTR nonsense mutation R1162X have mild or moderate lung disease.
J Med Genet. 1992 Aug;29(8):558-62., [PMID:1381442]

Abstract [show]
The clinical course of nine cystic fibrosis patients homozygous for the CF gene nonsense mutation R1162X was investigated. Since this mutation should lead to an interruption in the synthesis of the cystic fibrosis transmembrane regulator (CFTR) protein, a severe clinical course was expected. All patients showed pancreatic insufficiency, while the course of the lung disease was mild to moderate. These results suggest that this form of truncated CFTR protein, still containing the regulatory region, the first ATP binding domain, and both transmembrane domains, could be partially working in the lung tissues.

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92 It is noteworthy that among 16 RI 162X compound heterozygote CF patients we studied, pancreatic sufficiency was found in two 0° patients, one of whom was a compound hetero-Clz° °zygote for R347P, and the other had a still o 0o unknown mutation. Login to comment
95 RI 162X, therefore, when combined with Age (months) a mild mutation like R347P,31 leads to pancreatic sufficiency. Login to comment

[hide] Analysis of four diverse population groups indicat... Am J Hum Genet. 1992 Jun;50(6):1185-94. Cutting GR, Curristin SM, Nash E, Rosenstein BJ, Lerer I, Abeliovich D, Hill A, Graham C
Analysis of four diverse population groups indicates that a subset of cystic fibrosis mutations occur in common among Caucasians.
Am J Hum Genet. 1992 Jun;50(6):1185-94., [PMID:1376017]

Abstract [show]
To determine the nature and frequency of non-delta F508 cystic fibrosis (CF) mutations among diverse populations, we have sequenced exons 9-12 and 19-23 of the CF transmembrane conductance regulator (CFTR) gene from 128 CF chromosomes (39 U.S. Caucasian, 27 African-American, 42 Northern Irish, and 20 Israeli chromosomes). These regions were chosen because they encode the two putative ATP-binding folds of CFTR, domains which appear to have functional significance. In addition, CFTR exons 1 and 2 were analyzed in the American patients. Mutations were found on 49 of the 128 CF chromosomes. Nineteen different mutations were observed; six were novel, while the remaining 13 had been reported previously by our group or by other investigators. Six of nine different mutations found in African-American patients were unique to that population. However, the vast majority of the mutations found in U.S. Caucasians (eight of nine), Northern Irish (four of five), and Israelis (three of three) also occurred in other Caucasian groups. The preponderance of previously reported mutations in these three groups suggested that a subset of the non-delta F508 mutations occur in common among Caucasians. A survey of mutation frequencies in other Caucasian groups confirmed this observation. Unfortunately, this subset accounts for less than half of non-delta F508 CF mutations in most groups. These data suggest that screening for delta F508 and this select group of mutations will efficiently and economically maximize the number of CF mutations identified in Caucasian groups. However, it will be difficult to detect more than 90% of mutant CFTR alleles except in ethnically and geographically discrete populations where CF is the result of founder effect.

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49 Detection of Exons 4 and 7 Mutations Patients with one or more unknown mutations were screened for mutations R117H and 621 + 1G--T in exon 4, by using allele-specific oligonucleotide (ASO) hybridization, and mutations R334W and R347P in exon 7, by using restriction-enzyme digestion (Dean et al. 1990; Gasparini et al. 1991; Shrimpton et al. 1991). Login to comment
58 Mutations R334W and R347P were detected by using restriction digestion with enzymes MspI and HhaI, respectively, as reported elsewhere (Gasparini et al. 1991; Shrimpton et al. 1991). Login to comment
112 Four mutations, R117H (Dean et al. 1990) and 621 + 1 G-'T (Zielinski et al. 1991a) in exon 4 and R334W (Gasparini et al. 1991) and R347P (Dean et al. 1990) in exon 7, occur with some frequency in these populations. Login to comment

[hide] Genetic determination of exocrine pancreatic funct... Am J Hum Genet. 1992 Jun;50(6):1178-84. Kristidis P, Bozon D, Corey M, Markiewicz D, Rommens J, Tsui LC, Durie P
Genetic determination of exocrine pancreatic function in cystic fibrosis.
Am J Hum Genet. 1992 Jun;50(6):1178-84., [PMID:1376016]

Abstract [show]
We showed elsewhere that the pancreatic function status of cystic fibrosis (CF) patients could be correlated to mutations in the CF transmembrane conductance regulator (CFTR) gene. Although the majority of CF mutations--including the most common, delta F508--strongly correlated with pancreatic insufficiency (PI), approximately 10% of the mutant alleles may confer pancreatic sufficiency (PS). To extend this observation, genomic DNA of 538 CF patients with well-documented pancreatic function status were analyzed for a series of known mutations in their CFTR genes. Only 20 of the 25 mutations tested were found in this population. They accounted for 84% of the CF chromosomes, with delta F508 being the most frequent (71%), and the other mutations accounted for less than 5% each. A total of 30 different, complete genotypes could be determined in 394 (73%) of the patients. The data showed that each genotype was associated only with PI or only with PS, but not with both. This result is thus consistent with the hypothesis that PI and PS in CF are predisposed by the genotype at the CFTR locus; the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H, whereas the PI phenotype occurs in patients with two severe alleles, such as delta F508, delta I507, Q493X, G542X, R553X, W1282X, 621 + 1G----T, 1717-1G----A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T.

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10 This result is thus consistent with the hypothesis that PI and PS in CF are predisposed by the genotype at the CFTR locus; the PS phenotype occurs in patients who have one or two mild CFTR mutations, such as R117H, R334W, R347P, A455E, and P574H, whereas the PI phenotype occurs in patients with two severe alleles, such as AF508, A1507, Q493X, G542X, R553X, W1282X, 621 + 1G-PT, 1717-1G--'A, 556delA, 3659delC, I148T, G480C, V520F, G551D, and R560T. Login to comment
57 Intron 4: 621 + 1G-T Exon 7: R334W ......... R347P ........... Exon 9: A455E .......... G458V .......... G480C .......... Exon 10: Q493X .......... A1507 ........... AF508 .......... VS2OF .......... Login to comment
58 Intron 10: 1717-1G-'A Exon 11: G542X .......... S549R ........... G551D .......... R553X .......... R560T .......... Exon 12: Y563N .......... P574H .......... Exon 19: 3659delC ....... Exon 20: W1282X ....... Exon 21: N1303K ..... G460-C A deletion G482-'A A deletion T575-C 621 + 1G-T C1132-T C1172- G C1496-A G1505-'T G1570-T C1609-T 3-bp deletion 3-bp deletion G1690-T G1717-1-A G1756-T T1779-G G1784- A C1789-T G1811-C T1819- A C1853- A C deletion G3978-A C4041-G Asp 110-His Frameshift Arg 117-His Frameshift Ile 148-Thr Splice mutation Arg 334-Trp Arg 347-Pro Ala 455- Glu Gly 458-'Val Gly480-Cys Gln 493- stop del of Ile 507 del of Phe 508 Val 520-Phe Splice mutation Gly 542- stop Ser 549-'Arg Gly 551-WAsp Arg 553- stop Arg 560- Thr Tyr 563- Asn Pro 574-His Frameshift Trp 1282-stop Asn 1303-Lys Dean et al. 1990 White et al. 1991 Dean et al. 1990 Zielenski et al. 1991a F. Rininsland, D. Bozon, and L.-C. Tsui, unpublished data Zielenski et al. 1991a Gasparini et al. 1991 Dean et al. 1990 Kerem et al. 1990b Cuppens et al. 1990 Strong et al. 1991 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1989b Jones et al. 1991 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Cutting et al. 1990 Cutting et al. 1990 Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Kerem et al. 1990b Vidaud et al. 1990 Osborne et al. 1990 PI or PS, but not with both. Login to comment
66 As shown in table 3, meconium ileus Table 2 1181 Table 3 Frequency of 25 CF Mutations in Chromosomes of the Toronto Study Population Mutation AF508 ...... G551D...... G542X...... 621 +1G-'T N1303K..... W1282X..... R1 17H...... 1717-1G-~A R560T...... A1507 ...... R553X...... V52OF ...... R334W ..... A455E...... I148T ...... Q493X...... P574H...... R347P ...... SS6delA ..... 3659delC .... G480C...... 444delA ..... D110H...... G458V...... S549R ...... Y563N...... Login to comment
73 Complete CF Genotypes for 394 Patients No. OF PATIENTS GENOTYPE WITH Allele 1 Allele 2 pla P AF508 ...... AF508 277 (49) 2 G551D 21 (1) 0 G542X 18 (9)c 0 621+1G-~T 11 (1) 0 AI507 7 (1) 0 N1303K 6 (1) 0 R560T 5 0 1717-lG-A 5 (1) 0 556delA 3 0 Q493X 3 0 R553X 3 (1) 0 W1282X 3 0 3659delC 2 0 1148T 1 0 R117H 0 9 A445E 0 2 P574H 0 2 R347P 0 1 G551D ..... 1717-lG-~A 2 0 621+1G-~T 1 0 G480C 1 0 G551D 1 0 V520F 1 (1) 0 G542X ..... V520F 1 0 1148T ...... W1282X 1 (1) 0 W1282X .... W1282X 1 0 N1303K .... R553X 1 (1) 0 R117H ..... R117H 0 1 G542X 0 1 R334W ..... R334W 0 1 a1 Numbers in parentheses are number of patients with neonatal meconium ileus. Login to comment
81 Table 4 Classification of CF Gene Mutations as Severe or Mild with Respect to Pancreatic Function Type of Mutation Severe (location) Mild (location) Missense (point mutation) ...... 1148T (exon 4) R117H (exon 4) G480C (exon 9) R334W (exon 7) VS2OF (exon 10) GSS1D (exon 11) R347P (exon 7) RS60T (exon 11) A455E (exon 9) N1303K (exon 21) P574H (exon 12) Single amino acid deletion ........ AFS08 (exon 10) A1507 (exon 10) Stop codon (nonsense) ..... Q493X (exon 10) G542X (exon 11) R553X (exon 11) W1282X (exon 20) Splice junction ... 621 + 1G-T (intron 4) 1717-1G-T (intron 10) Frameshift ........ 556delA (exon 4) 3659delC (exon 19) with any of the mild mutations was associated with PS. Login to comment
85 Accordingly, the mutations R117H, R334W, R347P, A455E, and P574H may be regarded as mild, whereas AF508, AI507, Q493X, G542X, R553X, W1282X, 621 + 1G-T, 1717-1G--A, 556delA, 3659delC, 1148T, G480C, V520F, GSS1D, and R560T are severe. Login to comment

[hide] Intra- and extragenic marker haplotypes of CFTR mu... Hum Genet. 1992 Feb;88(4):417-25. Dork T, Neumann T, Wulbrand U, Wulf B, Kalin N, Maass G, Krawczak M, Guillermit H, Ferec C, Horn G, et al.
Intra- and extragenic marker haplotypes of CFTR mutations in cystic fibrosis families.
Hum Genet. 1992 Feb;88(4):417-25., [PMID:1371263]

Abstract [show]
In order to facilitate the screening for the less common mutations in the cystic fibrosis (CF) gene viz., the CF transmembrane conductance regulator gene (CFTR), marker haplotypes were determined for German non-CF (N) and CF chromosomes by polymerase chain reaction analysis of four polymorphisms upstream of the CF gene (XV-2c, KM.19, MP6-D9, J44) and six intragenic polymorphisms (GATT, TUB9, M470V, T854T, TUB18, TUB20) that span the CFTR gene from exon 6 through exon 21. Novel informative sequence variants of CFTR were detected in front of exons 10 (1525-61 A or G), 19 (3601-65 C or A), and 21 (4006-200 A or G). The CF locus exhibits strong long-range marker-marker linkage disequilibrium with breakpoints of recombination between XV-2c and KM.19, and between exons 10 and 19 of CFTR. Marker alleles of GATT-TUB9 and TUB18-TUB20 were found to be in absolute linkage disequilibrium. Four major haplotypes encompass more than 90% of German N and CF chromosomes. Fifteen CFTR mutations detected on 421 out of 500 CF chromosomes were each identified on one of these four predominant 7-marker haplotypes. Whereas all analysed delta F508 chromosomes carried the same KM.19-D9-J44-GATT-TUB9-M470V-T854T haplotype, another frequent mutation in Germany, R553X, was identified on two different major haplotypes. Hence, a priori haplotyping cannot exclude a particular CF mutation, but in combination with population genetic data, enables mutations to be ranked by decreasing probability.

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25 Most CFTR mutations were investigated by restriction analysis of PCR products (R334W, R347P, A455E, G551D, R553X, 2789+5 G---~A,Rl162X, W1282X) (Cutting et al. 1990; Dean et al. 1990b; Gasparini et al. 1991b; Highsmith et al. 1990; Kerem et al. 1990;Vidaud et al. 1990) (see Table 4). Login to comment
26 A few other mutations were analysed either by allele-specific oligonucleotide hybridization (Rl17H, G542X, 1717-1 G---~A) (Dean et al. 1990b; Guillermit et al. 1990; Kerem et al. 1990), single strand conformation polymorphism (Orita et al. 1989) (R347P, 3659delC) (Dean et al. 1990b; Kerem et al. 1990), temperature gradient gel electrophoresis (Rosenbaum and Riesner 1987) (1717-1 G--~A) (Guillermitet al. 1990; Kerem et al. 1990) or by allele-specific PCR (G542X, NI303K) (Kerem et al. 1990; Osborne et al. 1991). Login to comment
93 The other identified CFTR mutations either perturb acceptor (1717-1 G---~A) (Guillermit et al. 1990; Kerem et al. 1990) or donor splice sites (2789 + 5 G---~A) (Highsmith et al. 1990), or abolish positive charges in the transmembrane domains of CFTR (R117H, R334W, R347P) (Dean et al. 1990b; Gasparini et al. 1991b). Login to comment
98 ASO, Allele-specificoligonucleotide hybridization; TGGE, temperature gradient gel electrophoresis; SSCP, single strand conformation polymorphism Mutation Localization No. % Method of detectiona Reference R117H Exon 4 2 0.4 ASO Dean et al. (1990b) R334W Exon 7 2 0.4 RFLP MspI Gasparini et al. (1991b) R347P Exon 7 5 1.0 RFLP NcoI Dean et al. (1990b) A455E Exon 9 1 0.2 RFLP AciI Kerem et al. (1990) F508C2 Exon 10 1 0.2 Nondenaturing PAGE Kobayashi et al. (1990) AF508 Exon 10 370 74.0 Nondenaturing PAGE Kerem et al. (1989) 1717-1 G---~A Intron 10 2 0.4 TGGE Kerem et al. (1990) G542X Exon 11 5 1.0 Allele-specificPCR Kerem et al. (1990) G551D Exon 11 5 1.0 RFLP DpnII Cutting et al. (1990) R553X Exon 11 12 2.4 RFLP HincII Cutting et al. (1990) 2789 + 5 G---~A Intron 14B 3 0.6 RFLP SspI Highsmith et al. (1990) Rl162X Exon 19 1 0.2 RFLP DdeI Gasparini et al. (1991b) 3659delC Exon 19 3 0.6 SSCP Kerem et al. (1990) W1282X Exon 20 2 0.4 RFLP MnlI Vidaud et al. (1990) N1303K Exon 21 7 1.4 Allele-specificPCR Osborne et al. (1991) Unpublished 13 2.6 Unknown 66 13.2 Total 500 a All non-AF508 mutations were subsequently verified by direct genomic sequencing of the respective PCR product b F508C was first detected on an N chromosome (Kobayashi et al. 1990) and hence is suspected to represent a benign missense mutation Table 5. Login to comment
100 The four major haplotypes are indicated in bold type KM.19 D9 J44 GATT TUB9 M470V T854T TUB18 TUB20 Mutation 1 l 2 1 2 2 1 1 2 2 2 1 1 2 1 2 2 1 2 2 1 1 2 1 2 1 2 2 2 1 2 1 1 1 1 2 2 2 1 2 1 1 1 2 i 1 2 1 2 1 1 2 1 2 R347P, F508C, R1162X, 3659delC 1717-1 G--~A, G551D, R553X (n = 2), 2789 + 5 G---~A,W1282X R117H R334W, A455E, G542X, N1303K, AF508 (96%) ~F508 (4%) R553X (n = 10) a Haplotypes were assigned from the individual pedigrees mutation was located on a single KM. 19-D9-J44-GATT-TUB9-M470V-T854T haplotype. Login to comment
104 Four mutations, R347P, F508C, Rl162X, and 3659delC were found to be linked with the most common haplotype, whereas five mutations were identified on the second most frequent haplotype. Login to comment

[hide] Screening for non-delta F508 mutations in five exo... Am J Hum Genet. 1991 Jun;48(6):1127-32. Devoto M, Ronchetto P, Fanen P, Orriols JJ, Romeo G, Goossens M, Ferrari M, Magnani C, Seia M, Cremonesi L
Screening for non-delta F508 mutations in five exons of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in Italy.
Am J Hum Genet. 1991 Jun;48(6):1127-32., [PMID:1709778]

Abstract [show]
Analysis of exons 10, 11, 14a, 15, and 20 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by denaturing-gradient-gel electrophoresis (DGGE) allowed the identification of mutations causing cystic fibrosis (CF) in 25 of 109 non-delta F508 chromosomes, as well as identification of a number of polymorphisms and sequence variations. Direct sequencing of the PCR fragments which showed an altered electrophoretic behavior not attributable to known mutations has led to the characterization of four new mutations, two in exon 11, and one each in exons 15 and 20. Screening for the different mutations thus far identified in our patients by the DGGE analysis and other independent methods should allow detection of about 70% of the molecular defects causing CF in Italy. Mutations located in exons 11 and 20 account for at least 30% of the non-delta F508 mutations present in Italian CF patients.

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34 Table 2 Results of Screening for Known Mutations Total No. of No. of Chromosomes Chromosomes Overall Mutation Exon Method With the Mutationa Screenedb Frequencyc Reference R334W......... 7 MspI 2 198 1.01 X. Estivill, personal communication R347P......... 7 HhaI or NcoI 4 183 2.19 Dean et al. 1990 G542X ......... 11 ASO (DGGE) 15 (4) 176 (18) 9.79 Kerem et al. 1990 S549N......... 11 DdeI 1 159 .63 Cutting et al. 1990b G5S1D ......... 11 HincII or MboI 0 186 Cutting et al. 1990b R553X ......... 11 HincIl (DGGE) 5 (1) 186 (13) 3.02 Cutting et al. 1990b 1717-1G-A .... 11 (DGGE) (12) (109) 11.01 Guillermit et al. 1990 S1255X ......... 20 HindIII 0 130 Cutting et al. 1990a W1282X......... 20 MnlI (DGGE) 7 (3) 124 (53) 5.65 Vidaud et al. 1990 a Numbers in parentheses are number of mutations found through DGGE. Login to comment

[hide] Multiple mutations in highly conserved residues ar... Cell. 1990 Jun 1;61(5):863-70. Dean M, White MB, Amos J, Gerrard B, Stewart C, Khaw KT, Leppert M
Multiple mutations in highly conserved residues are found in mildly affected cystic fibrosis patients.
Cell. 1990 Jun 1;61(5):863-70., [PMID:2344617]

Abstract [show]
We have identified three different point mutations in the coding region of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Each mutation segregates with the disease in two- or three-generation pedigrees and is not found on the normal chromosome of any documented cystic fibrosis carrier. One of the mutations is found in two independent families that contain at least one individual with a mild course of disease. All of these alterations replace charged amino acids with less polar residues and are found in the putative transmembrane sections of the molecule. The mutated amino acids are found to be conserved in both rodents and amphibians and lie in a region of CFTR that is believed to form a channel in the membrane. Although these alterations are rare, they provide important clues to functionally important regions of the molecule.

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60 Family UT 1446 contains a C to G transversion at position 1172 that changes an aspartic acid residue to proline (R347P). Login to comment
99 1003 xenopur 1063 1123 CF R347P 1163 ACAGAACTGAAACTGACTCGGAAGGCAGCCTATGTGAGATAC~CAATAGCTCAGCC~C TELKLTRKAAYVRYFNSV .G.. AYVRYFNSSAF .G.. AYVRYFNSSAF TTCTTCTCAGGG~C~GTGGTG~ATCTGTGCCCCTATGCACTAATCAAAGGA FFSGFFVVFLSVLPYALI[KE T. Login to comment
117 of Chromosomes Mutation CF DllOH Wild Type Mutated x2 Normal CF CF R117H 94 0 14 1 6.0a Normal CF CF R347P 94 0 13 2 12b Normal CF 96 0 14 1 6.0a Allele Diagnosis D7S399 Number Pancreatic insufficient (PI) 1 2 2 34 Pancreatic sufficient (PS) 1 4 2 4 Number refers to number of chromosomes with the corresponding genotype for the marker MPW (D7S399). Login to comment
135 The third change (CF R347P) replaces an arginine with a proline residue. Login to comment
158 The R347P mutation can be directly assayed by restriction digestion and the others by allele-specific oligonucleotides. Login to comment
195 The R347P mutation was confirmed by Hhal and Ncol digestion of amplified DNA The DllOH and R117H mutations were confirmed by hybridization at 42% with CF-49 (5`TCCTATCACCCGGAT) and CF-48 (5`.GAGGAACACTCTATC). Login to comment

[hide] H2O2 stimulates cystic fibrosis transmembrane cond... Am J Respir Cell Mol Biol. 2013 Oct;49(4):672-9. doi: 10.1165/rcmb.2013-0156OC. Conner GE, Ivonnet P, Gelin M, Whitney P, Salathe M
H2O2 stimulates cystic fibrosis transmembrane conductance regulator through an autocrine prostaglandin pathway, using multidrug-resistant protein-4.
Am J Respir Cell Mol Biol. 2013 Oct;49(4):672-9. doi: 10.1165/rcmb.2013-0156OC., [PMID:23742099]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR) activity is essential for the maintenance of airway surface liquid depth, and therefore mucociliary clearance. Reactive oxygen species, increased during inflammatory airway diseases, alter CFTR activity. Here, H2O2 levels in the surface liquid of normal human bronchial epithelial cultures differentiated at the air-liquid interface were estimated, and H2O2-mediated changes in CFTR activity were examined. In Ussing chambers, H2O2-induced anion currents were sensitive to the CFTR inhibitors CFTRinh172 and GlyH-101. These currents were absent in cells from patients with cystic fibrosis. Responses to greater than 500 muM H2O2 were transient. Cyclooxygenase inhibitors blocked the H2O2 response, as did EP1 and EP4 receptor antagonists. A multidrug-resistant protein (MRP) inhibitor and short hairpin RNA directed against MRP4 blocked H2O2 responses. EP1 and EP4 agonists mimicked H2O2 in both control and MRP4 knockdown cells. Thus, H2O2 activates the synthesis, export, and binding of prostanoids via EP4 and, interestingly, EP1 receptors in normal, differentiated human airway epithelial cells to activate cyclic adenosine monophosphate pathways that in turn activate CFTR channels in the apical membrane.

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39 The genotypes of these lungs were ƊF508/R347P and ƊF508/D1152H. Login to comment

[hide] Pancreatic function and extended mutation analysis... J Pediatr. 2000 Aug;137(2):214-20. Massie RJ, Wilcken B, Van Asperen P, Dorney S, Gruca M, Wiley V, Gaskin K
Pancreatic function and extended mutation analysis in DeltaF508 heterozygous infants with an elevated immunoreactive trypsinogen but normal sweat electrolyte levels.
J Pediatr. 2000 Aug;137(2):214-20., [PMID:10931414]

Abstract [show]
BACKGROUND: Newborn screening for cystic fibrosis (CF) with immunoreactive trypsinogen (IRT) and DeltaF508 analysis followed by sweat testing misses some infants with CF and detects more DeltaF508 carriers than expected. Some of the apparent DeltaF508 carriers may be DeltaF508 compound heterozygotes with normal sweat electrolyte levels. METHODS: Infants identified by newborn screening with an elevated IRT level, one DeltaF508 allele, and a sweat chloride level <60 mmol/L underwent CF mutation analysis, pancreatic stimulation testing, and repeat IRT analysis followed by clinical review and repeat sweat test at 12 months. RESULTS: Over a 24-month period we identified 122 DeltaF508 heterozygotes and recruited 57; 4 had borderline sweat chloride levels (40 to 60 mmol/L), 5 (8.8%, 95% CI 1.4, 16.2) had a second CF mutation (R117H), and 11 (20%, 95% CI 10, 30) had the intron 8 5T allele. Three had clinical CF at 12 months (initial sweat chloride levels: 53, 51, and 32 mmol/L). Pancreatic electrolyte secretion in the subjects with a borderline sweat chloride level was similar to that in patients with known CF. CONCLUSION: The excess of DeltaF508 heterozygotes detected by IRT/DNA screening is associated with the presence of a second mutation or the 5T allele in some infants. Screened infants with borderline sweat chloride levels almost certainly have CF, but long-term follow-up of the infants with the genotype DeltaF508/R117H and DeltaF508/5T is required to determine their outcome. In the meantime, newborn screening should be confined to severe mutations associated with classic CF.

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26 Measurement of Cl levels was done by colorimetry, and measurement of sodium levels was done by flame cytometry.16 Gene Mutation Analysis Blood was taken and DNA extract- ed17 for an extended cystic fibrosis transmembrane conductance regulator protein gene mutation analysis as described previously.18 The following mutations were included: ࢞F508, ࢞I507, R117H, G551D, A455E, G542X, N1303K, W1282X, 1717-1G࢐A, R560T, R347P, R334W, R553X, R1162X, S549N, 3849+10C࢐T, and 621+1G࢐T. Login to comment

[hide] A simplified cyclic adenosine monophosphate-mediat... J Pediatr. 2000 Dec;137(6):849-55. Callen A, Diener-West M, Zeitlin PL, Rubenstein RC
A simplified cyclic adenosine monophosphate-mediated sweat rate test for quantitative measure of cystic fibrosis transmembrane regulator (CFTR) function.
J Pediatr. 2000 Dec;137(6):849-55., [PMID:11113843]

Abstract [show]
OBJECTIVE: Sweat production is stimulated by both cholinergic and beta-adrenergic pathways in the sweat gland secretory coil. beta-Adrenergic pathway-mediated sweating is absent in cystic fibrosis (CF) because cyclic adenosine monophosphate (cAMP)-mediated chloride transport through the cystic fibrosis transmembrane regulator (CFTR) is disrupted. We report the development of a rapid, reproducible, macroscopic, and quantitative methodology to test the hypothesis that beta-adrenergic sweat rate discriminates among 3 different CFTR phenotypes-CF, heterozygote CF carriers, and non-CF. STUDY DESIGN: Intradermal injection of a mixture of 50 micromol/L isoproterenol, 5 mmol/L aminophylline (to potentiate the beta-adrenergic stimulation), and 140 micromol/L atropine (to block potential cholinergic stimulation) in lactated Ringer's solution was performed in duplicate on one forearm. A single injection of 0.5 mmol/L methacholine to stimulate sweat production by the cholinergic pathway was performed on the other forearm. Sweat rate was determined as the amount of sweat collected on filter paper over 20 minutes. RESULTS AND CONCLUSIONS: Median cAMP-mediated sweat rates were 1.45 mg/20 min (CF, n = 29), 2.55 mg/20 min (CF heterozygote carriers, n = 30), and 3.65 mg/20 min (non-CF, n = 30) and were significantly different in all 3 groups (P =.0001, Kruskal-Wallis test). Methacholine-stimulated sweat rates were similar for all 3 groups. The cAMP-mediated sweat rate test may be a useful endpoint for studies of new agents to increase the function of CFTR.

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60 Among the females with CF, 7 had homozygous ࢞F508 genotypes; 2 had ࢞F508/unknown genotypes; and one each had a genotype of ࢞F508/G551D, ࢞F508/R117H, ࢞F508/3489 + 10 kb C to T, ࢞F508/G542X, ࢞F508/R347P, and R117H/unknown. Login to comment

[hide] Analysis of 31 CFTR mutations in 55 families from ... Early Hum Dev. 2001 Nov;65 Suppl:S161-4. Gomez-Llorente MA, Suarez A, Gomez-Llorente C, Munoz A, Arauzo M, Antunez A, Navarro M, Gil A, Gomez-Capilla JA
Analysis of 31 CFTR mutations in 55 families from the South of Spain.
Early Hum Dev. 2001 Nov;65 Suppl:S161-4., [PMID:11755047]

Abstract [show]
We carried out a molecular analysis of 350 chromosomes from 55 families originating from the South of Spain (Andalucia) who were diagnosed with cystic fibrosis (CF). We used polymerase chain reaction, followed by an oligonucleotide ligation assay (OLA) and sequence-coded separation using capillary electrophoresis. A frequency of 43.5% for DeltaF508 was found, making it the most common CF mutation in our sample. Seven more mutations (G542X, R334W, R1162X, 2789+5G-->A, R117H, DeltaI507 and W1282X) were detected and accounted for 24.7% of the total. The remaining mutations (31.8%) were undetectable with the methodology used in this study.

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30 T I.5 R553X E.11 1078delT E.7 R560T E.11 R347P E.7 S549R E.11 R347H E.7 S549N E.11 R334W E.7 3849 + 10kbC ! Login to comment

[hide] Therapeutic strategies to correct malfunction of C... Paediatr Respir Rev. 2001 Jun;2(2):159-64. Lim M, Zeitlin PL
Therapeutic strategies to correct malfunction of CFTR.
Paediatr Respir Rev. 2001 Jun;2(2):159-64., [PMID:12531063]

Abstract [show]
Cystic fibrosis (CF) is a systemic autosomal recessive inherited disorder that results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Although the gene was cloned 11 years ago, there still is no definitive treatment to correct the functional deficit. Current treatment strategies focus on pancreatic enzyme replacement and control of pulmonary inflammation and infection. This review examines novel strategies still in preclinical development or phase 1 clinical trials. Gene therapy is an evolving area of study that offers the potential for a cure for cystic fibrosis. CF lung disease is a significant barrier to effective gene delivery and transfer, but new vectors show promise in overcoming these limitations. There are also new pharmacological therapies aimed at correcting defects in CFTR processing and function. These are tailored to the specific class of mutation but may offer therapeutic benefit to many patients. They include phenylbutyrate, flavonoids, aminoglycosides and xanthines.

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60 Type Genotype Phenotypea Defect Potential therapeutics Class I G542X PI No CFTR synthesis, aminoglycosides 621 + 1 G ࢐T No cell surface Cl- 3905insT transport W1282X R553X 1717-1 G ࢐ A Class II F508b PI Defective CFTR 4-PBA, flavonoids, N1303K trafficking and chemical chaperones, P574Hb processing xanthines A455Eb Class III G551D PI Defective channel flavonoids, milrinone G551S regulation, reduced or absent Cl-transport Class IV R117H PS Reduced Cl-transport 4-PBA, xanthines, R334W flavonoids G314E R347P F508b P574Hb ClassV 3849 + 10 kb C࢐T PS Reduced number of flavonoids, milrinone, 2789 + 5 G ࢐A normal CFTR proteins 4-PBA 3272 - 26 A ࢐ G Reduced Cl-transport A455Eb 3120+1 G࢐A 1811 + 1.6 kb A ࢐ G a PI indicates pancreatic insufficiency; PS indicates pancreatic sufficiency. Login to comment

[hide] CFTR gene: molecular analysis in patients from Sou... Mol Genet Metab. 2003 Apr;78(4):259-64. Streit C, Burlamaque-Neto AC, de Abreu e Silva F, Giugliani R, Saraiva Pereira ML
CFTR gene: molecular analysis in patients from South Brazil.
Mol Genet Metab. 2003 Apr;78(4):259-64., [PMID:12706377]

Abstract [show]
Cystic fibrosis (CF) is the most common genetic disease among Caucasians. The CF gene, named cystic fibrosis transmembrane conductance regulator (CFTR), codifies a protein that acts as a channel through the epithelial membrane. The present work aimed (1) to detect sequence alterations in the nucleotide binding regions and at the membrane spanning domain of the CFTR gene and (2) to detect the following frequent mutations R347P, R347H, R334W, and Q359K (located in exon 7), DeltaF508 (located in exon 10), G542X, G551D, R553X, and S549N (located in exon 11), W1282X (located in exon 20), and N1303K (located in exon 21). Seventy-seven unrelated CF patients were analyzed, who were previously diagnosed and currently under treatment at the Pneumology Service of our hospital. Regions of interest were amplified by PCR using specific primers. Each sample was analyzed by a non-radioactive single-stranded conformational polymorphism (SSCP) analysis technique and restriction enzyme digestion. The DeltaF508 mutation was found in 48.7% of the alleles. Frequencies of G542X, R334W, R553X, and W1282X mutations in our population were 3.25, 1.3, 0.65, and 0.65%, respectively. No alleles were found to carry mutations G551D, R334W, R347P, R347H, Q359K, S549N, and N1303K, which were included in the screening protocol. This study allowed the characterization of 84 out of 154 CF mutant alleles (54.5%). The incidence of main CF mutations analyzed was similar to that of the south European population. Mutation data presented here will be useful for designing new DNA testing strategies for CF in South Brazil.

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2 The present work aimed (1) to detect sequence alterations in the nucleotide binding regions and at the membrane spanning domain of the CFTR gene and (2) to detect the following frequent mutations R347P, R347H, R334W, and Q359K (located in exon 7), DF508 (located in exon 10), G542X, G551D, R553X, and S549N (located in exon 11), W1282X (located in exon 20), and N1303K (located in exon 21). Login to comment
8 No alleles were found to carry mutations G551D, R334W, R347P, R347H, Q359K, S549N, and N1303K, which were included in the screening protocol. Login to comment
34 The main aims of the present work were (1) to establish the frequency of the DF508 mutation this studied population, (2) to identify alterations in the nucleotide sequence of the exons 3, 5, and 7 which are located in the first membrane spanning domain (MSD1); of exons 9, 10, 11, and 12 which are located in the first nucleotide binding domain (NBD1); of exons 19, 20, 21, and 22 which are located in the second nucleotide binding domain (NBD2) of the CFTR gene, and finally (3) to identify some specific frequent mutations (R347P, R347H, R334W, Q359K, G542X, G551D, R553X, S54 9N, W1282X, and N1303K) in these patients. Login to comment
59 Restriction fragment length polymorphism Mutations R347P, R347H, R334W, Q359K (located in exon 7), G542X, S549N, G551D, R553X mutations (exon 11), W1282X (exon 20), and N1303K (exon 21) were identified by restriction fragment length polymorphism (RFLP) protocol, using specific restriction endonucleases. Login to comment
76 Screening of four additional mutations (G542X, R553X, R334W, and W1282X) together with DF508 Table 2 Mutations detected in 77 CF patients from south region of Brazil Mutation Location Number of alleles Frequency (%) R334W Exon 7 2 1.3 R347P Exon 7 0 0 R347H Exon 7 0 0 Q359K Exon 7 0 0 DF508 Exon 10 75 48.7 S549N Exon 11 0 0 G542X Exon 11 5 3.2 G551D Exon 11 0 0 R553X Exon 11 1 0.7 W1282X Exon 20 1 0.7 N1303K Exon 21 0 0 ? Login to comment

[hide] Effect of genotype on phenotype and mortality in c... Lancet. 2003 May 17;361(9370):1671-6. McKone EF, Emerson SS, Edwards KL, Aitken ML
Effect of genotype on phenotype and mortality in cystic fibrosis: a retrospective cohort study.
Lancet. 2003 May 17;361(9370):1671-6., [PMID:12767731]

Abstract [show]
BACKGROUND: Over 1000 mutations of the cystic fibrosis transmembrane conductance regulator gene (CFTR) that cause cystic fibrosis have been identified. We examined the effect of CFTR genotype on mortality and disease phenotype. METHODS: Using the US Cystic Fibrosis Foundation National Registry, we did a retrospective cohort study to compare standardised mortality rates for the 11 most common genotypes heterozygous for DeltaF508 with those homozygous for DeltaF508. Of the 28455 patients enrolled in the registry at the time of our analysis, 17853 (63%) were genotyped. We also compared the clinical phenotype, including lung function, age at diagnosis, and nutritional measures, of 22 DeltaF508 heterozygous genotypes. Mortality rates and clinical phenotype were also compared between genotypes classified into six classes on the basis of their functional effect on CFTR production. FINDINGS: Between 1991 and 1999, genetic and clinical data were available for 17853 patients with cystic fibrosis, which was 63% of the total cohort. There were 1547 deaths during the 9 years of follow-up. In the analysis of the 11 most common genotypes, DeltaF508/R117H, DeltaF508/DeltaI507, DeltaF508/3849+10kbC-->T, and DeltaF508/2789+5G-->A had a significantly lower mortality rate (4.7, 8.0, 11.9, and 4.4, respectively) than the genotype homozygous for DeltaF508 (21.8, p=0.0060). DeltaF508/R117H, DeltaF508/DeltaI507, DeltaF508/ 3849+10 kbC-->T, DeltaF508/2789+5G-->A, and DeltaF508/A455E have a milder clinical phenotype. Outcomes for all functional classes were compared with that of class II (containing DeltaF508 homozygotes) and classes IV and V had a significantly lower mortality rate and milder clinical phenotype. INTERPRETATION: Patients with cystic fibrosis have distinct genetic subgroups that are associated with mild clinical manifestations and low mortality. These differences in phenotype are also related to the functional classification of CFTR genotype.

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47 ARTICLES 1672 THE LANCET ߦ Vol 361 ߦ May 17, 2003 ߦ www.thelancet.com Panel 1: Frequencies of CFTR mutations* CFTR Allele CFTR Allele mutation frequency (%) mutation frequency èc;F508 69&#b7;4% 2789+5G࢐A 0&#b7;3% Unknown 15&#b7;7% R1162X 0&#b7;3% G542X 2&#b7;3% G85E 0&#b7;3% G551D 2&#b7;2% R560T 0&#b7;2% èc;I507 1&#b7;6% R334W 0&#b7;2% W1282X 1&#b7;4% 3659èc;C 0&#b7;2% N1303K 1&#b7;2% A455E 0&#b7;1% R553X 0&#b7;9% 711+1G࢐T 0&#b7;1% 621+1G࢐T 0&#b7;8% 1898+1G࢐A 0&#b7;1% R117H 0&#b7;7% 2184èc;A 0&#b7;1% 3849+10 kbC࢐T 0&#b7;7% S549N 0&#b7;1% 1717-IG࢐A 0&#b7;5% 1078èc;T 0&#b7;03% R347P 0&#b7;3% *n=17 853. Login to comment
48 Panel 2: Functional classification of CFTR alleles Class Functional effect of Allele mutation I Defective protein G542X, R553X, W1282X, production R1162X, 621-1G࢐T, 1717-1G࢐A, 1078èc;T, 3659èc;C II Defective protein èc;F508, èc;I507, N1303K, processing S549N III Defective protein G551D, R560T regulation IV Defective protein R117H, R334W, G85E, conductance R347P V Reduced amounts of 3849+10KbC࢐T, functioning CFTR protein 2789+5G࢐A, A455E Unknown 711+1G࢐T, 2184DA, 1898+1G࢐A Total cohort Genotyped cohort (n=28 455) (n=17 853) Person-years at risk 152 011 96 870 Sex (% male) 53% 52% Race (% white) 96% 96% Age (years) 11&#b7;9 (11&#b7;1) 10&#b7;9 (11&#b7;2) Age at diagnosis (years) 3&#b7;5 (7&#b7;1) 3&#b7;6 (7&#b7;5) Sweat test (mmol/L) 101 (19) 100 (20) FEV1 (L) 1&#b7;72 (0&#b7;91) 1&#b7;80 (0&#b7;92) FEV1 (% predicted) 69 (29) 72 (28) FVC (L) 2&#b7;41 (1&#b7;18) 2&#b7;50 (1&#b7;21) FVC (% predicted) 81% (28) 84% (24) Height (cm) 121% (41) 117% (41) Weight (kg) 30&#b7;0 (21&#b7;3) 28&#b7;6 (21&#b7;8) Pancreatic insufficiency (%) 90% 87% P aeruginosa colonisation (%) 49% 46% Number of deaths (%) 3548 (12%) 1547 (9%) Data are mean (SD) unless otherwise stated. Login to comment
67 Table 2: Standardised and crude mortality rates (including organ transplantation) by genotype Genotype No of Age at Sweat FEV1 FVC Height Weight Pancreatic P&#b7; aeruginosa Subjects Diagnosis Chloride (% predicted)* (% predicted)* (cms)* (kg)* Insufficiency Colonization (yrs) (mmol) (%)ߤ (%)ߤ èc;F508/èc;F508 6 213 2&#b7;5 &#b1; 0&#b7;1 104 &#b1; 0&#b7;2 77 &#b1; 0&#b7;3 89 &#b1; 0&#b7;3 141 &#b1; 0&#b7;2 37&#b7;0 &#b1; 0&#b7;1 92 (91-92) 60 (59-61) èc;F508/G551D 411 3&#b7;7 &#b1; 0&#b7;3ߥ 108 &#b1; 0&#b7;9ߥ 76 &#b1; 1&#b7;2 89 &#b1; 1&#b7;2 142 &#b1; 0&#b7;7&#a7; 38&#b7;2 &#b1; 0&#b7;6&#a7; 92 (89-94) 59 (54-64) èc;F508/G542X 389 1&#b7;9 &#b1; 0&#b7;2 104 &#b1; 0&#b7;8 79 &#b1; 1&#b7;2 91 &#b1; 1&#b7;2 141 &#b1; 0&#b7;7 37&#b7;3 &#b1; 0&#b7;5 93 (89-95) 57 (52-62) èc;F508/N1303K 213 2&#b7;1 &#b1; 0&#b7;3 106 &#b1; 1&#b7;2 80 &#b1; 1&#b7;8 91 &#b1; 1&#b7;7 141 &#b1; 1&#b7;0 37&#b7;1 &#b1; 0&#b7;6 92 (87-95) 61 (55--68) èc;F508/W1282X 205 1&#b7;6 &#b1; 0&#b7;2 103 &#b1; 1&#b7;2 80 &#b1; 1&#b7;7 92 &#b1; 1&#b7;6 141 &#b1; 0&#b7;9 37&#b7;4 &#b1; 0&#b7;7 94 (90-97) 59 (52-65) èc;F508/R553X 164 2&#b7;5 &#b1; 0&#b7;4 106 &#b1; 1&#b7;4 76 &#b1; 1&#b7;8 89 &#b1; 1&#b7;6 139 &#b1; 0&#b7;9 35&#b7;4 &#b1; 0&#b7;7&#a7; 90 (85-94) 60 (53-67) èc;F508/621-1G 162 2&#b7;5 &#b1; 0&#b7;4 107 &#b1; 1&#b7;3 78 &#b1; 1&#b7;8 89 &#b1; 1&#b7;5 143 &#b1; 1&#b7;0&#a7; 38&#b7;8 &#b1; 0&#b7;8&#a7; 87 (80-91)&#a7; 57 (49-64) èc;F508/èc;I507 149 8&#b7;5 &#b1; 1&#b7;1ߥ 95 &#b1; 1&#b7;9ߥ 86 &#b1; 2&#b7;1ߥ 93 &#b1; 1&#b7;8&#a7; 137 &#b1; 1&#b7;4&#a7; 37&#b7;4 &#b1; 1&#b7;25 84 (78-89)ߥ 39 (31-48)ߥ èc;F508/R117H 123 13&#b7;7 &#b1; 1&#b7;2ߥ 80 &#b1; 1&#b7;9ߥ 91 &#b1; 2&#b7;1ߥ 97 &#b1; 1&#b7;7ߥ 143 &#b1; 1&#b7;8 42&#b7;9 &#b1; 1&#b7;7ߥ 65 (55-73)ߥ 22 (16-29)ߥ èc;F508/3849+10 kB 114 11&#b7;3 &#b1; 0&#b7;9ߥ 72 &#b1; 2&#b7;5ߥ 77 &#b1; 2&#b7;1 87 &#b1; 1&#b7;9 144 &#b1; 1&#b7;4&#a7; 41&#b7;2 &#b1; 1&#b7;2ߥ 66 (57-74)ߥ 69 (59-77) èc;F508/2789+5G 63 13&#b7;4 &#b1; 1&#b7;6ߥ 102 &#b1; 2&#b7;1 88 &#b1; 2&#b7;8ߥ 97 &#b1; 2&#b7;3ߥ 140 &#b1; 2&#b7;5 41&#b7;8 &#b1; 2&#b7;2&#a7; 71 (59-81)ߥ 32 (22-44)ߥ èc;F508/1717-1G 74 1&#b7;3 &#b1; 0&#b7;3 103 &#b1; 2&#b7;0 75 &#b1; 2&#b7;7 86 &#b1; 2&#b7;4 139 &#b1; 1&#b7;5 35&#b7;7 &#b1; 0&#b7;9 96 (88-99) 59 (48-69) èc;F508/R560T 46 1&#b7;7 &#b1; 0&#b7;5 104 &#b1; 2&#b7;0 84 &#b1; 3&#b7;3ߥ 96&#b1; 2&#b7;8&#a7; 142 &#b1; 1&#b7;9 38&#b7;4 &#b1; 1&#b7;4 91 (79-97) 63 (48-75) èc;F508/R347P 44 5&#b7;9 &#b1; 1&#b7;1&#a7; 105 &#b1; 2&#b7;6 76 &#b1; 3&#b7;0 90 &#b1; 2&#b7;9 142 &#b1; 2&#b7;4 38&#b7;7 &#b1; 1&#b7;8 67 (52-79)ߥ 53 (38-68) èc;F508/G85E 43 9&#b7;2 &#b1; 1&#b7;8ߥ 99 &#b1; 2&#b7;3&#a7; 76 &#b1; 2&#b7;5 90 &#b1; 2&#b7;5 142 &#b1; 2&#b7;9 38&#b7;3 &#b1; 2&#b7;2 88 (75-95) 52 (35-68) èc;F508/3659DC 40 1&#b7;1 &#b1; 0&#b7;4 105 &#b1; 2&#b7;1 76 &#b1; 3&#b7;9 88 &#b1; 4&#b7;1 139 &#b1; 1&#b7;9 36&#b7;6 &#b1; 1&#b7;2 92 (77-97) 55 (39-69) èc;F508/A455E 29 14&#b7;3 &#b1; 2&#b7;0ߥ 89 &#b1; 3&#b7;1ߥ 98 &#b1; 4&#b7;0ߥ 104 &#b1; 3&#b7;4ߥ 138 &#b1; 3&#b7;4 42&#b7;1 &#b1; 2&#b7;5&#a7; 60 (41--76)ߥ 17 (8-32)ߥ èc;F508/R334W 28 13&#b7;2 &#b1; 3&#b7;0ߥ 104 &#b1; 3&#b7;2 86 &#b1; 3&#b7;4&#a7; 94 &#b1; 3&#b7;3 138 &#b1; 3&#b7;2 42&#b7;3 &#b1; 3&#b7;5 67 (46-82)ߥ 51 (32--70) èc;F508/R1162X 26 1&#b7;9 &#b1; 1&#b7;1 101 &#b1; 2&#b7;3 77 &#b1; 4&#b7;2 92 &#b1; 4&#b7;6 138 &#b1; 1&#b7;8 36&#b7;5 &#b1; 1&#b7;4 92 (75-98) 65 (47-80) èc;F508/1898+1G 20 1&#b7;2 &#b1; 0&#b7;3 99 &#b1; 2&#b7;8 83 &#b1; 4&#b7;1 94 &#b1; 4&#b7;4 138 &#b1; 3&#b7;3 35&#b7;1 &#b1; 2&#b7;1 85 (61--95) 63 (39-82) èc;F508/2184DA 20 2&#b7;3 &#b1; 0&#b7;9 106 &#b1; 5&#b7;3 82 &#b1; 4&#b7;3 92 &#b1; 4&#b7;4 141 &#b1; 3&#b7;0 36&#b7;5 &#b1; 1&#b7;5 94 (69-99) 60 (38-79) èc;F508/711+1G 17 1&#b7;3 &#b1; 0&#b7;5 108 &#b1; 4&#b7;6 83 &#b1; 4&#b7;2 94 &#b1; 4&#b7;4 137 &#b1; 3&#b7;4 36&#b7;7 &#b1; 2&#b7;9 100 73 (50-88) èc;F508/S549N 11 6&#b7;4 &#b1; 1&#b7;9&#a7; 109 &#b1; 5&#b7;7 67 &#b1; 6&#b7;1 77 &#b1; 7&#b7;2 140 &#b1; 3&#b7;2 36&#b7;7 &#b1; 2&#b7;6 92 (62-99) 71 (40--90) èc;F508/Other 2 262 5&#b7;8 &#b1; 0&#b7;2ߥ 99 &#b1; 0&#b7;4ߥ 80 &#b1; 0&#b7;5ߥ 91 &#b1; 0&#b7;5ߥ 141 &#b1; 0&#b7;3 38&#b7;1 &#b1; 0&#b7;3ߥ 86 (84-87)ߥ 50 (48-52)ߥ Other/Other 1 551 7&#b7;5 &#b1; 0&#b7;3ߥ 93 &#b1; 0&#b7;6ߥ 82 &#b1; 0&#b7;6ߥ 90 &#b1; 0&#b7;6&#a7; 141 &#b1; 0&#b7;4 38&#b7;3 &#b1; 0&#b7;3ߥ 81 (80-84)ߥ 40 (38-43)ߥ Data are mean (SE) unless otherwise indicated. Login to comment

[hide] Simultaneous screening for 11 mutations in the cys... Mol Cell Probes. 1992 Feb;6(1):33-9. Cuppens H, Buyse I, Baens M, Marynen P, Cassiman JJ
Simultaneous screening for 11 mutations in the cystic fibrosis transmembrane conductance regulator gene by multiplex amplification and reverse dot-blot.
Mol Cell Probes. 1992 Feb;6(1):33-9., [PMID:1372093]

Abstract [show]
An assay is described in which 11 mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene can be screened simultaneously. Six different exons of the CFTR gene are amplified in a single multiplex amplification. Biotinylated dUTP is incorporated into the different fragments during the amplification process. A sample of this mixture is then hybridized to 21 different poly-dT tailed oligonucleotide probes which are bound to a nylon membrane. In order to screen the different mutations in a single step hybridization, the length of the different oligonucleotides and the amount used in the assay were optimized. The detection is performed by binding avidin-alkaline phosphatase to the biotin, followed by a chemiluminescent reaction. By means of this fast and sensitive assay, about 85% of all the cystic fibrosis mutations in the Belgian population can be detected.

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19 Frequency of 31 mutations in the CFTR gene in 194 Belgian CF chromosomes The 51255X, W1316X ;5 S549N, G551D, R553X, A559T;6 D110H, R117H, R347P;' Q493X, S5491, S549R(T-+G), R560T, Y563N, P574H ;9 W846X, Y913C;10 2556insAT;" R334W;" S549R(A-+C);'6 444delA, 3821deIT;" 621 +1G-*T18 mutations were not present in this random sample of the Belgian CF population . Login to comment

[hide] Simple non-radioactive detection of the CFTR mutat... Mol Cell Probes. 1992 Feb;6(1):9-11. Bal J, Rininsland F, Osborne L, Reiss J
Simple non-radioactive detection of the CFTR mutation N1303K by artificial creation of a restriction site.
Mol Cell Probes. 1992 Feb;6(1):9-11., [PMID:1372094]

Abstract [show]
N1303K is one of the most frequent non-delta F508 mutations causing cystic fibrosis in Central Europe. Since no restriction site is altered by this mutation and no other frequent mutations are known so far in exon 21, the detection requires a separate and laborious test. A mismatched primer was used to create an artificial Hin dIII site in amplified wildtype DNA, which is destroyed by the mutation. This allows for rapid and convenient detection by restriction enzyme digestion.

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6 The first is R347P in exon 7, which can easily be tested for by Hha 1 digestion of PCR amplified DNA.' Login to comment

[hide] Cystic fibrosis. Am J Clin Pathol. 2003 Dec;120 Suppl:S3-13. Lewis MJ, Lewis EH 3rd, Amos JA, Tsongalis GJ
Cystic fibrosis.
Am J Clin Pathol. 2003 Dec;120 Suppl:S3-13., [PMID:15298139]

Abstract [show]
On a daily basis, pathologists examine the fundamental basis of human diseases using morphologic, immunologic, and molecular techniques. Cystic fibrosis (CF), as a clinically heterogeneous disease, exemplifies the complex challenges of genetic diseases for the pathologist who attempts to explain the mechanisms of disease and provide rationale for clinical management. This review includes an overview of CF and a discussion of pathophysiologic features and practical components of clinical and anatomic pathology, and concludes with a review of molecular diagnostics.

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95 ēa; ēa;Table 3ēa; ēa; Recommended Mutation Panel for Cystic Fibrosis Carrier Screening ࢞F508 ࢞I507 G542X G551D W1282X N1303K R553X 621+1G>T R117H 1717-1G>A A455E R560T R1162X G85E R334W R347P 711+1G>T 1898+1G>A 2184delA 1078delT 3849+10kbC>T 2789+5G>A 3659delC I148T 3120+1G>A I506V* I507V* F508C* 5T/7T/9T* * Reflex tests. Login to comment

[hide] Diagnosis of cystic fibrosis in adults with diffus... J Cyst Fibros. 2004 Mar;3(1):15-22. Hubert D, Fajac I, Bienvenu T, Desmazes-Dufeu N, Ellaffi M, Dall'ava-Santucci J, Dusser D
Diagnosis of cystic fibrosis in adults with diffuse bronchiectasis.
J Cyst Fibros. 2004 Mar;3(1):15-22., [PMID:15463882]

Abstract [show]
We assessed the contribution of the sweat test, genotyping and nasal potential difference (NPD) in the diagnosis of cystic fibrosis (CF) in adults with diffuse bronchiectasis (DB). Among 601 adults referred for DB from 1992 to 2001, 46 were diagnosed with CF. The sweat test was positive in 37 patients and normal or intermediate in nine patients. Two CF mutations were identified in 18 patients (39%) by screening for 31 mutations and in 36 patients (78%) after complete genetic analysis. NPD was suggestive of CF in 71% of the patients. The combination of the sweat test and genetic analysis led to the diagnosis of CF in 45 patients. In the nine patients with normal or intermediate sweat test, the diagnosis was confirmed by screening for 31 mutations in five, by complete genetic screening in three, and by NPD in the remaining patient. Searching for CF should start with sweat test. If the sweat test is normal or intermediate, screening for 31 mutations may help to diagnose CF. A complete genetic analysis is indicated when only one mutation is detected and/or when other clinical features, such as obstructive azoospermia or pancreatic insufficiency, are suggestive of CF. NPD measurement is indicated in controversial cases.

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47 We used an oligonucleotide ligation assay using a commercially available kit (Cystic Fibrosis Assay, Applied Biosystems, Foster City, CA, USA) to seek 31 mutations in the CFTR gene (F508del, I507del, Q943X, V520F, 1717y1GࡊA, G542X, G551D, R553X, R560T, S549R, S549 N, 3849q10kbCࡊT, 3849q4AࡊG, R1162X, 3659delC, W1282X, 3905insT, 621q1GࡊT, R117H, Y122X, 711q1GࡊT, 1078delT, R347P, R347H, R334 W, A455E, N1303K, G85E, 1898q1GࡊA, 2183AAࡊG, 2789q5GࡊA) which allowed to detect 82% of the CF alleles in France. Login to comment
129 * 31 mutations: F508del, I507del, Q493X, V520F, 1717y1GࡊA, G542X, G551D, R553X, R560T, S549R, S549 N, 3849q10kbCࡊT, 3849q ** 4AࡊG, R1162X, 3659delC, W1282X, 3905insT, 621q1GࡊT, R117H, Y122X, 711q1GࡊT, 1078delT, R347P, R347H, R334 W, A455E, N1303K, G85E, 1898q1GࡊA, 2183AAࡊG, 2789q5GࡊA. that the laboratory criteria for the diagnosis of CF should be expanded to include identification of CFTR mutations and abnormal bioelectrical properties of the nasal epithelium, in addition to the sweat test w7x. Login to comment

[hide] A 96-well formatted method for exon and exon/intro... Anal Biochem. 2006 Jun 15;353(2):226-35. Epub 2006 Apr 5. Lucarelli M, Narzi L, Piergentili R, Ferraguti G, Grandoni F, Quattrucci S, Strom R
A 96-well formatted method for exon and exon/intron boundary full sequencing of the CFTR gene.
Anal Biochem. 2006 Jun 15;353(2):226-35. Epub 2006 Apr 5., [PMID:16635477]

Abstract [show]
Full genotypic characterization of subjects affected by cystic fibrosis (CF) is essential for the definition of the genotype-phenotype correlation as well as for the enhancement of the diagnostic and prognostic value of the genetic investigation. High-sensitivity diagnostic methods, capable of full scanning of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, are needed to enhance the significance of these genetic assays. A method for extensive sequencing of the CFTR gene was optimized. This method was applied to subjects clinically positive for CF and to controls from the general population of central Italy as well as to a single subject heterozygous for a mild mutation and with an uncertain diagnosis. Some points that are crucial for the optimization of the method emerged: a 96-well format, primer project and purification, and amplicon purification. The optimized method displayed a high degree of diagnostic sensitivity; we identified a subset of 13 CFTR mutations that greatly enhanced the diagnostic sensitivity of common methods of mutational analysis. A novel G1244R disease causing mutation, leading to a CF phenotype with pancreatic sufficiency but early onset of pulmonary involvement, was detected in the subject with an uncertain diagnosis. Some discrepancies between our results and previously published CFTR sequence were found.

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26 None of these subjects showed any clinical manifestations of CF, nor were any positive for CFTR mutations when analyzed by means of the PCR/OLA/SCS method (Celera Diagnostics) [21], which searches for the most common worldwide 31 CFTR mutations (G85E, R117H, Y122X, 621+1G->T, 711+1G->T, 1078delT, R347P, R347H, R334W, A455E, DF508, DI507, Q493X, V520F, 1717-1G->A, G542X, G551D, R553X, R560T, S549R(T->G), S549N, 1898+1G->A, 2183AA->G, 2789+5G->A, R1162X, 3659delC, 3849+10kbC->T, 3849+4A->G, W1282X, 3905insT, N1303K), including the 12 most common in Italy [1,22]. Login to comment

[hide] CFTR gene analysis in Latin American CF patients: ... J Cyst Fibros. 2007 May;6(3):194-208. Epub 2006 Sep 11. Perez MM, Luna MC, Pivetta OH, Keyeux G
CFTR gene analysis in Latin American CF patients: heterogeneous origin and distribution of mutations across the continent.
J Cyst Fibros. 2007 May;6(3):194-208. Epub 2006 Sep 11., [PMID:16963320]

Abstract [show]
BACKGROUND: Cystic Fibrosis (CF) is the most prevalent Mendelian disorder in European populations. Despite the fact that many Latin American countries have a predominant population of European-descent, CF has remained an unknown entity until recently. Argentina and Brazil have detected the first patients around three decades ago, but in most countries this disease has remained poorly documented. Recently, other countries started publishing their results. METHODS: We present a compilation and statistical analysis of the data obtained in 10 countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Uruguay and Venezuela), with a total of 4354 unrelated CF chromosomes studied. RESULTS: The results show a wide distribution of 89 different mutations, with a maximum coverage of 62.8% of CF chromosomes/alleles in the patient's sample. Most of these mutations are frequent in Spain, Italy, and Portugal, consistent with the origin of the European settlers. A few African mutations are also present in those countries which were part of the slave trade. New mutations were also found, possibly originating in America. CONCLUSION: The profile of mutations in the CFTR gene, which reflects the heterogeneity of its inhabitants, shows the complexity of the molecular diagnosis of CF mutations in most of the Latin American countries.

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42 Some have concentrated in the search of specific mutations that are Table 1 Mutations found in the Latin American CF patients Exon 1 p.L6VÌe; Exon 3 p.W57X, p.R75X, p.G85E Exon 4 p.R117H Exon 6a p.H199Y, p.V201M, p.L206W, p.Q220X, p.V232D, c.846delTÌe; Exon 6b p.Y275XÌe;, c.935delA Exon 7 p.R334W, p.R347P, p.Y362XÌe;, c.1078delT, c.1215delG Exon 8 c.1323_1324insAÌe; Exon 9 c.1460_1461delATÌe;, c.1353_1354insTÌe;,# Exon 10 p.I506T, p.I507del, p.F508del Exon 11 p.G542X, p.S549N, p.S549R, p.G551D, p.G551S, p.R553X, p.L558S, p.A559T, c.1782delA Exon 12 p.S589I Exon 13 p.H609RÌe;, p.P750L, p.V754M, c.1924_1930del, c.2055_2063del, c.2183AA NG;c.2184delA, c.2184delA, c.2185_2186insC, c.2347delG, c.2566_2567insTÌe;, c.2594_2595delGTÌe; Exon 14a p.R851L, c.2686_2687insTÌe; Exon 15 c.2869_2870insG Exon 16 c.3120+1GNA Exon 17a p.I1027T, c.3171delC, c.3199_3204del Exon 17b p.G1061R, p.R1066C, p.W1069X#, p.W1089X, p.Y1092X, p.W1098CÌe; Exon 19 p.R1162X, p.W1204X, p.Q1238X, c.3617_3618delGAÌe;#, c.3659delC Exon 20 p.W1282X, p.R1283M Exon 21 p.N1303K, c.4016_4017insT Exon 22 c.4160_4161insGGGGÌe; 5' flanking c.-834GNT Intron 2 c.297-1GNAÌe;, c.297-2ANG Intron 3 c.406-1GNA Intron 4 c.621+1GNT Intron 5 c.711+1GNT Intron 8 c.IVS8-5T Intron 10 c.1716GNA, c.1717-1GNA Intron 11 c.1811+1.6KbANG, c.1812-1GNA Intron 12 c.1898+1GNA, c.1898+3ANG Intron 14 c.2789+2_2789+3insA, c.2789+5GNA Intron 17a c.3272-26ANG Intron 17b c.3500-2ANGÌe; Intron 19 c.3849+1GNA, c.3849+10KbCNT Intron 20 c.4005+1GNA, c.4005-1GNA# Mutations are listed according to their position in the gene. Login to comment
46 of chromosomes analysed p.F508del p.G542X p.W1282X p.N1303K p.R1162X p.L6VÌe; p.W57X p.R75X p.G85E p.R117H p.H199Y p.V201M p.L206W p.Q220X p.V232D p.Y275XÌe; p.R334W p.R347P p.Y362XÌe; p.I506T Argentina 98 61 440 258 18 12 12 2 1 1 3 1 5 1 310 181 20 7 5 5 7 0 5 0 222 135 15 7 5 1 26 14 2 1 1 150 88 6 6 1 2 3 Subtotal and frequency (%) 1246 100 737 59.15 61 4.90 27 2.17 28 2.25 9 0.72 1 0.08 1 0.08 13 1.04 1 0.08 13 1.04 1 0.08 Brazil 468 221 26 11 74 38 2 1 320 155 28 3 8 8 4 1 2 1 1 8 122 62 120 38 10 3 148 38 4 0 0 48 15 154 75 5 1 0 2 0 386 154 24 6 10 17 9 0 10 1 18 4 0 0 2 0 0 0 0 Subtotal and frequency (%) 1858 100 800 43.06 99 5.33 11 0.59 34 1.83 25 1.35 13 0.70 1 0.05 2 0.11 1 0.05 1 0.05 20 1.07 1 0.05 Chile 72 21 36 11 3 0 44 22 4 3 1 1 100 45 7 5 0 2 0 2 0 Subtotal and frequency (%) 252 100 99 41.28 14 5.55 8 3.17 3 1.19 3 1.19 Colombia 184 77 7 2 1 2 1 34 13 2 1 1 Subtotal and frequency (%) 218 100 90 41.28 9 4.13 3 1.38 2 0.92 2 0.92 1 0.46 Costa Rica Frequency (%) 48 100 11 22.91 12 25.00 0 0 0 0 0 Cuba Frequency (%) 144 100 49 34.03 Ecuador 32 11 1 50 16 2 2 20 5 0 0 0 Subtotal and frequency (%) 102 100 32 31.37 2 1.96 1 0.98 2 1.96 Mexico 194 79 12 4 3 1 1 1 2 80 36 4 1 Subtotal and frequency (%) 274 100 115 41.97 16 5.84 5 1.82 3 1.09 1 0.36 1 0.36 1 0.36 2 0.73 Uruguay Frequency (%) 76 100 43 56.58 6 7.89 2 2.63 3 3.95 3 3.95 2 2.63 Venezuela 54 16 2 82 41 Subtotal and frequency (%) 136 100 57 41.91 2 1.47 Total 4354 2033 221 49 72 42 1 1 3 32 1 1 1 2 1 1 1 39 1 1 2 Frequency (%) 100 46.69 5.08 1.13 1.65 0.96 0.02 0.02 0.07 0.73 0.02 0.02 0.02 0.05 0.02 0.02 0.02 0.90 0.02 0.02 0.05 The five most frequent mutations are shown on the left-hand side, followed by the rest of the mutations in 5'-3' and exon-intron order. Login to comment
98 As an example, in the case of Argentina and Uruguay, the p.F508del mutation shows the highest frequencies (59% and Table 5 Mutations with frequencies less than 0.1% Panel A Mutation Number of chromosomes % Country p.R75X 3 0.07 Mexico c.W1089X 3 0.07 Argentina, Brazil c.406-1GNA 3 0.07 Mexico c.1898+1GNA 3 0.07 Argentina, Brazil c.2686_2687insTÌe; 3 0.07 Argentina, Brazil p.L206W 2 0.05 Brazil p.I506T 2 0.05 Mexico p.S589I 2 0.05 Argentina c.711+1GNT 2 0.05 Argentina c.935delA 2 0.05 Mexico c.2055_2063del 2 0.05 Mexico c.2347delG 2 0.05 Brazil c.2566_2567insTÌe; 2 0.05 Argentina c.2789+2_2789+3insA 2 0.05 Argentina c.3199_3204del 2 0.05 Mexico c.3272-26ANG 2 0.05 Argentina c.4016_4017insT 2 0.05 Argentina Panel B Mutation N % each Country p.L6VÌe;, p.W57X, p.Q220X, p.Y362XÌe;, p.I1027T, p.G1061R, p.R1283M, c.297-2ANG, c.1353_1354insTÌe;, c.1460_1461delATÌe;, c.1782delA, c.1898+3ANG, c.2184delA, c.2594_2595delGTÌe;, c.2869_2870insG, c.4005Ìe;1GNA, c.4005-1GNA# 17 0.02 Argentina p.R117H, p.H199Y, p.G551S, p.L558S, p.P750L, p.V754M, p.W1069X#, p.W1098CÌe;, p.W1204X, c.297-1GNAÌe;, c.846delTÌe;, c.1078delT, c.1716GNA, c.1924_1930del, c.4160_4161insGGGGÌe; 15 0.02 Mexico p.V201M, p.V232D, p.Y275XÌe;, p.R347P, p.R851L, p.Q1238X, c.3171delC, c.3617_3618delGAÌe;# 8 0.02 Brazil p.A559T, p.H609RÌe;, c.1215delG, c.1323_1324insAÌe;, c.2185_2186insC, c.3500-2ANGÌe;, c.3849+1GNA, 7 0.02 Colombia c.-834GNT 1 0.02 Uruguay The upper part (Panel A) shows the mutations found in more than one patient, whereas the lower part (Panel B) of the table shows all the mutations that are present only once in each country. Login to comment

[hide] [The French nationwide cystic fibrosis newborn scr... Arch Pediatr. 2008 Jun;15 Suppl 1:S1-6. doi: 10.1016/S0929-693X(08)73940-X. Munck A, Roussey M
[The French nationwide cystic fibrosis newborn screening program: strategy and results].
Arch Pediatr. 2008 Jun;15 Suppl 1:S1-6. doi: 10.1016/S0929-693X(08)73940-X., [PMID:18822253]

Abstract [show]
In 2002 France implemented a nationwide newborn screening program for cystic fibrosis (CF). The strategy combined immunoreactive trypsinogen and, in case of a value over the cut-off level, DNA analysis in dried blood samples at day 3. Data were centralized and periodically analyzed thus maintaining the percentage of samples requiring mutation analysis (0.6%), limiting the number of false-positive cases (0.1%) without increasing the number of false-negative cases (3.2%). 3.527.353 infants were screened between 2002 and 2006. The overall cystic fibrosis incidence was 1/ 4136 with a wide range of regional variations. Dilemma case presentation occurred for 14 % of the patients; an European working group is actively working on this topic, attempting to establish a consensus on the adequate procedures. Cystic fibrosis newborn screening is feasible all over a nation but needs a strong organization from maternity wards to CF care centers.

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50 L`organigramme du DNN (fig. 1) pr&#e9;voit une valeur seuil de TIR &#e0; J3 d&#e9;termin&#e9;e sur les donn&#e9;es des r&#e9;gions fran&#e7;aises ayant d&#e9;but&#e9; ce d&#e9;pistage il y a plus de 10 ans afin de s&#e9;lec- Mutations recherch&#e9;es par le Kit Elucigen dans le cadre du d&#e9;pistage n&#e9;onatal de la mucoviscidose (Kit CF30) : F508del ; I 507del ; 1078delT, 1717-1 G>A ; 2183AA>G ; 3659delC ; 3849+10kbC>T ; 621+1G>T ; A455E ; E60X ; G542X ; G551D ; N1303K ; R1162X ; R117H ; R334W ; R347P ; R553X ; S1251N ;W1282X ; 1811+1.6kbA>G ; 2789+5G>A ; 3120+1G>A ; 3272-26A>G ; 394delT ; 711+1G>T ; G85E ; Y1092X ; Y122X ;W846X. Login to comment

[hide] [Cystic fibrosis in a woman aged seventy]. Ned Tijdschr Geneeskd. 2010;154:A1342. Ras JE, van Velzen E, van Berkhout FT, van den Brand JJ
[Cystic fibrosis in a woman aged seventy].
Ned Tijdschr Geneeskd. 2010;154:A1342., [PMID:20619026]

Abstract [show]
A seventy-year-old woman was admitted to hospital with a Staphylococcus aureus respiratory tract infection. She had a history of extensive bronchiectasis and allergic bronchopulmonary aspergillosis (ABPA). Cystic fibrosis (CF) was suspected and cystic fibrosis transmembrane conductance regulator (CFTR) gene analysis showed F508del and R117H-7T mutations. In these mutations there is residual activity in the chloride channel in the cell membrane coded by the CFTR gene. This results in a much milder disease pattern varying from no disease at all to isolated organ disease. This type of disease is known as non-classical cystic fibrosis. In our patient the diagnosis of cystic fibrosis was made exceptionally late in life.

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63 TABEL 1 Classificatie van mutaties in het 'cystic fibrosis transmembrane conductance regulator`(CFTR)-gen op chromosoom 7 klasse mechanisme enkele bekende mutaties I geen synthese van het CFTR-eiwit G542X R553X W1282X R1162X 621-1G࢐T 1717-1G࢐A 1078࢞T 3659࢞C II defect in eiwitrijping met voortijdig afbraak ࢞F508 ࢞I507 N1303K S549N III verstoorde regulatie van de CFTR-functie G551D R56OT IV verstoorde conductie van chloride of verstoorde kanaalopening R117H R334W G85E R347P V minder synthese van het CFTR-eiwit 3849+10KbC࢐T 2789+5G࢐A A455E TABEL 2 Diagnostiek van cystische fibrose test testuitslag klassieke CF* niet-klassieke CFߤ zweettest chlorideconcentratie > 60 mmol/l chlorideconcentratie ࣘ 60 mmol/l neuspotentiaalmeting afwijkend niet-afwijkend CFTR-mutatie-analyse 2 mutaties 2 mutaties CF = cystische fibrose; CFTR = 'cystic fibrosis transporter regulator`-gen. Login to comment

[hide] Newborn screening for cystic fibrosis in Alberta: ... Paediatr Child Health. 2010 Nov;15(9):590-4. Lilley M, Christian S, Hume S, Scott P, Montgomery M, Semple L, Zuberbuhler P, Tabak J, Bamforth F, Somerville MJ
Newborn screening for cystic fibrosis in Alberta: Two years of experience.
Paediatr Child Health. 2010 Nov;15(9):590-4., [PMID:22043142]

Abstract [show]
On April 1, 2007, Alberta became the first province in Canada to introduce cystic fibrosis (CF) to its newborn screening program. The Alberta protocol involves a two-tier algorithm involving an immunoreactive trypsinogen measurement followed by molecular analysis using a CF panel for 39 mutations. Positive screens are followed up with sweat chloride testing and an assessment by a CF specialist. Of the 99,408 newborns screened in Alberta during the first two years of the program, 221 had a positive CF newborn screen. The program subsequently identified and initiated treatment in 31 newborns with CF. A relatively high frequency of the R117H mutation and the M1101K mutation was noted. The M1101K mutation is common in the Hutterite population. The presence of the R117H mutation has created both counselling and management dilemmas. The ability to offer CF transmembrane regulator full sequencing may help resolve diagnostic dilemmas. Counselling and management challenges are created when mutations are mild or of unknown clinical significance.

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46 These include the following mutations: delF508, I507del, G542X, G85E, R117H, 621+1G࢐T, 711+1G࢐T, G551D, R334W, R347P, A455E, 1717-1G࢐A, R560T, R553X, N1303K, 1898+1G࢐A, 2184delA, 2789+5G࢐A, 3120+1G࢐A, R1162X, 3659delC, 3849+10kbC࢐T, W1282X, 1078delT, 394delTT, Y122X, R347H, V520F, A559T, S549N, S549R, 1898+5G࢐T, 2183AA࢐G, 2307insA, Y1092X, M1101K, S1255X, 3876delA and 3905insT. Login to comment

[hide] Assessing the Disease-Liability of Mutations in CF... Cold Spring Harb Perspect Med. 2012 Dec 1;2(12):a009480. doi: 10.1101/cshperspect.a009480. Ferec C, Cutting GR
Assessing the Disease-Liability of Mutations in CFTR.
Cold Spring Harb Perspect Med. 2012 Dec 1;2(12):a009480. doi: 10.1101/cshperspect.a009480., [PMID:23209179]

Abstract [show]
Over 1900 mutations have been reported in the cystic fibrosis transmembrane conductance regulator (CFTR), the gene defective in patients with cystic fibrosis. These mutations have been discovered primarily in individuals who have features consistent with the diagnosis of CF. In some cases, it has been recognized that the mutations are not causative of cystic fibrosis but are responsible for disorders with features similar to CF, and these conditions have been termed CFTR-related disorders or CFTR-RD. There are also mutations in CFTR that do not contribute to any known disease state. Distinguishing CFTR mutations according to their penetrance for an abnormal phenotype is important for clinical management, structure/function analysis of CFTR, and understanding the molecular and cellular mechanisms underlying CF.

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94 Other C. Ferec and G.R. Cutting 4 Cite this article as Cold Spring Harb Perspect Med 2012;2:a009480 www.perspectivesinmedicine.org by Cold Spring Harbor Laboratory Press at SEMMELWEIS UNIV OF MEDICINE on December , mutations that alter residual CFTR function such as R117H (p.Arg117His) and R347P (p.Arg347Pro) have been associated with the pancreatic sufficiency (Kristidis et al. 1992). Login to comment

[hide] Distribution of CFTR mutations in the Czech popula... J Cyst Fibros. 2013 Sep;12(5):532-7. doi: 10.1016/j.jcf.2012.12.002. Epub 2012 Dec 29. Krenkova P, Piskackova T, Holubova A, Balascakova M, Krulisova V, Camajova J, Turnovec M, Libik M, Norambuena P, Stambergova A, Dvorakova L, Skalicka V, Bartosova J, Kucerova T, Fila L, Zemkova D, Vavrova V, Koudova M, Macek M, Krebsova A, Macek M Jr
Distribution of CFTR mutations in the Czech population: positive impact of integrated clinical and laboratory expertise, detection of novel/de novo alleles and relevance for related/derived populations.
J Cyst Fibros. 2013 Sep;12(5):532-7. doi: 10.1016/j.jcf.2012.12.002. Epub 2012 Dec 29., [PMID:23276700]

Abstract [show]
BACKGROUND: This two decade long study presents a comprehensive overview of the CFTR mutation distribution in a representative cohort of 600 Czech CF patients derived from all regions of the Czech Republic. METHODS: We examined the most common CF-causing mutations using the Elucigene CF-EU2v1 assay, followed by MLPA, mutation scanning and/or sequencing of the entire CFTR coding region and splice site junctions. RESULTS: We identified 99.5% of all mutations (1194/1200 CFTR alleles) in the Czech CF population. Altogether 91 different CFTR mutations, of which 20 were novel, were detected. One case of de novo mutation and a novel polymorphism was revealed. CONCLUSION: The commercial assay achieved 90.7%, the MLPA added 1.0% and sequencing increased the detection rate by 7.8%. These comprehensive data provide a basis for the improvement of CF DNA diagnostics and/or newborn screening in our country. In addition, they are relevant to related Central European populations with lower mutation detection rates, as well as to the sizeable North American "Bohemian diaspora".

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89 Mutations/HGVS nomenclature/ Mutations/traditional nomenclature, legacy name/ Czech Republic 2012 (this study) (N=1200) Slovakia 2010 (N=856) Eastern Hungary 2011 (N=80) Germany Bavaria 2002 (N=250) Austria Tyrol 1997 (N=126) Austria NorthEast, North- North 2002 (N=118) Poland (N=1726) c.1521_1523delCTT F508del 67.42 66.80 70.00 74.00 74,60 70.30 57.0 c.54-5940_273+10250del21 kb CFTRdele2,3/21kb 5.75 2.26 5.00 1.2* 2.6# NA 1.80 c.1652GNA G551D 2.91 b0.50 0.00 6.40 1.60 2.50 0.50 c.3909CNG N1303K 2.42 2.03 5.00 2.40 0.00 NA 1.80 c.1624GNT G542X 2.00 4.06 3.75 3.20 2.40 5.10 2.60 c.3718-2477CNT 3849+10kbCNT 1.67 4.28 0.00 NA 0.00 3.40 2.70 c.1766+1GNA 1898+1GNA 1.42 b0.50 0.00 NA 0.00 NA NA c.1040GNC R347P 0.92 1.10 1.25 0.80 1.60 2.50 NA c.2012delT 2143delT 0.92 1.10 0.00 NA 0.00 NA NA c.3140-26ANG 3272-26ANG 0.67 b0.50 0.00 NA 0.00 NA NA c.3846GNA W1282X 0.58 b0.50 0.00 NA 0.00 NA 0.70 c.1007TNA I336K 0.58 0.00 0.00 NA 0.00 NA NA c.1657CNT R553X 0.50 0.90 0.00 1.20 0.00 NA 1.90 c.2657+5GNA 2789+5GNA 0.50 0.00 0.00 NA 2.40 NA NA c.2834CNT S945L 0.50 0.00 0.00 NA 0.00 NA NA c.2052_2053insA 2184insA 0.42 1.58 5.00 NA 0.00 NA NA Legend: data for Slovakia [12], Eastern Hungary [14], Germany-Bavaria [13], Austria-Tyrol [18], Austria North East and North West [13], Poland and *[8], and # [16]. Login to comment

[hide] PGD for cystic fibrosis patients and couples at ri... Reprod Biomed Online. 2013 May;26(5):420-30. doi: 10.1016/j.rbmo.2013.01.006. Epub 2013 Jan 29. Rechitsky S, Verlinsky O, Kuliev A
PGD for cystic fibrosis patients and couples at risk of an additional genetic disorder combined with 24-chromosome aneuploidy testing.
Reprod Biomed Online. 2013 May;26(5):420-30. doi: 10.1016/j.rbmo.2013.01.006. Epub 2013 Jan 29., [PMID:23523379]

Abstract [show]
Preimplantation genetic diagnosis (PGD) for inherited disorders is presently applied for more than 300 different conditions. The most frequent PGD indication is cystic fibrosis (CF), the largest series of which is reviewed here, totalling 404 PGD cycles. This involved testing for 52 different CFTR mutations with almost half of the cases (195/404 cycles) performed for DeltaF508 mutation, one-quarter (103/404 cycles) for six other frequent mutations and only a few for the remaining 45 CFTR mutations. There were 44 PGD cycles performed for 25 CF-affected homozygous or double-heterozygous CF patients (18 male and seven female partners), which involved testing simultaneously for three mutations, resulting in birth of 13 healthy CF-free children and no misdiagnosis. PGD was also performed for six couples at a combined risk of producing offspring with CF and another genetic disorder. Concomitant testing for CFTR and other mutations resulted in birth of six healthy children, free of both CF and another genetic disorder in all but one cycle. A total of 96 PGD cycles for CF were performed with simultaneous aneuploidy testing, including microarray-based 24-chromosome analysis, as a comprehensive PGD for two or more conditions in the same biopsy material.

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42 [1075C>A; 1079C>A] p.[Gln359Lys; Thr360Lys] Exon 8 1 1 1 4 1 1 R297Q c.890G>A p.Arg297Gln Exon 8 1 1 1 2 0 0 R347P c.1040G>C p.Arg347Pro Exon 8 3 5 2 4 1 1 T338I c.1013C>T p.Thr338Ile Exon 8 1 1 1 2 1 1 DF508 c.1521_1523delCTT p.Phe508del Exon 11 130 195 172 345 88 (4) 92 DI507 c.1519_1521delATC p.Ile507del Exon 11 1 5 5 11 2 1 Q493R c.1478A>G p.Gln493Arg Exon 11 5 5 2 2 2 2 1717-1G-A c.1585-1G>A - Intron 11 6 10 9 18 6 8 G542X c.1624G>T p.Gly542X Exon 12 14 17 15 34 10 10 G551S c.1651G>A p.Gly551Ser Exon 12 1 1 1 2 1 1 G551D c.1652G>A p.Gly551Asp Exon 12 12 22 19 33 7 8 I556V c.1666A>G p.Ile556Val Exon 12 1 2 2 4 1 1 R553X c.1657C>T p.Arg553X Exon 12 3 4 2 4 0 0 R560T c.1679G>C p.Arg560Thr Exon 12 1 1 1 2 1 2 1898+1G-A c.1766 &#b1; 1G>A - Intron 13 1 1 1 2 1 1 2184delA c.2052delA p.Lys684AsnfsX38 Exon 14 1 1 0 0 0 0 G622D c.1865G>A p.Gly622Asp Exon 14 1 1 1 3 0 0 N703S c.2108A>G p.Asn703Ser Exon 14 1 2 2 3 2 2 S737F c.2210C>T p.Ser737Phe Exon 14 1 1 0 0 0 0 2622+1G-A c.2490 &#b1; 1G>A - Intron 14 1 5 5 13 1 1 2752-26A-G c.2620-26A>G - Intron 15 1 2 2 4 0 0 2789+5G-A c.2657 &#b1; 5G>A - Intron 16 3 5 4 8 0 0 3120G-A c.2988G>A - Exon 18 2 2 1 2 1 0 3067-72del c.3067_3072del p.Ile1023_Val1024del Exon 19 1 1 1 1 0 0 I1027T c.3080T>C p.Ile1027Thr Exon 19 1 1 1 1 0 0 L997F c.2991G>C p.Leu997Phe Exon 19 1 2 2 4 1 (1) 0 M1028R c.3083T>G p.Met1028Arg Exon 19 1 1 1 2 1 2 F1052V c.3154T>G p.Phe1052Val Exon 20 1 1 0 0 0 0 Y1092X c.3276C>A p.Tyr1092X Exon 20 1 2 1 2 1 1 A1136T c.3406G>A p.Ala1136Thr Exon 21 1 2 1 2 1 0 D1152H c.3454G>C p.Asp1152His Exon 21 3 7 7 15 1 1 3659 del C c.3528delC p.Lys1177SerfsX15 Exon 22 2 4 3 7 3 3 R1162X c.3484C>T p.Arg1162X Exon 22 1 3 2 5 2 2 S1235R c.3705T>G p.Ser1235Arg Exon 22 2 3 3 5 2 1 3849+10kbC>T c.3717 &#b1; 12191C>T - Intron 22 2 4 4 5 0 0 W1282X c.3846G>A p.Trp1282X Exon 23 15 20 20 42 11 11 N1303K c.3909C>G p.Asn1303Lys Exon 24 9 12 11 24 4 5 Q1352H c.4056G>C p.Gln1352His Exon 25 1 1 1 1 1 1 Total 265 404 345 685 172 (6a ) 175 Values are n unless otherwise stated. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... PLoS One. 2013 Apr 17;8(4):e61176. doi: 10.1371/journal.pone.0061176. Print 2013. Schippa S, Iebba V, Santangelo F, Gagliardi A, De Biase RV, Stamato A, Bertasi S, Lucarelli M, Conte MP, Quattrucci S
Cystic fibrosis transmembrane conductance regulator (CFTR) allelic variants relate to shifts in faecal microbiota of cystic fibrosis patients.
PLoS One. 2013 Apr 17;8(4):e61176. doi: 10.1371/journal.pone.0061176. Print 2013., [PMID:23613805]

Abstract [show]
INTRODUCTION: In this study we investigated the effects of the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene variants on the composition of faecal microbiota, in patients affected by Cystic Fibrosis (CF). CFTR mutations (F508del is the most common) lead to a decreased secretion of chloride/water, and to mucus sticky secretions, in pancreas, respiratory and gastrointestinal tracts. Intestinal manifestations are underestimated in CF, leading to ileum meconium at birth, or small bowel bacterial overgrowth in adult age. METHODS: Thirty-six CF patients, fasting and under no-antibiotic treatment, were CFTR genotyped on both alleles. Faecal samples were subjected to molecular microbial profiling through Temporal Temperature Gradient Electrophoresis and species-specific PCR. Ecological parameters and multivariate algorithms were employed to find out if CFTR variants could be related to the microbiota structure. RESULTS: Patients were classified by two different criteria: 1) presence/absence of F508del mutation; 2) disease severity in heterozygous and homozygous F508del patients. We found that homozygous-F508del and severe CF patients exhibited an enhanced dysbiotic faecal microbiota composition, even within the CF cohort itself, with higher biodiversity and evenness. We also found, by species-specific PCR, that potentially harmful species (Escherichia coli and Eubacterium biforme) were abundant in homozygous-F508del and severe CF patients, while beneficial species (Faecalibacterium prausnitzii, Bifidobacterium spp., and Eubacterium limosum) were reduced. CONCLUSIONS: This is the first report that establishes a link among CFTR variants and shifts in faecal microbiota, opening the way to studies that perceive CF as a 'systemic disease', linking the lung and the gut in a joined axis.

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37 Patient Sex Age (years) CFTR allele, = CFTR allele, R Criterion I(a) Criterion II (1 = severe, 0 = mild)(b) Pancreatic status(d) FEV1% BMI 1 M 17 F508del M1V 2 (1) 1 65 17.91 2 F 23 F508del Y569D 2 (1) 0 97 18.66 3 (s1)(c) F 20 P1013L F508del 2 (0) 0 87 18.67 4 M 11 F508del L997F (without R117L) 2 0 0 110 21.33 5 (s1)(c) M 11 P1013L F508del 2 (0) 0 100 23.14 6 M 8 R553X F508del 2 1 0 80 15.87 7 M 3 F508del unknown 2 (0) 0 nd nd 8 F 33 F508del F508del 1 1 1 73 18.61 9 M 10 F508del L1077P 2 1 0 94 19.79 10 M 9 F508del G542X 2 1 1 100 16.00 11 F 9 4167delCTAAGCC L1065P 3 nd 1 76 14.57 12 F 14 R117C (without (TG)12T5) F508del 2 0 0 94 18.44 13 F 11 F508del 991del5 2 1 1 109 17.80 14 M 42 (TG)12T5 F508del 2 0 0 106 23.78 15 (s2)(c) M 9 F508del F508del 1 1 1 82 15.45 16 M 10 F508del R347P 2 (0) 0 89 15.91 17 (s2)(c) F 6 F508del F508del 1 1 1 110 15.20 18 (s3)(c) M 39 2789+5G.A N1303K 3 nd 0 105 19.33 19 (s3)(c) F 41 2789+5G.A N1303K 3 nd 0 80 19.47 20 F 26 N1303K W1282X 3 nd 1 90 19.57 21 M 7 CFTRdele2,3 (21 kb) N1303K 3 nd 1 107 12.85 22 F 9 F508del L997F (without R117L) 2 0 0 113 25.21 23 M 7 P5L W1282X 3 nd 0 89 22.31 24 M 9 2789+5G.A F508del 2 (1) 1 97 15.60 25 F 2 F508del F508del 1 1 1 nd nd 26 F 32 N1303K N1303K 3 nd 1 107 21.22 27 M 14 L1065R T338I 3 nd 0 116 21.50 28 M 12 711+3A.G S549R(A.C) 3 nd 0 97 20.00 29 M 13 unknown R117H (without (TG)12T5) 3 nd 0 104 19.36 30 M 14 F508del G542X 2 1 1 84 21.87 31 F 13 F508del F508del 1 1 1 85 18.00 32 F 41 2789+5G.A N1303K 3 nd 1 84 21.08 33 F 21 L1065P F508del 2 (0) 0 62 18.29 34 F 50 D1152H F508del 2 (0) 0 63 23.74 35 M 29 F508del 2790-2A.G 2 (1) 0 92 24.46 36 F 45 unknown W1282X 3 nd 0 69 23.42 a (Hm = 1; Ht = 2; N = 3). Login to comment
63 Class IV or V: R117H, 2789+5G.A, TG12T5, R347P, D1152H, R117C. Login to comment

[hide] Newborn screening for cystic fibrosis in Switzerla... J Cyst Fibros. 2013 Dec;12(6):667-74. doi: 10.1016/j.jcf.2013.04.008. Epub 2013 May 24. Torresani T, Fingerhut R, Rueegg CS, Gallati S, Kuehni CE, Baumgartner MR, Barben J
Newborn screening for cystic fibrosis in Switzerland--consequences after analysis of a 4 months pilot study.
J Cyst Fibros. 2013 Dec;12(6):667-74. doi: 10.1016/j.jcf.2013.04.008. Epub 2013 May 24., [PMID:23712087]

Abstract [show]
BACKGROUND: Switzerland introduced newborn screening (NBS) for CF in 2011, using an IRT/DNA/IRT protocol. This paper describes the results of the first year and compares two versions of the protocol with different IRT cut-offs, particularly effects on recall rate, sensitivity and specificity. METHODS: IRT cut-offs were >45 ng/ml (99.0th percentile) in period 1 (months 1-4) and >50 ng/ml (99.2nd percentile) in period 2 (months 5-12). In period 2 we abstained from recalls when none of the 7 most common CF mutations were detected and IRT was <60 ng/ml. RESULTS: In periods 1 and 2, 26,535 and 56,663 tests were performed. Recall rates were 0.94% and 0.48%, respectively (p<0.001), PPV increased from 23% to 47% (p=0.024) and sensitivity was 90% and 100%. CONCLUSIONS: Raising initial IRT cut-off from the 99.0th to the 99.2nd percentile and abstaining from recalls for children with an IRT<60 ng/ml and carrying no major CFTR mutation significantly reduced the recall rate without affecting sensitivity.

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105 Case no GA (weeks) Weight at birth (g) 1st IRT (4th day of life) (ng/ml) 2nd IRT (repeat heel prick) (ng/ml) a CFTR mutation screening SWISS PANEL in NBS laboratory b CFTR mutation screening LUMINEX in NBS laboratory b CFTR mutation diagnosis in genetic reference laboratory c Sweat chloride macroduct method (mmol/l) d Sweat conductivity nanoduct method (mmol/l) d Pancreas function faecal elastase (ng) e Diagnosis 1 39 2980 183.0 F508del/- F508del/- F508del/420del9 97 113 45 CF 4 39 3290 150.2 F508del/F508del F508del/F508del F508del/F508del - 129 23 CF 11 37 3400 270.0 F508del/- F508del/- F508del/2347delG 105 98 b15 CF 14 40 3655 114.4 F508del/F508del F508del/F508del F508del/F508del - 116 37 CF 21 37 3280 119.5 F508del/F508del F508del/F508del F508del/F508del ND ND b15 CF with MI 23 f 38 2900 76.9 F508del/F508del F508del/F508del F508del/F508del ND ND b15 CF 35 37 2930 134.8 F508del/- F508del/621+1GNT F508del/621+1GNT 110 139 b15 CF 40 37 2980 39.5 41.8 F508del/F508del F508del/F508del F508del/F508del - 97 b15 CF with MI 12 41 3810 65.9 -/- R347P/- R347P/4006-46del5 h 38 37 ND i Equivocal CF 20 g 38 2720 63.0 122.9 -/- -/- T5/T1086A h 35 - 382 Equivocal CF 2 41 3250 50.1 F508del/- F508del/- - 39 No CF 10 38 2590 51.3 F508del/- F508del/- 14 47 No CF 13 39 3330 68.8 F508del/- F508del/- 11 36 No CF 17 39 2670 64.1 1717-1GNA/- 1717-1GNA/- 20 15 No CF 18 40 3360 58.9 3905insT/- 3905insT/- 13 36 No CF 22 38 2970 51.3 F508del/- F508del/- - 27 No CF 24 36 2790 49.1 F508del/- F508del/- 10 48 No CF 27 40 3420 60.7 F508del/- F508del/- 6 23 No CF 31 40 4400 55.5 F508del/- F508del/- 14 29 No CF 32 41 4460 89.5 F508del/- F508del/- 14 33 No CF 33 40 3700 130.6 F508del/- F508del/- ND 36 No CF 34 40 3005 65.4 N1303K/- N1303K/- 24 37 No CF 36 39 2780 61.5 F508del/- F508del/- F508del/- d ND - No CF 15 40 3310 49.3 -/- R347H/- 10 39 No CF 16 37 3240 56.0 -/- R347H/- 18 54 No CF 29 34 1870 126.5 -/- 2184delA/- 2184delA/- - - No CF 3 41 3860 46.2 72.6 -/- -/- 13 44 No CF 5 37 2840 60.1 61.0 -/- -/- - 51/34 No CF 6 40 3030 56.6 56.2 -/- -/- 16 34 No CF 7 37 3130 49.0 43.6 -/- -/- 6 18 No CF 8 39 4320 48.7 94.9 -/- -/- 13 27 No CF 9 37 2050 127.9 52.3 -/- -/- 28 28 No CF 19 38 3570 68.1 54.5 -/- -/- 6 45 No CF 25 35 2300 61.5 50.2 -/- -/- 12 37 No CF 26 40 2780 58.2 59.8 -/- -/- 10 48 No CF 28 40 3430 56.5 53.4 -/- -/- 13 31 No CF 30 37 2930 54.2 65.6 -/- -/- - 32 No CF 37 40 3615 65.9 191.4 -/- -/- ND 51 No CF 38 41 4350 56.2 65.1 -/- -/- ND 41 No CF 39 42 2900 51.6 68.5 -/- -/- 20 - No CF nine, CF diagnosis was confirmed either by a positive sweat test and/or two CFTR mutations (PPV = 23.1%; Table 1). Login to comment

[hide] Clinical and genetic features in patients with cys... Iran J Pediatr. 2013 Apr;23(2):212-5. Farjadian S, Moghtaderi M, Kashef S, Alyasin S, Najib K, Saki F
Clinical and genetic features in patients with cystic fibrosis in southwestern iran.
Iran J Pediatr. 2013 Apr;23(2):212-5., [PMID:23724185]

Abstract [show]
OBJECTIVE: Cystic fibrosis (CF) is a common autosomal recessive genetic disease caused by a mutation in the CF transmembrane conductance regulatory (CFTR) gene. This study attempted to identify the most common CFTR mutations and any correlations between certain mutations and the clinical presentation of the disease in CF patients in southwestern Iran. METHODS: Twenty nine common CFTR gene mutations were examined in 45 CF patients. FINDINGS: Chronic cough, intestinal obstruction, dehydration, heat exhaustion and steatorrhea were the most common early clinical symptoms among our patients. The most common mutation was DeltaF508, with an allele frequency of 21%. The homozygous DeltaF508 mutation was observed in eight patients (18%), and three patients (7%) were DeltaF508 carriers. The 2183AA > G mutation was observed in four patients, one of whom was also a DeltaF508 carrier. The R1162X mutation was detected in two patients. The G542X, R334W and N1303K mutations were detected each in one patient, the first of whom was also a DeltaF508 carrier. CONCLUSION: Out of 45 patients, 27 (60%) had none of the CFTR gene mutations we tested for. The most frequent mutations in southwestern Iranian patients with CF should be identified by sequencing the entire CFTR gene in order to optimize the design of a diagnostic kit for common regional mutations.

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26 Genomic DNA was extracted from 200 &#b5;L of whole blood with the QiaAmp DNA Mini Kit (Qiagen, Valencia, CA, USA) and 29 common CFTR gene mutations (D1152H, 1717-1G>A, G542X, W1282X, N1303K, ࢞F508, 3849+10kbC>T, 394delTT, 621+1G>T, S1251N, G551D, R117H, R1162X, R334W, A455E, 2183AA>G, 3659delC, 1078delT, ࢞I507, R347P, R553X, E60X, 3120+1G>A, 2789+5G>A, 1898+1G>A, 711+1G>T, G85E, 2184delA and R560T) were analyzed with the ELUCIGENE CF29 v. 2 kit using four multiplex PCR. Login to comment

[hide] Managing the underlying cause of cystic fibrosis: ... Paediatr Drugs. 2013 Oct;15(5):393-402. doi: 10.1007/s40272-013-0035-3. Galietta LJ
Managing the underlying cause of cystic fibrosis: a future role for potentiators and correctors.
Paediatr Drugs. 2013 Oct;15(5):393-402. doi: 10.1007/s40272-013-0035-3., [PMID:23757197]

Abstract [show]
Cystic fibrosis (CF), a severe genetic disease, is caused by mutations that alter the structure and function of CFTR, a plasma membrane channel permeable to chloride and bicarbonate. Defective anion transport in CF irreversibly damages the lungs, pancreas, liver, and other organs. CF mutations cause loss of CFTR function in multiple ways. In particular, class 3 mutations such as p.Gly551Asp strongly decrease the time spent by CFTR in the open state (gating defect). Instead, class 2 mutations impair the maturation of CFTR protein and its transport from the endoplasmic reticulum to the plasma membrane (trafficking defect). The deletion of phenylalanine 508 (p.Phe508del), the most frequent mutation among CF patients (70-90 %), destabilizes the CFTR protein, thus causing both a trafficking and a gating defect. These two defects can be overcome with drug-like molecules generically called correctors and potentiators, respectively. The potentiator Kalydeco (also known as Ivacaftor or VX-770), developed by Vertex Pharmaceuticals, has been recently approved by the US FDA and the European Medicines Agency (EMA) for the treatment of CF patients carrying at least one CFTR allele with the p.Gly551Asp mutation (2-5 % of all patients). In contrast, the corrector VX-809, which significantly improves p.Phe508del-CFTR trafficking in vitro, is still under study in clinical trials. Because of multiple defects caused by the p.Phe508del mutation, it is probable that rescue of the mutant protein will require combined treatment with correctors having different mechanisms of action. This review evaluates the status of experimental and clinical research in pharmacotherapy for the CF basic defect.

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78 Class 4 mutations (e.g. p.Arg347Pro), Fig. 2 Molecular defects associated with cystic fibrosis (CF) mutations and possibilities for pharmacological correction. Login to comment

[hide] A comprehensive assay for CFTR mutational analysis... Clin Chem. 2013 Oct;59(10):1481-8. doi: 10.1373/clinchem.2013.206466. Epub 2013 Jun 17. Abou Tayoun AN, Tunkey CD, Pugh TJ, Ross T, Shah M, Lee CC, Harkins TT, Wells WA, Tafe LJ, Amos CI, Tsongalis GJ
A comprehensive assay for CFTR mutational analysis using next-generation sequencing.
Clin Chem. 2013 Oct;59(10):1481-8. doi: 10.1373/clinchem.2013.206466. Epub 2013 Jun 17., [PMID:23775370]

Abstract [show]
BACKGROUND: Cystic fibrosis is a life-threatening genetic disorder that has been associated with mutations in the CFTR [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)] gene. Hundreds of CFTR mutations have been detected to date. Current CFTR genotyping assays target a subset of these mutations, particularly a mutation panel recommended by the American College of Medical Genetics for carrier screening of the general population. Fast sequencing of the entire coding sequence in a scalable manner could expand the detection of CFTR mutations and facilitate management of costs and turnaround times in the clinical laboratory. METHODS: We describe a proof-of-concept CFTR assay that uses PCR target enrichment and next-generation sequencing on the Ion Torrent Personal Genome Machine (PGM) platform. RESULTS: The scalability of the assay was demonstrated, with an average mean depth of coverage ranging from 500x to 3500x, depending on the number of multiplexed patient samples and the Ion Torrent chip used. In a blinded study of 79 previously genotyped patient DNA samples and cell lines, our assay detected most of the mutations, including single-nucleotide variants, small insertions and deletions, and large copy-number variants. The reproducibility was 100% for detecting mutations in independent runs. Our assay demonstrated high specificity, with only 2 false-positive calls (at 2184delA) found in 2 samples caused by a sequencing error in a homopolymer stretch of sequence. The detection rate for variants of unknown significance was very low in the targeted region. CONCLUSIONS: With continued optimization and system refinements, PGM sequencing promises to be a powerful, rapid, and scalable means of clinical diagnostic sequencing.

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53 of cases af9;/af9; c.1521_1523delCTT; c.1521_1523delCTT èc;F508; èc;F508 CF Yes 97 Dartmouth 1 af9;/af9; c.1521_1523delCTT; c.350Gb0e;A èc;F508; R117H CF Yes 53; 50 Dartmouth 1 af9;/af9; c.350Gb0e;A; c.1477Cb0e;T R117H; Q493*b CF Yes 52; 49 Dartmouth 1 af9;/af9; c.1521_1523delCTT; c.1000Cb0e;T èc;F508; R334W CF Yes 49; 54 Dartmouth 1 af9;/af9; c.1521_1523delCTT; c.489af9;1Gb0e;T èc;F508; 621af9;1Gb0e;T CF Yes 48; 47 Dartmouth 1 af9;/af9; c.1521_1523delCTT; c.1364Cb0e;A èc;F508; A455E CF Yes 51; 46 Dartmouth 1 af9;/af9; c.489af9;1Gb0e;T; c.2988af9;1Gb0e;A 621af9;1Gb0e;T; 3120af9;1Gb0e;A CF Yes 48; 49 Coriell 1 af9;/af9; c.1521_1523delCTT; c.1657Cb0e;T èc;F508; R553* CF Yes 44; 49c Coriell 2 af9;/af9; c.1521_1523delCTT; c.3528delC èc;F508; 3659delC CF Yes 46; 46 Coriell 1 af9;/af9; c.489af9;1Gb0e;T; c.579af9;1Gb0e;T 621af9;1Gb0e;T; 711af9;1Gb0e;T CF Yes 50; 51 Coriell 1 af9;/af9; c.489af9;1Gb0e;T; c.254Gb0e;A 621af9;1Gb0e;T; G85E CF Yes 50; 45 Coriell 1 af9;/af9; c.1521_1523delCTT; c.1679Gb0e;C èc;F508; R560T CF Yes 44; 52 Coriell 1 af9;/af9; c.489af9;1Gb0e;T; c.1364Cb0e;A 621af9;1Gb0e;T; A455E CF Yes 50; 49 Coriell 1 af9;/af9; c.3909Cb0e;G; c.4046Gb0e;A N1303K; G1349D CF Yes 47; 52 Coriell 1 af9;/af9; c.2657af9;5Gb0e;A; c.2657af9;5Gb0e;A 2789af9;5Gb0e;A; 2789af9;5Gb0e;A CF Yes 100 Coriell 1 af9;/af9; c.1040Gb0e;C; c.1652Gb0e;A R347P; G551D CF Yes 51; 49 Coriell 1 af9;/af9; c.1000Cb0e;T; c.3368-2Ab0e;T R334W; 3500-2Ab0e;G CF Yes 53; 45 Coriell 1 af9;/af9; c.254Gb0e;A; c.3454Gb0e;C G85E; D1152H CF Yes 44; 47 Coriell 1 af9;/af9; c.1521_1523delCTT; c.350Gb0e;A èc;F508; R117H CF Yes 49; 50 Coriell 1 af9;/af9; c.1521_1523delCTT; c.54-5940_273af9;10250del21kb èc;F508; CFTRdel2,3 CF Yes 47; N/Ad Coriell 1 af9;/af9; c.1521_1523delCTT; c.1766af9;1Gb0e;A èc;F508; 1898af9;1Gb0e;A CF Yes 47; 50 Coriell 1 af9;/af9; c.1521_1523delCTT; c.2051_2052delAAinsG èc;F508; K684Sfs CF Yes 47; 50 Coriell 1 af9;/af9; c.1521_1523delCTT; c.2052del èc;F508; K684Nfs*38 CF Yes 51; 55 Coriell 1 af9;/afa; c.1521_1523delCTT èc;F508 Carrier Yes 50c Dartmouth 16 af9;/afa; c.1652Gb0e;A G551D Carrier Yes 50c Dartmouth 5 af9;/afa; c.1519_1521delATC èc;I507 Carrier Yes 46 Dartmouth 1 af9;/afa; c.3454Gb0e;C D1152H Carrier Yes 50 Dartmouth 1 af9;/afa; c.1657Cb0e;T R553* Carrier Yes 51 Dartmouth 1 af9;/afa; c.178Gb0e;T E60* Carrier Yes 51 Dartmouth 1 af9;/afa; c.3846Gb0e;A W1282* Carrier Yes 45c Dartmouth 3 af9;/afa; c.1000Cb0e;T R334W Carrier Yes 51 Dartmouth 1 af9;/afa; c.1624Gb0e;T G542* Carrier Yes 47c Dartmouth 4 af9;/afa; c.3484Cb0e;T R1162* Carrier Yes 43 Dartmouth 1 af9;/afa; c.1766af9;1Gb0e;A 1898af9;1Gb0e;A Carrier Yes 57 Dartmouth 1 af9;/afa; c.3773_3774insT 3905insT (L1258Ffs*7) Carrier Yes 37 Dartmouth 1 af9;/afa; c.350Gb0e;A R117H Carrier Yes 50c Dartmouth 3 af9;/afa; c.1645Ab0e;C S549R Ab0e;C Carrier No N/A Dartmouth 1 af9;/afa; c.1040Gb0e;A R347H Carrier Yes 47 Dartmouth 1 af9;/afa; c.3909Cb0e;G N1303K Carrier Yes 46 Dartmouth 1 af9;/afa; c.3718-2477Cb0e;T 3849af9;10kbCb0e;T Carrier Yes 51 Coriell 1 af9;/afa; c.2988af9;1Gb0e;A 3120af9;1Gb0e;A Carrier Yes 49 Coriell 1 af9;/afa; c.489af9;1Gb0e;T 621af9;1Gb0e;T Carrier Yes 50 Coriell 1 af9;/afa; c.1585-1Gb0e;A 1717-1Gb0e;A Carrier Yes 51 Coriell 1 afa;/afa;e N/Af N/A Normal N/A N/A Dartmouth 9 a af9;/af9;, 2 pathogenic mutations; af9;/afa;, carrier of a single pathogenic mutation; afa;/afa;, absence of any pathogenic mutations. Login to comment
115 Mutation cDNA position Mutation class Sensitivity (TPa ) Specificity (TN) Accuracyb G85E c.254Gb0e;A Missense Detected (2/2) 100% (77/77) 100% R117H c.350Gb0e;A Missense Detected (6/6) 100% (73/73) 100% 621af9;1Gb0e;T c.489af9;1Gb0e;T Splice site Detected (6/6) 100% (73/73) 100% 711af9;1Gb0e;T c.579af9;1Gb0e;T Splice site Detected (1/1) 100% (78/78) 100% R334W c.1000Cb0e;T Missense Detected (3/3) 100% (76/76) 100% R347P c.1040Gb0e;C Missense Detected (1/1) 100% (78/78) 100% A455E c.1364Cb0e;A Missense Detected (2/2) 100% (77/77) 100% èc;I507 c.1519_1521delATC In-frame deletion Detected (1/1) 100% (78/78) 100% èc;F508 c.1521_1523delCTT In-frame deletion Detected (30/30) 100% (49/49) 100% G542* c.1624Gb0e;T Nonsense Detected (4/4) 100% (75/75) 100% G551D c.1652Gb0e;A Missense Detected (6/6) 100% (73/73) 100% R553* c.1657Cb0e;T Nonsense Detected (3/3) 100% (76/76) 100% R560T c.1679Gb0e;C Missense Detected (1/1) 100% (78/78) 100% 1898af9;1Gb0e;A c.1766af9;1Gb0e;A Splice site Detected (2/2) 100% (77/77) 100% 2789af9;5Gb0e;A c.2657af9;5Gb0e;A Splice site Detected (1/1) 100% (78/78) 100% 3120af9;1Gb0e;A c.2988af9;1Gb0e;A Splice site Detected (2/2) 100% (77/77) 100% R1162* c.3484Cb0e;T Nonsense Detected (1/1) 100% (78/78) 100% 3659delC c.3528del Frameshift deletion Detected (1/1) 100% (78/78) 100% 3849af9;10kbCb0e;T c.3718-2477Cb0e;T Splice site Detected (1/1) 100% (78/78) 100% W1282* c.3846Gb0e;A Nonsense Detected (3/3) 100% (75/75) 100% N1303K c.3909Cb0e;G Missense Detected (1/1) 100% (78/78) 100% 2184delA c.2052del Frameshift deletion Detected (1/1) 97% (76/78) 97% 1717-1Gb0e;A c.1585-1Gb0e;A Splice site Detected (1/1) 100% (78/78) 100% a TP, true-positive rate; TN, true-negative rate. Login to comment

[hide] Genetic testing of sperm donors for cystic fibrosi... Eur J Obstet Gynecol Reprod Biol. 2013 Sep;170(1):183-7. doi: 10.1016/j.ejogrb.2013.06.022. Epub 2013 Jul 15. Landaburu I, Gonzalvo MC, Clavero A, Ramirez JP, Yoldi A, Mozas J, Zamora S, Martinez L, Castilla JA
Genetic testing of sperm donors for cystic fibrosis and spinal muscular atrophy: evaluation of clinical utility.
Eur J Obstet Gynecol Reprod Biol. 2013 Sep;170(1):183-7. doi: 10.1016/j.ejogrb.2013.06.022. Epub 2013 Jul 15., [PMID:23866907]

Abstract [show]
OBJECTIVE: To evaluate the clinical utility of genetic testing for cystic fibrosis (CF) and spinal muscular atrophy (SMA) in sperm donors. STUDY DESIGN: We studied the results of the genetic tests for CF and SMA applied to 372 sperm donor candidates. The CF carrier screening test analysed 32 mutations on the CFTR gene. Regarding SMA, the carrier test studied possible deletions of SMN1/2 by Multiplex Ligation-dependent Probe Amplification (MLPA) methodology. RESULTS: The carrier frequency obtained was greater for SMA than for CF. After adjusting the results obtained for the sensitivity of the tests, and taking into account the prevalence of female carriers in our population, the probability of transmission of the disease to the child from a donor with a negative genetic test was about five times lower in the case of SMA than in CF, although this difference was not statistically significant. The number of donors needed to screen (NNS) to avoid the occurrence of a child being affected by CF and SMA in our population was similar in both cases (1591 vs. 1536). CONCLUSIONS: This study demonstrates the need to include SMA among the diseases for which genetic screening is performed in the process of sperm donor selection. We believe that testing donors for SMA is as important and as useful as doing so for CF.

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51 The panel of mutations studied was: S549N, S549R, R553X, G551D, V520F, I507del, F508del, 3876delA, 1717-1G->A, G542X, R560T, 3120+1G->A, A455E, R117H, 394delTT, 2183AA- >G, 2184delA, 2789+5G->A, 1898+1G->A, 621+1G->T, 711+1G- >T, G85E, R347P, R347H, W1282X, R334W, 1078delT, 3849+10kbC->T, R1162X, N1303K, 3659delC, 3905insT. Login to comment

[hide] Comparison of different IRT-PAP protocols to scree... J Cyst Fibros. 2014 Jan;13(1):15-23. doi: 10.1016/j.jcf.2013.06.003. Epub 2013 Jul 25. Sommerburg O, Krulisova V, Hammermann J, Lindner M, Stahl M, Muckenthaler M, Kohlmueller D, Happich M, Kulozik AE, Votava F, Balascakova M, Skalicka V, Stopsack M, Gahr M, Macek M Jr, Mall MA, Hoffmann GF
Comparison of different IRT-PAP protocols to screen newborns for cystic fibrosis in three central European populations.
J Cyst Fibros. 2014 Jan;13(1):15-23. doi: 10.1016/j.jcf.2013.06.003. Epub 2013 Jul 25., [PMID:23891278]

Abstract [show]
BACKGROUND: In recent years different IRT/PAP protocols have been evaluated, but the individual performance remains unclear. To optimize the IRT/PAP strategy we compared protocols from three regional CF newborn screening centers (Heidelberg, Dresden, and Prague). METHODS: We evaluated the effect of elevating the IRT-cut-off from 50 to 65 mug/l (~97.5th to ~99.0th percentile), the need of a failsafe protocol (FS, IRT >/= 99.9th percentile) and the relative performance using either two IRT-dependent PAP-cut-offs or one PAP-cut-off. FINDINGS: Elevation of the IRT cut-off to 65 mug/l (~99.0th percentile) increased the PPV significantly (Dresden: 0.065 vs. 0.080, p < 0.0001, Prague: 0.052 vs. 0.074, p < 0.0001) without reducing sensitivity. All three IRT/PAP protocols showed a trend towards a higher sensitivity with FS than without and when using one PAP-cut-off instead of two IRT-dependent PAP-cut-offs. CONCLUSIONS: For best performance we suggest an IRT/PAP protocol with an IRT-cut-off close to the 99.0th percentile, FS, and a single PAP-cut-off.

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172 Alternatively, the low PAP in this patient (HD-29) might be explained by expression of R347P mutation which is partially associated with exocrine pancreatic sufficiency and might therefore result in a lower PAP value after birth. Login to comment

[hide] Effect of ivacaftor on CFTR forms with missense mu... J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23. Van Goor F, Yu H, Burton B, Hoffman BJ
Effect of ivacaftor on CFTR forms with missense mutations associated with defects in protein processing or function.
J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23., [PMID:23891399]

Abstract [show]
BACKGROUND: Ivacaftor (KALYDECO, VX-770) is a CFTR potentiator that increased CFTR channel activity and improved lung function in patients age 6 years and older with CF who have the G551D-CFTR gating mutation. The aim of this in vitro study was to evaluate the effect of ivacaftor on mutant CFTR protein forms with defects in protein processing and/or channel function. METHODS: The effect of ivacaftor on CFTR function was tested in electrophysiological studies using a panel of Fischer rat thyroid (FRT) cells expressing 54 missense CFTR mutations that cause defects in the amount or function of CFTR at the cell surface. RESULTS: Ivacaftor potentiated multiple mutant CFTR protein forms that produce functional CFTR at the cell surface. These included mutant CFTR forms with mild defects in CFTR processing or mild defects in CFTR channel conductance. CONCLUSIONS: These in vitro data indicated that ivacaftor is a broad acting CFTR potentiator and could be used to help stratify patients with CF who have different CFTR genotypes for studies investigating the potential clinical benefit of ivacaftor.

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44 None M1V A46D E56K P67L R74W G85E E92K D110E D110H R117C R117H E193K L206W R334W I336K T338I S341P R347H R347P R352Q A455E L467P S492F F508del V520F A559T R560S R560T A561E Y569D D579G R668C L927P S945L S977F L997F F1052V H1054D K1060T L1065P R1066C R1066H R1066M A1067T R1070Q R1070W F1074L L1077P H1085R M1101K D1152H S1235R D1270N N1303K 0 100 200 300 400 500 600 * * * CFTR Mutation mRNA (% Normal CFTR) Fig. 1. Login to comment
64 Mutant CFTR form CFTR processing Mature/total % Normal CFTR Normal 0.89 &#b1; 0.01 100.0 &#b1; 18.5 G85E -0.05 &#b1; 0.04 -1.0 &#b1; 0.9 R560S 0.00 &#b1; 0.00 0.0 &#b1; 0.0 R1066C 0.02 &#b1; 0.01 0.0 &#b1; 0.0 S492F 0.00 &#b1; 0.00 0.1 &#b1; 0.1 R560T 0.01 &#b1; 0.01 0.2 &#b1; 0.1 V520F 0.05 &#b1; 0.03 0.3 &#b1; 0.2 M1101K 0.05 &#b1; 0.03 0.3 &#b1; 0.1 A561E 0.08 &#b1; 0.04 0.5 &#b1; 0.2 R1066M 0.02 &#b1; 0.02 0.5 &#b1; 0.4 N1303K 0.02 &#b1; 0.02 0.5 &#b1; 0.3 A559T 0.16 &#b1; 0.09 0.6 &#b1; 0.2 M1V 0.06 &#b1; 0.06 0.7 &#b1; 0.6 Y569D 0.11 &#b1; 0.04 0.6 &#b1; 0.2 R1066H 0.08 &#b1; 0.02a 0.7 &#b1; 0.2a L1065P 0.05 &#b1; 0.05 1.0 &#b1; 0.8 L467P 0.10 &#b1; 0.07 1.2 &#b1; 0.8 L1077P 0.08 &#b1; 0.04 1.5 &#b1; 0.6 A46D 0.21 &#b1; 0.08 1.9 &#b1; 0.5a E92K 0.06 &#b1; 0.05 1.9 &#b1; 1.3 H1054D 0.09 &#b1; 0.04 1.9 &#b1; 0.8 F508del 0.09 &#b1; 0.02a 2.3 &#b1; 0.5a H1085R 0.06 &#b1; 0.01a 3.0 &#b1; 0.7a I336K 0.42 &#b1; 0.05a 6.5 &#b1; 0.7a L206W 0.35 &#b1; 0.10a 6.8 &#b1; 1.7a F1074L 0.52 &#b1; 0.03a 10.9 &#b1; 0.6a A455E 0.26 &#b1; 0.10a 11.5 &#b1; 2.5a E56K 0.29 &#b1; 0.04a 12.2 &#b1; 1.5a R347P 0.48 &#b1; 0.04a 14.6 &#b1; 1.8a R1070W 0.61 &#b1; 0.04a 16.3 &#b1; 0.6a P67L 0.36 &#b1; 0.04a 28.4 &#b1; 6.8a R1070Q 0.90 &#b1; 0.01a 29.5 &#b1; 1.4a S977F 0.97 &#b1; 0.01a 37.3 &#b1; 2.4a A1067T 0.78 &#b1; 0.03a 38.6 &#b1; 6.1a D579G 0.72 &#b1; 0.02a 39.3 &#b1; 3.1a D1270N 1.00 &#b1; 0.00a,c 40.7 &#b1; 1.2a S945L 0.65 &#b1; 0.04a 42.4 &#b1; 8.9a L927P 0.89 &#b1; 0.01a,b 43.5 &#b1; 2.5a,b R117C 0.87 &#b1; 0.02a,b 49.1 &#b1; 2.9a,b T338I 0.93 &#b1; 0.03a,b 54.2 &#b1; 3.7a,b L997F 0.90 &#b1; 0.04a,b 59.8 &#b1; 10.4a,b D110H 0.97 &#b1; 0.01a,b 60.6 &#b1; 1.5a,b S341P 0.79 &#b1; 0.02a 65.0 &#b1; 4.9a,b R668C 0.94 &#b1; 0.03a,b 68.5 &#b1; 1.9a,b R74W 0.78 &#b1; 0.01a 69.0 &#b1; 2.7a,b D110E 0.92 &#b1; 0.05a,b 87.5 &#b1; 9.5a,b R334W 0.91 &#b1; 0.05a,b 97.6 &#b1; 10.0a,b K1060T 0.87 &#b1; 0.02a,b 109.9 &#b1; 28.0a,b R347H 0.96 &#b1; 0.02a,c 120.7 &#b1; 2.8a,b S1235R 0.96 &#b1; 0.00a,c 139.0 &#b1; 9.0a,b E193K 0.84 &#b1; 0.02a,b 143.0 &#b1; 17.1a,b R117H 0.86 &#b1; 0.01a,b 164.5 &#b1; 34.2a,b R352Q 0.98 &#b1; 0.01a,b 179.9 &#b1; 8.0a,c F1052V 0.90 &#b1; 0.01a,b 189.9 &#b1; 33.1a,b D1152H 0.96 &#b1; 0.02a,c 312.0 &#b1; 45.5a,b Notes to Table 1: Quantification of steady-state CFTR maturation expressed as the mean (&#b1;SEM; n = 5-9) ratio of mature CFTR to total CFTR (immature plus mature) or level of mature mutant CFTR relative to mature normal-CFTR (% normal CFTR) in FRT cells individually expressing CFTR mutations. Login to comment
74 Because the level of CFTR mRNA was similar across the panel of cell lines tested, the range in baseline activity and ivacaftor response likely reflects the severity of the functional defect and/or the 0 50 100 150 200 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L E56K P67L R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V Baseline With ivacaftor * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Chloride transport (% Normal) Mutant CFTR form 0 100 200 300 400 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L P67L E56K R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Mature CFTR (% Normal) Mutant CFTR form A B Fig. 2. Login to comment
82 Mutation Patientsa Chloride transport (bc;A/cm2 ) Chloride transport (% normal) EC50 Baseline With ivacaftor Baseline With ivacaftor Fold increase over baselineb Normal 204.5 &#b1; 33.3 301.3 &#b1; 33.8c 100.0 &#b1; 16.3 147.3 &#b1; 16.5c 1.5 266 &#b1; 42 G551D 1282 1.5 &#b1; 0.7 113.2 &#b1; 13.0c 1.0 &#b1; 0.5 55.3 &#b1; 6.3c 55.3 312 &#b1; 73 F1052V 12 177.3 &#b1; 13.7 410.2 &#b1; 11.3c 86.7 &#b1; 6.7 200.7 &#b1; 5.6c 2.3 177 &#b1; 14 S1235R ND 160.6 &#b1; 25.7 352.1 &#b1; 43.4c 78.5 &#b1; 12.6 172.2 &#b1; 21.2c 2.2 282 &#b1; 104 D1152H 185 117.3 &#b1; 23.0 282.7 &#b1; 46.9c 57.4 &#b1; 11.2 138.2 &#b1; 22.9c 2.4 178 &#b1; 67 D1270N 32 109.5 &#b1; 20.5 209.5 &#b1; 27.4c 53.6 &#b1; 10.0 102.4 &#b1; 13.4c 1.9 254 &#b1; 56 R668C 45 99.0 &#b1; 9.4 217.6 &#b1; 11.7c 48.4 &#b1; 4.6 106.4 &#b1; 5.7c 2.2 517 &#b1; 105 K1060T ND 89.0 &#b1; 9.8 236.4 &#b1; 20.3c 43.5 &#b1; 4.8 115.6 &#b1; 9.9c 2.7 131 &#b1; 73 R74W 25 86.8 &#b1; 26.9 199.1 &#b1; 16.8c 42.5 &#b1; 13.2 97.3 &#b1; 8.2c 2.3 162 &#b1; 17 R117H 739 67.2 &#b1; 13.3 274.1 &#b1; 32.2c 32.9 &#b1; 6.5 134.0 &#b1; 15.7c 4.1 151 &#b1; 14 E193K ND 62.2 &#b1; 9.8 379.1 &#b1; 1.1c 30.4 &#b1; 4.8 185.4 &#b1; 1.0c 6.1 240 &#b1; 20 A1067T ND 55.9 &#b1; 3.2 164.0 &#b1; 9.7c 27.3 &#b1; 1.6 80.2 &#b1; 4.7c 2.9 317 &#b1; 214 L997F 27 43.7 &#b1; 3.2 145.5 &#b1; 4.0c 21.4 &#b1; 1.6 71.2 &#b1; 2.0c 3.3 162 &#b1; 12 R1070Q 15 42.0 &#b1; 0.8 67.3 &#b1; 2.9c 20.6 &#b1; 0.4 32.9 &#b1; 1.4c 1.6 164 &#b1; 20 D110E ND 23.3 &#b1; 4.7 96.4 &#b1; 15.6c 11.4 &#b1; 2.3 47.1 &#b1; 7.6c 4.1 213 &#b1; 51 D579G 21 21.5 &#b1; 4.1 192.0 &#b1; 18.5c 10.5 &#b1; 2.0 93.9 &#b1; 9.0c 8.9 239 &#b1; 48 D110H 30 18.5 &#b1; 2.2 116.7 &#b1; 11.3c 9.1 &#b1; 1.1 57.1 &#b1; 5.5c 6.2 249 &#b1; 59 R1070W 13 16.6 &#b1; 2.6 102.1 &#b1; 3.1c 8.1 &#b1; 1.3 49.9 &#b1; 1.5c 6.2 158 &#b1; 48 P67L 53 16.0 &#b1; 6.7 88.7 &#b1; 15.7c 7.8 &#b1; 3.3 43.4 &#b1; 7.7c 5.6 195 &#b1; 40 E56K ND 15.8 &#b1; 3.1 63.6 &#b1; 4.4c 7.7 &#b1; 1.5 31.1 &#b1; 2.2c 4.0 123 &#b1; 33 F1074L ND 14.0 &#b1; 3.4 43.5 &#b1; 5.4c 6.9 &#b1; 1.6 21.3 &#b1; 2.6c 3.1 141 &#b1; 19 A455E 120 12.9 &#b1; 2.6 36.4 &#b1; 2.5c 6.3 &#b1; 1.2 17.8 &#b1; 1.2c 2.8 170 &#b1; 44 S945L 63 12.3 &#b1; 3.9 154.9 &#b1; 47.6c 6.0 &#b1; 1.9 75.8 &#b1; 23.3c 12.6 181 &#b1; 36 S977F 9 11.3 &#b1; 6.2 42.5 &#b1; 19.1c 5.5 &#b1; 3.0 20.8 &#b1; 9.3c 3.8 283 &#b1; 36 R347H 65 10.9 &#b1; 3.3 106.3 &#b1; 7.6c 5.3 &#b1; 1.6 52.0 &#b1; 3.7c 9.8 280 &#b1; 35 L206W 81 10.3 &#b1; 1.7 36.4 &#b1; 2.8c 5.0 &#b1; 0.8 17.8 &#b1; 1.4c 3.6 101 &#b1; 13 R117C 61 5.8 &#b1; 1.5 33.7 &#b1; 7.8c 2.9 &#b1; 0.7 16.5 &#b1; 3.8c 5.7 380 &#b1; 136 R352Q 46 5.5 &#b1; 1.0 84.5 &#b1; 7.8c 2.7 &#b1; 0.5 41.3 &#b1; 3.8c 15.2 287 &#b1; 75 R1066H 29 3.0 &#b1; 0.3 8.0 &#b1; 0.8c 1.5 &#b1; 0.1 3.9 &#b1; 0.4c 2.6 390 &#b1; 179 T338I 54 2.9 &#b1; 0.8 16.1 &#b1; 2.4c 1.4 &#b1; 0.4 7.9 &#b1; 1.2c 5.6 334 &#b1; 38 R334W 150 2.6 &#b1; 0.5 10.0 &#b1; 1.4c 1.3 &#b1; 0.2 4.9 &#b1; 0.7c 3.8 259 &#b1; 103 G85E 262 1.6 &#b1; 1.0 1.5 &#b1; 1.2 0.8 &#b1; 0.5 0.7 &#b1; 0.6 NS NS A46D ND 2.0 &#b1; 0.6 1.1 &#b1; 1.1 1.0 &#b1; 0.3 0.5 &#b1; 0.6 NS NS I336K 29 1.8 &#b1; 0.2 7.4 &#b1; 0.1c 0.9 &#b1; 0.1 3.6 &#b1; 0.1c 4 735 &#b1; 204 H1054D ND 1.7 &#b1; 0.3 8.7 &#b1; 0.3c 0.8 &#b1; 0.1 4.2 &#b1; 0.1c 5.3 187 &#b1; 20 F508del 29,018 0.8 &#b1; 0.6 12.1 &#b1; 1.7c 0.4 &#b1; 0.3 5.9 &#b1; 0.8c 14.8 129 &#b1; 38 M1V 9 0.7 &#b1; 1.4 6.5 &#b1; 1.9c 0.4 &#b1; 0.7 3.2 &#b1; 0.9c 8.0 183 &#b1; 85 E92K 14 0.6 &#b1; 0.2 4.3 &#b1; 0.8c 0.3 &#b1; 0.1 2.1 &#b1; 0.4c 7.0 198 &#b1; 46 V520F 58 0.4 &#b1; 0.2 0.5 &#b1; 0.2 0.2 &#b1; 0.1 0.2 &#b1; 0.1 NS NS H1085R ND 0.3 &#b1; 0.2 2.1 &#b1; 0.4 0.2 &#b1; 0.1 1.0 &#b1; 0.2 NS NS R560T 180 0.3 &#b1; 0.3 0.5 &#b1; 0.5 0.1 &#b1; 0.1 0.2 &#b1; 0.2 NS NS L927P 15 0.2 &#b1; 0.1 10.7 &#b1; 1.7c 0.1 &#b1; 0.1 5.2 &#b1; 0.8c 52.0 313 &#b1; 66 R560S ND 0.0 &#b1; 0.1 -0.2 &#b1; 0.2 0.0 &#b1; 0.0 -0.1 &#b1; 0.1 NS NS N1303K 1161 0.0 &#b1; 0.0 1.7 &#b1; 0.3 0.0 &#b1; 0.0 0.8 &#b1; 0.2 NS NS M1101K 79 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1077P 42 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066M ND 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066C 100 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1065P 25 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS Y569D 9 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS A561E ND 0.0 &#b1; 0.1 0.0 &#b1; 0.1 0.0 &#b1; 0.0 0.0 &#b1; 0.1 NS NS A559T 43 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S492F 16 0.0 &#b1; 0.0 1.7 &#b1; 1.2 0.0 &#b1; 0.0 0.8 &#b1; 0.6 NS NS L467P 16 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R347P 214 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S341P 9 0.0 &#b1; 0.0 0.2 &#b1; 0.2 0.0 &#b1; 0.0 0.1 &#b1; 0.1 NS NS a Number of individuals with the individual mutation in the CFTR-2 database (www.CFTR2.org). Login to comment
89 For mutant CFTR forms that have multiple defects (e.g., R117H, F508del, S945L, R1070Q, A1067T, R1070W, and R347P), the relative impact of each defect is likely to affect the magnitude of the baseline chloride transport and ivacaftor response in vitro and in a clinical setting. Login to comment
107 Similarly, patients with CF who have the most common class IV mutation, R117H, typically have a lower sweat chloride concentration than those with R347P (60 mmol/L vs. 99 mmol/L, respectively) [22]. Login to comment

[hide] Molecular testing for cystic fibrosis carrier stat... J Genet Couns. 2014 Feb;23(1):5-15. doi: 10.1007/s10897-013-9636-9. Epub 2013 Sep 7. Langfelder-Schwind E, Karczeski B, Strecker MN, Redman J, Sugarman EA, Zaleski C, Brown T, Keiles S, Powers A, Ghate S, Darrah R
Molecular testing for cystic fibrosis carrier status practice guidelines: recommendations of the National Society of Genetic Counselors.
J Genet Couns. 2014 Feb;23(1):5-15. doi: 10.1007/s10897-013-9636-9. Epub 2013 Sep 7., [PMID:24014130]

Abstract [show]
PURPOSE: To provide practice recommendations for genetic counselors whose clients are considering cystic fibrosis (CF) carrier testing or seeking information regarding CF molecular test results. The goals of these recommendations are to: 1) Provide updated information about the natural history, diagnosis, and treatment of CF and related conditions. 2) Supplement genetic counselors' knowledge and understanding of the available carrier screening and diagnostic testing options. 3) Describe the current state of genotype/phenotype correlations for CFTR mutations and an approach to interpreting both novel and previously described variants. 4) Provide a framework for genetic counselors to assist clients' decision-making regarding CF carrier testing, prenatal diagnosis, and pregnancy management. Disclaimer The practice guidelines of the National Society of Genetic Counselors (NSGC) are developed by members of the NSGC to assist genetic counselors and other health care providers in making decisions about appropriate management of genetic concerns; including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue, and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the NSGC practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are only current as of their publication date, and are subject to change without notice as advances emerge.In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population.Practice guidelines are published by NSGC for educational and informational purposes only, and NSGC does not "approve" or "endorse" any specific methods, practices, or sources of information.

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175 R334W, R347P V Lead to a quantitative defect in the amount of CFTR protein that reaches the cell surface due to decreased stability of mRNA. Login to comment

[hide] Analysis of CFTR Gene Mutations in Children with C... Iran J Basic Med Sci. 2013 Aug;16(8):917-21. Mehdizadeh Hakkak A, Keramatipour M, Talebi S, Brook A, Tavakol Afshari J, Raazi A, Kianifar HR
Analysis of CFTR Gene Mutations in Children with Cystic Fibrosis, First Report from North-East of Iran.
Iran J Basic Med Sci. 2013 Aug;16(8):917-21., [PMID:24106596]

Abstract [show]
OBJECTIVE(S): More than 1500 registered mutations in cystic fibrosis transmembrane regulator (CFTR) gene are responsible for dysfunction of an ion channel protein and a wide spectrum of clinical manifestations in patients with cystic fibrosis (CF). This study was performed to investigate the frequency of a number of well-known CFTR mutations in North Eastern Iranian CF patients. MATERIAL AND METHODS: A total number of 56 documented CF patients participated in this study. Peripheral blood was obtained and DNA extraction was done by the use of routin methods. Three steps were taken for determining the target mutations: ARMS-PCR was performed for common CFTR mutations based on previous reports in Iran and neighboring countries. PCR-RFLP was done for detection of R344W and R347P, and PCR-Sequencing was performed for exon 11 in patients with unidentified mutation throughout previous steps. Samples which remained still unknown for a CFTR mutation were sequenced for exon 12. RESULTS: Among 112 alleles, 24 mutated alleles (21.42%) were detected: DeltaF508 (10.71%), 1677delTA (3.57%), S466X (3.57%), N1303K (0.89%), G542X (0.89%), R344W (0.89%), L467F (0.89%). Eight out of 56 individuals analyzed, were confirmed as homozygous and eight samples showed heterozygous status. No mutations were detected in exon 12 of sequenced samples. CONCLUSION: Current findings suggest a selected package of CFTR mutations for prenatal, neonatal and carrier screening along with diagnosis and genetic counseling programs in CF patients of Khorasan.

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5 PCR-RFLP was done for detection of R344W and R347P, and PCR-Sequencing was performed for exon 11 in patients with unidentified mutation throughout previous steps. Login to comment
42 In the second step, restriction fragment length polymorphism technique (PCR-RFLP) was used to investigate p.Arg1303Lys and p.Arg347Pro mutations in exon eight. Login to comment
53 Demographic, clinical, and family characterizations of patients with specific CFTR mutation No of patients Sex Sweat chloride (meq/lit) Pancreatic insufficiency Age of clinical presentation onset (month) First clinical symptom/sign Consanguinity of parents Mutation status 1 M 110 + 6 Steatorrhea/Hepatomegaly First cousin ƊF508/ ƊF508 2 M 115 + 5 Steatorrhea/Cough/ Hepatomegaly First cousin ƊF508/ ƊF508 3 F 130 + 2 Steatorrhea/Cough Wheezing/Skin rash First cousin ƊF508/ ƊF508 4 F 180 + 1 Steatorrhea/Cough/Vomiting/E dema/Hepatomegaly First cousin ƊF508/ ƊF508 5 M 93 + 3.5 FTT/Steatorrhea First cousin once removed ƊF508/ ƊF508 6 M 100 + At birth Wheezing/Meconium ileus - ƊF508/U* 7 M 115 + 2 Steatorrhea/Cough/Fever First cousin once removed ƊF508/U 8 M 90 + 6 Cough/Wheezing - N1303K/U 9 F 70 + At birth Meconium ileus/Crackle First cousin G542X/U 10 F 80 - 5 Cough/Wheezing/Fever - R334W/U 11 M 109 + 1 Fever/Wheezing/Cough Second cousin S466X/ S466X 12 M 120 + 10 Cough/Wheezing/Steatorrhea - S466X/U 13 M 100 + At birth Wheezing/Meconium ileus First cousin S466X/U 14 M 100 + 5.5 Rectal prolapse/Cough/ Wheezing/Steatorrhea First cousin 1677delTA/ 1677delTA 15 M 85 + 3 FTT/Sreatorrhea/Wheezing/ Cough First cousin 1677delTA/ 1677delTA 16 F 93 + 4 Steatorrhea - 1531C/T (L467F)/U * Unknown mutation PCR-RFLP was operated for identification of p.Arg334Trp and p.Arg347Pro mutations and revealed only one heterozygote status for p.Arg334Trp mutation. Login to comment
60 Exon eight was probed for p.Arg334Trp and p.Arg347Pro mutations by PCR-RFLP which revealed only one p.Arg334Trp mutation. Login to comment

[hide] Cystic fibrosis carrier screening in a North Ameri... Genet Med. 2014 Jul;16(7):539-46. doi: 10.1038/gim.2013.188. Epub 2013 Dec 19. Zvereff VV, Faruki H, Edwards M, Friedman KJ
Cystic fibrosis carrier screening in a North American population.
Genet Med. 2014 Jul;16(7):539-46. doi: 10.1038/gim.2013.188. Epub 2013 Dec 19., [PMID:24357848]

Abstract [show]
PURPOSE: The aim of this study was to compare the mutation frequency distribution for a 32-mutation panel and a 69-mutation panel used for cystic fibrosis carrier screening. Further aims of the study were to examine the race-specific detection rates provided by both panels and to assess the performance of extended panels in large-scale, population-based cystic fibrosis carrier screening. Although genetic screening for the most common CFTR mutations allows detection of nearly 90% of cystic fibrosis carriers, the large number of other mutations, and their distribution within different ethnic groups, limits the utility of general population screening. METHODS: Patients referred for cystic fibrosis screening from January 2005 through December 2010 were tested using either a 32-mutation panel (n = 1,601,308 individuals) or a 69-mutation panel (n = 109,830). RESULTS: The carrier frequencies observed for the 69-mutation panel study population (1/36) and Caucasian (1/27) and African-American individuals (1/79) agree well with published cystic fibrosis carrier frequencies; however, a higher carrier frequency was observed for Hispanic-American individuals (1/48) using the 69-mutation panel as compared with the 32-mutation panel (1/69). The 69-mutation panel detected ~20% more mutations than the 32-mutation panel for both African-American and Hispanic-American individuals. CONCLUSION: Expanded panels using race-specific variants can improve cystic fibrosis carrier detection rates within specific populations. However, it is important that the pathogenicity and the relative frequency of these variants are confirmed.

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63 This threshold could not be reached Table 1ߒ CFTR allele frequency identified by the CF32 mutation panel Varianta Number of detected alleles Mutation (%) Legacy nomenclature HGVS nomenclature F508delb p.F508del 31,142 68.69 R117Hb p.R117H 5,198 11.46 G542Xb p.G542X 1,162 2.56 G551Db p.G551D 989 2.18 W1282Xb p.W1282X 824 1.82 3120ߙ+ߙ1G>Ab c.2988ߙ+ߙ1G>A 706 1.56 N1303Kb p.N1303K 648 1.43 R553Xb p.R553X 487 1.07 3849ߙ+ߙ10kbC>Tb c.3717ߙ+ߙ12191C>T 436 0.96 621ߙ+ߙ1G>Tb c.489ߙ+ߙ1G>T 410 0.90 1717-1G>Ab c.1585-1G>A 388 0.86 2789ߙ+ߙ5G>Ab c.2657ߙ+ߙ5G>A 382 0.84 I507delb p.I507del 258 0.57 R334Wb p.R334W 257 0.57 R1162Xb p.R1162X 211 0.47 G85Eb p.G85E 199 0.44 1898ߙ+ߙ1G>Ab c.1766ߙ+ߙ1G>A 170 0.37 R347Hc p.R347H 160 0.35 3659delCb c.3528delC 155 0.34 3876delAc c.3744delA 153 0.34 R560Tb p.R560T 132 0.29 S549Nc p.S549N 125 0.28 3905insTc c.3773dupT 121 0.27 R347Pb p.R347P 117 0.26 2184delAb c.2052delA 107 0.24 A455Eb p.A455E 106 0.23 711ߙ+ߙ1G>Tb c.579ߙ+ߙ1G>T 65 0.14 394delTTc c.262_263delTT 56 0.12 V520Fc p.V520F 54 0.12 1078delTc c.948delT 52 0.11 2183AA>Ga,c c.2051_2052delAAinsG 37 0.08 S549Rc p.S549R 31 0.07 Total 45,338 100 a 2183AA>G variant was added to the panel in 2010. b Variants from ACMG/ACOG CF screening panel. c Classified as a CF-causing mutation by the CFTR2 Database. ACMG, American College of Medical Genetics and Genomics; ACOG, American College of Obstetricians and Gynecologists; CF, cystic fibrosis; HGVS, Human Genome Variation Society. Table 2ߒ Continued on next page Table 2ߒ CFTR allele frequency identified by the CF69 mutation panel Varianta Allele frequency Mutation (%) Legacy nomenclature HGVS nomenclature F508delb p.F508del 1,868 60.49 R117Hb p.R117H 274 8.87 D1152Hc p.D1152H 125 4.05 G542Xb p.G542X 98 3.17 L206Wd p.L206W 73 2.36 3120ߙ+ߙ1G>Ab c.2988ߙ+ߙ1G>A 65 2.10 G551Db p.G551D 47 1.52 N1303Kb p.N1303K 42 1.36 W1282Xb p.W1282X 38 1.23 3849ߙ+ߙ10kbC>Tb c.3717ߙ+ߙ12191C>T 28 0.91 3876delAd c.3744delA 28 0.91 F311dele p.F312del 24 0.78 I507delb p.I507del 24 0.78 R553Xb p.R553X 24 0.78 R117Cd p.R117C 22 0.71 621ߙ+ߙ1G>Tb c.489ߙ+ߙ1G>T 21 0.68 1717-1G>Ab c.1585-1G>A 18 0.58 S549Nd p.S549N 18 0.58 R334Wb p.R334W 17 0.55 2789ߙ+ߙ5G>Ab c.2657ߙ+ߙ5G>A 16 0.52 G85Eb p.G85E 14 0.45 3199del6e c.3067_3072delATAGTG 12 0.39 R1066Cd p.R1066C 11 0.36 1898ߙ+ߙ1G>Ab c.1766ߙ+ߙ1G>A 10 0.32 R347Hd p.R347H 10 0.32 R1162 Xb p.R1162X 9 0.29 W1089Xd p.W1089X 9 0.29 2184delAb c.2052delA 8 0.26 2307insAd c.2175dupA 8 0.26 1078delTd c.948delT 7 0.23 R75Xd p.R75X 7 0.23 3120G>Ad c.2988 G>A 6 0.19 3659delCb c.3528delC 6 0.19 Q493Xd p.Q493X 6 0.19 R1158Xd p.R1158X 6 0.19 R560Tb p.R560T 6 0.19 1812-1G>Ad c.1680-1G>A 5 0.16 2055del9>Ad c.1923_1931del9insA 5 0.16 406-1G>Ad c.274-1G>A 5 0.16 A559Td p.A559T 5 0.16 R347Pb p.R347P 5 0.16 S1255Xd p.S1255X 5 0.16 1677delTAd c.1545_1546delTA 4 0.13 711ߙ+ߙ1G>Tb c.579ߙ+ߙ1G>T 4 0.13 E60Xd p.E60X 4 0.13 R352Qd p.R352Q 4 0.13 Y1092Xd p.Y1092X 4 0.13 2183AA>Gd c.2051_2052delAAinsG 3 0.10 3791delCd c.3659delC 3 0.10 3905insTd c.3773dupT 3 0.10 by 10 variants: the 2143delT, A455E, S549R, Y122X, and M1101K mutations, typically observed in Caucasians; 935delA, 2869insG, and Q890X in Hispanics; and 405+3A>C and G480C in the African-American population. Login to comment

[hide] The relative frequency of CFTR mutation classes in... J Cyst Fibros. 2014 Jul;13(4):403-9. doi: 10.1016/j.jcf.2013.12.003. Epub 2014 Jan 16. De Boeck K, Zolin A, Cuppens H, Olesen HV, Viviani L
The relative frequency of CFTR mutation classes in European patients with cystic fibrosis.
J Cyst Fibros. 2014 Jul;13(4):403-9. doi: 10.1016/j.jcf.2013.12.003. Epub 2014 Jan 16., [PMID:24440181]

Abstract [show]
More than 1900 different mutations in the CFTR gene have been reported. These are grouped into classes according to their effect on the synthesis and/or function of the CFTR protein. CFTR repair therapies that are mutation or mutation class specific are under development. To progress efficiently in the clinical phase of drug development, knowledge of the relative frequency of CFTR mutation classes in different populations is useful. Therefore, we describe the mutation class spectrum in 25,394 subjects with CF from 23 European countries. In 18/23 countries, 80% or more of the patients had at least one class II mutation, explained by F508del being by far the most frequent mutation. Overall 16.4% of European patients had at least one class I mutation but this varied from 3 countries with more than 30% to 4 countries with less than 10% of subjects. Overall only respectively 3.9, 3.3 and 3.0% of European subjects had at least one mutation of classes III, IV and V with again great variability: 14% of Irish patients had at least one class III mutation, 7% of Portuguese patients had at least one class IV mutation, and in 6 countries more than 5% of patients had at least one class V mutation.

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56 Class Type of defect List of mutations attributed to this class Class I Defective protein production Nonsense mutations Large deletions and insertions 1078delT; 1717-1G࢐A; 3659delC; 621+1G࢐T Class II Defective protein processing G85E, F508del, I507del, R560T, N1303K Class III Defective protein regulation ('gating`) G178R, S549N, S549R, G551D, G551S, G970R, G1244E, S1251N, S1255P, G1349D Class IV Defective protein conductance R117H, R334W, R347P Class V Reduced amount of functioning protein 2789+5G࢐A, 3849+10KbC࢐T, A455E Unclassified All other mutations, including those unknown. Login to comment

[hide] Impact of heterozygote CFTR mutations in COPD pati... Respir Res. 2014 Feb 11;15:18. doi: 10.1186/1465-9921-15-18. Raju SV, Tate JH, Peacock SK, Fang P, Oster RA, Dransfield MT, Rowe SM
Impact of heterozygote CFTR mutations in COPD patients with chronic bronchitis.
Respir Res. 2014 Feb 11;15:18. doi: 10.1186/1465-9921-15-18., [PMID:24517344]

Abstract [show]
BACKGROUND: Cigarette smoking causes Chronic Obstructive Pulmonary Disease (COPD), the 3rd leading cause of death in the U.S. CFTR ion transport dysfunction has been implicated in COPD pathogenesis, and is associated with chronic bronchitis. However, susceptibility to smoke induced lung injury is variable and the underlying genetic contributors remain unclear. We hypothesized that presence of CFTR mutation heterozygosity may alter susceptibility to cigarette smoke induced CFTR dysfunction. Consequently, COPD patients with chronic bronchitis may have a higher rate of CFTR mutations compared to the general population. METHODS: Primary human bronchial epithelial cells derived from F508del CFTR heterozygotes and mice with (CFTR+/-) and without (CFTR+/+) CFTR heterozygosity were exposed to whole cigarette smoke (WCS); CFTR-dependent ion transport was assessed by Ussing chamber electrophysiology and nasal potential difference measurements, respectively. Caucasians with COPD and chronic bronchitis, age 40 to 80 with FEV1/FVC < 0.70 and FEV1 < 60% predicted, were selected for genetic analysis from participants in the NIH COPD Clinical Research Network's Azithromycin for Prevention of Exacerbations of COPD in comparison to 32,900 Caucasian women who underwent prenatal genetic testing. Genetic analysis involved an allele-specific genotyping of 89 CFTR mutations. RESULTS: Exposure to WCS caused a pronounced reduction in CFTR activity in both CFTR (+/+) cells and F508del CFTR (+/-) cells; however, neither the degree of decrement (44.7% wild-type vs. 53.5% F508del heterozygous, P = NS) nor the residual CFTR activity were altered by CFTR heterozygosity. Similarly, WCS caused a marked reduction in CFTR activity measured by NPD in both wild type and CFTR heterozygous mice, but the severity of decrement (91.1% wild type vs. 47.7% CF heterozygous, P = NS) and the residual activity were not significantly affected by CFTR genetic status. Five of 127 (3.9%) COPD patients with chronic bronchitis were heterozygous for CFTR mutations which was not significantly different from controls (4.5%) (P = NS). CONCLUSIONS: The magnitude of WCS induced reductions in CFTR activity was not affected by the presence of CFTR mutation heterozygosity. CFTR mutations do not increase the risk of COPD with chronic bronchitis. CFTR dysfunction due to smoking is primarily an acquired phenomenon and is not affected by the presence of congenital CFTR mutations.

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81 As expected based on genotype-phenotype correlations in the disease [33], HBE cells derived from a F508del CFTR heterozygote had slightly lower CFTR activity at baseline than wild type monolayers as measured by Table 1 List of CFTR mutations analyzed F508del R117H 1717-1G > A R117C G85E R334W 1898 + 1G > A Y122X A455E R347P 2184delA G178R I507del R553X 2789 + 5G > A G314E G542X R560T 3120 + 1G > A G330X G551D W1282X 3659delC R347H N1303K 621 + 1G > T K710X 406-1G > A R1162X 711 + 1G > T E60X G480C R1066C W1089X V520F A559T S1196X Q1238X S1251N S1255X 663delT 935delA 1161delC 1288insTA 2184insA 2307insA 2711delT 2869insG R709X R764X R1158X 574delA Q493X 1898 + 5G > T 3905insT I506T 3849 + 10kbC > T 712-1G > T Q98R Q552X S549N 1078delT H199Y 444delA S549R (T > G) 2143delT P205S 2043delG 1811 + 1.6kbA > G 3272-26A > G L206W 3791delC Y1092X (C > G) 3199del6 F508C 2108delA Y1092X (C > A) D1152H V520I 3667del4 394delTT 3876delA M1101K 1677delTA W1098X (TGA) 1812-1G > A 4016insT 1609delCA 3171delC response to forskolin stimulation (49.3 &#b1; 11.5 bc;A/cm2 in CFTR (+/+) vs. 40.5 &#b1; 5.3 bc;A/cm2 in CFTR (+/-), although this was not statistically significant (Figure 1A,B). Login to comment

[hide] CFTR mutations spectrum and the efficiency of mole... PLoS One. 2014 Feb 26;9(2):e89094. doi: 10.1371/journal.pone.0089094. eCollection 2014. Zietkiewicz E, Rutkiewicz E, Pogorzelski A, Klimek B, Voelkel K, Witt M
CFTR mutations spectrum and the efficiency of molecular diagnostics in Polish cystic fibrosis patients.
PLoS One. 2014 Feb 26;9(2):e89094. doi: 10.1371/journal.pone.0089094. eCollection 2014., [PMID:24586523]

Abstract [show]
Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane regulator gene (CFTR). In light of the strong allelic heterogeneity and regional specificity of the mutation spectrum, the strategy of molecular diagnostics and counseling in CF requires genetic tests to reflect the frequency profile characteristic for a given population. The goal of the study was to provide an updated comprehensive estimation of the distribution of CFTR mutations in Polish CF patients and to assess the effectiveness of INNOLiPA_CFTR tests in Polish population. The analyzed cohort consisted of 738 patients with the clinically confirmed CF diagnosis, prescreened for molecular defects using INNOLiPA_CFTR panels from Innogenetics. A combined efficiency of INNOLiPA CFTR_19 and CFTR_17_TnUpdate tests was 75.5%; both mutations were detected in 68.2%, and one mutation in 14.8% of the affected individuals. The group composed of all the patients with only one or with no mutation detected (109 and 126 individuals, respectively) was analyzed further using a mutation screening approach, i.e. SSCP/HD (single strand conformational polymorphism/heteroduplex) analysis of PCR products followed by sequencing of the coding sequence. As a result, 53 more mutations were found in 97 patients. The overall efficiency of the CF allele detection was 82.5% (7.0% increase compared to INNOLiPA tests alone). The distribution of the most frequent mutations in Poland was assessed. Most of the mutations repetitively found in Polish patients had been previously described in other European populations. The most frequent mutated allele, F508del, represented 54.5% of Polish CF chromosomes. Another eight mutations had frequencies over 1%, 24 had frequencies between 1 and 0.1%; c.2052-2053insA and c.3468+2_3468+3insT were the most frequent non-INNOLiPA mutations. Mutation distribution described herein is also relevant to the Polish diaspora. Our study also demonstrates that the reported efficiency of mutation detection strongly depends on the diagnostic experience of referring health centers.

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71 Exon / intron (legacy) Exon / intron (Ensembl) Protein change SVM value cDNA (HGVS nomenclature) gDNA (cDNA +132 bp) Number of PL CF chromosomes Reference a Mutations in trans Pathogenic mutations 1 1 L15Ffs10X c.43delC 175delC 1 CFMDB 1717-1G.A 2 2 G27V 21.92 c.80G.T 212G.T 1 Novel F508del 2 2 S18RfsX16 c.54-5940_273 +10250del21kb exon2,3del21kb 66 IL19 various CF mutations i2 i2 IVS2_Donor c.164+1G.A 296+1G.A 3 CFMDB various CF mutations 3 3 G85E 22.61 c.254G.A 386G.A 1 IL17 unknown 3 3 E60X c.178G.T 310G.T 0 IL17 x 3 3 L88IfsX22 c.262_263delTT 394delTT 0 IL17 x 4 4 E92K 21.92 c.274G.A 406G.A 2 CFMDB c.164+1G.A; c.2051- 2AA.G 4 4 L101X c.302T.G 434T.G 1 CFMDB c.3717+12191C.T 4 4 K114IfsX5 c.341_353del13bp 473del13bp 1 Novel F508del 4 4 R117H 20.35 c.350G.A 482G.A 5 IL17 F508del; 2x unknown 4 4 R117C 22.07 c.349C.T 481C.T 2 CFMDB S1206X;1x unknown 4 4 L137_L138insT c.412_413insACT L138ins 1 CFMDB F508del 4 4 R153I 22.61 c.458G.T 590G.T 2 Novel F508del; c.3527delC i4 i4 IVS4_Donor c.489+1G.T 621+1G.T 5 IL17 F508del; c.489+1G.T 5 5 L165X c.494T.A 626T.A 1 Novel F508del i5 i5 IVS5_Donor c.579+1G.T 711+1G.T 0 IL19 x i5 i5 IVS5_Donor c.579+3A.G 711+3A.G 2 CFMDB 2,3del21kb; c.2052-3insA i5 i5 IVS5_Donor c.579+5G.A 711+5G.A 0 IL17 x 7 8 F311L 20.90 c.933C.G 965C.G 2 CFMDB 2x F508 7 8 G314R 20.58 c.940G.A 1072G.A 4 CFMDB various CF mutations 7 8 F316LfsX12 c.948delT 1078delT 1 IL17 unkown 7 8 R334W 22.41 c.1000C.T 1132C.T 6 IL17 various CF mutations 7 8 I336K 22.07 c.1007T.A 1139T.A 2 CFMDB 2,3de21kb; F508del 7 8 R347P 22.27 c.1040G.C 1172G.C 11 IL17 various CF mutations i7 i8 IVS8_Donor c.1116+2T.A 1248+2T.A 1 Novel Q1412X 9 10 A455E 22.61 c.1364C.A 1496C.A 0 IL17 x i9 i10 IVS10_Donor c.1392+1G.A 1524+1G.A 1 CFMDB c.3816-7delGT 10 11 S466X c.1397C.G 1529C.G 1 CFMDB G542X 10 11 I507del c.1519_1521delATC 1651delATC 2 IL19 F508del 10 11 F508del c.1521_1523delCTT 1654delCTT 805 IL19 various CF mutations i10 i11 IVS11_Acceptor c.1585-1G.A 1717-1G.A 27 IL19 various CF mutations 11 12 G542X c.1624G.T 1756G.T 25 IL19 various CF mutations 11 12 G551D 21.24 c.1624G.T 1756G.T 5 IL19 various CF mutations 11 12 Q552X c.1654C.T 1786C.T 0 IL19 x 11 12 R553X c.1657C.T 1789C.T 14 IL19 various CF mutations 11 12 R560T 21.92 c.1679G.C 1811G.C 0 IL19 x i12 i13 IVS13_Donor c.1766+1G.A 1898+1G.A 6 IL19 various CF mutations i12 i13 IVS13_Donor c.1766+1G.C 1898+1G.C 1 CFMDB F508del 13 14 H620P 21.73 c.1859A.C 1991A.C 1 CFMDB F508del 13 14 R668C//G576A 21.61//1.73 c.2002C.T//c.1727G.C 2134C.T// 1859G.C 5 b CFMDB// rs1800098 c.1585-1G.A; 4 unknown 13 14 L671X c.2012delT 2143delT 27 IL17 various CF mutations 13 14 K684SfsX38 c.2051_2052delAAinsG 2183AA.G 10 IL17 various CF mutations 13 14 K684NfsX38 c.2052delA 2184delA 0 IL17 x 13 14 Q685TfsX4 c.2052_2053insA 2184insA 15 CFMDB various CF mutationsc , 1 unknown Table 2. Cont. Exon / intron (legacy) Exon / intron (Ensembl) Protein change SVM value cDNA (HGVS nomenclature) gDNA (cDNA +132 bp) Number of PL CF chromosomes Reference a Mutations in trans 13 14 L732X c.2195T.G 2327T.G 1 CFMDB F508del 14A 15 R851X c.2551C.T 2683C.T 3 CFMDB various CF mutations 14A 15 I864SfsX28 c.2589_2599del11bp 2721del11bp 2 CFMDB F508del; 2,3del21kb i14B i16 IVS16_Donor c.2657+2_2657+3insA 2789+2insA 1 CFMDB F508del i14B i16 IVS16_Donor c.2657+5G.A 2789+5G.A 0 IL17 unkown 15 17 Y919C 21.02 c.2756A.G 2888A.G 1 CFMDB unknown 15 17 H939HfsX27 c.2817_2820delTACTC 2949delTACTC 1 Novel unkown i15 i17 IVS17_Donor c.2908+3A.C 3040+3A.C 1 Novel F508del i16 i18 IVS18_Donor c.2988+1G.A 3120+1G.A 0 IL19 x 17A 19 I1023_V1024del c.3067_3072delATAGTG 3199del6 0 IL19 x i17A i19 IVS19 c.3140-26A.G 3272-26A.G 9 IL19 various CF mutations 17B 20 L1065R 21.90 c.3194T.G 3326T.G 1 CFMDB F508del 17B 20 Y1092X c.3276C.A 3408C.A 1 CFMDB R334W i18 i21 IVS21_Donor c.3468+2_3468+3insT 3600+2insT 11 CFMDB various CF mutationsd , 1 unknown 18 21 E1126EfsX7 c.3376_3379delGAAG 3508delGAAG 1 Novel F508del 19 22 R1158X c.3472C.T 3604C.T 2 CFMDB F508del; R553X 19 22 R1162X c.3484C.T 3616C.T 1 IL17 F508del 19 22 L1177SfsX15 c.3528delC 3659delC 4 IL17 various CF mutations 19 22 S1206X c.3617C.A 3749C.A 1 CFMDB R117C i19 i22 IVS22 c.3717+12191C.T 3849+10kbC.T 58 IL17 various CF mutations 20 23 G1244R 22.62 c.3730G.C 3862G.C 1 CFMDB F508del 20 23 S1251N 22.28 c.3752G.A 3884G.A 0 IL19 x 20 23 L1258FfsX7 c.3773_3774insT 3905insT 0 IL19 x 20 23 V1272VfsX28 c.3816_3817delGT 3944delGT 1 CFMDB c.1392+1G.A 20 23 W1282X c.3846G.A 3978G.A 9 IL19 various CF mutations 21 24 N1303K 22.62 c.3909C.G 4041C.G 18 IL19 various CF mutations 22 25 V1327X c.3979delG 4111delG 1 Novel F508del 22 25 S1347PfsX13 c.4035_4038dupCCTA c.4167dupCCTA 1 CFMDB 2,3del21kb 23 26 Q1382X c.4144C.T 4276C.T 1 CFMDB F508del 23 26 Q1412X c.4234C.T 4366C.T 2 CFMDB F508del; c.1116+2T.A i23 i26 IVS26_Donor c.4242+1G.T 4374+1G.T 1 CFMDB F508del Sequence changes of uncertain pathogenic effect, tentatively counted as mutations 6A 6 E217G 0.30 c.650A.G 782A.G 1 CFMDB; rs1219109046 unknown 7 8 R352Q 20.01 c.1055G.A 1187G.A 1 CFMDB; rs121908753 F508del 7 8 Q359R 0.33 c.1076A.G 1208A.G 1 CFMDB F508del i8 i9 IVS9 c.1210-12T5_1210- 34_35 (TG)12 1332-12Tn_- 34TGm 6 CFMDB F508del; 3x unknown i8 i9 IVS9 c.1210-12T5_1210- 34_35 (TG)13 1332-12Tn_- 34TGm 2 CFMDB 2143delT; 1x unknown i8 i9 IVS9 c.1210-12T8 1332-12Tn 1 Novel unknown 10 11 I506V 20.21 c.1516A.G 1648A.G 1 CFMDB; rs1800091 unknown 12 13 V562L 0.79 c.1684G.C 1816G.C 1 CFMDB; rs1800097 unknown 13 14 G723V 0.44 c.2168G.T 2300G.T 1 CFMDB; rs200531709 unknown 15 17 D924N 0.03 c.2770G.A 2902G.A 1 CFMDB; rs201759207 unknown patient with F508del on another allele) was not supported by the SVM value (+0.35); the patient was PS and had ambiguous chloride values (45, 64 and 83 mmol/L). 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103 IL17 (INNOLiPA_CFTR17_TnUpdate): 621+1G.T; 3849+10kbC.T; 2183AA.G; 394delTT; 2789+5G.A; R1162X; 3659delC; R117H; R334W; R347P; G85E; 1078delT; A455E; 2143delT; E60X; 2184delA; 711+5G.A; polymorphism 5T/7T/9T. Login to comment
137 Mutations a Poland Czechs Slovakia c Germany Lithuania W. Ukraine E. Hungary Romania c Bulgaria Serbia Greece Number of chromosomes 1476 1200 856 700 98 264 80 256 208 352 874 F508del 54.54 b 67.42 d 66.80 d 72.00 d 52.0 54.17 70.00 56.3 65.38 d 72.28 d 53.40 exon2,3del21kb (l.n.CFTRdele2,3_21kb) 4.47 5.75 2.26 1.2 f 2.0 4.17 5.00 1.6 NA 0 e 0.34 e c.3717+12191C.T (l.n.3849+10kbC.T) 3.93 1.67 e 4.28 1.00 e NA 0.76 0 0.4 e 1.44 0 e 0.11 e c.2012delT (l.n.2143delT) 1.83 0.92 1.10 0.71 0 1.14 0 0 e 0 0 e 0 e c.1585-1G.A (l.n.1717-1G.A) 1.83 0.33 e NA 0.86 0 0.38 1.25 0.4 0 0 e 0 e G542X 1.69 2.00 4.06 d 1.43 0 2.65 3.75 3.9 3.37 2.57 3.90 d R347P 1.57 0.92 1.10 1.57 0 0 1.25 NA 1.44 0 e 0.11 e N1303K 1.22 2.42 2.03 2.29 2.0 4.92 d 5.00 0.8 6.73 d 0 2.63 c.2052-2053insA (l.n.2184insA) 1.02 0.42 1.58 0.57 0 7.20 d 5.00 d 0 0.48 0.28 0 e R553X 0.95 0.50 0.90 2.29 4.2 d 0.38 0 NA 0 0 0 c.3468+223insT (l.n.3600+2insT) 0.75 0.25 NA 0 e 0 NA 0 NA 0 0 0 e c.2051-2052AA.G (l.n.2183AA.G) 0.68 0.08 NA 0.57 0 0.38 0 0.8 0 0 1.38 W1282X 0.61 0.58 0.50 0.71 1.0 2.27 0 2.3 d 0.96 0 0.67 c.3140-26A.G (l.n.3272-26A.G) 0.61 0.67 0.50 0.86 0 0.76 0 0.4 0 0 0.81 l.n.IVS8 T 5 _TG 12-13 0.54 NA NA NA 0 NA NA NA NA 0 NA R334W 0.41 0.25 NA 0.29 0 0.76 0 0.4 0 0.28 0.81 c.1766+1G.A (l.n.1898+1G.A) 0.41 1.42 d 0.50 0 0 1.14 0 NA 0 0 0.11 c.489+1G.T (l.n.621+1G.T) 0.34 0.42 NA 0.14 0 0.76 0 0.8 0 2.86 d 5.72 d R117H 0.34 NA NA 0.29 0 0 0 0.4 0 0 0.23 G551D 0.34 2.91 d 0.50 1.00 0 0 0 0 0 0 0.34 G314R 0.37 0 NA 0 0 0 0 NA 0 0 0 R668C 0.34 0 NA 0 0 0 0 NA 0 0 0 c.3528delC (l.n.3659delC) 0.27 0.17 NA 0.57 0 0 0 NA 0 0 0 c.164+1G.A (l.n.296+1G.A) 0.20 0.08 NA 0 0 0 0 NA 0 0 0 R851X 0.20 0.08 NA 0 0 0 0 NA 0 0 0 I336K 0.14 0.58 NA 0.45 0 0 0 NA 0 0 0 R1158X 0.14 0.08 NA 0 0 0 0 NA 0 0 1.03 E92K 0.14 0.08 NA 0 0 0.38 0 NA 0 0 0 R153I 0.14 0 NA 0 0 0 0 NA 0 0 0 c.579+3A.G (l.n.711+3A.G) 0.14 0.17 NA 0 0 0 0 NA 0 0 0.69 c.2589-2599del11bp (l.n.2721- 31del11bp) 0.14 0.08 NA 0 0 0.38 0 NA 0 0 0 I507del 0.14 0.08 NA 0.15 0 0 0 0 0 0.28 0.69 R117C 0.14 0.08 NA 0.15 0 0 0 NA 0 0 0.23 of mutation panels [20]), listed in Table 4, were compared to those reported for several Central and Southeastern European countries [21-29]. Login to comment

[hide] Genetics of cystic fibrosis: CFTR mutation classif... Int J Biochem Cell Biol. 2014 Jul;52:94-102. doi: 10.1016/j.biocel.2014.02.023. Epub 2014 Mar 12. Fanen P, Wohlhuter-Haddad A, Hinzpeter A
Genetics of cystic fibrosis: CFTR mutation classifications toward genotype-based CF therapies.
Int J Biochem Cell Biol. 2014 Jul;52:94-102. doi: 10.1016/j.biocel.2014.02.023. Epub 2014 Mar 12., [PMID:24631642]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes an epithelial anion channel. Since the identification of the disease in 1938 and up until 2012, CF patients have been treated exclusively with medications aimed at bettering their respiratory, digestive, inflammatory and infectious symptoms. The identification of the CFTR gene in 1989 gave hopes of rapidly finding a cure for the disease, for which over 1950 mutations have been identified. Since 2012, recent approaches have enabled the identification of small molecules targeting either the CFTR protein directly or its key processing steps, giving rise to novel promising therapeutic tools. This review presents the current CFTR mutation classifications according to their clinical consequences and to their effect on the structure and function of the CFTR channel. How these classifications are essential in the establishment of mutation-targeted therapeutic strategies is then discussed. The future of CFTR-targeted treatment lies in combinatory therapies that will enable CF patients to receive a customized treatment.

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74 23 ACMG recommended panel of classic CF-causing mutations G85E R117H R334W R347P A455E I507del F508del G542X G551D R553X R560T R1162X W1282X N1303K 621 + 1G > T 711 + 1G > T 1717 - 1G > A 1898 + 1G > A 2184delA 2789 + 5G > A 3120 + 1G > A 3659delC 3849 + 10kbC > T Additional or alternative mutations present at significant frequencies in an ethnic population served by a newborn screening program may be assessed. Login to comment

[hide] Understanding how cystic fibrosis mutations disrup... Int J Biochem Cell Biol. 2014 Jul;52:47-57. doi: 10.1016/j.biocel.2014.04.001. Epub 2014 Apr 13. Wang Y, Wrennall JA, Cai Z, Li H, Sheppard DN
Understanding how cystic fibrosis mutations disrupt CFTR function: from single molecules to animal models.
Int J Biochem Cell Biol. 2014 Jul;52:47-57. doi: 10.1016/j.biocel.2014.04.001. Epub 2014 Apr 13., [PMID:24727426]

Abstract [show]
Defective epithelial ion transport is the hallmark of the life-limiting genetic disease cystic fibrosis (CF). This abnormality is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), the ATP-binding cassette transporter that functions as a ligand-gated anion channel. Since the identification of the CFTR gene, almost 2000 disease-causing mutations associated with a spectrum of clinical phenotypes have been reported, but the majority remain poorly characterised. Studies of a small number of mutations including the most common, F508del-CFTR, have identified six general mechanisms of CFTR dysfunction. Here, we review selectively progress to understand how CF mutations disrupt CFTR processing, stability and function. We explore CFTR structure and function to explain the molecular mechanisms of CFTR dysfunction and highlight new knowledge of disease pathophysiology emerging from large animal models of CF. Understanding CFTR dysfunction is crucial to the development of transformational therapies for CF patients.

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1988 3.4. Class IV mutations: defective channel conduction Analysis of three CF-PS mutations located in MSD1 (R117H [M2], R334W [M6] and R347P [M6]) provided the first evidence that some CF mutations perturb anion flow through the CFTR pore (Fig. 3). Login to comment
1998 ~15%, but for R347P, it was ~70% and for R334W, discrete channel openings were not resolved (Sheppard et al., 1993). Login to comment

[hide] New pharmacological approaches for cystic fibrosis... Pharmacol Ther. 2015 Jan;145:19-34. doi: 10.1016/j.pharmthera.2014.06.005. Epub 2014 Jun 14. Bell SC, De Boeck K, Amaral MD
New pharmacological approaches for cystic fibrosis: promises, progress, pitfalls.
Pharmacol Ther. 2015 Jan;145:19-34. doi: 10.1016/j.pharmthera.2014.06.005. Epub 2014 Jun 14., [PMID:24932877]

Abstract [show]
With the discovery of the CFTR gene in 1989, the search for therapies to improve the basic defects of cystic fibrosis (CF) commenced. Pharmacological manipulation provides the opportunity to enhance CF transmembrane conductance regulator (CFTR) protein synthesis and/or function. CFTR modulators include potentiators to improve channel gating (class III mutations), correctors to improve abnormal CFTR protein folding and trafficking (class II mutations) and stop codon mutation read-through drugs relevant for patients with premature stop codons (most class I mutations). After several successful clinical trials the potentiator, ivacaftor, is now licenced for use in adults and children (>six years), with CF bearing the class III G551D mutation and FDA licence was recently expanded to include 8 additional class III mutations. Alternative approaches for class I and class II mutations are currently being studied. Combination drug treatment with correctors and potentiators appears to be required to restore CFTR function of F508del, the most common CFTR mutation. Alternative therapies such as gene therapy and pharmacological modulation of other ion channels may be advantageous because they are mutation-class independent, however progress is less well advanced. Clinical trials for CFTR modulators have been enthusiastically embraced by patients with CF and health care providers. Whilst novel trial end-points are being evaluated allowing CFTR modulators to be efficiently tested, many challenges related to the complexity of CFTR and the biology of the epithelium still need to be overcome.

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547 Class Type of defect List of mutations attributed to this class Class I Defective protein production Nonsense mutations: G542X, R1162X, RW1282X Deletions and insertions: CFTRdele2,3; 1078delT; 1717-1G ࢐ A; 3659delC; 621+1G N T Class II Defective protein processing G85E, F508del, I507del, R560T, A561E, R1066C, N1303K Class III Defective protein regulation (gating) G178R, S549N, S549R, G551D, G551S, G970R, G1244E, S1251N, S1255P, G1349D Class IV Defective protein conductance R334W, R347P, R117H Class V Reduced amount of functioning protein 2789+5G ࢐ A, 3272-26ANG, 3849+10KbC ࢐ T, A455E Class VI Reduced cell surface stability Rescued F508del, c.120del23 Unclassified All other mutations, including those unknown a F508del-CFTR pocket (at NBD1:ICL4 interface) (Farinha et al., 2013). Login to comment

[hide] Mechanisms of CFTR functional variants that impair... PLoS Genet. 2014 Jul 17;10(7):e1004376. doi: 10.1371/journal.pgen.1004376. eCollection 2014 Jul. LaRusch J, Jung J, General IJ, Lewis MD, Park HW, Brand RE, Gelrud A, Anderson MA, Banks PA, Conwell D, Lawrence C, Romagnuolo J, Baillie J, Alkaade S, Cote G, Gardner TB, Amann ST, Slivka A, Sandhu B, Aloe A, Kienholz ML, Yadav D, Barmada MM, Bahar I, Lee MG, Whitcomb DC
Mechanisms of CFTR functional variants that impair regulated bicarbonate permeation and increase risk for pancreatitis but not for cystic fibrosis.
PLoS Genet. 2014 Jul 17;10(7):e1004376. doi: 10.1371/journal.pgen.1004376. eCollection 2014 Jul., [PMID:25033378]

Abstract [show]
CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system.

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269 67 SNPs (125GtoC, 1716G.A, 1717-1G.A, 1898+1G.A, 2183AA.G, 2184delA, 2789+5G.A, 3120+1G.A, 3659delC, 3849+10kbC.T, 621+ 1G.T, 711+5G.A, A455E, D110H, D1152H, D1270N, D443Y, D579G, F1052V, F1074L, F508C, F508del, G1069R, G1244E, G1349D, G178R, G542X, G551D, G551S, I1131L/V, I148T, I336K/T, I507del, I807M, IVS8T5, K1180T, L1065P, L967S, L997F, M1V, M470V, M952I, M952T, N1303K, P67L, Q1463Q, R1070Q, R1162X, R117C, R117H, R170H, R258G, R297Q, R31C, R352Q, R553X, R668C, R74W, R75Q, S1235R, S1255P, S485R, S977F, T338I, T854T, V201M, W1282X) were multiplexed into 6 wells; 14 SNPs (S492F, S945L, R74Q, R560T, R1162L, G85E, I1027T, R334W, R347P, G576A, 711+1G.T, 1001+11C.T, P1290P, 3199del6) were ascertained separately via TaqMan Gene Expression Assays, with repeat confirmation of all positive results. Login to comment

[hide] Molecular genetic testing for cystic fibrosis: lab... Genet Med. 2015 Mar;17(3):219-25. doi: 10.1038/gim.2014.93. Epub 2014 Jul 31. Lyon E, Schrijver I, Weck KE, Ferreira-Gonzalez A, Richards CS, Palomaki GE
Molecular genetic testing for cystic fibrosis: laboratory performance on the College of American Pathologists external proficiency surveys.
Genet Med. 2015 Mar;17(3):219-25. doi: 10.1038/gim.2014.93. Epub 2014 Jul 31., [PMID:25077647]

Abstract [show]
BACKGROUND: Molecular testing for cystic fibrosis mutations is widespread and routine in reproductive decision making and diagnosis. Our objective was to assess the level of performance of laboratories for this test. METHODS: The College of American Pathologists administers external proficiency testing with multiple DNA samples distributed biannually. RESULTS are analyzed, reviewed, and graded by the joint College of American Pathologists/American College of Medical Genetics and Genomics Biochemical and Molecular Genetics Committee. Assessment is based on genotype and associated clinical interpretation. RESULTS: Overall, 357 clinical laboratories participated in the proficiency testing survey between 2003 and 2013 (322 in the United States and 35 international). In 2013, US participants reported performing nearly 120,000 tests monthly. Analytical sensitivity and specificity of US laboratories were 98.8% (95% confidence interval: 98.4-99.1%) and 99.6% (95% confidence interval: 99.4-99.7%), respectively. Analytical sensitivity improved between 2003 and 2008 (from 97.9 to 99.3%; P = 0.007) and remained steady thereafter. Clinical interpretation matched the intended response for 98.8, 86.0, and 91.0% of challenges with no, one, or two mutations, respectively. International laboratories performed similarly. DISCUSSION: Laboratory testing for cystic fibrosis in the United States has improved since 2003, and these data demonstrate a high level of quality. Neither the number of samples tested nor test methodology affected performance.

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87 These included 621+1, F508del, A455A, 1717-1, R117H, I507del, 3659delC, G85E, G542X, G551D, R553X, R347P, W1282X, N1303K, and R560T. Login to comment
111 Given the previously discussed issues with the potential problems with missing data and the known problems with some methods for distinguishing the Table 1ߒ Results from external proficiency testing for CFTR mutations: common types of genotyping errors Sample switch ߓ Two genotypes and associated clinical interpretations are correct, but results are reversed from the original challenge ߓ ߓ Samples actually reversed before testing ߓ ߓ Testing correct but genotypes reversed during reporting False-positive genotypes ߓ Genotype reported as homozygous instead of heterozygous ߓ ߓ Data entry error ߓ ߓ Methodology cannot distinguish zygosity and reported incorrectly ߓ Wrong mutation (examples) ߓ ߓ R347H reported when R347P was challenged ߓ ߓ R553X homozygosity reported instead of compound heterozygosity ߓ ߓ I507del reported for a F508del challenge ߓ ߓ I507del/F508del for I507del False-negative genotype ߓ Reported a homozygous genotype as heterozygous Table 2ߒ Results from external proficiency testing for CFTR mutations: analytic sensitivity and specificity for US and international clinical laboratories Time period (survey) Total alleles True positive False negative Analytical sensitivity (95% CI) True negative False positive Analytical specificity (95% CI) 2003-2013 (All) 10,952 3,941 49 98.8 (98.4-99.1) 6,932 30 99.6 (99.4-99.7) 2008-2013 (All) 5,521 2,525 19 99.3 (98.8-99.5) 2,965 12 99.6 (99.3-99.8) 2008-2013 (MGL2) 2,444 737 8 98.9 (97.8-99.5) 1,696 3 99.8 (99.4-99.9) 2008-2013 (MGL5) 3,077 1,788 11 99.4 (98.9-99.7) 1,269 9 99.3 (98.6-99.7) 2008-2013 (international) 770 288 12 96.0 (92.9-97.8) 470 0 100 (99.9-100) CI, confidence interval. Login to comment

[hide] Comprehensive CFTR gene analysis of the French cys... Genet Med. 2015 Feb;17(2):108-16. doi: 10.1038/gim.2014.113. Epub 2014 Aug 14. Audrezet MP, Munck A, Scotet V, Claustres M, Roussey M, Delmas D, Ferec C, Desgeorges M
Comprehensive CFTR gene analysis of the French cystic fibrosis screened newborn cohort: implications for diagnosis, genetic counseling, and mutation-specific therapy.
Genet Med. 2015 Feb;17(2):108-16. doi: 10.1038/gim.2014.113. Epub 2014 Aug 14., [PMID:25122143]

Abstract [show]
PURPOSE: Newborn screening (NBS) for cystic fibrosis (CF) was implemented throughout France in 2002. It involves a four-tiered procedure: immunoreactive trypsin (IRT)/DNA/IRT/sweat test [corrected] was implemented throughout France in 2002. The aim of this study was to assess the performance of molecular CFTR gene analysis from the French NBS cohort, to evaluate CF incidence, mutation detection rate, and allelic heterogeneity. METHODS: During the 8-year period, 5,947,148 newborns were screened for cystic fibrosis. The data were collected by the Association Francaise pour le Depistage et la Prevention des Handicaps de l'Enfant. The mutations identified were classified into four groups based on their potential for causing disease, and a diagnostic algorithm was proposed. RESULTS: Combining the genetic and sweat test results, 1,160 neonates were diagnosed as having cystic fibrosis. The corresponding incidence, including both the meconium ileus (MI) and false-negative cases, was calculated at 1 in 4,726 live births. The CF30 kit, completed with a comprehensive CFTR gene analysis, provides an excellent detection rate of 99.77% for the mutated alleles, enabling the identification of a complete genotype in 99.55% of affected neonates. With more than 200 different mutations characterized, we confirmed the French allelic heterogeneity. CONCLUSION: The very good sensitivity, specificity, and positive predictive value obtained suggest that the four-tiered IRT/DNA/IRT/sweat test procedure may provide an effective strategy for newborn screening for cystic fibrosis.

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53 Because only a limited number of functional studies have assessed the pathogenicity of variants, mutations have been classified in previous studies according to their disease-causing potential.16,22,23 Based on the recommendations and data from these studies (UMD-CFTR-France),24 variants were classified into four groups: A, CF-causing; B, associated with CFTR-RDs; C, no clinical consequences; and D, unknown or Table 1ߒ Allelic frequencies of CF30-kit mutations, identified in neonates with CF, and correspondence between traditional mutation nomenclature and that on the Human Genome Variation Society website Frequency (F) % Mutation Legacy mutation nomenclature Number of alleles/2,320 % of alleles/2,320 Cumulative % ࣙ5 p.Phe508del F508del 1,560 67.24 67.24 p.Gly542* G542X 113 3.19 10.51 p.Asn1303Lys N1303K 81 1.98 c.1585-1G>A 1717-1G>A 48 1.47 1.00ࣙFࣙ4.99 c.2657ߙ+ߙ5G>A 2789ߙ+ߙ5G>A 37 1.42 p.Arg553* R553X 36 1.29 p.Gly551Asp G551D 31 1.16 p.Tyr122* Y122X 26 0.97 6.86 c.2988ߙ+ߙ1G>A 3120ߙ+ߙ1G>A 22 0.82 c.579ߙ+ߙ1G>T 711ߙ+ߙ1G>T 18 0.67 p.Ile507del I507del 17 0.63 c.3140-26A>G 3272-26A>G 16 0.59 0.40ࣙFࣙ0.99 p.Arg347Pro R347P 15 0.56 p.Arg1162* R1162X 15 0.56 p.Trp1282* W1282X 14 0.52 p.Tyr1092* Y1092X 13 0.48 c.2051_2052delinsG 2183AA>G 12 0.45 c.3528delC 3659delC 11 0.41 c.1680-886A>G 1811ߙ+ߙ1.6kbA>G 9 0.39 p.Gly85Glu G85E 8 0.34 3.06 p.Ser1251Asn S1251N 7 0.30 p.Arg334Trp R334W 7 0.30 p.Arg117His R117H 7 0.30 0.1ࣙFࣙ0.39 p.Trp846* W846X 6 0.26 c.489ߙ+ߙ1G>T 621ߙ+ߙ1G>T 6 0.26 c.948delT 1078delT 5 0.22 p.Ala455Glu A455E 5 0.22 p.Glu60* E60X 4 0.17 c.262_263delTT 394delTT 4 0.17 c.3718-2477C>T 3849ߙ+ߙ10kbC>T 3 0.13 Total 2,034 87.67 87.67 Mutations are clustered into four groups of frequency intervals (>5%, 1-4.99%, 0.99-0.4%, and <0.4%). Login to comment

[hide] Intestinal current measurement versus nasal potent... BMC Pulm Med. 2014 Oct 4;14:156. doi: 10.1186/1471-2466-14-156. Bagheri-Hanson A, Nedwed S, Rueckes-Nilges C, Naehrlich L
Intestinal current measurement versus nasal potential difference measurements for diagnosis of cystic fibrosis: a case-control study.
BMC Pulm Med. 2014 Oct 4;14:156. doi: 10.1186/1471-2466-14-156., [PMID:25280757]

Abstract [show]
BACKGROUND: Nasal potential difference (NPD) and intestinal current measurement (ICM) are functional CFTR tests that are used as adjunctive diagnostic tools for cystic fibrosis (CF). Smoking has a systemic negative impact on CFTR function. A diagnostic comparison between NPD and ICM and the impact of smoking on both CFTR tests has not been done. METHODS: The sweat chloride test, NPD, and ICM were performed in 18 patients with CF (sweat chloride >60 mmol/l), including 6 pancreatic sufficient (PS) patients, and 13 healthy controls, including 8 smokers. The NPD CFTR response to Cl-free and isoproterenol perfusion (Delta0Cl- + Iso) was compared to the ICM CFTR response to forskolin/IBMX, carbachol, and histamine (DeltaIsc, forskolin/IBMX+ carbachol+histamine). RESULTS: The mean NPD CFTR response and ICM CFTR response between patients with CF and healthy controls was significantly different (p <0.001), but not between patients with CF who were PS and those who were pancreatic insufficient (PI). Smokers have a decreased CFTR response measured by NPD (p = 0.049). For ICM there is a trend towards decreased CFTR response (NS). Three healthy control smokers had NPD responses within the CF-range. In contrast to NPD, there was no overlap of the ICM response between patients with CF and controls. CONCLUSIONS: ICM is superior to NPD in distinguishing between patients with CF who have a sweat chloride > 60 mmol/l and healthy controls, including smokers. Neither NPD nor ICM differentiated between patients with CF who were PS from those who were PI. Smoking has a negative impact on CFTR function in healthy controls measured by NPD and challenges the diagnostic interpretation of NPD, but not ICM.

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39 For sweat stimulation and collection, the Macroduct&#ae; system (Wescor, Table 1 Characteristics and CFTR response of pancreatic insufficient (CF-PI) and pancreatic sufficient (CF-PS) patients with CF and controls CF-PI (n = 12) CF-PS (n = 6) CF-all (n = 18) Controls (n = 13) Age, years 24.0 &#b1; 6.1 23.3 &#b1; 11.8 22.8 &#b1; 8.0 30.6 &#b1; 10.4 22.0 (19.0 - 26.0) 16.0 (14.5 - 30.5) 20.5 (18.3 - 25.3) 25.0 (23.5 - 35.5) Gender, females:males 3:9 5:1 8:10 7:6 Body mass index Z-score -1.18 &#b1; 0.80 -0.62 &#b1; 1,41 -0.99 &#b1; 1.03* 0.00 &#b1; 0.65* -1.05 (-2.40 - 0.00) 1.41 (-0.20 - 0.70) -0.90 (-2.60 - 0.70) 0.00 (-1.10 - 1.30) Sweat chloride (mmol/l) 110 &#b1; 13** 86 &#b1; 14** 102 &#b1; 17* 19 &#b1; 8* 106 (92 - 140) 90 (70 - 99) 104 (70 - 140) 19 (10 - 36) NPD CFTR response average Ɗ0Cl- + Iso (mV) 4.6 &#b1; 3.9 1.5 &#b1; 4.1 3.6 &#b1; 4.1* -13.6 &#b1; 8.5* 5.1 (-3.0 -11.9) 1.5 (-3.2 - 6.23) 4.5 (-3.2 - 11.9) -12.7 (-26.4 - -1.92) ICM CFTR response average ƊIsc (bc;A/cm2) ) (forskolin/IBMX + carbachol + histamine) -0.3 &#b1; 8.1 5.3 &#b1; 10.9 1.6 &#b1; 9.2* 77.8 &#b1; 34.8* -0.6 (-12.6 - 17.9) 5.0 (-9.7 - 19.0) 0.1 (-12.6 - 19.0) 65.3 (39.6 -140.9) Genotyping F508/F508 (6&#d7;) F508/R347P (2&#d7;) 148 T/R117H-7 T F508/G551D (2&#d7;) F508/3849 + 10 kb C- > T (2&#d7;) F508/- F508/G542X F508/R334W --/-- F508/N1303K F508/? Login to comment

[hide] Full-open and closed CFTR channels, with lateral t... Cell Mol Life Sci. 2015 Apr;72(7):1377-403. doi: 10.1007/s00018-014-1749-2. Epub 2014 Oct 7. Mornon JP, Hoffmann B, Jonic S, Lehn P, Callebaut I
Full-open and closed CFTR channels, with lateral tunnels from the cytoplasm and an alternative position of the F508 region, as revealed by molecular dynamics.
Cell Mol Life Sci. 2015 Apr;72(7):1377-403. doi: 10.1007/s00018-014-1749-2. Epub 2014 Oct 7., [PMID:25287046]

Abstract [show]
In absence of experimental 3D structures, several homology models, based on ABC exporter 3D structures, have provided significant insights into the molecular mechanisms underlying the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel whose defects are associated with cystic fibrosis (CF). Until now, these models, however, did not furnished much insights into the continuous way that ions could follow from the cytosol to the extracellular milieu in the open form of the channel. Here, we have built a refined model of CFTR, based on the outward-facing Sav1866 experimental 3D structure and integrating the evolutionary and structural information available today. Molecular dynamics simulations revealed significant conformational changes, resulting in a full-open channel, accessible from the cytosol through lateral tunnels displayed in the long intracellular loops (ICLs). At the same time, the region of nucleotide-binding domain 1 in contact with one of the ICLs and carrying amino acid F508, the deletion of which is the most common CF-causing mutation, was found to adopt an alternative but stable position. Then, in a second step, this first stable full-open conformation evolved toward another stable state, in which only a limited displacement of the upper part of the transmembrane helices leads to a closure of the channel, in a conformation very close to that adopted by the Atm1 ABC exporter, in an inward-facing conformation. These models, supported by experimental data, provide significant new insights into the CFTR structure-function relationships and into the possible impact of CF-causing mutations.

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346 First, almost all CF-causing mutations involving residues located in the MSD transmembrane segments are encountered in MSD1 and generally concern positions lining the pore (G85E, E92K, D110H, P205S, R334W, I336K, T338I, S341P, R347H/R347P, and R352Q) (Fig. 7a). Login to comment

[hide] Analysis of cystic fibrosis gene mutations in chil... J Med Case Rep. 2014 Oct 10;8:339. doi: 10.1186/1752-1947-8-339. Dell'Edera D, Benedetto M, Gadaleta G, Carone D, Salvatore D, Angione A, Gallo M, Milo M, Pisaturo ML, Di Pierro G, Mazzone E, Epifania AA
Analysis of cystic fibrosis gene mutations in children with cystic fibrosis and in 964 infertile couples within the region of Basilicata, Italy: a research study.
J Med Case Rep. 2014 Oct 10;8:339. doi: 10.1186/1752-1947-8-339., [PMID:25304080]

Abstract [show]
INTRODUCTION: Cystic fibrosis is the most common autosomal recessive genetic disease in the Caucasian population. Extending knowledge about the molecular pathology on the one hand allows better delineation of the mutations in the CFTR gene and the other to dramatically increase the predictive power of molecular testing. METHODS: This study reports the results of a molecular screening of cystic fibrosis using DNA samples of patients enrolled from January 2009 to December 2013. Patients were referred to our laboratory for cystic fibrosis screening for infertile couples. In addition, we identified the gene mutations present in 76 patients affected by cystic fibrosis in the pediatric population of Basilicata. RESULTS: In the 964 infertile couples examined, 132 subjects (69 women and 63 men) resulted heterozygous for one of the CFTR mutations, with a recurrence of carriers of 6.85%. The recurrence of carriers in infertile couples is significantly higher from the hypothetical value of the general population (4%). CONCLUSIONS: This study shows that in the Basilicata region of Italy the CFTR phenotype is caused by a small number of mutations. Our aim is to develop a kit able to detect not less than 96% of CTFR gene mutations so that the relative risk for screened couples is superimposable with respect to the general population.

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59 As mentioned before, molecular screening Table 2 Comparison between the results obtained in this study and those obtained in a previous study Castaldo et al. [14] Mutations observed in the present study F508del 55.8% (29) 48.62% (141) N1303K 3.8% (2) 9.31% (27) G542X 3.8% (2) 8.96% (26) W1282X 3.8% (2) 1.03% (3) 2183AA>G 5.8% (3) 2.76% (8) R1162X 0 0 1717-1G>A 1.9% (1) 0 T338I 0 0 R347P 0 0.69% (2) 711+5G>A 0 0 852del22 5.8% (3) 1.03% (3) 4382delA 0 0.69% (2) 1259insA 0 0.34% (1) 4016insT 0 0.34% (1) R553X 0 0.34% (1) R1158X 0 0 L1077P 0 1.03% (3) I502T 0 0 3849+10kbC>T 1.9% (1) 0.34% (1) D579G 0 0.69% (2) G1244E 3.8% (2) 0 G1349D 0 0.34% (1) 2789+5G>A 0 1.03% (3) 711+1G>T 0 0 L1065P 0 0 2522insC 0 0 E585X 0 0 G85E 0 0 G178R 0 0 D1152H 0 3.10% (9) I148T-3195del6 0 0 I148T (alone) 0 4.48% (13) R334W 0 0 DI507 0 0.69% (2) I1005R 0 0 3272-26A>G 0 0 2711delT 0 0 L558S 1.9% (1) 0.34% (1) W1063X 0 0 D110H 0 0 S549R (A>C) 1.9% (1) 0.69% (2) 2184insA 0 0 3131del22 0 0 Table 2 Comparison between the results obtained in this study and those obtained in a previous study (Continued) R709N 0 0 A349V 0 0 4015insA 0 0 Y849X 1.9% (1) 0.34% (1) G551D 0 1.03% (3) 621+3A>G 0 0.34% (1) E831X 0 0 I507del 0 0.69% (2) IVS8 TG12/t5 0 1.03% (3) H139R (A->G) 0 0.34% (1) 1248+1G>A 0 0.34% (1) R74W;V201M;D1270N 0 0.69% (2) S1455X 0 0.34% (1) dele 2,3 (21kb) 0 0.34% (1) 991del5 0 0.34% (1) UNKNOWN 7 %(4) 4.83% (14) F508C 0 0.69% (2) TOTAL 52 290 of CF is highly recommended in the USA by the National Institutes of Health Consensus Development Conference Statement on genetic testing for cystic fibrosis [17]. Login to comment
79 The test has a sensitivity and a specificity of more than Table 3 List of 60 mutations in the cystic fibrosis transmembrane regulator gene (specificity 100%) F508del I507del F508C 621+1G>T D110H E585X G1349D I502T 1706del17 1677delTA R117H H139R 1898+1G>A 4015delA G542X 1717-1G>A Q552X 852del22 G178R 1898+3A>G G551D S549R(A>C) 2183AA>G T338I 991del5 1898+5G>T N1303K 4016insT 3849+10kb C>T R347P R334W 2184insA G85E 711+5G>A 711+1G>T 1259insA R347H 2522insC 2789+5G>A W1282X G1244E R1066H R352Q 3120+1G>A I148T 3199del6 S912X R1158X 1717-8G>A R1066C R1162X 4382delA D1152H L1077P D579G 3272-26A>G L1065P R553X PoliT: 5T, 7T, 9T 1874insT 3659delC 99%. Login to comment

[hide] Clinical expression of patients with the D1152H CF... J Cyst Fibros. 2015 Jul;14(4):447-52. doi: 10.1016/j.jcf.2014.12.012. Epub 2015 Jan 10. Terlizzi V, Carnovale V, Castaldo G, Castellani C, Cirilli N, Colombo C, Corti F, Cresta F, D'Adda A, Lucarelli M, Lucidi V, Macchiaroli A, Madarena E, Padoan R, Quattrucci S, Salvatore D, Zarrilli F, Raia V
Clinical expression of patients with the D1152H CFTR mutation.
J Cyst Fibros. 2015 Jul;14(4):447-52. doi: 10.1016/j.jcf.2014.12.012. Epub 2015 Jan 10., [PMID:25583415]

Abstract [show]
BACKGROUND: Discordant results were reported on the clinical expression of subjects bearing the D1152H CFTR mutation, and also for the small number of cases reported so far. METHODS: A retrospective review of clinical, genetic and biochemical data was performed from individuals homozygous or compound heterozygous for the D1152H mutation followed in 12 Italian cystic fibrosis (CF) centers. RESULTS: 89 subjects carrying at least D1152H on one allele were identified. 7 homozygous patients had very mild clinical expression. Over half of the 74 subjects compound heterozygous for D1152H and a I-II-III class mutation had borderline or pathological sweat test and respiratory or gastrointestinal symptoms; one third had pulmonary bacteria colonization and 10/74 cases had complications (i.e. diabetes, allergic bronchopulmonary aspergillosis, and hemoptysis). However, their clinical expression was less severe as compared to a group of CF patients homozygous for the F508del mutation. Finally, 8 subjects compound heterozygous for D1152H and a IV-V class mutation showed very mild disease. CONCLUSIONS: The natural history of subjects bearing the D1152H mutation is widely heterogeneous and is influenced by the mutation in trans.

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85 Legacy name Protein name CDNA name Patients Homozygous for the D1152Ha D1152H p.Asp1152His c.3454GNC 7 Compound heterozygous for class I-II-III mutationsa : 74 F508del p.Phe508del c.1521_1523delCTT 43 G542X p.Gly542X c.1624GNT 7 N1303K p.Asn1303Lys c.3909CNG 4 1717-1GNA No protein name c.1585-1GNA 4 R1158X p.Arg1158X c.3472CNT 4 2183AANG p.Lys684SerfsX38 c.2051_2052delAAinsG 2 W1282X p.Trp1282X c.3846GNA 2 711 + 1GNT No protein name c.579 + 1GNT 1 Y849X p.Tyr849X c.2547CNA 1 L1065P p.Leu1065Pro c.3194 TNC 1 4016insT p.Ser1297PhefsX5 c.3884_3885insT 1 R1066H p.Arg1066His c.3197GNA 2 R1066C p.Arg1066Cys c.3196CNT 1 4382delA p.Glu1418ArgfsX14 c.4251delA 1 Compound heterozygous for class IV-V mutationsa : 8 (TG)12T5 No protein name Not available 2 2789 + 5GNA No protein name c.2657 + 5GNA 1 D579G p.Asp579Gly c.1736ANG 1 [R74W;V201M; D1270N] No protein name Not available 1 3849 + 10KbCNT No protein name c.3717 + 12191CNT 1 R347H p.Arg347His c.1040GNA 1 R347P p.Arg347Pro c.1040GNC 1 a Protein name and cDNA name from the CFTR2 database (http://www.http. com//www.cftr2) and http://www.genet.sickkids.on.ca/Home.html. Login to comment

[hide] Improving newborn screening for cystic fibrosis us... Genet Med. 2015 Feb 12. doi: 10.1038/gim.2014.209. Baker MW, Atkins AE, Cordovado SK, Hendrix M, Earley MC, Farrell PM
Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study.
Genet Med. 2015 Feb 12. doi: 10.1038/gim.2014.209., [PMID:25674778]

Abstract [show]
Purpose:Many regions have implemented newborn screening (NBS) for cystic fibrosis (CF) using a limited panel of cystic fibrosis transmembrane regulator (CFTR) mutations after immunoreactive trypsinogen (IRT) analysis. We sought to assess the feasibility of further improving the screening using next-generation sequencing (NGS) technology.Methods:An NGS assay was used to detect 162 CFTR mutations/variants characterized by the CFTR2 project. We used 67 dried blood spots (DBSs) containing 48 distinct CFTR mutations to validate the assay. NGS assay was retrospectively performed on 165 CF screen-positive samples with one CFTR mutation.Results:The NGS assay was successfully performed using DNA isolated from DBSs, and it correctly detected all CFTR mutations in the validation. Among 165 screen-positive infants with one CFTR mutation, no additional disease-causing mutation was identified in 151 samples consistent with normal sweat tests. Five infants had a CF-causing mutation that was not included in this panel, and nine with two CF-causing mutations were identified.Conclusion:The NGS assay was 100% concordant with traditional methods. Retrospective analysis results indicate an IRT/NGS screening algorithm would enable high sensitivity, better specificity and positive predictive value (PPV). This study lays the foundation for prospective studies and for introducing NGS in NBS laboratories.Genet Med advance online publication 12 February 2015Genetics in Medicine (2015); doi:10.1038/gim.2014.209.

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15 Correspondence: Mei W. Baker (mwbaker@wisc.edu) Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study Mei W. Baker, MD1,2 , Anne E. Atkins, MPH2 , Suzanne K. Cordovado, PhD3 , Miyono Hendrix, MS3 , Marie C. Earley, PhD3 and Philip M. Farrell, MD, PhD1,4 Table 1ߒ CF-causing or varying consequences mutations in the MiSeqDx IUO Cystic Fibrosis System c.1521_1523delCTT (F508del) c.2875delG (3007delG) c.54-5940_273ߙ+ߙ10250del21kb (CFTRdele2,3) c.3909C>G (N1303K) c.3752G>A (S1251N) Mutations that cause CF when combined with another CF-causing mutation c.1624G>T (G542X) c.2988ߙ+ߙ1G>A (3120ߙ+ߙ1G->A) c.3964-78_4242ߙ+ߙ577del (CFTRdele22,23) c.613C>T (P205S) c.1021T>C (S341P) c.948delT (1078delT) c.2988G>A (3120G->A) c.328G>C (D110H) c.200C>T (P67L) c.1397C>A (S466X(C>A)) c.1022_1023insTC (1154insTC) c.2989-1G>A (3121-1G->A) c.3310G>T (E1104X) c.3937C>T (Q1313X) c.1397C>G (S466X(C>G)) c.1081delT (1213delT) c.3140-26A>G (3272-26A->G) c.1753G>T (E585X) c.658C>T (Q220X) c.1466C>A (S489X) c.1116ߙ+ߙ1G>A (1248ߙ+ߙ1G->A) c.3528delC (3659delC) c.178G>T (E60X) c.115C>T (Q39X) c.1475C>T (S492F) c.1127_1128insA (1259insA) c.3659delC (3791delC) c.2464G>T (E822X) c.1477C>T (Q493X) c.1646G>A (S549N) c.1209ߙ+ߙ1G>A (1341ߙ+ߙ1G->A) c.3717ߙ+ߙ12191C>T (3849ߙ+ߙ10kbC->T) c.2491G>T (E831X) c.1573C>T (Q525X) c.1645A>C (S549R) c.1329_1330insAGAT (1461ins4) c.3744delA (3876delA) c.274G>A (E92K) c.1654C>T (Q552X) c.1647T>G (S549R) c.1393-1G>A (1525-1G->A) c.3773_3774insT (3905insT) c.274G>T (E92X) c.2668C>T (Q890X) c.2834C>T (S945L) c.1418delG (1548delG) c.262_263delTT (394delTT) c.3731G>A (G1244E) c.292C>T (Q98X) c.1013C>T (T338I) c.1545_1546delTA (1677delTA) c.3873ߙ+ߙ1G>A (4005ߙ+ߙ1G->A) c.532G>A (G178R) c.3196C>T (R1066C) c.1558G>T (V520F) c.1585-1G>A (1717-1G->A) c.3884_3885insT (4016insT) c.988G>T (G330X) c.3197G>A (R1066H) c.3266G>A (W1089X) c.1585-8G>A (1717-8G->A) c.273ߙ+ߙ1G>A (405ߙ+ߙ1G->A) c.1652G>A (G551D) c.3472C>T (R1158X) c.3611G>A (W1204X) c.1679ߙ+ߙ1.6kbA>G (1811ߙ+ߙ1.6kbA->G) c.274-1G>A (406-1G->A) c.254G>A (G85E) c.3484C>T (R1162X) c.3612G>A (W1204X) c.1680-1G>A (1812-1G->A) c.4077_4080delTGTTinsAA (4209TGTT->AA) c.2908G>C (G970R) c.349C>T (R117C) c.3846G>A (W1282X) c.1766ߙ+ߙ1G>A (1898ߙ+ߙ1G->A) c.4251delA (4382delA) c.595C>T (H199Y) c.1000C>T (R334W) c.1202G>A (W401X) c.1766ߙ+ߙ3A>G (1898ߙ+ߙ 3A->G) c.325_327delTATinsG (457TAT->G) c.1007T>A (I336K) c.1040G>A (R347H) c.1203G>A (W401X) c.2012delT (2143delT) c.442delA (574delA) c.1519_1521delATC (I507del) c.1040G>C (R347P) c.2537G>A (W846X) c.2051_2052delAAinsG (2183AA->G) c.489ߙ+ߙ1G>T (621ߙ+ߙ 1G->T) c.2128A>T (K710X) c.1055G>A (R352Q) c.3276C>A (Y1092X (C>A)) c.2052delA (2184delA) c.531delT (663delT) c.3194T>C (L1065P) c.1657C>T (R553X) c.3276C>G (Y1092X (C>G)) c.2052_2053insA (2184insA) c.579ߙ+ߙ1G>T (711ߙ+ߙ 1G->T) c.3230T>C (L1077P) c.1679G>A (R560K) c.366T>A (Y122X) c.2175_2176insA (2307insA) c.579ߙ+ߙ3A>G (711ߙ+ߙ 3A->G) c.617T>G (L206W) c.1679G>C (R560T) - c.2215delG (2347delG) c.579ߙ+ߙ5G>A (711ߙ+ߙ 5G->A) c.1400T>C (L467P) c.2125C>T (R709X) - c.2453delT (2585delT) c.580-1G>T (712-1G->T) c.2195T>G (L732X) c.223C>T (R75X) - c.2490ߙ+ߙ1G>A (2622ߙ+ߙ1G->A) c.720_741delAGGGAG AATGATGATGAAGTAC (852del22) c.2780T>C (L927P) c.2290C>T (R764X) - c.2583delT (2711delT) c.1364C>A (A455E) c.3302T>A (M1101K) c.2551C>T (R851X) - c.2657ߙ+ߙ5G>A (2789ߙ+ߙ5G->A) c.1675G>A (A559T) c.1A>G (M1V) c.3587C>G (S1196X) - Mutations/variants that were validated in this study are in bold. CF, cystic fibrosis. Table 1ߒ Continued on next page reduce carrier detection and potentially improve the positive predictive value (PPV), the NBS goals of equity and the highest possible sensitivity become more difficult to achieve. Login to comment

[hide] Mutation analysis of PRSS1, SPINK1 and CFTR gene i... Turk J Gastroenterol. 2015 Mar;26(2):176-80. doi: 10.5152/tjg.2015.4287. Sisman G, Tugcu M, Ayla K, Sebati O, Senturk H
Mutation analysis of PRSS1, SPINK1 and CFTR gene in patients with alcoholic and idiopathic chronic pancreatitis: A single center study.
Turk J Gastroenterol. 2015 Mar;26(2):176-80. doi: 10.5152/tjg.2015.4287., [PMID:25835118]

Abstract [show]
BACKGROUND/AIMS: A relation between some genetic mutations and chronic pancreatitis (CP) has been reported. However, the relation of genetic mutation to alcoholic CP (ACP) and idiopathic CP (ICP) still remains controversial. In this study, we investigated the prevalence of protease serine 1 (PRSS1), serine protease inhibitor, Kazal type 1 (SPINK1) SPINK1 and cystic fibrosis transmembrane conductance regulator (CFTR) mutations in ACP and ICP patients in Turkey. MATERIALS AND METHODS: Forty-one patients with ACP and 38 patients with ICP were enrolled, and 35 healthy individuals served as controls. The PRSS1 and SPINK1 mutations were investigated by the polymerase chain reaction (PCR)-restriction fragment-length polymorphism (RFLP) technique. The CFTR mutation was examined with PCR direct sequencing. RESULTS: The mean ages of the ACP, ICP and healthy control groups were 53.2, 40.4 and 46.3 years, respectively. A CFTR F508 mutation was detected as a heterozygote in one (2.4%) patient with ACP. In the ICP and control populations, PRSS1, SPINK1 and CFTR mutations were not detected. CONCLUSION: This study shows that PRSS1, SPINK1 and CFTR mutations do not play a role in ACP and ICP patients.

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45 DNA samples were multiplied by multiplex PCR with a CF 22Mut and CF 14Mut+Tn strip assay kit which has 36 common mutations of the CFTR gene (DF508, DI507, F508C, I502T, 1706del17, 1677del TA, G542X, 1717-1G>A, R553X, Q552X, G551D, S549R(A>C), N1303K, 4016insT, R1162X, R1158X, W1282X, G1244E, 2789+5G>A, 2183AA>G, 711+5G>A, 711+1G>T, G85E, 3849+10kbC>T, 621+1G>T, R117H, D1152H, L1065P, R1066H, L1077P, 4382delA, 1259insA, 852del22, R347P, T338I, S912X and Allele5T-7T-9T). Login to comment

[hide] A Genotypic-Oriented View of CFTR Genetics Highlig... Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229. Lucarelli M, Bruno SM, Pierandrei S, Ferraguti G, Stamato A, Narzi F, Amato A, Cimino G, Bertasi S, Quattrucci S, Strom R
A Genotypic-Oriented View of CFTR Genetics Highlights Specific Mutational Patterns Underlying Clinical Macrocategories of Cystic Fibrosis.
Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229., [PMID:25910067]

Abstract [show]
Cystic fibrosis (CF) is a monogenic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The genotype-phenotype relationship in this disease is still unclear, and diagnostic, prognostic and therapeutic challenges persist. We enrolled 610 patients with different forms of CF and studied them from a clinical, biochemical, microbiological and genetic point of view. Overall, there were 125 different mutated alleles (11 with novel mutations and 10 with complex mutations) and 225 genotypes. A strong correlation between mutational patterns at the genotypic level and phenotypic macrocategories emerged. This specificity appears to largely depend on rare and individual mutations, as well as on the varying prevalence of common alleles in different clinical macrocategories. However, 19 genotypes appeared to underlie different clinical forms of the disease. The dissection of the pathway from the CFTR mutated genotype to the clinical phenotype allowed to identify at least two components of the variability usually found in the genotype-phenotype relationship. One component seems to depend on the genetic variation of CFTR, the other component on the cumulative effect of variations in other genes and cellular pathways independent from CFTR. The experimental dissection of the overall biological CFTR pathway appears to be a powerful approach for a better comprehension of the genotype-phenotype relationship. However, a change from an allele-oriented to a genotypic-oriented view of CFTR genetics is mandatory, as well as a better assessment of sources of variability within the CFTR pathway.

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370 991del5 c.859_863delAACTT CF-PI nd p.Asn287LysfsX19 L320V c.958T>G uncertain: CF-PI and/or CF-PS and/or CFTR-RD nd p.Leu320Val R334W c.1000C>T CF-PI,CF-PS CF-causing p.Arg334Trp R334L c.1001G>T CF-PS nd p.Arg334Leu T338I c.1013C>T CF-PS,CFTR-RD,CBAVD CF-causing p.Thr338Ile R347P c.1040G>C CF-PI,CF-PS CF-causing p.Arg347Pro R347H c.1040G>A CF-PS CF-causing p.Arg347His [M348K;S912X] c. Login to comment

[hide] Translating the genetics of cystic fibrosis to per... Transl Res. 2015 Apr 15. pii: S1931-5244(15)00131-0. doi: 10.1016/j.trsl.2015.04.008. Corvol H, Thompson KE, Tabary O, le Rouzic P, Guillot L
Translating the genetics of cystic fibrosis to personalized medicine.
Transl Res. 2015 Apr 15. pii: S1931-5244(15)00131-0. doi: 10.1016/j.trsl.2015.04.008., [PMID:25940043]

Abstract [show]
Cystic fibrosis (CF) is the most common life-threatening recessive genetic disease in the Caucasian population. This multiorgan disease is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, a chloride channel recognized as regulating several apical ion channels. The gene mutations result either in the lack of the protein at the apical surface or in an improperly functioning protein. Morbidity and mortality because of the mutation of CFTR are mainly attributable to lung disease resulting from chronic infection and inflammation. Since its discovery as the causative gene in 1989, much progress has been achieved not only in clinical genetics but also in basic science studies. Recently, combinations of these efforts have been successfully translated into development and availability for patients of new therapies targeting specific CFTR mutations to correct the CFTR at the protein level. Current technologies such as next gene sequencing and novel genomic editing tools may offer new strategies to identify new CFTR variants and modifier genes, and to correct CFTR to pursue personalized medicine, which is already developed in some patient subsets. Personalized medicine or P4 medicine ("personalized," "predictive," "preventive," and "participatory") is currently booming for CF. The various current and future challenges of personalized medicine as they apply to the issues faced in CF are discussed in this review.

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56 C p.Arg347Pro (R347P) 0.33% c.3717 1 12191C . Login to comment

[hide] The improvement of the best practice guidelines fo... Eur J Hum Genet. 2015 May 27. doi: 10.1038/ejhg.2015.99. Girardet A, Viart V, Plaza S, Daina G, De Rycke M, Des Georges M, Fiorentino F, Harton G, Ishmukhametova A, Navarro J, Raynal C, Renwick P, Saguet F, Schwarz M, SenGupta S, Tzetis M, Roux AF, Claustres M
The improvement of the best practice guidelines for preimplantation genetic diagnosis of cystic fibrosis: toward an international consensus.
Eur J Hum Genet. 2015 May 27. doi: 10.1038/ejhg.2015.99., [PMID:26014425]

Abstract [show]
Cystic fibrosis (CF) is one of the most common indications for preimplantation genetic diagnosis (PGD) for single gene disorders, giving couples the opportunity to conceive unaffected children without having to consider termination of pregnancy. However, there are no available standardized protocols, so that each center has to develop its own diagnostic strategies and procedures. Furthermore, reproductive decisions are complicated by the diversity of disease-causing variants in the CFTR (cystic fibrosis transmembrane conductance regulator) gene and the complexity of correlations between genotypes and associated phenotypes, so that attitudes and practices toward the risks for future offspring can vary greatly between countries. On behalf of the EuroGentest Network, eighteen experts in PGD and/or molecular diagnosis of CF from seven countries attended a workshop held in Montpellier, France, on 14 December 2011. Building on the best practice guidelines for amplification-based PGD established by ESHRE (European Society of Human Reproduction and Embryology), the goal of this meeting was to formulate specific guidelines for CF-PGD in order to contribute to a better harmonization of practices across Europe. Different topics were covered including variant nomenclature, inclusion criteria, genetic counseling, PGD strategy and reporting of results. The recommendations are summarized here, and updated information on the clinical significance of CFTR variants and associated phenotypes is presented.European Journal of Human Genetics advance online publication, 27 May 2015; doi:10.1038/ejhg.2015.99.

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78 Table 1 Examples of common CF-causing, indetermined, and non CF-causing variants (modified from5,8,17) HGVS nomenclature Legacy name cDNA nucleotide name Protein name CF-causing variantsa F508del c.1521_1523delCTT p.Phe508del G542X c.1624G4T p.Gly542* G551D c.1652G4A p.Gly551Asp N1303K c.3909C4G p.Asn1303Lys W1282X c.3846G4A p.Trp1282* 621+1G4T c.489+1G4T CFTRdele2,3 c.54-5940_273 +10250del21080 p.Ser18Argfs*16 E60X c.178G4T p.Glu60* G85E c.254G4A p.Gly85Glu 394delTT c.262_263delTT p.Leu88Ilefs*22 711+1G4T c.579+1G4T R347P c.1040G4C p.Arg347Pro A455E c.1364C4A p.Ala455Glu Q493X c.1477C4T p.Gln493* I507del c.1519_1521delATC p.Ile507del R553X c.1657C4T p.Arg553* R560T c.1679G4C p.Arg560Thr 1898+1G4A c.1766+1G4A 2183AA4G c.2051_2052delAAinsG p.Lys684Serfs*38 2789+5G4A c.2657+5G4A 3120+1G4A c.2988+1G4A M1101K c.3302 T4A p.Met1101Lys R1162X c.3484C4T p.Arg1162* 3659delC c.3528delC p.Lys1177Serfs*15 M1V c.1 A4G p.? Login to comment
92 Well known examples include missense variants D110H, R117C, L206W, R347P, R347H, R1066H, or splice variants that produce both aberrant and full-length transcript such as 3849+10kbC4T, 2789+5G4A, 3272-26 A4G, 711+3 A4G. Login to comment

[hide] Prevalence of meconium ileus marks the severity of... Genet Med. 2015 Jun 18. doi: 10.1038/gim.2015.79. Dupuis A, Keenan K, Ooi CY, Dorfman R, Sontag MK, Naehrlich L, Castellani C, Strug LJ, Rommens JM, Gonska T
Prevalence of meconium ileus marks the severity of mutations of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene.
Genet Med. 2015 Jun 18. doi: 10.1038/gim.2015.79., [PMID:26087176]

Abstract [show]
RATIONALE: Meconium ileus (MI) is a perinatal complication in cystic fibrosis (CF), which is only minimally influenced by environmental factors. We derived and examined MI prevalence (MIP) scores to assess CFTR phenotype-phenotype correlation for severe mutations. METHOD: MIP scores were established using a Canadian CF population (n = 2,492) as estimates of the proportion of patients with MI among all patients carrying the same CFTR mutation, focusing on patients with p.F508del as the second allele. Comparisons were made to the registries from the US CF Foundation (n = 43,432), Italy (Veneto/Trentino/Alto Adige regions) (n = 1,788), and Germany (n = 3,596). RESULTS: The prevalence of MI varied among the different registries (13-21%). MI was predominantly prevalent in patients with pancreatic insufficiency carrying "severe" CFTR mutations. In this severe spectrum MIP scores further distinguished between mutation types, for example, G542X (0.31) with a high, F508del (0.22) with a moderate, and G551D (0.08) with a low MIP score. Higher MIP scores were associated with more severe clinical phenotypes, such as a lower forced expiratory volume in 1 second (P = 0.01) and body mass index z score (P = 0.04). CONCLUSIONS: MIP scores can be used to rank CFTR mutations according to their clinical severity and provide a means to expand delineation of CF phenotypes.Genet Med advance online publication 18 June 2015Genetics in Medicine (2015); doi:10.1038/gim.2015.79.

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63 Canadian studies for CF modfier genes 2,492 3,153 43,432 3,596 1,788 2,230 23,397 16,023 3 716 3,438 860 15% (19%) 1,902 2,576 PIP and MIP derivation FEV1 and zBMI modeling MIP calculation following correction of MI variable 23,301 2,413 510 21% (25%) 20% (23%) 13% (15%) Total F508del/others MI prevalence uncorrected (estimated) Missing or incomplete genotype Available for analysis Canadian CF patient registry, born after 1980 US CF patient registry German CF patient registry CF patient registry, North Italy Table 1ߒ Meconium ileus prevalence scores for the most common cystic fibrosis-causing variants p. F508del/other variants Class PIP Canada, (n) MIP, (n) Canada United States Germany Italy HGVS Legacy name c.262_263delTT 394delTT I 0.38 (50) c.3472C>T R1158X I 0.37 (35) c.1558G>T V520F 0.35 (43) c.3484C>T R1162X I 0.34 (135) 0.17 (14) 0.22 (45) c.2012delT 2143delT I 0.33 (13) c.3276C>A or G Y1092X I 0.92 (13) 0.09 (12) 0.33 (55) c.3846G>A W1282X I 1.00 (13) 0.29 (13) 0.32 (442) 0.17 (20) c.1477C>T Q493X I 1.00 (11) 0.19 (11) 0.32 (102) c.3528delC 3659delC I 0.31 (139) c.579ߙ+ߙ1G>T 711ߙ+ߙ1G>T 0.97 (39) 0.30 (38) 0.31 (54) c.178G>T E60X I 0.30 (66) c.1657C>T R553X I 1.00 (16) 0.28 (16) 0.30 (415) 0.24 (107) c.1585-1G>A 1717-1G>A I 1.00 (12) 0.23 (12) 0.29 (367) 0.22 (38) 0.16 (22) c.1766ߙ+ߙ1G>A 1898ߙ+ߙ1G>A 0.29 (139) c.1624G>T G542X I 0.99 (73) 0.31 (72) 0.29 (976) 0.21 (79) 0.22 (33) c.1521_1523delCTT F508del II 0.99 (1292) 0.22 (1260) 0.27 (15391) 0.21 (1910) 0.20 (230) c.1679G>C R560T II 0.27 (123) c.3744delA 3876delA 0.27 (22) c.2128A>T K710X I 0.26 (12) c.1519_1521delATC I507del II 1.00 (20) 0.21 (19) 0.25 (162) c.3909C>G N1303K II 0.98 (40) 0.13 (39) 0.25 (534) 0.23 (80) 0.14 (62) c.489ߙ+ߙ1G>T 621ߙ+ߙ1G>T I 1.00 (90) 0.24 (88) 0.25 (369) 0.21 (11) c.3266G>A W1089X I 0.25 (17) c.1675G>A A559T 0.24 (21) c.988G>T G330X 0.24 (10) c.3773_3774insT 3905insT 0.23 (78) c.2988ߙ+ߙ1G>A 3120ߙ+ߙ1G>A 0.22 (121) c.443T>C I148T;3199del6 1.00 (15) 0.22 (15) c.2052delA 2184delA I 0.21 (89) 0.22 (10) c.2051_2052delAAinsG 2183AA>G 0.20 (73) 0.20 (42) c.948delT 1078delT 0.19 (20) c.1652G>A G551D III 0.96 (54) 0.08 (53) 0.15 (979) 0.09 (84) c.254G>A G85E 0.50 (24) 0.06 (24) 0.14 (137) 0.00 (10) c.3196C>T R1066C 0.14 (42) c.1466C>A S489X 1.00 (14) 0.14 (14) c.3808G>A D1270N 0.13 (19) c.1055G>A R352Q 0.12 (18) c.579ߙ+ߙ5G>A 711ߙ+ߙ5G>A 0.12 (30) c.2175_2176insA 2307insA 0.11 (24) c.349C>T R117C 0.10 (37) c.1040G>C R347P IV 0.18 (11) 0.19 (11) 0.10 (130) 0.02 (56) c.350G>A R117H IV 0.05 (21) 0.00 (21) 0.07 (666) 0.02 (19) c.2657ߙ+ߙ5G>A 2789ߙ+ߙ5G>A V 0.25 (20) 0.00 (20) 0.06 (271) 0.01 (21) c.1040G>A R347H 0.06 (55) c.2988G>A 3120G->A 0.06 (36) c.328G>C D1152H IV 0.06 (124) c.3717ߙ+ߙ12191C>T 3849ߙ+ߙ10kbC>T V 0.07 (14) 0.00 (14) 0.05 (299) 0.01 (42) 0.00 (15) c.1364C>A A455E V 0.16 (45) 0.01 (41) 0.05 (109) c.1000C>T R334W IV 0.18 (11) 0.00 (10) 0.05 (92) c.617T>G L206W 0.06 (18) 0.05 (17) 0.04 (52) c.3302T>A M1101K 0.04 (17) c.200C>T P67L V 0.07 (14) 0.00 (14) Meconium ileus prevalence (MIP) and pancreas insufficiency prevalence (PIP) scores are presented. Login to comment
101 The mutations M1101K and R347P, however, showed no CFTR function, with a low MIP score and intermediate PIP score, suggesting that the functional consequences of these mutations may be very organ-specific and/or are greatly influenced by non-CFTR-modifying factors. Login to comment
102 This finding does seem to reflect previous reports of various outcomes of patients with M1101K or R347P, ranging from PI and an early decline in lung function to PS and only mild lung disease.25,26 MIP scores distinguished between the "molecular" classification of CFTR mutations, especially regarding the distinctive class III or gating mutations. Login to comment
109 While non-CFTR modifier genes as well as environmental factors largely influence the development and progression of lung disease and nutritional decline,33-36 we demonstrate that the severity of the underlying CFTR genotype Table 2ߒ Meconium ileus prevalence scores and CFTR function CFTR mutation MIP score CFTR function (%wt) High MIP score ߓ V520F 0.38 0.2 ߓ N1303K 0.25 0.5 ߓ F508del 0.27 0.4 ߓ R560T 0.27 0.1 ߓ A559T 0.24 0 ߓ G551D 0.15 1 ߓ G85E 0.14 0.8 ߓ R1066C 0.13 0 Low MIP score ߓ R347P 0.1 0 ߓ R117C 0.1 2.9 ߓ R117H 0.07 33 ߓ R347H 0.06 5 ߓ R334W 0.05 1.3 ߓ A455E 0.05 6 ߓ L206W 0.04 5 ߓ M1101K 0.04 0 ߓ P67L 0.0 8 The table compares meconium ileus prevalence (MIP) scores and measured cystic fibrosis transmembrane conductance regulator (CFTR) function in Fisher rat thyroid determined by VanGoor et al.24 for the major and missense cystic fibrosis-causing variants for which patient group size was ࣙ10 in at least the US group. Login to comment

[hide] Exogenous and endogenous determinants of vitamin K... Sci Rep. 2015 Jul 10;5:12000. doi: 10.1038/srep12000. Krzyzanowska P, Pogorzelski A, Skorupa W, Moczko J, Grebowiec P, Walkowiak J
Exogenous and endogenous determinants of vitamin K status in cystic fibrosis.
Sci Rep. 2015 Jul 10;5:12000. doi: 10.1038/srep12000., [PMID:26160248]

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Cystic fibrosis (CF) patients are at high risk for vitamin K deficiency. The effects of vitamin K supplementation are very ambiguous. Therefore, we aimed to define the determinants of vitamin K deficiency in a large cohort of supplemented - 146 (86.9%) and non-supplemented - 22 (13.1%) CF patients. Vitamin K status was assessed using prothrombin inducted by vitamin K absence (PIVKA-II) and undercarboxylated osteocalcin (u-OC). The pathological PIVKA-II concentration (>/= 2 ng/ml) and abnormal percentage of osteocalcin (>/= 20%) were found in 72 (42.8%) and 60 (35.7%) subjects, respectively. We found that liver involvement, diabetes, and glucocorticoid therapy were potential risk factors for vitamin K deficiency. Pathological concentrations of PIVKA-II occurred more frequently in patients with pancreatic insufficiency and those who have two severe mutations in both alleles of the CFTR gene. Pathological percentage of u-OC was found more frequently in adult CF patients and those not receiving vitamin K. However, it seems that there are no good predictive factors of vitamin K deficiency in CF patients in everyday clinical care. Early vitamin K supplementation in CF patients seems to be warranted. It is impossible to clearly determine the supplementation dose. Therefore, constant monitoring of vitamin K status seems to be justified.

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122 The genotypes of the studied patients were as follows: F508del/F508del (nߙ=Èa;ߙ74); F508del/- (nߙ=Èa;ߙ23); F508del/3849ߙ+Èa;ߙ10ߙkbCߙ>Èa;ߙT (nߙ=Èa;ߙ6); F508del/2143delT (nߙ =Èa;ߙ 6); F508del/R553X (nߙ =Èa;ߙ4); F508del/2183AAߙ>Èa;ߙG (nߙ=Èa;ߙ3); F508del/1717-1G>Èa;A (nߙ=Èa;ߙ3); F508del/CFTRdele2,3(21ߙkb) (nߙ=Èa;ߙ3); F508del/3272-26Aߙ>Èa;ߙG (nߙ=Èa;ߙ 2); F508del/N1303K (nߙ =Èa;ߙ2); F508del/4374ߙ+Èa;ߙ1Gߙ>Èa;ߙT (nߙ=Èa;ߙ1); F508del/621ߙ+Èa;ߙ1Gߙ>Èa;ߙT (nߙ=Èa;ߙ 1); F508del/3659delC (nߙ =Èa;ߙ1); F508del/ G1244R (nߙ =Èa;ߙ 1); F508del/G542X (nߙ =Èa;ߙ 1); F508del/R117H (nߙ =Èa;ߙ 1); F508del/R334W (nߙ =Èa;ߙ1); G542X/- (nߙ=Èa;ߙ2); CFTRdele2,3(21ߙkb)/- (nߙ=Èa;ߙ2); CFTRdele2,3(21ߙkb)/CFTRdele2,3(21ߙkb) (nߙ=Èa;ߙ1); 1717-1-Gߙ>Èa;ߙA/ CFTRdele2,3(21ߙkb) (nߙ=Èa;ߙ1); 3849ߙ+Èa;ߙ10ߙkbCߙ>Èa;ߙT/- (nߙ=Èa;ߙ1); 3849ߙ+Èa;ߙ10ߙkbCߙ>Èa;ߙT/1717ߙ-Èa;ߙ1Aߙ>Èa;ߙG (nߙ=Èa;ߙ1); N1303K/- (nߙ=Èa;ߙ1); N1303K/3272-26Aߙ>Èa;ߙG (nߙ=Èa;ߙ1); G542X/R553X (nߙ=Èa;ߙ1); 1524ߙ+Èa;ߙ1Gߙ>Èa;ߙA/E585X (nߙ=Èa;ߙ1); 2183AAߙ>Èa;ߙG/- (nߙ=Èa;ߙ1); 2184insA/622-1Gߙ>Èa;ߙA (nߙ=Èa;ߙ1); 2143delT/R1102X (nߙ=Èa;ߙ1); 3272-26Aߙ>Èa;ߙG/- (nߙ=Èa;ߙ1); 3659delC/- (nߙ=Èa;ߙ1); R347P/R347P (nߙ=Èa;ߙ1); S1196X/Q1382X (nߙ=Èa;ߙ1). Login to comment

[hide] Identification and frequencies of cystic fibrosis ... Clin Biochem. 2015 Oct 21. pii: S0009-9120(15)00473-7. doi: 10.1016/j.clinbiochem.2015.10.007. Pepermans X, Mellado S, Chialina S, Wagener M, Gallardo L, Lande H, Bordino W, Baran D, Bours V, Leal T
Identification and frequencies of cystic fibrosis mutations in central Argentina.
Clin Biochem. 2015 Oct 21. pii: S0009-9120(15)00473-7. doi: 10.1016/j.clinbiochem.2015.10.007., [PMID:26500004]

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99 rs name HGVS p. name HGVS c. name Legacy name n (%) Screening panel CFTR1 database CFTR2 database rs199826652 p.Phe508del c.1521_1523delCTT F508del 94 (56.6) Yes Yes CF-causing rs113993959 p.Gly542* c.1624G N T G542X 7 (4.2) Yes Yes CF-causing No p.Asn1303Lys c.3909C N G N1303K 5 (3) Yes Yes CF-causing rs74767530 p.Arg1162* c.3484C N T R1162X 4 (2.4) Yes Yes CF-causing rs75961395 p.Gly85Glu c.254G N A G85E 3 (1.8) Yes Yes CF-causing rs78756941 NA c.489 + 1G N T 621 + 1G N T 3 (1.8) Yes Yes CF-causing rs76713772 NA c.1585-1G N A 1717-1G N A 3 (1.8) Yes Yes CF-causing No p.Lys684Serfs*38 c.2051_2052delAAinsG 2183AA N G 3 (1.8) Yes Yes CF-causing rs397508173 p.Ser4* c.11C N A S4X 2 (1.2) No Yes No rs121909011 p.Arg334Trp c.1000C N T R334W 2 (1.2) Yes Yes CF-causing rs77010898 p.Trp1282* c.3846G N A W1282X 2 (1.2) Yes Yes CF-causing rs397508141 p.Leu34_Gln39del c.100_117delTTGTCAGACATATACCAA 232del18 1 (0.6) No Yes No No p.Leu49Pro c.146 T N C L49P &#a7; 1 (0.6) No No No rs77834169 p.Arg117Cys c.349C N T R117C 1 (0.6) Yes Yes CF-causing No p.Arg117Pro c.350G N C R117P 1 (0.6) No Yes No rs80282562 p.Gly178Arg c.532G N A G178R 1 (0.6) Yes Yes CF-causing rs121908803 p.Pro205Ser c.613C N T P205S 1 (0.6) No Yes CF-causing rs121908752 p.Leu206Trp c.617 T N G L206W 1 (0.6) Yes Yes CF-causing No p.Arg347Pro c.1040G N C R347P 1 (0.6) Yes Yes CF-causing rs397508155 p.Tyr362* c.1086 T N A Y362X 1 (0.6) No Yes No rs74597325 p.Arg553* c.1657C N T R553X 1 (0.6) Yes Yes CF-causing rs1800098 + rs1800100 p.[Gly576Ala(;)Arg668Cys] c. Login to comment
126 Genotype N Frequency (%) Total N Total frequency (%) Category I: p.Phe508del/p.Phe508del p.Phe508del/p.Phe508del 30 36.1 30 36.1 Category II: p.Phe508del/Other p.Phe508del/p.Gly542* 5 6 p.Phe508del/p.Asn1303Lys 3 3.6 p.Phe508del/p.Gly85Glu 2 2.4 p.Phe508del/c.1585-1G N A 2 2.4 p.Phe508del/c.2051_2052delAAinsG 2 2.4 p.Phe508del/p.Trp1282* 2 2.4 p.Phe508del/p.Arg117Pro 1 1.2 p.Phe508del/p.Pro205Ser 1 1.2 p.Phe508del/p.Leu206Trp 1 1.2 p.Phe508del/p.Arg553* 1 1.2 p.Phe508del/p.Ser589Ile 1 1.2 p.Phe508del/p.Ser737Phe 1 1.2 p.Phe508del/p.Arg1162* 1 1.2 p.Phe508del/c.1766 + 1G N A 1 1.2 p.Phe508del/p.Leu34_Gln39del 1 1.2 p.Phe508del/p.Leu812Phefs*11 1 1.2 p.Phe508del/c.3140-26A N G 1 1.2 p.Phe508del/c.3873 + 1G N A 1 1.2 p.Phe508del/p.Ser1297Phefs*5 1 1.2 p.Phe508del/c.4242_4242 + 1delGGinsTT 1 1.2 p.Phe508del/c.489 + 1G N T 1 1.2 31 37.5 Category III: Other/other p.Gly542*/p.Asn1303Lys 1 1.2 p.Asn1303Lys/p.Gly85Glu 1 1.2 c.489 + 1G N T/p.Lys684Serfs*38 1 1.2 c.489 + 1G N T/p.Gly542* 1 1.2 p.Arg1162*/p.Ser4* 1 1.2 p.Arg1162*/p.Tyr362* 1 1.2 p.Arg334Trp/c.1585-1G N A 1 1.2 p.Arg334Trp/p.Ser821Argfs*4 1 1.2 p.Arg347Pro/p.Ser4* 1 1.2 c.2657 + 5G N A/p.Tyr852Leufs*44 # 1 1.2 p.Arg1162*/p.Leu49Pro # 1 1.2 11 13.2 Category IV: A single mutation p.Phe508del/WT 3 3.6 c.2988 + 1G N A/WT 1 1.2 p.Arg117Cys/WT 1 1.2 p.Gly178Arg/WT 1 1.2 p.[Gly576Ala(;)Arg668Cys]/TG11-5T 1 1.2 7 8.4 Category V: Wild type 4 4.8 #: new mutation submitted to CFTR1 database [1]; other = other mutation than p.Phe508del. Login to comment

[hide] [Male infertility caused by bilateral agenesis of ... Rev Med Interne. 1997;18(2):114-8. Durieu I, Bey-Omar F, Rollet J, Boggio D, Bellon G, Morel Y, Vital Durand D
[Male infertility caused by bilateral agenesis of the vas deferens: a new clinical form of cystic fibrosis?].
Rev Med Interne. 1997;18(2):114-8., [PMID:9092029]

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Congenital bilateral absence of vas deferens causes male excretory infertility and represents 1 to 2% of male infertility. Because of a genotypic similarity with cystic fibrosis, the possible in vitro fertilization with epididymal sperm requires careful genetic counselling. We studied genotype, sweat chloride concentration, respiratory function tests, sinus abnormalities, pancreatic and hepatic functions in 22 subjects with congenital bilateral absence of vas deferens. Among them, four were compound heterozygotus, all of them with the R117H mutation. Ten had a positive sweat test, one of them also being compound heterozygotus. Congenital bilateral absence of vas deferens and double mutation or positive sweat test led to high probable cystic fibrosis diagnosis in 13 subjects. Six subjects were heterozygotus for one cystic fibrosis mutation, criterium which is not sufficient for cystic fibrosis diagnosis; five of them had sinus abnormalities, present in 11 of the 22 subjects. Only three patients had no mutation nor sweat chloride abnormalities. This work confirms the high frequency of cystic fibrosis mutations in males with congenital bilateral absence of vas deferens, with a higher frequency of positive sweat test than in other publications, and a high frequency of sinus abnormalities. This monosymptomatic phenotype of cystic fibrosis suggests new hypotheses for a relationship between genotype and phenotype.

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46 Vingt-deux mutations du gene CFTR ont Cte recher- chtes : les cinq plus frequentes (AF508, G542X, N1303K, 1717-G--A, G85E) et les 17 suivantes : R117H, 556delA, R334W, R347H, R347P, S549N, S5491, S549R, G551D, R553X,R560T,G1244E3,S1255X,W1282X,R1283K,3898 ins C, D1270N. Login to comment