ABCMdb

ABCC7 p.Arg1070Gln

Admin's notes:	Class II-III (maturation defect, gating defect) Veit et al.
ClinVar:	c.3209G>C , p.Arg1070Pro ? , not provided c.3209G>A , p.Arg1070Gln D , Pathogenic/Likely pathogenic, not provided c.3208C>T , p.Arg1070Trp ? , not provided
CF databases:	c.3209G>A , p.Arg1070Gln ? , Varying clinical consequence ; CFTR1: This missense mutation was found in one Italian CF patient. The nucleotide change was G->A at position 3341 of exon 17b leading to R 1070 Q amino acid change. It was found once using DGGE screening and DNA sequencing among 50 Italian CF chromosomes. c.3208C>T , p.Arg1070Trp ? , Varying clinical consequence ; CFTR1: Teh R1070W mutation was detected on 1 US Caucasian chromosome out of 48 screened. ASO analysis of 100 non-CF Caucasian chromosomes did not reveal this mutation on any of the tested chromosomes. The 15 months old CBAVD patient carries the [delta]F508 mutation on the other allele. c.3209G>C , p.Arg1070Pro (CFTR1) ? , This 26 year old individual of Polish extraction with mild CF presented at age 11 with nasal polyps. He had noted salt crystals on his skin in warm weather, but did not have a chronic cough or gastrointestinal complaints. Pulmonary function tests and chest X-ray were normal. Sweat chloride was 121 mMol/L (repeat value was 104 mMol/L). No formal pancreatic function testing was performed. Most recent pulmonary function tests show mild obstructive airways disease. This individual is a compound heterozygote for the 2143delT CF mutations. R1070P was originally detected by SSC/HA and can be detected by virtue of the creation of a Sau96I or destruction of a BslI site. Mutation R1070P was also reported by DÃ¶rk T, Hughes D, Dworniczak B, Stuhrmann M (Jan 30, (NL#69)) in a CF patient from Northern Ireland who carried R1070P on his paternal and [delta]F508 on his maternal allele.
Predicted by SNAP2:	A: N (66%), C: D (53%), D: D (85%), E: D (75%), F: D (91%), G: D (71%), H: N (57%), I: D (63%), K: N (66%), L: D (63%), M: D (66%), N: D (63%), P: D (71%), Q: D (75%), S: D (53%), T: D (63%), V: D (63%), W: D (95%), Y: D (71%),
Predicted by PROVEAN:	A: N, C: N, D: N, E: N, F: D, G: D, H: N, I: D, K: N, L: D, M: N, N: N, P: D, Q: N, S: N, T: N, V: D, W: D, Y: N,

[switch to compact view]
Comments [show]

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

Publications
[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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[hide] Aberrant CFTR-dependent HCO3- transport in mutatio... Nature. 2001 Mar 1;410(6824):94-7. Choi JY, Muallem D, Kiselyov K, Lee MG, Thomas PJ, Muallem S
Aberrant CFTR-dependent HCO3- transport in mutations associated with cystic fibrosis.
Nature. 2001 Mar 1;410(6824):94-7., 2001-03-01 [PMID:11242048]

Abstract [show]
Cystic fibrosis (CF) is a disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). Initially, Cl- conductance in the sweat duct was discovered to be impaired in CF, a finding that has been extended to all CFTR-expressing cells. Subsequent cloning of the gene showed that CFTR functions as a cyclic-AMP-regulated Cl- channel; and some CF-causing mutations inhibit CFTR Cl- channel activity. The identification of additional CF-causing mutants with normal Cl- channel activity indicates, however, that other CFTR-dependent processes contribute to the disease. Indeed, CFTR regulates other transporters, including Cl(-)-coupled HCO3- transport. Alkaline fluids are secreted by normal tissues, whereas acidic fluids are secreted by mutant CFTR-expressing tissues, indicating the importance of this activity. HCO3- and pH affect mucin viscosity and bacterial binding. We have examined Cl(-)-coupled HCO3- transport by CFTR mutants that retain substantial or normal Cl- channel activity. Here we show that mutants reported to be associated with CF with pancreatic insufficiency do not support HCO3- transport, and those associated with pancreatic sufficiency show reduced HCO3- transport. Our findings demonstrate the importance of HCO3- transport in the function of secretory epithelia and in CF.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
49 The E193K, D648V, H949Yand R1070Q mutants, all associated with CF with pancreatic suf®ciency, had no effect on Cl-transport but reduced HCO3 transport by 50±65%. Login to comment
60 In this respect, the R1070Q mutation, in the few documented cases, has been found to be associated with CF with either pancreatic suf®ciency or pancreatic insuf®ciency. Login to comment
186 letters to nature 96 NATURE |VOL 410 |1 MARCH 2001 |www.nature.com HCO3 -/Cl- transportratio 0 0.25 0.50 0.75 1.00 WT I148T G178R R297Q G551D H620Q G970R A1067T G1244E S1255P G1349D E193K G551S A800G H949Y R1070Q Pancreatic insufficient Pancreatic sufficientD648V N CI148T G178R E193K R297Q R117H A1067T R1070Q G1244E S1255P G1349D NBD2 RD H949Y G970R CL4CL3CL2CL1 NBD1 G551D G551S H620Q D648V A800G Figure 3 The HCO3:Cl-transport ratio of CFTR mutants associated with CF. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[hide] Spectrum of cystic fibrosis mutations in Serbia an... Genet Test. 2004 Fall;8(3):276-80. Radivojevic D, Djurisic M, Lalic T, Guc-Scekic M, Savic J, Minic P, Antoniadi T, Tzetis M, Kanavakis E
Spectrum of cystic fibrosis mutations in Serbia and Montenegro and strategy for prenatal diagnosis.
Genet Test. 2004 Fall;8(3):276-80., [PMID:15727251]

Abstract [show]
We have screened 175 patients for molecular defects in the cystic fibrosis transmembrane conductance regulator (CFTR) gene using nondenaturing polyacrylamide gel electrophoresis (PAGE), denaturing gradient gel electrophoresis (DGGE), and sequencing. Six different mutations (F508del, G542X, 621+1G --> T, 2789+5G --> A, R1070Q, and S466X) accounted for 79.71% of CF alleles, with the F508del mutation showing a frequency of 72.28%. Another 12 mutations (R334W, 2184insA, I507del, 1525-1G --> A, E585X, R75X, M1I, 457TAT --> G, 574delA, 2723delTT, A120T, and 2907delTT) covered an additional 3.36%. A novel mutation (2723delTT) was found in one CF patient (F508del/2723delTT). Thus, a total of 18 mutations cover 82.57% of CF alleles. During our study, 72% of families at risk for having a CF child were found to be fully informative for prenatal diagnosis. Prenatal diagnosis was performed on 56 families; 76 analyses resulting in 16 affected, 38 carriers, and 22 healthy fetuses. These results imply that the molecular basis of CF in Serbia and Montenegro is highly heterogeneous, as is observed in other eastern and southern European populations. Because we detected more then 80% of CFTR alleles, results could be used for planning future screening and appropriate genetic counseling programs in our country.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
2 Six different mutations (F508del, G542X, 621؉1G Ǟ T, 2789؉5G Ǟ A, R1070Q, and S466X) accounted for 79.71% of CF alleles, with the F508del mutation showing a frequency of 72.28%. Login to comment
40 Six different mutations (F508del, 621ϩ1G Ǟ T, G542X, S466X, R1070Q, and 2789ϩ5G Ǟ A) accounted for 79.71% of the CF alleles in Yugoslavian population, of which the F508del mutation had a frequency of 72.28% (253/350). Login to comment
44 CFTR MUTATIONS IDENTIFIED IN 175 YUGOSLAVIAN CF PATIENTS Location Number of positive Frequency Mutation (exon/intron) CF alleles (percentage) F508del Exon 10 253 72.28 621 ϩ 1G → T Intron 4 10 2.86 G542X Exon 11 9 2.57 S466X Exon 10 3 0.86 2789 ϩ 5 G → A Intron 14b 2 0.57 R1070Q Exon 17b 2 0.57 MI1 Exon 1 1 0.28 R75X Exon 3 1 0.28 457TAT → G Exon 4 1 0.28 574delA Exon 4 1 0.28 A120T Exon 4 1 0.28 R334W Exon 7 1 0.28 1525-1 G → A Intron 9 1 0.28 I507del Exon 10 1 0.28 E585X Exon 12 1 0.28 2184insA Exon 13 1 0.28 2723delTTa Exon 14a 1 0.28 2907delTT Exon 15 1 0.28 Unknown - 61 17.43 aNew frameshift mutation. Login to comment
49 Both patients, although unrelated, were compound heterozygous for F508del inherited from one parent, and S466X with R1070Q in cis, inherited from the other parent. Login to comment
55 Nine different mutations were detected: F508del, 2907delTT, S466X, 457TAT Ǟ G, R75X, 2184insA, G542X, 621ϩ1G Ǟ T, and R1070Q in a total of 76 prenatal analyses (Table 2). Login to comment
71 RESULTS OF PRENATAL DIAGNOSIS OF CF IN SERBIA AND MONTENEGRO Number of prenatal Genotype Material diagnoses Outcome F508del/F508del CVS, AF, CBa 51 11 Affected, 25 carriers, 15 normal, F508del/2907delTT CVS 2 1 Affected, 1 carrier F508del/S466X CVS, AF 2 2 Carriers F508del/457TATϾG CVS 1 1 Carrier F508del/2184insA CVS 1 1 Affected F508del/621ϩ1GϾT CVS 1 1 Normal F508del/R1070Q CVS 1 1 Normal G542X/621ϩ1GϾT CVS 4 1 Affected, 2 carriers, 1 normal G542X/R7X CVS 3 2 Carriers, 1 normal F508del/? Login to comment
74 Eleven mutations detected in Yugoslavian (YU) CF alleles were also found in the neighboring region: R1070Q (Albania, Bulgaria, Greece), 2789ϩ5G Ǟ A (Bulgaria, Greece, FYROM, Slovenia), R334W (Greece), 2184insA (Bulgaria, FYROM), I507del (Greece, Italy), 1525-1G Ǟ A (Greece), R75X (Greece), 457TAT Ǟ G (Greece, FYROM, Slovenia), 574delA (Bulgaria), A120T (Greece), and 2907delTT (Slovenia) (Audrezet et al., 1994; CFGAC, 1994; Estivill et al., 1997; Kremensky et al., 2000; Vouk et al., 2000; Koceva et al., 2001; Bobadilla et al., 2002; Kanavakis et al., 2003). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
50 In effect, virtually no func- Table 2 Unusually Common Cystic Fibrosis Mutations in Specific Populationsa Total Exon/ Number Number Frequency Mutation Intron Ethnic Origin Observed Screened (%) 296+12T→C intron 02 Pakistani 02 24 8.33 E60X exon 03 Belgian 06 394 1.52 G91R exon 03 French 04 266 1.50 394delTT exon 03 Scandinavian 78 1588 4.91 457TAT→G exon 04 Austrian 04 334 1.20 Y122X exon 04 Réunion Island 14 29 48.27 I148T exon 04 French Canadian 06 66 9.09 711+5G→A intron 05 Italian (North East) 06 225 2.67 1078delT exon 07 Celtic 27 475 5.68 1161delC exon 07 Pakistani 02 24 8.33 T338I exon 07 Italian, Sardinian 04 86 4.65 Q359K/T360K exon 07 Georgian Jews 07 8 87.50 R347H exon 07 Turkish 04 134 2.98 1609delCA exon 10 Spanish 03 96 3.12 1677delTA exon 10 Bulgarian 05 222 2.25 S549I exon 11 Arabs 02 40 5.00 Q552X exon 11 Italian (North East) 03 225 1.33 A559T exon 11 African-American 02 79 2.53 1811+1.2kbA→G intron 11 Spanish 22 1068 2.06 1898+5G→T intron 12 Chinese 03 10 30.00 1949del84 exon 13 Spanish 02 136 1.47 2143delT exon 13 Russian 04 118 3.39 2183AA→G exon 13 Italian (North East) 21 225 9.33 2184insA exon 13 Russian 03 118 2.54 3120+1G→A intron 16 African-American 14 112 12.50 3272-26A→G intron 17a Portugese, French 06 386 1.55 R1066C exon 17b Portugese 05 105 4.76 R1070Q exon 17b Bulgarian 04 166 2.41 Y1092X exon 17b French Canadian, 11 725 1.52 French M1101K exon 17b Hutterite 22 32 68.75 3821delT exon 19 Russian 03 118 2.54 S1235R exon 19 French (South) 04 340 1.18 S1251N exon 20 Dutch, Belgian 11 792 1.39 S1255X exon 20 African-American 02 79 2.53 3905insT exon 20 Swiss 45 982 4.58 Amish, Arcadian 13 86 15.12 W1282X Exon 20 Jewish-Ashkenazi 50 95 52.63 R1283M exon 20 Welsh 03 183 1.64 aAccording to the Cystic Fibrosis Genetic Analysis Consortium, http://www.genet.sickkids.on.ca/cftr/. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] Extended gene analysis can increase specificity of... Acta Paediatr. 2006 Nov;95(11):1424-8. Merelle ME, Scheffer H, De Jong D, Dankert-Roelse JE
Extended gene analysis can increase specificity of neonatal screening for cystic fibrosis.
Acta Paediatr. 2006 Nov;95(11):1424-8., [PMID:17062471]

Abstract [show]
AIM: To assess whether carriers and patients can be accurately identified by extended gene analysis for cystic fibrosis (CF) in dried blood spots. METHODS: A blinded analysis was performed in 10-mm2 blood spots on Guthrie cards, punched as if to remove material for the IRT test, from 10 CF patients and 10 carriers with known CF mutations. Genomic DNA was isolated. Aliquots of 1 microl dissolved DNA were used for subsequent PCRs. Analysis of the deltaF508 mutation was followed by an oligonucleotide ligation assay. Denaturing gradient gel electrophoresis of the whole CFTR gene was carried out in samples with only one identified mutation. Amplicons revealing an aberrant pattern were sequenced. RESULTS: In all cases, the blood-spot genotype was identical to that previously determined from whole-blood analysis. Estimated time needed to complete the procedure in a series of Guthrie cards was 3-4 wk. CONCLUSION: Extended gene analysis in dried blood spots can discriminate CF patients and carriers. If proven equally reliable in larger series, an approach to neonatal screening in which tests are only considered as screen positive when two CF mutations are found is possible. This can increase the specificity of the screening programme, and carrier detection can practically be avoided.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
58 Results Reliability of the extended gene analysis The following mutations were found in the study population: DF508, 3659delC, R553X, S589N, R1070Q and E60X (Table I). Login to comment
59 The 3659delC, R553X, S589N and R1070Q mutations were identified by OLA analysis. Login to comment
94 Genotypes Number DF508/DF508 5 DF508/3659delC 1 DF508/R553X 1 DF508/S589N 1 DF508/R1070Q 1 DF508/E60X 1 DF508/N 8 3659delC/N 1 S589N/N 1 Total 20 N: no CFTR mutation. Login to comment

[hide] Contribution of the CFTR gene, the pancreatic secr... Clin Genet. 2007 May;71(5):451-7. Tzetis M, Kaliakatsos M, Fotoulaki M, Papatheodorou A, Doudounakis S, Tsezou A, Makrythanasis P, Kanavakis E, Nousia-Arvanitakis S
Contribution of the CFTR gene, the pancreatic secretory trypsin inhibitor gene (SPINK1) and the cationic trypsinogen gene (PRSS1) to the etiology of recurrent pancreatitis.
Clin Genet. 2007 May;71(5):451-7., [PMID:17489851]

Abstract [show]
Acute recurrent/chronic pancreatitis (CP) is a complex multigenic disease. This is a case-control study consisting of 25 Greek patients with CP and a control population of 236 healthy Greek subjects. The whole coding area and neighboring intronic regions of the three genes were screened. Seventeen of 25 patients (68%) had mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene: nine compound heterozygotes with either mild or severe mutations and eight heterozygotes. Four patients (16%) carried CFTR-modulating haplotypes V470-TG11-T5 and V470-TG12-T7. All were negative for PRSS1 gene mutations, while variants c.486C/T and c.738C/T were found in nine patients each, three homozygotes for the minor alleles. Two carried SPINK1 gene mutation p.N34S, one being transheterozygote with CFTR mutation p.F1052V. The promoter variant -253T>C was found in four individuals (one homozygous for the minor allele), all four being transheterozygotes with mutations in the CFTR gene as well. Finally two carried c.272C/T in the 3' untranslated region, one being a p.N34S carrier as well. In total, 80% (20/25) of patients had a molecular defect in one or both of the CFTR and SPINK1 genes, suggesting that mutations/variants in the CFTR plus or minus mutations in the SPINK1, but not the PRSS1 gene, may confer a high risk for recurrent pancreatitis.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
62 Molecular findings for the CFTR gene Eight patients were carriers (16%): three with p.R1070Q and five with p.F508del, p.G576A, p.F1052V, CFTRdel2,3 (21 kb), and c.2752215G/C, each, representing a heterozygote frequency 2.1-fold higher than that found in the 211 general population controls (7.6%, p , 0.0001). Login to comment
83 This could especially apply for p.R334W, p.R347H, p.R1070Q, p.R75Q and c.278915G.A, for which the difference in mutation frequency between patients and classic CF cohort, reached statistical significance (Table 2). Login to comment
88 The function modulating CFTR haplotypes (V470-TG11-T5 and V470-TG12-T7) were found either alone (patient 1650) or more commonly either in compound heterozygosity with p.R1070Q (patient 1523) or in trans-heterozygous state in two cases with c.272C/T SPINK1 variant (Table 1). Login to comment
90 Mutations and variants in the CFTR gene CFTR mutation/variant Patients with pancreatitis, n ¼ 25 (%) Controlsa , n ¼ 211 (%) Classic patients with CF, n ¼ 426 (%) p vs controls p vs patients with CF p.F508del 5 (10) 2 (0.47) 465 (54.6) ,0.0001 ,0.0001 p.R334W 4 (8) - 7 (8.2) 0.00011 0.0019 c.444delA 1 (2) - 1 (0.1) c.278915G.A 2 (4) - 11 (1.3) 0.011 CFTRdel2,3 (21 kb) 1 (2) - 2 (0.2) c.E822X 2 (4) - 12 (1.5) 0.011 p.R347H 1 (2) - - 0.055 p.R1070Q 3 (6) 1 (0.24) 7 (0.8) 0.004 0.013 p.G576A 1 (2) - 1 (0.1) p.F1052V 1 (2) 4 (0.95) 1 (0.1) p.I148T 1 (2) - 1 (0.1) c.3272226A.G 1 (2) - 7 (0.82) p.R75Q 2 (4) 4 (0.95) 1 (0.1) 0.0086 c.2752215G/C 1 (2) 4 (1) 5 (0.6) TG11T7 26 (52) 286 (67.7) ND TG11T5 2 (4) 5 (1.18) ND TG10T7 8 (16) 79 (18.7) ND TG10T9 8 (16) 14 (3.3) ND 0.0005 TG12T7 2 (4) 8 (1.9) ND M470 6 (12) 48 (11.4) ND V470 8 (16) 166 (39.3) ND 0.008 CF, cystic fibrosis; ND, not determined. Login to comment
99 Promoter variant 2253T/C was detected in three patients all trans-heterozygotes with CFTR: two with p.R1070Q, and one with p.G576A. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
90 In some additional examples, a number of mutations found in the fourth intracellular loop (H1054D, G1061R, L1065P, R1066C/H/L, Q1071P, L1077P, H1085R, W1098R, M1101K/ R) also affect the biosynthetic processing of CFTR (although function was not tested) (73); some intracellular loop 4 mutants (F1052V, K1060T, A1067T, G1069R, R1070Q/W) can process CFTR to the complex-glycosylated ("Band C") form but have altered channel activity compared to wild type. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
259 Among these, several missense mutations have been observed for the critical R1070 residue (R1070W, R1070Q, R1070P; http:// www.genet.sickkids.on.ca/cftr/), but no functional data are available for them. Login to comment

[hide] Localization studies of rare missense mutations in... Hum Mutat. 2008 Nov;29(11):1364-72. Krasnov KV, Tzetis M, Cheng J, Guggino WB, Cutting GR
Localization studies of rare missense mutations in cystic fibrosis transmembrane conductance regulator (CFTR) facilitate interpretation of genotype-phenotype relationships.
Hum Mutat. 2008 Nov;29(11):1364-72., [PMID:18951463]

Abstract [show]
We have been investigating the functional consequences of rare disease-associated amino acid substitutions in the cystic fibrosis transmembrane conductance regulator (CFTR). Mutations of the arginine residue at codon 1070 have been associated with different disease consequences; R1070P and R1070Q with "severe" pancreatic insufficient cystic fibrosis (CF) and R1070W with "mild" pancreatic sufficient CF or congenital bilateral absence of the vas deferens. Intriguingly, CFTR bearing each of these mutations is functional when expressed in nonpolarized cells. To determine whether R1070 mutations cause disease by affecting CFTR localization, we created polarized Madin Darby canine kidney (MDCK) cell lines that express either wild-type or mutant CFTR from the same genomic integration site. Confocal microscopy and biotinylation studies revealed that R1070P was not inserted into the apical membrane, R1070W was inserted at levels reduced from wild-type while R1070Q was present in the apical membrane at levels comparable to wild-type. The abnormal localization of CFTR bearing R1070P and R1070W was consistent with deleterious consequences in patients; however, the profile of CFTR R1070Q was inconsistent with a "severe" phenotype. Reanalysis of 16 patients with the R1070Q mutation revealed that 11 carried an in cis nonsense mutation, S466X. All 11 patients carrying the complex allele R1070Q-S466X had severe disease, while 4 out of 5 patients with R1070Q had "mild" disease, thereby reconciling the apparent discrepancy between the localization studies of R1070Q and the phenotype of patients bearing this mutation. Our results emphasize that localization studies in relevant model systems can greatly assist the interpretation of the disease-causing potential of rare missense mutations.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
1 Mutations of the arginine residue at codon 1070 have been associated with different disease consequences; R1070P and R1070Q with ''severe`` pancreatic insufficient cystic fibrosis (CF) and R1070W with ''mild`` pancreatic sufficient CF or congenital bilateral absence of the vas deferens. Login to comment
4 Confocal microscopy and biotinylation studies revealed that R1070P was not inserted into the apical membrane, R1070W was inserted at levels reduced from wild-type while R1070Q was present in the apical membrane at levels comparable to wild-type. Login to comment
5 The abnormal localization of CFTR bearing R1070P and R1070W was consistent with deleterious consequences in patients; however, the profile of CFTR R1070Q was inconsistent with a ''severe`` phenotype. Login to comment
6 Reanalysis of 16 patients with the R1070Q mutation revealed that 11 carried an in cis nonsense mutation, S466X. Login to comment
7 All 11 patients carrying the complex allele R1070Q-S466X had severe disease, while 4 out of 5 patients with R1070Q had ''mild`` disease, thereby reconciling the apparent discrepancy between the localization studies of R1070Q and the phenotype of patients bearing this mutation. Login to comment
27 Patients with R1070W (c.3208C4T; p.Arg1070Trp) have pancreatic sufficient CF or congenital bilateral absence of the vas deference (CBAVD) and a normal life span, whereas patients with R1070Q (c.3209G4A; p.Arg1070Gln) and R1070P (c3209G4C; p.Arg1070Pro) have classic CF with significant clinical features of lung disease, pancreatic insufficiency, and elevated sweat chloride levels [Mickle et al., 2000]. Login to comment
29 However, CFTR with R1070Q had a less severe channel gating abnormality than R1070W and either no defect [Seibert et al., 1996; Mickle et al., 2000] or a milder defect than R1070W upon protein processing [Seibert et al., 1996]. Login to comment
30 These functional studies indicate that the R1070Q mutation should cause a milder phenotype than R1070W, rather than the more severe phenotype observed. Login to comment
32 We therefore hypothesized that the severe CF phenotype attributed to R1070Q was due to a localization defect in native epithelial cells. Login to comment
36 While CFTR bearing R1070W and R1070P displayed localization defects consistent with their associated phenotypes, R1070Q was difficult to distinguish from wild-type CFTR. Login to comment
37 These localization studies prompted a search for alternate explanations for the CF phenotype associated with the R1070Q mutation. Login to comment
85 RESULTS Wild-Type CFTR Is Localized toApical Membranes of MDCK Cells To determine the effect of R1070 mutations on CFTR localization, we expressed heterologous CFTR (wild-type or 1 of 3 CFTR mutants-R1070P, R1070Q, or R1070W) from an FRT integration site in MDCK type II cell lines (Fig. 1A). Login to comment
106 On the other hand, CFTR bearing R1070Q localized primarily to the apical membrane of MDCK cells. Login to comment
107 Staining R1070Q cells with the apical surface dye, WGA, revealed yellow signal (Fig. 2; R1070Q, right column), indicating overlap of green GFP-CFTR and red WGA signals at the apical membrane. Login to comment
108 Green signal was observed in other locations in the cell (Fig. 2; R1070Q, left column) and colocalization of this signal with Na1 /K1 ATPase (Fig. 2; R1070Q, right column) suggests that a minor fraction of R1070Q is present in the basolateral membranes. Login to comment
109 Overall, CFTR R1070Q is preferentially located at the apical membrane, a pattern very similar to that observed for wild-type CFTR. Login to comment
115 CFTR bearing R1070Q is also processed to mature band C protein (Fig. 3A; lane 2) that is accessible to biotinylation at the apical membrane (Fig. 3B; lane 3). Login to comment
116 Thus, wild-type and R1070Q CFTR are processed to fully mature protein that is inserted into the apical membrane, consistent with the localization studies above. Login to comment
125 CFTR R1070P and R1070Wshow di¡erent cellular distribution patterns in polarized epithelial cells, whereas CFTR R1070Q shows an apical localization pattern similar to wild-type CFTR. Login to comment
127 Each panel shows MDCK-FRT cells expressing either wild-type, R1070P, R1070W, or R1070Q CFTR. Login to comment
133 Altered Function of CFTR Bearing R1070W and R1070P Is ConsistentWith Phenotype of Patients CarryingThese Mutations A worldwide survey identified 29 patients who carried the R1070W mutation (24 of whom had detailed clinical information); 26 patients with R1070Q (16 of whom had detailed data), and 2 patients with R1070P (1 of whom had detailed data). Login to comment
150 CFTR R1070Q With an in cis Nonsense Mutation, S466X (c.1397C4G; p.Ser466X), Is Associated With Severe CF Previous studies have reported that patients with R1070Q have classic CF; however, studies shown here indicate that CFTR FIGURE 3. Login to comment
152 A: Western blotting of MDCK cell lysates expressing wild-type, R1070Q, R1070W, or R1070P CFTR. Login to comment
154 CFTR R1070Q (lane 2) has a pattern similar to wild-type, primarily C band with some B band visible. Login to comment
155 The quantity of CFTR R1070Q mutant protein is slightly lower than wild-type CFTR (note actin control loading in lower panel). Login to comment
159 B:Western blotting of the apical biotinylated fraction (odd-numbered lanes) or total lysates (even-numbered lanes) of MDCK cells expressing wild-type, R1070Q, R1070W, or R1070P CFTR.Wild-type CFTR (lanes 1 and 2) and CFTR R1070Q (lanes 3 and 4) have a 205-kDa band in the biotinylated fraction that is consistent with the presence of mature protein in the apical membrane.The fraction of R1070Q inserted into the apical membrane is similar to wild-type.CFTR R1070W (lanes 5 and 6) has a faint 205-kDa band and a very faint 175-kDa band, suggesting that mature and some immature protein is inserted in the apical membrane.CFTR R1070P (lanes 7 and 8) has no bands visible in the biotinylated fraction and only a 175-kDa band is seen in the total lysate, indicating that this mutant protein is not present in the apical membrane.The lower panel is an immunoblot of each apical fraction and each total lysate after incubation with an actin antibody. Login to comment
162 Summarized Clinical Information on R1070 Patients Patient mutations R1070W R1070P R1070Q R1070Q in cis S466X Number of patientsa 24 2 5 11 Second mutaiton dF508 16 1 0 7 other 8 1 5 4 Disease diagnosis CBACD (infertility) 15 0 3 0 Nonclassic CF 9 1 1 0 Classic CF 1 1 1 11 Pancreatic status Su/cient 9 0 1 0 Insu/cient 4a 1 1 10 Not reported 11b 1 3b 1 Sweat chloride levels Normal or low 12 0 1 0 Elevated460 mmol/L 4 1 1 10 Not reported 8b 1 2b 1 a One patient has classic CF; the other three have normal sweat chloride levels and high FVC values. Login to comment
165 R1070Q functions and localizes like wild-type CFTR, suggesting that an alternative mechanism exists to create the severe phenotype associated with the R1070Q mutation. Login to comment
166 A literature review of patients carrying R1070Q uncovered a report that briefly mentioned two Serbian patients with classic CF who carried the R1070Q mutation in cis with S466X, both having the F508del mutation on the other CFTR gene [Radivojevic et al., 2004]. Login to comment
167 We found 14 R1070Q patients with detailed clinical information (16 patients in total when including those of the Radivojevic et al. [2004] group) and sequencing of CFTR exon 10 showed that 11 out of 16 patients carried an in cis S466X mutation (Table 1). Login to comment
168 Seven of these 11 R1070Q-S466X patients had F508del as the other allele and the remaining four had a variety of CF alleles in trans, one each of N1303 K, 62111G4T (c.48911G4T), 7111 3A4G (c.57913A4G), and R1070Q-S466X (Supplementary Table S1). Login to comment
169 Regardless of the CF mutation on the other CFTR gene, all 11 R1070Q-S466X patients had pancreatic insufficient CF. Login to comment
170 Of the five patients with R1070Q only, three had CBAVD and two were diagnosed as CF. Login to comment
174 In summary, R1070Q alone appears to be able to confer mild disease (i.e., CBAVD) in some cases when paired with a known ''severe`` CF mutation, while the presence of the in cis S466X mutation was consistently associated with pancreatic-insufficient CF. Login to comment
178 Prior studies had evaluated the effect of R1070Q in nonpolarized cells [Cotten et al., 1996; Seibert et al., 1996; Mickle et al., 2000]. Login to comment
180 We had hypothesized that the severe CF phenotype associated with the R1070Q mutation was caused by abnormal trafficking of CFTR to apical membranes. Login to comment
181 However, CFTR bearing R1070Q localizes to apical membranes in a manner that is qualitatively similar to wild-type CFTR. Login to comment
182 This result led to new theories explaining the phenotype associated with R1070Q that ranged from underestimation of the chloride transport defect to lack of interaction with the macromolecular complex at the apical membrane. Login to comment
183 Before embarking on more detailed analysis of R1070Q CFTR properties, the clinical features of patients bearing this mutation were revisited to confirm its propensity to cause disease. Login to comment
184 Additionally, other deleterious variants that may exist in the CFTR gene bearing R1070Q were considered. Login to comment
185 A literature review uncovered a report that the nonsense mutation S466X had been found in cis with R1070Q in two patients [Radivojevic et al., 2004]. Login to comment
186 Demonstration that S466X correlated with the CF phenotype in 11 patients combined with the known severe functional consequences of nonsense mutations (nonsense-mediated RNA decay or, less commonly, protein truncation) indicated that S466X, rather than R1070Q, was responsible for the observed severe phenotype. Login to comment
187 Thus, functional studies were informative for all three R1070 mutations, whereby R1070P and R1070W revealed processing defects that are consistent with their role in disease, while the properties of CFTR bearing R1070Q provoked a reevaluation of the established genotype-phenotype relationship that led to a more plausible explanation for the pathology observed in patients with a glutamine substitution at codon 1070. Login to comment
199 The presence of nonsense mutation S466X in CFTR genes bearing R1070Q provides a parsimonious explanation for the CF phenotype in patients with this combination. Login to comment
200 However, the five patients carrying R1070Q alone manifested phenotypes ranging from male infertility (mild) to pancreatic insufficient CF (severe). Login to comment
201 While it is possible that the severe phenotype was due to other environmental factors, genetic modifiers, or erroneous information, the abnormal clinical features in the remaining four patients indicate that R1070Q has some deleterious effect upon CFTR function. Login to comment
202 This conclusion is consistent with the observation that CFTR R1070Q has a reduced steady-state protein level compared to CFTR wild type in MDCK cells. Login to comment
203 On the other hand, studies in nonpolarized COS-1 cells showed wild-type-like levels of R1070Q protein yet generation of only one-half the chloride efflux of wild-type cells; additionally, R1070Q had normal levels of conductance in CHO cells but a decreased open probability [Seibert et al., 1996]. Login to comment
204 One or more of these moderate dysfunctions caused by R1070Q may explain why it is associated with disease of varying severity when appearing alone. Login to comment
205 The combination of R1070Q and S466X adds to the growing list of complex alleles reported in CFTR [Claustres et al., 2000]. Login to comment
208 Similarly, interpretation of the clinical spectrum associated with R1070Q also requires determination of the presence or absence of S466X. Login to comment

[hide] Molecular models of the open and closed states of ... Cell Mol Life Sci. 2009 Nov;66(21):3469-86. Epub 2009 Aug 26. Mornon JP, Lehn P, Callebaut I
Molecular models of the open and closed states of the whole human CFTR protein.
Cell Mol Life Sci. 2009 Nov;66(21):3469-86. Epub 2009 Aug 26., [PMID:19707853]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR), involved in cystic fibrosis (CF), is a chloride channel belonging to the ATP-binding cassette (ABC) superfamily. Using the experimental structure of Sav1866 as template, we previously modeled the human CFTR structure, including membrane-spanning domains (MSD) and nucleotide-binding domains (NBD), in an outward-facing conformation (open channel state). Here, we constructed a model of the CFTR inward-facing conformation (closed channel) on the basis of the recent corrected structures of MsbA and compared the structural features of those two states of the channel. Interestingly, the MSD:NBD coupling interfaces including F508 (DeltaF508 being the most common CF mutation) are mainly left unchanged. This prediction, completed by the modeling of the regulatory R domain, is supported by experimental data and provides a molecular basis for a better understanding of the functioning of CFTR, especially of the structural features that make CFTR the unique channel among the ABC transporters.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
34 In contrast, the protein with the R1070Q mutation was found to be located at the apical membrane of the polarized epithelial cells [23]. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
98 Diagnostic features in 42 D1152H subjects according to the other CFTR mutation class Subject Sex (M/F) Other CFTR mutation Sweat Cl- mean (mmol/l) Age at diagnosis (years) Presentation at diagnosis Class I mutations 1 F W1282X 58 4 Pneumonia recurrent bronchitis 2 F W1282X 25 74 Bronchiectasis 3 M W1282X 43 33 CBAVD 4 M G542X 48 39 CBAVD 5 M G542X 72 27 CBAVD 6 F S1206X 18 13 Recurrent bronchitis+ diarrhea 7 F 394delTT 19 41 Bronchiectasis 8 F 394delTT 25 18 Bronchiectasis 9 F Q552X 56 43 Bronchiectasis Class II mutations 10 F F508del 13 42 Bronchiectasis 11 F F508del 40 32 Bronchiectasis 12 F F508del 52 23 Bronchiectasis 13 M F508del 51 15 Bronchiectasis 14 F F508del 100 24 Bronchiectasis 15 M F508del 79 26 Bronchiectasis 16 F F508del - 43 Bronchiectasis 17 M F508del - 23 Bronchiectasis 18 F F508del 19 55 Bronchiectasis 19 F F508del 25 33 Bronchiectasis 20 F F508del 78 15 Bronchiectasis 21 M F508del 90 40 Bronchiectasis 22 F F508del 44 42 Bronchiectasis 23 M F508del 88 11 Bronchiectasis 24 F F508del 63 47 Bronchiectasis 25 F F508del 43 33 Bronchiectasis 26 M F508 del 62 49 Bronchiectasis 27 M F508del 20 - CBAVD 28 M F508del - 27 CBAVD 29 M F508del 42 36 CBAVD 30 M F508del 36 34 CBAVD 31 M F508del 40 36 CBAVD 32 M F508del 41 30 CBAVD 33 M F508del 82 9 Asymptomatic genetic counseling 34 M F508del - 0 Neonatal screening 35 F F508del 53 0 Neonatal screening 36 F F508del 35 0 Neonatal screening 37 M F508del 35 0 Neonatal screening Class III mutation 38 F S549N 75 31 Bronchiectasis Class IV mutations 39 M E116K 80 41 ABPA+ diarrhea 40 M D1152H 34 34 CBAVD 41 M R1070Q 56 38 CBAVD Class V mutation 42 M 3849+10kbC>T 31 40 Asymptomatic genetic counseling ABPA, allergic bronchopulmonary aspergillosis; CBAVD, congenital bilateral absence of the vas deferens. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
97 CF mutation General adult population MAR population n=1879 n=236 ΔF508 42.6 45.7 2183AA→G 5.9 5.9 R1162X 5.7 8.2 N1303K 5.4 5.9 G542X 4.2 3.7 D1152H 3.9 5.0 R553X 3.7 3.1 R117H 3.3 1.8 711+5G→A 2.8 4.1 Q552X 2.8 0.4 2789+5G→A 2.2 3.1 1717-1G→A 2.6 2.8 E527G 2.4 - G85E 2.4 0.9 R334Q 0.9 0.4 W1282X 0.7 0.9 R334W 0.6 - 1898+3A→G 0.5 0.4 R1158X 0.4 - R1066H 0.4 0.4 T338I 0.4 1.8 3849+10Kb C→T 0.4 1.3 3272-26 A→G - 0.9 3132delTG - 0.9 3659 del C - 0.4 4016 ins T - 0.4 1717-8G→A - 0.4 R347H - 0.4 ΔI507 - 0.4 R1070Q - 0.4 Other (16) 5.4 - Table 2a List of CFTR compound heterozygotes in the adult general population. Mutation Health status Disorder Gender Age (years) Notes and refs ΔF508/A238V Infertile CBAVD M 36 (A) ΔF508/R352W Infertile CBAVD M 45 (A) R553X/R334Q M 38 ΔF508/R347H M 53 [17] S42F/D372E (1251T→G) M 39 (A) (B) ΔF508/D110H Infertile M 38 ΔF508/L1414S (4373T→C) Infertile CBAVD M 44 (A) (B) ΔF508/V201M, D1270N & R74W Infertile CBAVD M 44 (A) [18,19] 2183AA→G/L206W Infertile CBAVD M 40 (A) 711+5G→A/ L206W Infertile CBAVD M 40 (A) Table 2b List of CFTR compound heterozygotes in the population enrolled for medically assisted reproduction. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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

[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%.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] Relationships between nasal potential difference a... Eur Respir J. 1998 Dec;12(6):1295-300. Fajac I, Hubert D, Bienvenu T, Richaud-Thiriez B, Matran R, Kaplan JC, Dall'Ava-Santucci J, Dusser DJ
Relationships between nasal potential difference and respiratory function in adults with cystic fibrosis.
Eur Respir J. 1998 Dec;12(6):1295-300., [PMID:9877480]

Abstract [show]
This study investigated the relations between nasal transepithelial electric potential difference (PD) and the phenotype and genotype of cystic fibrosis (CF) adult patients. Basal nasal PD was measured in 95 adult CF patients who were classified into three groups of nasal PD (expressed as absolute values) according to the 10th and the 90th percentiles (28.3 and 49.2 mV, respectively), which defined group 1 (nasal PD < or =28.3 mV), group 2 (nasal PD 28.3-49.2 mV) and group 3 (nasal PD > or =49.2 mV). Patients from group 1 had a higher forced vital capacity (FVC) than patients from groups 2 and 3 (76.5+/-22.4 versus 57.4+/-21.2 and 55.7+/-21.1% predicted, respectively, p<0.05) and a higher forced expiratory volume in one second (FEV1) (69.3+/-24.0 versus 42.5+/-22.4 and 42.2+/-21.4% pred, respectively, p<0.01). Among patients with severe mutations (deltaF508 homozygotes, or one deltaF508 mutation plus another "severe" mutation, or two "severe" mutations), patients from group 1 had a higher FVC, FEV1 and arterial oxygen tension than patients from groups 2 and 3 (p<0.05 for each comparison). The results show that in adult cystic fibrosis patients a normal basal nasal potential difference is related to milder respiratory disease, irrespective of the severity of the genotype.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
34 Only three patients had a normal sweat test: one was homozygotic for the ∆F508 mutation and two patients were compound heterozygotic for the G542X and 3849+10 kb cytosine (C) → thymine (T) mutations and for the R1070Q and D1152H mutations, respectively. Login to comment
131 ∆F508/W846X ∆F508/∆F508 ∆F508/∆F508 ∆I507/Q980X ∆F508/∆F508 ∆F508/∆F508 ∆F508/∆F508 R1070Q/? Login to comment

[hide] Genetic aspects of tropical calcific pancreatitis. Rev Endocr Metab Disord. 2008 Sep;9(3):213-26. Witt H, Bhatia E
Genetic aspects of tropical calcific pancreatitis.
Rev Endocr Metab Disord. 2008 Sep;9(3):213-26., [PMID:18604651]

Abstract [show]
Tropical calcific pancreatitis (TCP) is a subtype of chronic pancreatitis which is unique to tropical regions. Patients present at young age with recurrent abdominal pain, nutritional deficiencies, and insulin-requiring diabetes. For a long time, the aetiology of this disorder was poorly understood. Several environmental factors, such as malnutrition or the consumption of toxic food components such as cyanogenic glycosides, were proposed as pathogenic factors. In the last decade, a major impact on the understanding of the aetiology of TCP has come from genetic studies on hereditary and idiopathic chronic pancreatitis. Genetic alterations in at least five genetic loci are clearly associated with chronic pancreatitis in the Western world. These include alterations in genes coding for trypsinogens, the most abundant digestive enzymes (PRSS1 and PRSS2), the trypsin inhibitor (SPINK1) and the trypsin-degrading enzyme, chymotrypsinogen C (CTRC). In addition, alterations in the cystic fibrosis (CFTR) gene are associated with idiopathic pancreatitis. TCP clinically resembles non-alcoholic chronic pancreatitis of Western countries, suggesting that similar genetic defects might also be of importance in this disease entity. Indeed, alterations in at least two genes, SPINK1 and CTRC, are strongly associated with TCP. The current review focuses on the recent developments in the understanding of the genetic basis of inherited pancreatitis, with special emphasis on TCP.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
271 Two patients (11%) showed a CFTR variant: one subject was homozygous for 5T and the other heterozygous for p.R1070Q, which is presumed to be a mild missense variant. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
60 From the total number of 128 patients with CF we detected both mutations in the majority of them (77), one mutation in 30 Table 2 Distribution of CFTR gene mutations in the group of 128 patients with CF Mutation Number of chromosomes Percent of chromosomes (128 patients, 256 chromosomes) Cumulative frequency F508del 144 56.3% 56.3% G542X 10 3.9% 60.2% W1282X 6 2.3% 62.5% CFTRdele2,3(21 kb) 4 1.6% 64.1% 621+1GNT 2 0.8% 64.8% N1303K 2 0.8% 65.6% 2183AANG 2 0.8% 66.4% R1070Q 2 0.8% 67.2% 457TATNG 1 0.4% 67.6% R117H 1 0.4% 68.0% R334W 1 0.4% 68.4% R735K 1 0.4% 68.8% R785X 1 0.4% 69.1% E831X 1 0.4% 69.5% 3849+10 kb(CNT) 1 0.4% 69.9% R1162X 1 0.4% 70.3% 3272-26ANG 1 0.4% 70.7% 1677delTA 1 0.4% 71.1% 1717-2ANG 1 0.4% 71.5% E585X 1 0.4% 71.9% 2789+5GNA 1 0.4% 72.3% Unknown 71 27.7% 100.0% Total 256 100.0% Fig. 1. Login to comment
92 Regarding the mutations detected, we noted a moderate heterogeneity with 21 mutations detected, the Table 3 Distribution of genotypes in CF patients from Romania (n=128; 256 chromosomes) Genotype Number Ethnicity F508del/F508del 46 Romanian 42 Hungarian 3 Gypsy 1 F508del/x 25 Romanian 23 Hungarian 1 Turkish-Romanian 1 F508del/G542X 8 Romanian F508del/CFTRdele2,3(21 kb) 4 Romanian 3 Hungarian 1 F508del/W1282X 3 Romanian F508del/F508del/R117H 1 Romanian F508del/R334W 1 Romanian F508del/621+1GNT 1 Romanian F508del/N1303K 1 Romanian F508del/2183AANG 1 Romanian F508del/3849+10 kb(CNT) 1 Romanian F508del/3272-26ANG 1 Romanian F508del/R1162X 1 Romanian F508del/R785X 1 Romanian F508del/1717-2ANG 1 Romanian F508del/2789+5GNA 1 Romanian G542X/G542X 1 Romanian W1282X/W1282X 1 Romanian N1303K/457TATNG 1 Romanian 621+1GNT/2183AANG 1 Romanian W1282X/x 1 Romanian R1070Q/E585X 1 Romanian R1070Q/x 1 Romanian E831X/x 1 Gypsy R735K/x 1 Romanian 1677delTA/x 1 Romanian x/x 21 Romanian 18 Hungarian 2 Gypsy 1 presence of common mutations (excepting the Celtic mutation G551D), and a similarity with the mutations detected in Italy, France and Spain [5]. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
54 (5) In one case this mutation has been found in cis with the R1070Q variant. Login to comment

[hide] MBL2 polymorphisms screening in a regional Italian... J Cyst Fibros. 2005 Sep;4(3):189-91. Trevisiol C, Boniotto M, Giglio L, Poli F, Morgutti M, Crovella S
MBL2 polymorphisms screening in a regional Italian CF Center.
J Cyst Fibros. 2005 Sep;4(3):189-91., [PMID:16046196]

Abstract [show]
We performed MBL2 genotyping in 47 CF patients-cared of at the regional CF Centre of Trieste-trying to establish a correlation within allelic variants of MBL2 and modification of patients' clinical outcome. FEV1 values were significantly lowered and a significantly earlier age at onset of Pseudomonas aeruginosa colonisation was found in CF patients with at least one MBL2 variant.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
42 Table 4 CFTR and MBL2 genotypes CFTR genotypes MBL2 genotypes AA A0 00 Severe/Severe CFTR genotype deltaF508/deltaF508 (20) 10 8 2 deltaF508/N1303K (1) 0 1 0 deltaF508/621+1GYT (3) 2 1 0 1717-1GYA/1717-1GYA (1) 1 0 0 deltaF508/1677delTA (1) 1 0 0 G542X/G542X (1) 0 1 0 deltaF508/1717-1GYA (1) 0 1 0 Total 28 14 12 2 Mild; unknown/unknown CFTR genotype R1162X/2789+5GYA (6) 3 3 0 2183 AAYG/4016insT (4) 2 2 0 R1162X/R1162X (3) 1 2 0 DI507/2183 AAYG (4) 2 1 0 S466X/R1070Q; T (2) 2 1 0 Total 19 10 9 0 C. Trevisiol et al. / Journal of Cystic Fibrosis 4 (2005) 189-191190 0/0 CF patients (6.29 years) when compared to A/A patients (11.24; p =0.037). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
53 Table 1. Continued CFTR location Amino acid change Nucleotide change 141 IVS 16 Splicing defect 3120 ϩ 1GϾA 142 IVS 16 Splicing defect 3121 - 2AϾG 143 IVS 16 Splicing defect 3121 - 2AϾT 144 E 17a Frameshift 3132delTG 145 E 17a I1005R 3146TϾG 146 E 17a Frameshift 3171delC 147 E 17a Frameshift 3171insC 148 E 17a del V1022 and I1023 3199del6 149 E 17a Splicing defect 3271delGG 150 IVS 17a Possible splicing defect 3272 - 26AϾG 151 E 17b G1061R 3313GϾC 152 E 17b R1066C 3328CϾT 153 E 17b R1066S 3328CϾA 154 E 17b R1066H 3329GϾA 155 E 17b R1066L 3329GϾT 156 E 17b G1069R 3337GϾA 157 E 17b R1070Q 3341GϾA 158 E 17b R1070P 3341GϾC 159 E 17b L1077P 3362TϾC 160 E 17b W1089X 3398GϾA 161 E 17b Y1092X (TAA) 3408CϾA 162 E 17b Y1092X (TAG) 3408CϾG 163 E 17b L1093P 3410TϾC 164 E 17b W1098R 3424TϾC 165 E 17b Q1100P 3431AϾC 166 E 17b M1101K 3434TϾA 167 E 17b M1101R 3434TϾG 168 IVS 17b 3500 - 2AϾT 3500 - 2AϾT 169 IVS 17b Splicing defect 3500 - 2AϾG 170 E 18 D1152H 3586GϾC 171 E 19 R1158X 3604CϾT 172 E 19 R1162X 3616CϾT 173 E 19 Frameshift 3659delC 174 E 19 S1196X 3719CϾG 175 E 19 S1196T 3719TϾC 176 E 19 Frameshift and K1200E 3732delA and 3730AϾG 177 E 19 Frameshift 3791delC 178 E 19 Frameshift 3821delT 179 E 19 S1235R 3837TϾG 180 E 19 Q1238X 3844CϾT 181 IVS 19 Possible splicing defect 3849 ϩ 4AϾG 182 IVS 19 Splicing defect 3849 ϩ 10 kb CϾT 183 IVS 19 Splicing defect 3850 - 1GϾA 184 E 20 G1244E 3863GϾA 185 E 20 G1244V 3863GϾT 186 E 20 Frameshift 3876delA 187 E 20 G1249E 3878GϾA 188 E 20 S1251N 3884GϾA 189 E 20 T1252P 3886AϾC 190 E 20 S1255X 3896CϾA and 3739AϾG in E19 191 E 20 S1255L 3896CϾT 192 E 20 Frameshift 3905insT 193 E 20 D1270N 3940GϾA 194 E 20 W1282R 3976TϾC 195 E 20 W1282X 3978GϾA 196 E 20 W1282C 3978GϾT 197 E 20 R1283M 3980GϾT 198 E 20 R1283K 3980GϾA 199 IVS 20 Splicing defect 4005 ϩ 1GϾA 200 E 21 Frameshift 4010del4 201 E 21 Frameshift 4016insT 202 E 22 Inframe del E21 del E21 203 E 21 N1303K 4041CϾG 204 E 24 Frameshift 4382delA Genomic and Synthetic Template Samples Where possible, native genomic DNA was collected. 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]

Abstract [show]

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
246 Mutations in TMD2 cluster in ␣-helix a loop between predicted ␣-helices 10 and 11 and include R1030E, R1066H, R1066C, R1066L, and R1070Q (100). Login to comment

[hide] Genotype-phenotype relationships in a cohort of ad... Eur Respir J. 1996 Nov;9(11):2207-14. Hubert D, Bienvenu T, Desmazes-Dufeu N, Fajac I, Lacronique J, Matran R, Kaplan JC, Dusser DJ
Genotype-phenotype relationships in a cohort of adult cystic fibrosis patients.
Eur Respir J. 1996 Nov;9(11):2207-14., [PMID:8947061]

Abstract [show]
In cystic fibrosis (CF), relationships between genotype and phenotype have been shown for pancreatic status but not for pulmonary disease. One hundred and ten adult CF patients were classified according to the expected effect of their mutations on cystic fibrosis transmembrane conductance regulator (CFTR) protein: Group 1 (n=48) included deltaF508 homozygotes; Group 2 (n=26), patients with two "severe" mutations and no expected CFTR production; Group 3 (n=17), patients with expected partly functional CFTR corresponding to at least one "mild" mutation; Group 4 (n=19), patients with no mutation identified or only one identified "severe" mutation. As compared to Groups 1 and 2: patients from Groups 3 and 4 had higher arterial oxygen tension (Pa,O2) (9.5+/-1.9 and 9.9+/-1.5 vs 8.8+/-1.5 and 8.3+/-1.7 kPa, respectively p<0.02); and a slower decline in their pulmonary function, estimated by the mean annual loss in forced vital capacity (FVC) (1.2+/-1.0 and 1.5+/-1.1 vs 2.0+/-0.9 and 2.2+/-1.0%, respectively; p<0.01) and in forced expiratory volume in one second (FEV1) (1.7+/-1.1 and 1.9+/-1.3 vs 2.6+/-1.0 and 2.8+/-1.0%, respectively; p<0.005). They had fewer episodes of colonization of the airways by Pseudomonas aeruginosa, and colonization occurred at a more advanced age (median age 25 and 19 vs 15 and 17 yrs, respectively; p<0.01) and required fewer intravenous antibiotic courses (p<0.01). Pancreatic insufficiency was less frequent in Groups 3 (23%) and 4 (63%) than in Groups 1 (100%) and 2 (96%). This study suggests that the phenotype of adult cystic fibrosis patients, including the severity of the lung disease, is related to the severity of the cystic fibrosis transmembrane conductance regulator mutations.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
32 Only three patients had a normal sweat test: two related patients, who were compound heterozygotes for the G542X and 3849+10 kb cytosine (C)→thymine (T) mutations, and one patient who was compound heterozygote for the R1070Q and D1152H mutations. Login to comment
77 - Genotype of the 110 CF patients: details of the CF mutations and classification into four groups Genotype Genotype Pts groups n 1 ∆F508/∆F508 48* 2 ∆F508/G542X 6 ∆F508/E827X 3† ∆F508/R553X 2 ∆F508/W1282X 2 ∆F508/E595X 1 ∆F508/E60X 1 ∆F508/W846X 1 ∆F508/1078delT 1 ∆F508/2143delT 1 ∆F508/2347delG 1 ∆F508/3659delC 1 ∆F508/4382delA 1 ∆F508/2183 AA→G 1 ∆F508/1717-1 G→A 1 ∆F508/1811+1.6 kb A→G 1 E595X/Y1092X 1 1717-1 G→A/1078delT 1 3 ∆F508/I336K 1 ∆F508/G27E 1 ∆F508/D192N 1 ∆F508//I980K 1 ∆F508/P205S 1 ∆F508/2789+5 G→A 1 ∆F508/3272-26 A→G 1 G542X/3849+10 kb C→T 2‡ G542X/2789+5 G→A 1 W361R/297-3 C→T 1 G551D/1717-1 G→A 1 N1303H/2183 AA→G 1 2789+5 Gș2;A/2183 AA→G 1 R1070Q/D1152H 1 R1070Q/unidentified 1 S1251N/unidentified 1 4 ∆F508/unidentified 7 ∆I507/unidentified 2 1811+1.6 kb A→G/unidentified 1 1161delC/unidentified 1 unidentified/unidentified 8 *: two patients are brothers; †: three brothers; ‡: two sisters. Login to comment

[hide] Effect of cystic fibrosis-associated mutations in ... J Biol Chem. 1996 Aug 30;271(35):21279-84. Cotten JF, Ostedgaard LS, Carson MR, Welsh MJ
Effect of cystic fibrosis-associated mutations in the fourth intracellular loop of cystic fibrosis transmembrane conductance regulator.
J Biol Chem. 1996 Aug 30;271(35):21279-84., [PMID:8702904]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) contains multiple membrane spanning sequences that form a Cl- channel pore and cytosolic domains that control the opening and closing of the channel. The fourth intracellular loop (ICL4), which connects the tenth and eleventh transmembrane spans, has a primary sequence that is highly conserved across species, is the site of a preserved sequence motif in the ABC transporter family, and contains a relatively large number of missense mutations associated with cystic fibrosis (CF). To investigate the role of ICL4 in CFTR function and to learn how CF mutations in this region disrupt function, we studied several CF-associated ICL4 mutants. We found that most ICL4 mutants disrupted the biosynthetic processing of CFTR, although not as severely as the most common DeltaF508 mutation. The mutations had no discernible effect on the channel's pore properties; but some altered gating behavior, the response to increasing concentrations of ATP, and stimulation in response to pyrophosphate. These effects on activity were similar to those observed with mutations in the nucleotide-binding domains, suggesting that ICL4 might help couple activity of the nucleotide-binding domains to gating of the Cl- channel pore. The data also explain how these mutations cause a loss of CFTR function and suggest that some patients with mutations in ICL4 may have a milder clinical phenotype because they retain partial activity of CFTR at the cell membrane.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
81 For example, levels of mature F1052V were similar to wild-type, whereas L1065P, R1070Q, and H1085R were similar to ⌬F508 in that they produced little mature protein (Fig. 2, A and B). Login to comment
80 For example, levels of mature F1052V were similar to wild-type, whereas L1065P, R1070Q, and H1085R were similar to DF508 in that they produced little mature protein (Fig. 2, A and B). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
64 The mature forms of the other six mutants (F1052V, K1060T, A1067T, G1069R, R1070W, R1070Q) were produced in relatively normal amounts (band C), although for A1067T and R1070W CFTR the ratio of the complex-glycosylated to core-glycosylated bands was significantly lower than for wild-type CFTR. Login to comment
82 A1067T, R1070W, and R1070Q CFTR had significantly lower efflux levels and significantly lower protein expression than wild-type CFTR in COS-1 cells. Login to comment
128 B: छ, WT; E, G1069R; µ, R1070Q; Ç, R1070W; Ⅺ, control. Login to comment
132 Different substitutions at the same residue always produced the same effect, i.e. R1066C, R1066H, and R1066L, as well as M1101K and M1101R all inhibited maturation, whereas R1070W and R1070Q were both normally processed. Login to comment
142 A, examples of wild-type, F1052V, K1060T, A1067T, G1069R, R1070Q, and R1070W CFTR single channel currents recorded from inside-out membrane patches at a membrane potential of -30 mV. Login to comment
71 The mature forms of the other six mutants (F1052V, K1060T, A1067T, G1069R, R1070W, R1070Q) were produced in relatively normal amounts (band C), although for A1067T and R1070W CFTR the ratio of the complex-glycosylated to core-glycosylated bands was significantly lower than for wild-type CFTR. Login to comment
89 A1067T, R1070W, and R1070Q CFTR had significantly lower efflux levels and significantly lower protein expression than wild-type CFTR in COS-1 cells. Login to comment
134 B: L, WT; E, G1069R; &#b5;, R1070Q; &#c7;, R1070W; M, control. Login to comment
138 Different substitutions at the same residue always produced the same effect, i.e. R1066C, R1066H, and R1066L, as well as M1101K and M1101R all inhibited maturation, whereas R1070W and R1070Q were both normally processed. Login to comment
148 A, examples of wild-type, F1052V, K1060T, A1067T, G1069R, R1070Q, and R1070W CFTR single channel currents recorded from inside-out membrane patches at a membrane potential of 230 mV. Login to comment

[hide] Mutation analysis of ten exons of the CFTR gene in... Hum Genet. 1995 Sep;96(3):364-6. Kanavakis E, Tzetis M, Antoniadi T, Traeger-Synodinos J, Doudounakis S, Adam G, Matsaniotis N, Kattamis C
Mutation analysis of ten exons of the CFTR gene in Greek cystic fibrosis patients: characterization of 74.5% of CF alleles including one novel mutation.
Hum Genet. 1995 Sep;96(3):364-6., [PMID:7544320]

Abstract [show]
To initiate the complete characterization of mutations in the CFTR gene in Greek cystic fibrosis (CF) patients, we screened 184 patients for six relatively common mutations (delta F 508, G542X, G551D, 621 + 1 G-->T, N1303K, W1282X) using allele-specific hybridization and, in addition, analyzed exons 4, 5, 7, 8, 10, 11, 17b, 19, 20 and 21 using the method of denaturing gradient gel electrophoresis (DGGE). Six mutations accounted for 65.9% of the CF alleles in Greek patients, of which the delta F 508 mutation had a frequency of 52.7%. A further 15 previously described mutations accounted for another 8.3% CF alleles and one previously undescribed mutation (3272-4A-->G) was found in one chromosome. The W1282X mutation was not detected at all. Thus, so far, we have identified 21 mutations in the CFTR gene in Greek CF patients, accounting for 74.5% of the CF alleles.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
26 (ASO allele-specific hybridization, DGGE denaturing gradient gel electrophoresis, Seq direct genomic sequencing) Mutation Method Number of Percentage positive alleles AF 508 621+lG---~T G542X N1303K Rll7H R334W 574delA 3272-26A---~G R1158X 1677delTA R1070Q G551D G 1244V R553X 444delA 3849+4A---)G 457-TAT--)G 4010delTATT 4040delA W361R 3272-4A--)Ga Known Unknown Total number alleles ASO, DGGE ASO, DGGE ASO, DGGE ASO, DGGE DGGE, Seq DGGE, Seq DGGE, Seq DGGE, Seq DGGE, Seq DGGE DGGE, Seq ASO, DGGE DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec DGGE, Sec 194 52.7 17 4.6 16 4.3 14 3.8 4 1.1 4 1.1 3 0.8 3 0.8 3 0.8 3 0.8 2 0.5 2 0.5 1 0.3 1 O.3 1 0.3 1 0.3 1 0.3 1 0.3 1 0.3 1 0.3 1 0.3 274 74.5% 94 25.5% 368 aNovel mRNA splicing mutations Acknowledgements This work was supported by the Greek Ministry of Health, the Hellenic Cystic Fibrosis Association and the Bodosakis Foundation. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence 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

[hide] A cluster of cystic fibrosis mutations in exon 17b... J Med Genet. 1994 Sep;31(9):731-4. Mercier B, Lissens W, Novelli G, Kalaydjieva L, de Arce M, Kapranov N, Canki Klain N, Estivill X, Palacio A, Cashman S, et al.
A cluster of cystic fibrosis mutations in exon 17b of the CFTR gene: a site for rare mutations.
J Med Genet. 1994 Sep;31(9):731-4., [PMID:7529319]

Abstract [show]
Intensive screening has improved our understanding of the profile of mutations in the CFTR gene in which more than 400 mutations have been detected to date. In collaboration with several European laboratories we are involved in such analysis. We have identified 14 new mutations in exon 17b of CFTR, having analysed 780 CF chromosomes, and have compared the frequency of mutations in this exon with that of other regions of the CFTR gene. The results obtained indicate an accumulation of mutations, not only in regions encoding the two nucleotide binding folds, but also in those encoding transmembrane domains of the CFTR gene, in particular exon 17b.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
19 Most of these are missense mutations and as no functional test has been 732 Table 1 Mutations identified in exon 17b of the CFTR gene Mutation Nucleotide Modificationl Ethnic Rcferencesposition ongini (No) 3271-1 G--A 3272-1 G-A Belgian (1) 11F1052V 3286 T-G Belgian (1) 11HI054D 3292 CG French (1) 13G1061R 3313 G-C French (1) 113320 Dup 3320 Duplication of Breton (1) 6 CTATG R1066C 3328 CT French (1) 14 R1066L R1066H A1067T G1069R R1070Q 3359 del CT L1077P H1085R W1089X Y1092X M1IOIR 3329 3329 3331 3337 3341 G-T G-+A G-A G,A G--A 3359 3362 3386 3398 3408 3434 del CT T--C A-.G G-+A C +A T--G Spanish (5) French (1) Breton (1) Breton (1) Bulgarian (1) Bulgarian (3) Rumanian (1) Albanian (1) French (1) Italian (1) French (1) Spanish (1) French (4) Turkish (1I) * Bozon et al, personal communication. Login to comment
33 (1) HI085R, (2) 3320 ins 5, (3) R1066C, (4)R1066H, (5) A1067V, (6) 3272-16 GA, (7) F1052V, (8) R1070Q, (9) nornmal, (10) Y1092X, (11) G1069R,(12) nornial A cluster of cystic fibrosis mutations in exon I 7b of the CFTR gene: a site for rare mutations 14b, 17a, 23, 24) (table 3). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence 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] 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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
34 One of these was a British Caucasian whose genotype was AFJ08/R347H and the second, a Pakistani Asian, was heterozygous for the S549N and R1070Q mutations (Table 1). Login to comment

[hide] Effects of cystic fibrosis and congenital bilatera... Am J Hum Genet. 2000 May;66(5):1485-95. Epub 2000 Apr 4. Mickle JE, Milewski MI, Macek M Jr, Cutting GR
Effects of cystic fibrosis and congenital bilateral absence of the vas deferens-associated mutations on cystic fibrosis transmembrane conductance regulator-mediated regulation of separate channels.
Am J Hum Genet. 2000 May;66(5):1485-95. Epub 2000 Apr 4., [PMID:10762539]

Abstract [show]
The protein defective in cystic fibrosis (CF), the CF transmembrane-conductance regulator (CFTR), functions as an epithelial chloride channel and as a regulator of separate ion channels. Although the consequences that disease-causing mutations have on the chloride-channel function have been studied extensively, little is known about the effects that mutations have on the regulatory function. To address this issue, we transiently expressed CFTR-bearing mutations associated with CF or its milder phenotype, congenital bilateral absence of the vas deferens, and determined whether mutant CFTR could regulate outwardly rectifying chloride channels (ORCCs). CFTR bearing a CF-associated mutation in the first nucleotide-binding domain (NBD1), DeltaF508, functioned as a chloride channel but did not regulate ORCCs. However, CFTR bearing disease-associated mutations in other domains retained both functions, regardless of the associated phenotype. Thus, a relationship between loss of CFTR regulatory function and disease severity is evident for NBD1, a region of CFTR that appears important for regulation of separate channels.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
52 The mutations R1070P and R1070Q were created directly in pRSV-CFTR, by use of a transformer site-directed mutagenesis kit (Clontech). Login to comment
68 Mutations at codon 1070 of TMD2 were selected, since two mutations (R1070P and R1070Q) have been associated with CF, whereas a third (R1070W) has been observed in men with CBAVD (table 1). Login to comment
91 Thus, mutations R1070Q and R1070W altered but did not prohibit complex glycosylation. Login to comment
97 OF CASES PHENOTYPE Lung Status Pancreatic Status Sweat Cl2 Fertility Normala Abnormal Not Reported Sufficient Insufficient Not Reported Reported (Mean 5 SEM [mmol/literb ]) Not Reported Subfertilec Not Reported R1070W (7)d 5 0 2 5 0 2e 6 ( ) 50.2 5 13.4 1 6 1 CBAVD R1070P (2)f 0 1 1 0 1 1 1 (Positive) 1 0 2 CF R1070Q (14)g 0 7 7 0 7 7 7 (Positive) 7 2 12 CF D1270N (9)h 4 0 5 4 0 5 3 ( ) 77.5 5 16.7 6 3 6 CBAVD G1349D (3)i 0 0 3 0 0 3 ) 3 1 2 CF a No history of chronic lung disease. Login to comment
172 B, CBAVD(R1070W)- and CF(R1070P and R1070Q)-associated mutants in TMD2 had I-V plots similar to those of wild-type CFTR: outwardly rectified currents (blackened circles) that responded to DIDS (unblackened circles) and glibenclamide (crosses). Login to comment
180 Thus, the combination of I-V relationship and response to inhibitors allowed dissection of whole-cell Cl-currents into two components: outwardly rectified and DIDS sensitive, carried by separate channels such as ORCCs; and linear, DIDS insensitive, and gli- Table 2 Summary of Processing and Whole-Cell Function of CFTR Mutants DOMAIN AND MUTATION PHENOTYPE CFTR STATUS a Processingb Function Band A Band B Band C Cl2 Channel Regulatoryc Not applicable: Wild type Normal 2 2 111 111 1 NBF1:d A455Ee CFe 1 11 2 111 1 DF508 CF 1 11 2 1 2 G551D CF 2 2 111 1 2 TMD2: R1070W CBAVD 2 1 11 111 1 R1070P CF 1 11 2 111 1 R1070Q CF 2 1 11 111 1 NBF2: D1270N CBAVD 2 2 111 111 1 G1349D CF 2 2 111 111 1 a A minus sign (2) denotes absence; a single plus sign (1) denotes "low"; a double plus sign (11) denotes "intermediate"; and a triple plus sign denotes "high." Login to comment
188 .05 mutant (R1070W) and the CF mutants (R1070P and R1070Q) in TMD2 generated outwardly rectified Cl2 currents that were inhibited by DIDS (fig. 3B). Login to comment

[hide] Cystic fibrosis: the 'bicarbonate before chloride'... Curr Biol. 2001 Jun 26;11(12):R463-6. Wine JJ
Cystic fibrosis: the 'bicarbonate before chloride' hypothesis.
Curr Biol. 2001 Jun 26;11(12):R463-6., [PMID:11448786]

Abstract [show]
The specific effects of some mutations that cause cystic fibrosis suggest that reduced HCO(3)(-) transport is the key to understanding cystic fibrosis pathology. But there is a puzzling discrepancy between measures of CFTR-mediated chloride conductance in expression systems and the sweat chloride values of patients.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
42 A fifth mutation, R1070Q, was originally reported to be associated with a positive sweat test and both pancreatic sufficient and insufficient phenotypes. Login to comment
43 More complete data indicate that R1070Q patients are pancreatic insufficient, with sweat chloride values >100 mM (Aleksey Savov, personal communication). Login to comment
52 Ion transport (% WT) 42 41 69 75 >100 >100 98 + 103 100 + + 120 Pancreatic sufficient Pancreatic insufficient Bicarbonate Chloride - intermediate Chloride - high Unknown WT D648V R117H R1070Q H949Y G551S H620Q I148T A1067T G178R G970R S1255P G1244E G551D G1349D 0 0.5 1 1.5 2 2.5 Current Biology ࢞F508 Dispatch R absence of the vas deferens [16]. Login to comment
76 Critical information was provided by Thilo D&#f6;rk (H620Q); R. Moss (R117H & G551D homozygotes); David Kessler, Theresa Grebe and Elizabeth Perkett (D648V); Monica Brooks and contributors to the Cystic Fibrosis Foundation Registry (G178R and G1244E); Aleksey Savov and Luba Kalaydjieva (R1070Q); and Christiane De Boeck and Harry Cuppens (G970R). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
72 Mutations elsewhere in the gene that caused loss of stability include missense mutations such as G480C (p.Gly480Cys) and others that affect domain-domain interactions in CFTR such as R1070Q (p.Arg1070Gln) (Smit et al. 1995; Serohijos et al. 2008). 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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
86 For example, the baseline level of chloride transport and ivacaftor response was higher for mutant CFTR forms associated with mild defects in CFTR processing (e.g., E56K, P67L, L206W, A455E, D579G, S945L, S977F, A1067T, R1070Q, R1070W, F1074L, and D1270N) than for those associated with severe defects in CFTR processing (e.g., F508del, H1054D, R1066H). 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
92 Mutant CFTR forms that did not significantly respond to ivacaftor under the experimental conditions used in this study were generally associated with severe defects in CFTR processing A B C D E F 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 S1235R D1152H F1052V D1270N ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R668C K1060T R74W R117H ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 E193K A1067T L997F R1070Q ivacaftor [Log M] Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 D110E D579G D110H R1070W ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F1074L E56K P67L A455E ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R347H S945L L206W S977F ivacaftor [Log M] 0 100 200 300 400 -8 -6 -4 0 T338I R1066H R117C R352Q ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K ivacaftor [Log M] 0 5 10 15 20 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K R1066H T338I ivacaftor [Log M] G H I Fig. 3. Login to comment

[hide] Defining the disease liability of variants in the ... Nat Genet. 2013 Oct;45(10):1160-7. doi: 10.1038/ng.2745. Epub 2013 Aug 25. Sosnay PR, Siklosi KR, Van Goor F, Kaniecki K, Yu H, Sharma N, Ramalho AS, Amaral MD, Dorfman R, Zielenski J, Masica DL, Karchin R, Millen L, Thomas PJ, Patrinos GP, Corey M, Lewis MH, Rommens JM, Castellani C, Penland CM, Cutting GR
Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene.
Nat Genet. 2013 Oct;45(10):1160-7. doi: 10.1038/ng.2745. Epub 2013 Aug 25., [PMID:23974870]

Abstract [show]
Allelic heterogeneity in disease-causing genes presents a substantial challenge to the translation of genomic variation into clinical practice. Few of the almost 2,000 variants in the cystic fibrosis transmembrane conductance regulator gene CFTR have empirical evidence that they cause cystic fibrosis. To address this gap, we collected both genotype and phenotype data for 39,696 individuals with cystic fibrosis in registries and clinics in North America and Europe. In these individuals, 159 CFTR variants had an allele frequency of l0.01%. These variants were evaluated for both clinical severity and functional consequence, with 127 (80%) meeting both clinical and functional criteria consistent with disease. Assessment of disease penetrance in 2,188 fathers of individuals with cystic fibrosis enabled assignment of 12 of the remaining 32 variants as neutral, whereas the other 20 variants remained of indeterminate effect. This study illustrates that sourcing data directly from well-phenotyped subjects can address the gap in our ability to interpret clinically relevant genomic variation.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
112 dVariants p.[Gln359Lys; Thr360Lys], p.Leu558Ser and p.Arg1070Gln. Login to comment
119 The remaining three variants (p.[Gln359Lys; Thr360Lys], p.Leu558Ser and p.Arg1070Gln) exhibited processing greater than 10% of that of wild-type CFTR and were not functionally classified. Login to comment
137 In addition to these ten variants, c.1210-12(7) (legacy name 7T) had already been reported to be non-penetrant48 and was identified as a second variant in numerous fathers, and a twelfth variant, p.Ile1027Thr, was deemed 159 variants ࣙ0.01% frequency in CFTR2 127 variants meet clinical and functional criteria Clinical and functional analysis 13 variants meet neither criteria 14 variants 5 variants 7 variants 6 variants Evidence of non-penetrance No evidence of non-penetrance 19 variants meet clinical or functional criteria 127 variants are CF causing 12 variants are non CF causing 20 variants are indeterminate p.Arg117HisߤC p.Arg75Gln p.Gly576Alaߤ p.Arg668Cys ߤ p.Met470Val C p.IIe1027Thr ߤC p.Val754Met ߤC p.IIe148Thr ߤC p.Arg31Cys C p.Ser1235Arg ߤ p.Leu997Phe ߤ p.Arg1162Leu p.Leu227Arg F p.Gln525* F p.Leu558SerC p.Asp614Gly C c.2657+2_2657+3insA C c.1418delG F c.1210-12(7) ߤ p.Arg1070Gln C p.Asp1270Asn ߤC p.[Gln359Lys; Thr360Lys] p.Gly1069Argߤ p.Asp1152His p.Phe1052Val c.1210-12(5) p.Arg74Trpߤ p.IIe1234Val ߤC p.Arg1070Trp ߤF p.Ser977Phe F p.Asp579Gly C p.Tyr569Asp F Penetrance analysis Figure 4ߒ Assignment of disease liability to the 159 most frequent CFTR variants using three criteria. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
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] 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
358 Some other CFTR mutations of varying clinical consequences, such as F1052 V, G1069R, and R1070W/R1070Q complete the list in this region. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
31 Both methods used 5 &#b5;l of isolated DNA for the NGS assay. NGS assay for detection of CFTR mutations/variants CFTR mutations are described using both the international nomenclature of the Human Genome Variation Society Mutations that have varying consequences c.3454G>C (D1152H) c.3154T>G (F1052V) c.3208C>T (R1070W) c.2930C>T (S977F) - c.3808G>A (D1270N) c.3205G>A (G1069R) c.350G>A (R117H) PolyTG/ polyT - c.1736A>G (D579G) c.3209G>A (R1070Q) c.220C>T (R74W) - - Mutations still under evaluation c.2657ߙ+ߙ2_2657ߙ+ߙ3insA (2789ߙ+ߙ2insA) c.680T>G (L227R) c.1705T>G (Y569D) - - c.1841A>G (D614G) c.1673T>C (L558S) - - - c.3700A>G (I1234V) c. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
275 [Ser466*; Arg1070Gln]) complex allele was found in 3 patients (2 CF-PI and 1 CF-PS). Login to comment
378 [1397C>G;3209G>A] CF-PI S466X(TGA) CF-causing; R1070Q varying clinical p. 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.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
87 [Gln359Lys; Thr360Lys] L558S c.1673 T4C p.Leu558Ser Y569D c.1705 T4G p.Tyr569Asp D579G c.1736 A4G p.Asp579Gly D614G c.1841 A4G p.Asp614Gly S977F c.2930C4T p.Ser977Phe F1052V c.3154 T4G p.Phe1052Val G1069R c.3205G4A p.Gly1069Arg R1070Q c.3209G4A p.Arg1070Gln D1152H c.3454G4C p.Asp1152His I1234V c.3700 A4G p.Ile1234Val 5T c.1210 - 12[5] Examples of common not CF-causing variantsc R31C c.91C4T p.Arg31Cys R74W c.220C4T p.Arg74Trp R75Q c.224G4A p.Arg75Gln I148T c.443 T4C p.Ile148Thr M470V c.1408 A4G p.Met470Val G576A c.1727G4C p.Gly576Ala R668C c.2002C4T p.Arg668Cys V754M c.2260G4A p.Val754Met L997F c.2991G4C p.Leu997Phe I1027T c.3080 T4C p.Ile1027Thr R1070W c.3208C4T p.Arg1070Trp R1162L c.3485G4T p.Arg1162Leu Table 1 (Continued) HGVS nomenclature Legacy name cDNA nucleotide name Protein name S1235R c.3705 T4G p.Ser1235Arg D1270N c.3808G4A p.Asp1270Asn 7T c.1210-12[7] Abbreviation: HGVS, Human Genome Variation Society. Login to comment