ABCMdb

ABCC7 p.Arg31Cys

ClinVar:	c.92G>T , p.Arg31Leu ? , not provided c.91C>T , p.Arg31Cys ? , Uncertain significance
CF databases:	c.91C>T , p.Arg31Cys N , Non CF-causing ; CFTR1: This missens mutation (in the CFTR gene) had a nucleotide change of C to T at position 223 in exon 2 leading to a cysteine for arginine substitution at codon 31 (R31C). The substitution has been found in a 35 years old man having an atypical form of CF. c.92G>T , p.Arg31Leu (CFTR1) ? , This change has been detected by SSCP analysis of DNA amplified by PCR using the following primers: 21-5s; 5'-GTGAATATCTGTTCCTCCTC-3' and 21-3s; 5'-AGCCACCATACTTGGCTCCT-3'. The mutation can be analyzed by enzymatic digestion since the G224->T creates a new restriction site and destroys the existing one. It has been found once among 284 CF chromosomes and 144 normal chromosomes. The mutation on the other chromosome of the pancreatic sufficient CF patient is unknown.
Predicted by SNAP2:	A: D (85%), C: D (85%), D: D (91%), E: D (91%), F: D (91%), G: D (91%), H: N (53%), I: D (85%), K: N (57%), L: D (66%), M: D (85%), N: D (91%), P: D (95%), Q: D (75%), S: D (91%), T: D (91%), V: D (85%), W: D (95%), Y: D (91%),
Predicted by PROVEAN:	A: N, C: N, D: N, E: N, F: N, G: N, H: N, I: N, K: N, L: N, M: N, N: N, P: N, Q: N, S: N, T: N, V: N, W: N, Y: N,

[switch to compact view]
Comments [show]

None has been submitted yet.

Publications
[hide] Complete mutational screening of the cystic fibros... Hum Reprod. 1999 Dec;14(12):3035-40. Pallares-Ruiz N, Carles S, Des Georges M, Guittard C, Arnal F, Humeau C, Claustres M
Complete mutational screening of the cystic fibrosis transmembrane conductance regulator gene: cystic fibrosis mutations are not involved in healthy men with reduced sperm quality.
Hum Reprod. 1999 Dec;14(12):3035-40., [PMID:10601093]

Abstract [show]
Based on the analysis of the most frequent mutations responsible for cystic fibrosis (CF), a higher than expected frequency of CF mutations was recently reported in men with infertility due to reduced sperm quality. To further document whether this condition is associated with severe or mild abnormalities of cystic fibrosis transmembrane conductance regulator (CFTR) functions, we carried out a complete scanning of CFTR sequences using a strategy that detects almost all 850 mutations and 150 polymorphisms reported to date in the CFTR gene. We have investigated a cohort of 56 patients with severe oligoasthenoteratozoospermia (OAT) and 50 controls from southern France for CFTR gene mutations and variations. The frequencies of CF-causing mutations and CFTR variations identified in this OAT sample did not differ significantly from the frequencies found in the normal population. However, we observed a 1.7-fold increase in the proportion of homozygotes for a specific CFTR haplotype (TG11-T7-G1540) in the OAT group (P = 0.025). Our results do not confirm a link between CF mutations and reduced sperm quality. Further studies are needed to substantiate the hypothesis that a combination of variants affecting expression and function of the CFTR protein is associated with male infertility.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
63 Frequency distribution of CFTR gene variants in populations from southern France infertile men with OAT and in controls (T)n-1540A/G-(TG)n Controls OAT PVariants Allele frequency, % of chromosomes (n ϭ 50) (n ϭ 56) Controls CBAVDa OAT 9/9 A/A 10/10 1 (2) 1 (2) NS(n ϭ 100) (n ϭ 100) (n ϭ 112) 7/9 A/A 10/12 1 0 11/10 0 1223C/T (R31C) 0.01 0 0 10/10 0 3356G/A (R75Q) 0.02 0.01 0.009 Total 1 (2) 4 (7) NS1655T/G (F508C) 0 0.01 0.009 7/9 A/G 11/10 2 41716 G/A (E528E) 0 0.01 0.018 10/12 5 21859G/C (G576A)ϩ2134C/T 0.01 0.04c 0.009 7 (14) 6 (11) NS(R668C)b 7/7 A/A 12/12 0 12377C/T (L749L) 0 0.01d 0.009 11/12 1 03417A/T (T1095T) 0.01 0 0.018 10/11 3 03419T/G (L1096R) 0.01 0 0 10/10 1 44002A/G (P1290P) 0.01 0 0.018 Total 5 (10) 5 (9) NS4404C/T (T1424T) 0.01 0.01 0.018 7/7 A/G 12/12 0 2125G/C (5ЈUTR) 0.07 0.01 0.027 11/12 0 3405ϩ46G/T 0 0 0.018 11/11 5 0406-6T/C 0.01 0 0 10/11 3 3875ϩ40A/G 0.05 0.06 0.045 10/10 8 03041-71G/Cϩ4002A/Gb 0.02 0.02 0.009 Total 16 (32) 8 (14) NS3499ϩ37G/A 0 0 0.009 7/7 G/G 11/11 16 (32) 31 (55) Ͻ 0.024374ϩ13A/G 0 0 0.009 8/11 0 1 Total 16 (32) 32 (57) 0.018aGroup of CBAVD patients whose genotypes had been previously analysed 7/5 A/G 11/11 2 (4) 0 -in our laboratory. Login to comment
75 Several missense variations identified in this study (R31C, R75Q, F508C, G576A, R668C, or E528E) have previously Table IV. Login to comment

[hide] A new approach for identifying non-pathogenic muta... Hum Genet. 2000 Feb;106(2):172-8. Bombieri C, Giorgi S, Carles S, de Cid R, Belpinati F, Tandoi C, Pallares-Ruiz N, Lazaro C, Ciminelli BM, Romey MC, Casals T, Pompei F, Gandini G, Claustres M, Estivill X, Pignatti PF, Modiano G
A new approach for identifying non-pathogenic mutations. An analysis of the cystic fibrosis transmembrane regulator gene in normal individuals.
Hum Genet. 2000 Feb;106(2):172-8., [PMID:10746558]

Abstract [show]
Given q as the global frequency of the alleles causing a disease, any allele with a frequency higher than q minus the cumulative frequency of the previously known disease-causing mutations (threshold) cannot be the cause of that disease. This principle was applied to the analysis of cystic fibrosis transmembrane conductance regulator (CFTR) mutations in order to decide whether they are the cause of cystic fibrosis. A total of 191 DNA samples from random individuals from Italy, France, and Spain were investigated by DGGE (denaturing gradient gel electrophoresis) analysis of all the coding and proximal non-coding regions of the gene. The mutations detected by DGGE were identified by sequencing. The sample size was sufficient to select essentially all mutations with a frequency of at least 0.01. A total of 46 mutations was detected, 20 of which were missense mutations. Four new mutations were identified: 1341+28 C/T, 2082 C/T, L1096R, and I11131V. Thirteen mutations (125 G/C, 875+40 A/G, TTGAn, IVS8-6 5T, IVS8-6 9T, 1525-61 A/G, M470V, 2694 T/G, 3061-65 C/A, 4002 A/G, 4521 G/A, IVS8 TG10, IVS8 TG12) were classified as non-CF-causing alleles on the basis of their frequency. The remaining mutations have a cumulative frequency far exceeding q; therefore, most of them cannot be CF-causing mutations. This is the first random survey capable of detecting all the polymorphisms of the coding sequence of a gene.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
79 Out of the 20 missense mutations, three (G85E, ∆F508, and N1303K) are certainly CF-causing, and several (R31C, K68E, R75Q, I148T, V562L, G576A-R668C, L997F, F1052V, S1235R) have been described in congenital bilateral absence of the vas deferens, in disseminated bronchiectasis, in pancreatitis, or in atypical CF cases mutations as reported in the CFGAC website (). Login to comment
80 Many (13 out of 20) of the missense mutations change highly conserved (5/5 species analyzed) amino acid residues (R75Q, G85E, I148T, I506V, R668C, G622D, L997F, I1027T, F1052V, L1096R, I1131V, R1162L, N1303K); others affect amino acid residues conserved in 4/5 species (K68 E, R170H, M470V, V562L, S1235R), or in 3/5 species (R31C and G576A; Tucker et al. 1992). Login to comment
96 Moreover, 1525-61 A/G (i 9) and 3601-65 C/A (i 18) were detected by SSCA performed in the Spanish sample only (14/82 and 12/80, respectively); these mutations were not identifiable by DGGE as used in the present work The totals are: a378; b362; c380; d356 genes eCertainly a CF-causing mutations fThe most common allele at this site is (TTGA)7 gThe most common allele at this site is T7 hThe frequency shown is that of the M allele Mutation Position North-Central Southern Spain Total East Italy Italy France 82 genes 100 genes 100 genes 100 genes 382 genes % 125 G/C 5`UTR 1 2 7 3 13 3.4 R31C 2 1 1 1 0 3 0.8 K68E 3 1 0 0 0 1 0.3 R75Q 3 1 1 2 0 4 1.0 G85Ee 3 0 1 0 0 1 0.3 406-6 T/C i 3 0 0 1 0 1 0.3 I148T 4 1 0 0 0 1 0.3 621+3 A/G i 4 0 1 0 0 1 0.3 R170H 5 1 0 0 0 1 0.3 875+40 A/G i 6a 11 5 5 2 23 6.0 (TTGA)6 f i 6a 17 11 7 13 48 12.6 1341+28 C/T i 8 1 0 0 0 1 0.3 IVS8-6g T5 i 8 8 2 4 3/78 17a 4.5 IVS8-6g T9 i 8 10 7 10 11/78 38a 10.0 M470Vh 10 42 30 39 27 138 36.1 I506V 10 1 0 0 0 1 0.3 ∆F508e 10 1 0 2 0 3 0.8 1716 G/A 10 2 1 0 5 8 2.1 V562L 12 0 0 1 0 1 0.3 G576A 12 1 0/80 1 0 2b 0.6 G622D 13 0 0/80 1 0 1b 0.3 R668C 13 1 0/80 1 0 2b 0.6 2082 C/T 13 1 0/80 0 0 1b 0.3 2377 C/T 13 0 0/80 0 1 1b 0.3 2694 T/G i 14a 33 23 33 14/80 103c 27.1 2752-15 C/G i 14b 0 3 0 0 3 0.8 3041-71 G/C i 15 0 1 2 0 3 0.8 L997F 17a 0 2 0 0 2 0.5 I1027T 17a 1 0 0 0 1 0.3 F1052V 17b 1 0 0 0 1 0.3 L1096R 17b 0 0 1 0 1 0.3 3417 A/T 17b 1 0 1 0 2 0.5 I1131V 18 0 1 0 0 1 0.3 R1162L 19 0 1 0 0 1 0.3 3690 A/G 19 0 0 0 1/80 1c 0.3 S1235R 19 1 0 0 0 1 0.3 4002 A/G 20 2 3 3 3/80 11c 2.9 4005+28insA i 20 0 1 0 0 0.3 4029 A/G 21 1 0 0 0 1 0.3 N1303Ke 21 1 0 0 0 1 0.3 4404 C/T 24 1 0 1 0 2 0.5 4521 G/A 24 21 16 14/80 15/76 66d 18.5 Total 165 113 137 98 513 encountered in the present survey are possible. Login to comment
115 The density of polymorphic sites, which is essentially the proportion of sites susceptible to evolving among the total number of sites (bp) of that gene, can be estimated by counting the number n of polymorphic sites existing in 177 Table 4 A list of the 13 ED-C mutations detected in this survey Mutation q±SE q-2.5SE 125 G/C 0.0340±0.0093 0.011 875+40 A/G 0.0602±0.0122 0.030 876-5 (GATT)6 0.1257±0.0170 0.083 IVS8 T5 0.0450±0.0107 0.018 IVS8 T9 0.1005±0.0155 0.062 IVS8 (TG)10 0.2900±0.0262 0.223 IVS8 (TG)12 0.0867±0.0162 0.046 1525-61 A/Ga 0.1750±0.0420 0.070 M470V 0.3613±0.0246 0.300 2694 T/G 0.2711±0.0228 0.214 3601-65 C/Aa 0.1500±0.0399 0.050 4002 A/G 0.0289±0.0086 0.007 4521 G/A 0.1854±0.0206 0.134 aSearched by SSCA in the sample of 40 Spanish individuals only: frequency and standard error are those of that sample Table 5 Distribution in the four subsamples of mutations found a few times but not classified Total number of Subsample times the mutation has been found NE Italy Central Southern Spain Italy France Twice G576A 1 - 1 - R668C 1 - 1 - L997F - 2 - - 3417 A/T 1 - 1 - 4404 C/T 1 - 1 - Three times R31C 1 1 1 - 2752-15 C/G - 3 - - 3041-71 G/C - 1 - Four times R75Q 1 1 2 - Eight times 1716 G/Aa 2 1 - 5 aGiven its frequency and distribution, this mutant will probably turn out to be a C mutant the stretch under study of N bp and dividing n by N. Usually, the number of sites identified as polymorphic sites is merely a minimum estimate of the total number n of polymorphic sites of the N stretch, because the number of polymorphic sites of the stretch that escaped detection remains unknown. Login to comment

[hide] Germline mutations in CFTR and PSTI genes in chron... Dig Dis Sci. 2002 Nov;47(11):2416-21. Gaia E, Salacone P, Gallo M, Promis GG, Brusco A, Bancone C, Carlo A
Germline mutations in CFTR and PSTI genes in chronic pancreatitis patients.
Dig Dis Sci. 2002 Nov;47(11):2416-21., [PMID:12452372]

Abstract [show]
Mutations in the cationic trypsinogen, cystic fibrosis transmembrane conductance regulator (CFTR) and pancreatic secretory trypsinogen inhibitor (PSTI) genes have recently been associated with chronic pancreatitis. This paper investigates the frequency of CFTR and PSTI gene mutation in patients with idiopathic and alcoholic chronic pancreatitis, the clinical course of patients with these two kinds of disease, and examines the clinical differences between carriers and noncarriers of mutation. In idiopathic pancreatitis a significant increase was found in mutation frequency both in the CFTR gene (13%) and N34S mutation in the PSTI gene (3.9%), as well as an increase in familial disposition to pancreatic disorders. In alcohol-induced pancreatitis an increase in calcification, exocrine insufficiency, and diabetes mellitus was observed. In conclusions, mutations in the genes investigated are involved in causing idiopathic pancreatitis. Such mutations have no connection either with the age at onset or the clinical course of the disease.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
56 All mutations (W1282X, N187K, R352Q, ⌬F508, R75Q, R31C, 621ϩ2T-ϾG, I197V, K68N, R1162X) were found in heterozygotes, indicating that these patients are carriers of a single mutation. Login to comment
78 PATIENTS CARRYING THE CFTR MUTATION* Pt Sex Age (yr) Age at onset (yr) Alcohol (g/day)† Familial CFTR mutations Exocrine insufficiency Diabetes mellitus(Յ10) (10-40) (40-80) T.B. M 59 23 (Յ10) No W1282X Yes No B.G. M 40 29 (Յ10) Yes N187K No No E.P. M 40 34 (Յ10) No R352Q No Yes D.N. M 53 47 (10-40) No R75Q Yes No R.L. F 57 44 (Յ10) No R31C No No T.F. M 56 *‡ (Յ10) No 621 ϩ 2T 3 G Yes No F.G. M 54 46 (10-40) No I197V Yes No V.M. M 65 *† (10-40) No K68N Yes No B.L. F 57 56 (10-40) Yes ⌬F508 No Yes T.G. M 25 24 (Յ10) No R1162X No No *This table shows the characteristics of chronic pancreatitis patients, carriers of CFTR mutations. Login to comment
88 Four mutations were found in patients with mild forms of CF (R31C, K68N, R75Q, and R352Q). Login to comment

[hide] CFTR, PRSS1 and SPINK1 mutations in the developmen... JOP. 2003 Sep;4(5):169-77. Bernardino AL, Guarita DR, Mott CB, Pedroso MR, Machado MC, Laudanna AA, Tani CM, Almeida FL, Zatz M
CFTR, PRSS1 and SPINK1 mutations in the development of pancreatitis in Brazilian patients.
JOP. 2003 Sep;4(5):169-77., [PMID:14526128]

Abstract [show]
CONTEXT: Mutations in cystic fibrosis transmembrane conductance regulator (CFTR), in cationic trypsinogen (PRSS1) and in serine protease inhibitor Kazal type 1 (SPINK1) genes have been associated with chronic pancreatitis (alcohol related, idiopathic and hereditary). However, the inheritance pattern is still not clear. PATIENTS: Eighty-two unrelated Brazilian patients with chronic pancreatitis (alcohol-related disease in 64, idiopathic disease in 16, and hereditary disease in 2). Two hundred unrelated individuals with an ethnic distribution comparable to the patients were studied as controls. MAIN OUTCOME MEASURE: Detection of mutations in CFTR, PRSS1, and SPINK1 genes. RESULTS: Mutations in the CFTR gene were found in 8 patients (9.8%) with chronic pancreatitis, 5 of them with idiopathic disease. Interestingly, the only clinical symptom in a male patient in the alcoholic group, who was a compound heterozygote (DeltaF508/R170C) for two CFTR mutations, was pancreatitis without infertility or pulmonary involvement. In the PRSS1 gene, the E79K change in exon 3 was found in one patient (1.2%) with alcohol-related chronic pancreatitis. Four different alterations were identified in the SPINK1 gene. CONCLUSIONS: Mutations in the CFTR gene represent the major cause of idiopathic chronic pancreatitis in Brazilian patients. No mutation was found in the PRSS1 gene among our patients suggesting further genetic heterogeneity for hereditary and idiopathic chronic pancreatitis. Interestingly, the most frequent SPINK1 N34S mutation was not present in patients or controls. Moreover, the -253C allele for the SPINK1 gene was significantly more frequent in patients than controls (P=0.004), suggesting that it might represent a risk factor for the development of pancreatitis in our population.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
68 A total of 13 changes were found: 7 in the CFTR gene (∆F508/R851L, ∆F508/R170C, ∆F508/L206W, 2 N/∆F508, N/P205S, N/R31C and N/V920M), 2 in the PRSS1 gene (E79K and N246N) and 4 in the SPINK1 gene (-253T>C, -164G>C, -7T>G, c75C>T) (Table 1). Login to comment
69 The CFTR Gene Molecular analysis showed that 8 patients (9.8%) had mutations in the CFTR gene: 3 were compound heterozygotes (∆F508/R851L, ∆F508/R170C and ∆F508/L206W) and 5 had mutations on just one allele (2 N/∆F508, N/P205S, N/R31C and N/V920M). Login to comment
72 One (∆F508/R851L) referred only bronchitis in childhood and the last two (N/∆F508 and N/V920M) had no other additional signs. Three of the 64 patients (4.7%) with alcohol-related chronic pancreatitis but with no pulmonary problems also had CFTR mutations: N/∆F508, N/R31C and compound heterozygote ∆F508/R170C. None of these 3 patients reported azoospermia. Login to comment
78 Gene Localization Mutation Polymorphism Frequency in patients' chromosomes Frequency in controls' chromosomes P value Exon 2 R31C 1/164 (0.6%) - - Exon 5 R170C 1/164 (0.6%) - - P205S 1/164 (0.6%) - -Exon 6 L206W 1/164 (0.6%) - - Exon 10 ∆F508 5/164 (3.0%) - - Exon 14a R851L 1/164 (0.6%) - - CFTR Exon 15 V920M 1/164 (0.6%) - - Exon 3 E79K 1/164 (0.6%) 1/300 (0.3%) 1.000a PRSS1 Exon 5 N246N 47/164 (28.7%) 85/300 (28.3%) 1.000b -253T>C 20/164 (12.2%) 20/400 (5.0%) 0.004b Promoter -164G>C 4/164 (2.4%) 13/400 (3.3%) 0.788a Exon 1 -7T>G 5/164 (3.0%) 8/300 (2.7%) 0.777a SPINK1 Exon 2 c75C>T 1/164 (0.6%) 3/300 (1.0%) 1.000a a Fisher's exact test b Yates' corrected chi-squared test alcohol-related chronic pancreatitis, but with no family history. Login to comment
94 Molecular analysis showed that 9.8% of the total group of patients had mutations in the CFTR gene: 3 were compound heterozygotes (∆F508/R851L, ∆F508/R170C and ∆F508/L206W) and 5 had mutations on just one allele (2 N/∆F508, N/P205S, N/R31C and N/V920M). Login to comment
98 One (∆F508/R851L) referred only bronchitis in childhood and the last two (N/∆F508 and N/V920M) had no other additional signs. Three (4.7%) of the 64 patients with alcohol-related chronic pancreatitis but with no pulmonary problems also had CFTR mutations: N/∆F508, N/R31C and compound heterozygote ∆F508/R170C. None of these 3 patients reported azoospermia. Login to comment

[hide] A large-scale study of the random variability of a... Eur J Hum Genet. 2005 Feb;13(2):184-92. Modiano G, Bombieri C, Ciminelli BM, Belpinati F, Giorgi S, Georges M, Scotet V, Pompei F, Ciccacci C, Guittard C, Audrezet MP, Begnini A, Toepfer M, Macek M, Ferec C, Claustres M, Pignatti PF
A large-scale study of the random variability of a coding sequence: a study on the CFTR gene.
Eur J Hum Genet. 2005 Feb;13(2):184-92., [PMID:15536480]

Abstract [show]
Coding single nucleotide substitutions (cSNSs) have been studied on hundreds of genes using small samples (n(g) approximately 100-150 genes). In the present investigation, a large random European population sample (average n(g) approximately 1500) was studied for a single gene, the CFTR (Cystic Fibrosis Transmembrane conductance Regulator). The nonsynonymous (NS) substitutions exhibited, in accordance with previous reports, a mean probability of being polymorphic (q > 0.005), much lower than that of the synonymous (S) substitutions, but they showed a similar rate of subpolymorphic (q < 0.005) variability. This indicates that, in autosomal genes that may have harmful recessive alleles (nonduplicated genes with important functions), genetic drift overwhelms selection in the subpolymorphic range of variability, making disadvantageous alleles behave as neutral. These results imply that the majority of the subpolymorphic nonsynonymous alleles of these genes are selectively negative or even pathogenic.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
33 In the Tajima`s test,19 the null hypothesis of neutrality is rejected if a statistically significant difference between p Common and rare nonsynonymous and synonymous cSNSs G Modiano et al European Journal of Human Genetics Table 1 List of the 61 cSNSsa encountered in the present survey The random samples of genes (and the technique utilized) cSNS variants found NE Italy (DGGE) Central Italy (DGGE) Southern France (DGGE) Northern France (DHPLC) Spain (SSCA) Czechia (DGGE) Hb Â 104 Exon Exon Length (bp) Ref. no. SNS SASc 1st 100d 2nd 500 1st 100d 2nde 1st 100d 2nd 500 1st 100 2nde 82d 72 Abs. Freq. Total sample size q Â 104 se Â 104 NSf Sf 1g 53 0 0 0 0 0/452 0 924 2 111 1 223C4T R31C 1 1 1/500 1 1 0 0/450 0 5 (11) 1 932 (2 432) 45.23 13.61 90 2 224G4T R31L 0 0 0/500 0 0 0 1/450 0 1 1 932 5.17 5.17 10 3 257C4T S42F 0 0 1/500 0 0 0 0/450 0 1 1 932 5.17 5.17 10 3 109 4 334A4G K68E 1 0 0 0/498 0 0 0 0/452 0 0 1 2 504 3.99 3.99 8 5 352C4T R74W 0 0 0 0/498 0 0 0 1/452 0 0 1 2 504 3.99 3.99 8 6 356G4A R75Q 1 7 1 7/498 2 9 2 9/452 0 2 40 (40) 2 504 (2 544) 157.23 24.66 310 7 386G4A G85E 0 0 1 1/498 0 0 0 0/452 0 0 2 2 504 7.99 5.65 16 4 216 8 482G4A R117H 0 0 0 0/292 0 2 0 1/456 0 0 3 2 302 13.03 7.52 26 9 528T4G I132M 0 0 0 0/292 0 0 0 1/456 0 0 1 2 302 4.34 4.34 8 10 575T4C I148T 1 2 0 1/292 0 0 0 1/456 0 1 6 2 302 26.06 10.63 52 5 90 11 640C4T R170C 0 0 0 0/6 0 0 1/448 0 1 1 436 6.96 6.96 14 12 641G4A R170H 1 1 0 0/6 0 0 2/448 0 4 (4) 1 436 (1 930) 20.73 10.35 41 6a 164 0 0 0/6 0 0 0/432 0 0 992 6b 126 0 0 0/6 0 0 0/454 0 942 7 247 0 0 0/6 0 0 0/796 0 1 284 8 93 13 1281G4A L383 0 0 0 0/6 0 0 1/456 0 0 1 1 516 6.60 6.60 13 9 183 14 1402G4A G424S 0 0 0/6 0 0 1/454 0 1 940 10.64 10.64 21 15 1459G4T D443Y 0 0 0/6 0 0 1/454 0 1 940 10.64 10.64 21 10 192 16 1540A4G M470Vh 42 197 30 37/96 39 199 (i) (i) 27 571(736) 1 484 (1 912) 3849.37 111.28 4 735 17 1598C4A S489X 0 0 0 0/96 0 0 0 1/796 0 1 2 374 4.21 4.21 8 18 1648A4G I506V 1 0 0 0/96 0 0 0 0/796 0 1 2 374 4.21 4.21 8 19 1655T4G F508C 0 1 0 0/96 0 0 0 1/796 0 2 2 038 8.42 5.96 17 20 1716G4A Q528 2 16 1 0/96 0 19 i I 5 43 (58) 1 478 (2 024) 286.56 37.08 557 11 95 21 1756G4T G542X 0 2 0 0/134 0 0 0/796 0 0 2 1 984 10.08 7.12 20 22 1764T4G G544 0 0 0 0/134 0 0 1/796 0 0 1 1 984 5.04 5.04 10 23 1784G4A G551D 0 0 0 0/134 0 0 1/796 0 0 1 1 984 5.04 5.04 10 12 87 24 1816G4A V562I 0 0 0 0 1 0 0/450 0 0 1 (1) 2 004 (2 504) 3.99 3.99 8 25 1816G4C V562L 0 0 0 1 0 0 1/450 0 0 2 (3) 2 004 (2 504) 11.98 6.91 24 26 1859G4C G576A 1 2 0 1 11 0 8/450 0 0 23 (27) 2 004 (2 538) 106.38 20.36 213 13 724j 449 27 1997G4A G622D 0 0 0/80 0/96 1 0 0 0/444 0 1 2 002 5.00 5.00 10 28 2082C4T F650 1 0 0/80 0/20 0 0 0 0/444 0 1 (1) 1 926 (2 412) 4.15 4.15 8 29 2134C4T R668C 1 2 0/80 0/96 1 11 0 12/444 0 27(32) 2 002 (2 558) 125.10 21.98 247 275 30 2377C4T L748 0 0 0/6 0 1 1 388 25.77 25.77 52 14a 129 31 2670G4A W846X 0 0 0/6 0 1 0/452 0/80 0 1 1 010 9.90 9.90 20 32 2694T4G T854 33 23 0/6 33 38 149/452 14/80 11 301 1 010 2980.20 143.92 4 184 33 2695G4A V855I 0 0 0/6 0 0 1/452 0/80 0 1 1 010 9.90 9.90 20 14b 38 0 0 0 0/520 0 0 0 0/446 0 2 448 15 251 34 2816G4C S895T 0 0 0/6 0 0 2/436 0 0 2 996 20.08 14.18 40 35 2831A4C N900T 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 36 2988G4C M952I 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 37 3030G4A T966 (2)k (1)k 0 6/436 0 6 (25)k 618 (1814)k 137.82 27.37 272 38 3032T4C L967S 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 16 80 0 0 0/498 0 0 0/450 0 0 1 502 17a 151 39 3123G4C L997F 0 2 2 1/494 0 7 1 4/454 0 0 17 2 502 67.95 16.42 135 40 3157G4A A1009T 0 2 0 0/494 0 0 0 0/454 0 0 2 2 502 7.99 5.65 16 41 3212T4C I1027T 1 0 0 0/494 0 0 0 0/454 0 0 1 2 502 4.00 4.00 8 17b 228 42 3286T4G F1052V 1 1 0 1/194 0 0 0 0/452 0 0 3 (3) 2 200 (2 240) 13.39 7.73 27 43 3337G4A G1069R 0 1 0 0/194 0 0 0 0/452 0 0 1 2 200 4.55 4.55 9 CommonandrarenonsynonymousandsynonymouscSNSs GModianoetal 186 EuropeanJournalofHumanGenetics 44 3345G4T Q1071H 0 0 0 0/194 0 1 0 0/452 0 0 1 2 200 4.55 4.55 9 45 3417A4T T1995 1 3 0 0/194 1 1 0 0/452 0 0 6 (8) 2 200 (2 506) 31.92 11.27 64 46 3419T4G L1096R 0 0 0 0/194 1 0 0 0/452 0 0 1 2 200 4.55 4.55 9 47 3477C4A T1115 0 0 0 0/194 0 0 0 1/452 0 0 1 2 200 4.55 4.55 9 18 101 48 3523A4G I1131V 0 0 1 0/10 0 0 0/448 0 0 1 (2) 1 512 (1 908) 10.48 7.07 21 49 3586G4C D1152H 0 0 0 0/10 0 0 1/448 0 0 1 1 512 6.61 6.61 13 19 249 50 3617G4T R1162L 0 0 1 1/494 0 0/260 0 0/454 0 0 2 2 262 8.84 6.25 18 51 3690A4G Q1186 0 0 0 0/494 0 0/260 0 0/454 1 0 1 2 262 4.42 4.42 9 52 3813A4G L1227 0 1 0 0/494 0 0/260 0 0/454 0 0 1 2 262 4.42 4.42 9 53 3837T4G S1235R 1 1 0 1/494 0 4/260 0 7/454 0 1 15 (15) 2 262 (2 310) 69.94 16.71 140 20 156 54 4002A4G P1290 2 3 0/6 3 5 18/454 3/80 2 36 1 012 357.73 58.22 690 21 90 55 4009G4A V1293I 0 0 0/6 0 0/300 0 1/456 0 0 1 1 316 7.60 7.60 15 56 4029A4G T1299 1 0 0/6 0 1/300 0 1/456 0 0 3 (8) 1 316 (2 330) 34.33 12.12 69 57 4041C4G N1303K 1 0 0/6 0 0/300 0 0/456 0 0 1 1 316 7.60 7.60 15 58 4085T4C V1318A 0 0 0/6 0 0/300 0 1/456 0 0 1 1 316 7.60 7.60 15 22 173 0 0 0/18 0 0 0/450 0 0 1 022 23 106 0 0 0 0/6 0 0 0/448 0 1 436 24l 198+3 59 4404C4T Y1424 1 0 0/6 1 2 5/420 0 2 11 (32) 980 (2 516) 127.19 22.34 251 60m 4521G4A Q1463 (21) (16) (3/32) (14/80) (30) (94/420) 15/76 (17) 15 (227) 76 (1052) 2142.86 131.07 3 367 61 4563T4C D1477 0 0 0/6 0 1 0/420 0 0 1 980 10.20 10.20 20 Totals 6 525 9 584 16 109 The bracketed figures include also the RFLP analysis data (see Materials and methods); the NE Italy, Central Italy, Southern and Northern France are each subdivided into two samples where the 1st is made up of 100 genes. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
237 In the group of ICP patients being heterozygous for a single CFTR mutation one severe (2184insA, this insertion causes a frame shift) and eight mild/uncommon mutations (26 S1235R, R31C, R75Q, R347P, G576A, M348V, and V754M) were identified. Login to comment
256 The reason why numbers for compound heterozygous ICP patients in these studies are diverse (4/67 = 6% in our study) may be due to differences Table 1 CFTR and SPINK1 sequence variations identified in 30 of the 67 ICP patients PatientSex CFTR mutation T allele TG repeats PSTI mutation 1 M DF508/R117H 7/7 9/10 -/- 2 W DF508/A1087P 7/9 10/11 -/- 3 M DF508/D1152H 7/9 10/10 -/- 4 M S1235R/R668C 7/7 11/12 -/- 5 M 2184insA/- 7/7 10/12 -/- 6 M R31C/- 7/7 10/11 -/- 7 M R75Q/- 7/7 11/11 -/- 8 M R347P/- 7/7 11/12 -/- 9 M S1235R/- 7/7 11/12 -/- 10 W S1235R/- 7/7 11/12 -/- 11 M G576A/- 7/7 10/10 -/- 12 W M348V/- 7/9 10/10 -/- 13 M V754M/- 7/7 10/11 -/- 14 M -/- 5/7 11/12 -/- 15 W -/- 5/7 11/12 -/- 16 M -/- 5/7 11/12 -/- 17 W -/- 5/9 11/12 -/- 18 M -/- 5/7 11/12 -/- 19 M -/- 5/7 10/10 -/- 20 W -/- 5/7 10/10 -/- 21 W -/- 5/7 11/12 N34S/- 22 W -/- 7/7 10/11 N34S/- 23 M -/- 7/9 10/11 N34S/- 24 M -/- 7/7 11/11 N34S/- 25 M -/- 7/7 11/11 N34S/- 26 W -/- 7/7 11/11 N34S/- 27 M -/- 7/7 11/11 N34S/- 28 W -/- 7/7 10/11 N34S/- 29 W -/- 7/7 11/11 P55S/- 30 W -/- 7/7 11/11 IVS3+2TC/- Table 2 CFTR sequence variations identified in 11 of 60 healthy controls Control group Number DF508/- 3 R117H/- 2 I148T/- 1 L997F/- 1 5T/12TG 1 5T/11TG 3 in patient recruitment, the catchment populations, or the stringency with which cystic fibrosis patients were excluded. Login to comment

[hide] Haplotype block structure study of the CFTR gene. ... Eur J Hum Genet. 2006 Jan;14(1):85-93. Pompei F, Ciminelli BM, Bombieri C, Ciccacci C, Koudova M, Giorgi S, Belpinati F, Begnini A, Cerny M, Des Georges M, Claustres M, Ferec C, Macek M Jr, Modiano G, Pignatti PF
Haplotype block structure study of the CFTR gene. Most variants are associated with the M470 allele in several European populations.
Eur J Hum Genet. 2006 Jan;14(1):85-93., [PMID:16251901]

Abstract [show]
An average of about 1700 CFTR (cystic fibrosis transmembrane conductance regulator) alleles from normal individuals from different European populations were extensively screened for DNA sequence variation. A total of 80 variants were observed: 61 coding SNSs (results already published), 13 noncoding SNSs, three STRs, two short deletions, and one nucleotide insertion. Eight DNA variants were classified as non-CF causing due to their high frequency of occurrence. Through this survey the CFTR has become the most exhaustively studied gene for its coding sequence variability and, though to a lesser extent, for its noncoding sequence variability as well. Interestingly, most variation was associated with the M470 allele, while the V470 allele showed an 'extended haplotype homozygosity' (EHH). These findings make us suggest a role for selection acting either on the M470V itself or through an hitchhiking mechanism involving a second site. The possible ancient origin of the V allele in an 'out of Africa' time frame is discussed.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
30 The T2A rate was much lower than 1 Frequencies of the CFTR variants within the M or the V alleles exon or intron VARIANT SITES in the M genes (MM subjects) in the V genes (VV subjects) A 5' UTR 125 g/c 8/144 (0.056) 3/356 (0.008) -80 1 2 R31C 5/226 (0.004) 1/576 (0.002) -56 in M genes in V genes 6 2 R75Q 1/226 (0.004) 15/576 (0.026) -51 M V (ttga)n 0.461 0.017 7 3 G85E 0/226 (0) 1/576 (0.002) -51 2.214 0.362 (tg)n 0.616 0.114 B i 3 406-6 t/c 0/226 (0) 6/576 (0.010) -29 (t)n 0.499 0.036 8 4 R117H 2/226 (0.009) 0/576 (0) -29 10 4 I148T 3/224 (0.013) 0/576 (0) -29 C i 4 621+3 a/g 1/224 (0.004) 0/576 (0) -29 12 5 R170H 1/158 (0.006) 0/402 (0) -26 D i 6a 875+40 a/g 6/36 (0.167)c 0/118 (0)c -25 i 6b (ttga)6 13/36 (0.361) 1/118 (0.008) -23 E i 6b 1001+11 c/t 5/60 (0.083) 0/166 (0) -23 F i 8 1341+28 c/t 1/152 (0.007) 0/464 (0) -18 i 8 (tg)10 39/76 (0.513) 5/218 (0.023) -11 i 8 (tg)11 21/76 (0.276) 205/218 (0.940) -11 i 8 (tg)12 16/76 (0.211) 8/218 (0.037) -11 i 8 t5 4/76 (0.053) 2/218 (0.009) -11 i 8 t7 48/76 (0.632) 214/218 (0.982) -11 i 8 t9 24/76 (0.316) 2/218 (0.009) -11 16 10 M470V H ex 10 F508del 3/226 (0.013) 0/572 (0) 0 19 10 F508C 0/226 (0) 1/572 (0.002) 0 20 10 1716g/a 15/226 (0.066) 0/572 (0) 0 21 11 G542X 1/158 (0.006) 0/400 (0) +28 24 12 V562I 1/226 (0.004) 0/576 (0) +30 25 12 V562L 1/226 (0.004) 0/576 (0) +30 26 12 G576A 3/226 (0.013) 0/576 (0) +30 28 13 2082c/t 1/104 (0.010) 0/226 (0) +32 29 13 R668C 3/224 (0.013) 0/562 (0) +32 32 14a 2694t/g 45/70 (0.643) 9/208 (0.043) +35 I i 14a 2752-15 c/g 0/226 (0) 5/576 (0.009) +44 37 15 3030g/a 1/158 (0.006) 7/402 (0.017) +44 O i 15 3041-71 g/c 5/226 (0.022) 0/576 (0) +47 39 17a L997F 1/226 (0.004) 4/576 (0.007) +51 40 17a A1009T 0/226 (0) 1/572 (0.002) +51 42 17b F1052V 1/226 (0.004) 0/572 (0) +52 43 17b G1069R 1/226 (0.004) 0/572 (0) +52 44 17b Q1071H 1/226 (0.004) 0/572 (0) +52 45 17b 3417a/t 0/226 (0) 4/572 (0.007) +52 46 17b L1096R 1/226 (0.004) 0/572 (0) +52 52 19 3813a/g 0/118 (0) 1/484 (0.002) +68 53 19 S1235R 3/100 (0.030) 0/294 (0) +68 54 20 4002a/g 5/56 (0.089) 1/168 (0.006) +83 q in the M alleles q in the V alleles 56 21 4029a/g 0/194 (0) 3/506 (0.006) +93 57 21 N1303K 1/92 (0.011) 0/272 (0) +93 59 24 4404c/t 3/226 (0.013) 14/576 (0.024) +107 60 24 4521g/a 21/56 (0.375) 2/172 (0.012) +107 "slow evolution" markers "fast evolution" markers (i.e. STRs) H is the sum of the degrees of heterozygosity of all the markers Ref.No.a ABSOLUTE AND RELATIVE FREQUENCIES distance from the M470V siteb (Kb) H associated with the…. Login to comment

[hide] Mutations in the amino terminus of the cystic fibr... J Biol Chem. 2006 Feb 10;281(6):3329-34. Epub 2005 Dec 8. Jurkuvenaite A, Varga K, Nowotarski K, Kirk KL, Sorscher EJ, Li Y, Clancy JP, Bebok Z, Collawn JF
Mutations in the amino terminus of the cystic fibrosis transmembrane conductance regulator enhance endocytosis.
J Biol Chem. 2006 Feb 10;281(6):3329-34. Epub 2005 Dec 8., 2006-02-10 [PMID:16339147]

Abstract [show]
Efficient endocytosis of the cystic fibrosis transmembrane conductance regulator (CFTR) is mediated by a tyrosine-based internalization signal in the CFTR carboxyl-terminal tail 1424YDSI1427. In the present studies, two naturally occurring cystic fibrosis mutations in the amino terminus of CFTR, R31C, and R31L were examined. To determine the defect that these mutations cause, the Arg-31 mutants were expressed in COS-7 cells and their biogenesis and trafficking to the cell surface tested in metabolic pulse-chase and surface biotinylation assays, respectively. The results indicated that both Arg-31 mutants were processed to band C at approximately 50% the efficiency of the wild-type protein. However, once processed and delivered to the cell surface, their half-lives were the same as wild-type protein. Interestingly, indirect immunofluorescence and cell surface biotinylation indicated that the surface pool was much smaller than could be accounted for based on the biogenesis defect alone. Therefore, the Arg-31 mutants were tested in internalization assays and found to be internalized at 2x the rate of the wild-type protein. Patch clamp and 6-methoxy-N-(3-sulfopropyl)quinolinium analysis confirmed reduced amounts of functional Arg-31 channels at the cell surface. Together, the results suggest that both R31C and R31L mutations compromise biogenesis and enhance internalization of CFTR. These two additive effects contribute to the loss of surface expression and the associated defect in chloride conductance that is consistent with a disease phenotype.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
1 In the present studies, two naturally occurring cystic fibrosis mutations in the amino terminus of CFTR, R31C, and R31L were examined. Login to comment
8 Together, the results suggest that both R31C and R31L mutations compromise biogenesis and enhance internalization of CFTR. Login to comment
25 In the present studies, we examined two naturally occurring mutations, R31C and R31L, which cause mild CF.3 To determine the defects caused by these missense mutations, we expressed them in COS-7 cells and analyzed their biogenesis and trafficking. Login to comment
26 Our results indicate that both R31C and R31L have compromised biogenesis and enhanced endocytosis compared with wild-type CFTR. Login to comment
29 MATERIALS AND METHODS Construction of CFTR Mutants-The R31C and R31L mutants were prepared by PCR mutagenesis. Login to comment
32 Using the CFTR gene contained in plasmid pCDNA3.1ϩ as template, the R31L and R31C mutants were constructed by PCR-mutagenesis using a pair of internal primers for each mutant, annealing at the Arg-31 coding site, and a pair of external primers, one annealing at the Nhe-I site of the multilinker of the vector, and one annealing at the BspE-I site in the CFTR gene. Login to comment
96 EC, extracellular; IC, intracellular; L/C, R31L and R31C mutations. Login to comment
102 With the R31C and R31L mutants, however, very little processing occurredduringthefirst2hofchase(0and4.7 Ϯ 1.5%,respectively).By4h, 10.3 Ϯ 3.0% (R31C) and 11.3 Ϯ 2.1% (R31L) of CFTR was converted to the mature form, indicating that, although there is a processing defect, it does not cause complete inhibition. Login to comment
106 The results indicate that the protein half-life of the wild-type protein is 13.3 Ϯ 1.2 h, and the R31C and R31L half-lives are 12.7 Ϯ 0.6 and 14.3 Ϯ 3.1 h, respectively, indicating that, FIGURE 3. Login to comment
108 Wild-type, R31C, and R31L CFTR half-lives were determined in COS-7 cells 24 h after transfection. Login to comment
111 A, representative gels of wild-type (WT), R31C, and R31L CFTR half-lives are shown. Login to comment
115 Protein maturation of R31C and R31L CFTR is inefficient compared with wild-type CFTR. Login to comment
120 A, representative metabolic labeling experiments are shown for wild type (WT), R31C, and R31L (left panels). Login to comment
126 Maturation efficiencies of wild type, R31C, and R31L were calculated after 4 h of chase (average Ϯ S.D., n ϭ 3; *, p Ͻ 0.005; **, p Ͻ 0.001). Login to comment
127 C, R31C (C) and R31L (L) are not temperature-sensitive. Login to comment
128 WT, R31C and R31L CFTR were immunoprecipitated from COS-7 cells 48 h after transfection. Login to comment
131 A 27 °C incubation increased the amount of B band but did not influence C band production for R31C or R31L CFTR. Login to comment
133 Reduced Surface Expression of R31C and R31L-Because some mutant protein was processed correctly and the protein half-life appeared normal, the surface pool of the Arg-31 mutants was examined next. Login to comment
136 For the R31C and R31L mutants, however, staining was much more restricted to an intracellular, reticular pattern. Login to comment
138 To confirm this observation, cells expressing wild-type, R31C, and R31L CFTR were surface-biotinylated (Fig. 4B), CFTR was immunoprecipitated, and the biotinylated fraction was detected by Western blot analysis. Login to comment
139 The results indicate that the surface pool of the R31C and R31L mutants is 20.3 Ϯ 7.5 and 33.6 Ϯ 11.7% of the wild-type protein, respectively (n ϭ 4, p Ͻ 0.005, and p Ͻ 0.05, respectively. Login to comment
141 R31C and R31L Are Internalized More Rapidly than the Wild-type CFTR-Because the surface pool was smaller than predicted, we next tested whether the mutations affected CFTR clearance from the cell surface. Login to comment
145 The R31C and R31L mutants, however, have dramatically altered internalization kinetics with 54 Ϯ 4 and 55 Ϯ 13.9% of the R31C and R31L mutants, respectively (internalized during the same warm-up period). Login to comment
147 The Functional Activity of the R31C and R31L Mutants Is Severely Compromised-As a final measure of the total CFTR chloride channels at the cell surface, we tested the functional activity of the R31C and R31L mutants in two complementary functional assays, macroscopic patch clamp experiments and SPQ assays. Login to comment
152 Cells transfected with the R31L and R31C mutants exhibited two differences as compared with wild-type-transfected cells. Login to comment
157 R31C and R31L surface expression is lower than wild-type CFTR. Login to comment
158 A, wild-type, R31C, and R31L CFTR distributions were examined in COS-7 cells 48 h after transfection using indirect immunofluorescence. Login to comment
160 Arrows indicate the prominant cell surface expression of the wild-type protein CFTR and the diminished amount of surface staining in the R31C and R31L CFTR-expressing cells. Login to comment
165 Internalization of the R31C and R31L CFTR mutants is dramatically enhanced compared with the wild-type protein. Login to comment
166 A, wild-type, R31C, and R31L CFTR internalization in COS-7 cells. Login to comment
181 DISCUSSION The R31C and R31L are naturally occurring missense CF mutations that appear to have a mild phenotype (31).3 Both of these mutations are rare (identified once in 284 CF chromosomes, for the R31L mutation). Login to comment
182 The R31C mutation was found in a 45-year-old male CF patient diagnosed in childhood who was pancreatic-sufficient with moderate pulmonary symptoms and a positive sweat test. Login to comment
194 R31C and R31L mutants have diminished channel activity compared with the wild-type protein. Login to comment
195 A-C, representative current traces for wild-type (WT) and R31C and R31L mutants. Login to comment
204 Note that the data for the L and C mutants overestimate their functional activities, because unlike WT, most excised mutant patches exhibited undetectable CFTR activity and were excluded from this analysis (R31L, 4 active patches of 13 total; R31C, 4 active patches of 19 total; wild type, 4 active patches of 6 total). Login to comment
206 E, functional analysis of wild-type and R31C and R31L CFTR using SPQ fluorescence. Login to comment
207 The change in SPQ fluorescence is shown for COS-7 cells expressing wild-type, R31C, and R31L CFTR. Login to comment
232 Analysis of the ⌬F508, N287Y, and R31L and R31C indicate that alterations in the transport of CFTR at the cell surface, whether it is enhanced internalization or compromised recycling, can result in a disease phenotype. Login to comment

[hide] Revertant mutants G550E and 4RK rescue cystic fibr... Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17891-6. Epub 2006 Nov 10. Roxo-Rosa M, Xu Z, Schmidt A, Neto M, Cai Z, Soares CM, Sheppard DN, Amaral MD
Revertant mutants G550E and 4RK rescue cystic fibrosis mutants in the first nucleotide-binding domain of CFTR by different mechanisms.
Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17891-6. Epub 2006 Nov 10., 2006-11-21 [PMID:17098864]

Abstract [show]
The revertant mutations G550E and 4RK [the simultaneous mutation of four arginine-framed tripeptides (AFTs): R29K, R516K, R555K, and R766K] rescue the cell surface expression and function of F508del-cystic fibrosis (CF) transmembrane conductance regulator (-CFTR), the most common CF mutation. Here, we investigate their mechanism of action by using biochemical and functional assays to examine their effects on F508del and three CF mutations (R560T, A561E, and V562I) located within a conserved region of the first nucleotide-binding domain (NBD1) of CFTR. Like F508del, R560T and A561E disrupt CFTR trafficking. G550E rescued the trafficking defect of A561E but not that of R560T. Of note, the processing and function of V562I were equivalent to that of wild-type (wt)-CFTR, suggesting that V562I is not a disease-causing mutation. Biochemical studies revealed that 4RK generates higher steady-state levels of mature CFTR (band C) for wt- and V562I-CFTR than does G550E. Moreover, functional studies showed that the revertants rescue the gating defect of F508del-CFTR with different efficacies. 4RK modestly increased F508del-CFTR activity by prolonging channel openings, whereas G550E restored F508del-CFTR activity to wt levels by altering the duration of channel openings and closings. Thus, our data suggest that the revertants G550E and 4RK might rescue F508del-CFTR by distinct mechanisms. G550E likely alters the conformation of NBD1, whereas 4RK allows F508del-CFTR to escape endoplasmic reticulum retention/retrieval mediated by AFTs. We propose that AFTs might constitute a checkpoint for endoplasmic reticulum quality control.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
180 Jurkuvenaite et al. (42) recently studied R31C and R31L, two CF mutations in the N terminus of CFTR that affect the first AFT (R29QR31). Login to comment

[hide] Association of pancreas divisum and recurrent acut... Pancreas. 2007 Jul;35(1):90-3. Dray X, Fajac I, Bienvenu T, Chryssostalis A, Sogni P, Hubert D
Association of pancreas divisum and recurrent acute pancreatitis with the IVS8-5T-12TG allele of the CFTR gene and CFTR dysfunction.
Pancreas. 2007 Jul;35(1):90-3., [PMID:17575549]

Abstract [show]
OBJECTIVES: Pancreas divisum (PD) occurs in approximately 10% of individuals. Although a minority of patients with PD develop acute pancreatitis (AP), PD is found in up to 25% of patients with unexplained AP. Mild mutations or variants of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, including the IVS8-5T variant, are associated with idiopathic pancreatitis, but their relationship with PD is unknown. We hypothesized for such association. METHODS: Case of 2 patients with PD, recurrent AP, and CFTR-related disease are reported. RESULTS: Both patients had similar clinical patterns (young female adults, nonsevere onsets of AP, mild upper airway manifestations, no major clinical criteria for cystic fibrosis). They had 2 mutations or variants of the CFTR gene (including the IVS8-5T-12TG allele) and mild abnormalities of the CFTR function (increased sweat chloride concentrations in one patient, normal basal but low responses to low-chloride and/or isoproterenol solutions on nasal potential difference). CONCLUSIONS: These observations suggest that impaired epithelial ion transport due to mild CFTR genotype (namely, IVS8-5T-TG12) might be involved as a triggering factor in acute onsets of pancreatitis in PD, possibly through abnormal pancreatic fluid secretion. Further studies on CFTR mutations and abnormal nasal airway ion transport in patients with PD, either with or without recurrent AP, should be conducted.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
34 Genetic testing showed no mutation in the cationic trypsinogen gene and found the R31C and IVS8-5T-12TG variants in the CFTR gene. Login to comment
65 Sweat Chloride Concentrations, NPD, Respiratory Function, and CFTR mutations Test Patient 1 Patient 2 Sweat chloride concentration (mM) Test 1 11 48 Test 2 11 81 NPD (mV) Basal j21 j16 $Amil 9 3 $Clj /Amil j7 j1 $Iso/Clj 0 2 Respiratory function FVC (% pred.) 118 84 FEV1 (% pred.) 115 86 FEF25-75 (% pred.) 100 114 PaO2 (mm Hg) 104 101 PaCO2 (mm Hg) 32 39 CFTR mutations Patient R31C F508del IVS8-5T-12TG IVS8-5T-12TG Father IVS8-5T-12TG Not done IVS8-9T-10TG Mother R31C IVS8-5T-11TG IVS8-7T-11TG IVS8-5T-12TG $Amil (mV) indicates the response to superfusion with 10j4 M amiloride, a blocker of epithelial sodium channel; $Clj /Amil (mV), change in NPD after a perfusion of a low-chloride solution; FVC, forced vital capacity; FEF25-75, forced midexpiratory flow rate; FEV1, forced expiratory volume in 1 second; $Iso/Clj (mV), response to the A-adrenergic agonist isoproterenol (10j5 M) added to the low-chloride solution containing amiloride; PaO2, arterial oxygen tension at rest; PaCO2, arterial carbon dioxide tension at rest; % pred., percentage of predicted value. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
145 2 223CϾT R31C 3 355CϾT R75X 386GϾA G85E 4 482GϾA R117H 575TϾC I148T 621 ؉ 1GϾTb 5 711 ؉ 1GϾT 7 1078delT 1132CϾT R334W 1150delA 1172GϾC R347P 8 1341 ϩ 18AϾCc 9 1496CϾA A455E 10 1651-1653del I507del 1653-1655del F508deld 11 1717 - 1GϾA 1756GϾT G542Xe 1784GϾA G551Db 1789CϾT R553Xf 1811GϾC R560T 12 1898 ؉ 1GϾA 13 2184delA 14b 2789 ؉ 5GϾAe 16 3120 ؉ 1GϾA 18 3500 - 2AϾTg 19 3616CϾT R1162X 3659delC Intron 19 3849 ؉ 10kbCϾTe 20 3978GϾA W1282X 21 4041CϾG N1303K 22 4178GϾA G1349Dc a Disease-causing variants recommended for genotyping by the ACMG (4) are in bold. Login to comment

[hide] N-terminal CFTR missense variants severely affect ... Hum Mutat. 2008 May;29(5):738-49. Gene GG, Llobet A, Larriba S, de Semir D, Martinez I, Escalada A, Solsona C, Casals T, Aran JM
N-terminal CFTR missense variants severely affect the behavior of the CFTR chloride channel.
Hum Mutat. 2008 May;29(5):738-49., [PMID:18306312]

Abstract [show]
Over 1,500 cystic fibrosis transmembrane conductance regulator (CFTR) gene sequence variations have been identified in patients with cystic fibrosis (CF) and related disorders involving an impaired function of the CFTR chloride channel. However, detailed structure-function analyses have only been established for a few of them. This study aimed evaluating the impact of eight N-terminus CFTR natural missense changes on channel behavior. By site-directed mutagenesis, we generated four CFTR variants in the N-terminal cytoplasmic tail (p.P5L, p.S50P, p.E60K, and p.R75Q) and four in the first transmembrane segment of membrane-spanning domain 1 (p.G85E/V, p.Y89C, and p.E92K). Immunoblot analysis revealed that p.S50P, p.E60K, p.G85E/V, and p.E92K produced only core-glycosylated proteins. Immunofluorescence and whole cell patch-clamp confirmed intracellular retention, thus reflecting a defect of CFTR folding and/or trafficking. In contrast, both p.R75Q and p.Y89C had a glycosylation pattern and a subcellular distribution comparable to the wild-type CFTR, while the percentage of mature p.P5L was considerably reduced, suggesting a major biogenesis flaw on this channel. Nevertheless, whole-cell chloride currents were recorded for all three variants. Single-channel patch-clamp analyses revealed that the channel activity of p.R75Q appeared similar to that of the wild-type CFTR, while both p.P5L and p.Y89C channels displayed abnormal gating. Overall, our results predict a major impact of the CFTR missense variants analyzed, except p.R75Q, on the CF phenotype and highlight the importance of the CFTR N-terminus on channel physiology.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
247 A recent report analyzing the natural mutations p.R31C and p.R31L, has shown that these subtle N-terminus alterations compromise biogenesis and enhance internalization of CFTR, contributing to the loss of surface expression and the associated defect in chloride conductance of the channel [Jurkuvenaite et al., 2006]. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
64 Determination of the transepithelial nasal potential difference has been beneficial in establishing a CF Table 1 Mutations, sites, and molecular consequences associated with either an atypical presentation of CF respiratory disease or pancreatic sufficiency or late-onset pancreatic insufficiency (http:// www.genet.sickkids.on.ca) Mutation Site Consequence Atypical presentation M1210I Exon 19 Met to Ile at 1210 S1455X Exon 24 Ser to Stop at 1455 1811+18G→A Intron 11 mRNA splicing defect L346P Exon 7 Leu to Pro at 346 Y161D Exon 4 Tyr to Asp at 161 R31C Exon 2 Arg to Cys at 31 I752S Exon 13 Ile to Ser at 752 2811G/T Exon 15 Sequence variation Pancreatic sufficiency or late-onset pancreatic insufficiency R600G Exon 13 Arg to Gly at 600 D1152H Exon 18 Asp to His at 1152 Y89C Exon 3 Tyr to Cys at 89 R117H Exon 4 Arg to His at 117 D110E Exon 4 Asp to Glu at 110 296 + 3insT Intron 2 mRNA splicing defect E217G Exon 6a Glu to Gly at 217 V392G Exon 8 Val to Gly at 392 N1088D Exon 17b Asn to Asp at 1088 S737F Exon 13 Missense 1716+1G→A Intron 10 mRNA splicing defect R334W Exon 7 Arg to Trp at 334 R347P Exon 7 Arg to Pro at 347 A455E Exon 9 Ala to Glu at 455 P574H Exon 12 Pro to His at 574 3850-3T→G Intron 19 mRNA splicing defect diagnosis in many atypical cases. Login to comment

[hide] A novel computational and structural analysis of n... Genomic Med. 2008 Jan;2(1-2):23-32. Epub 2008 May 14. George Priya Doss C, Rajasekaran R, Sudandiradoss C, Ramanathan K, Purohit R, Sethumadhavan R
A novel computational and structural analysis of nsSNPs in CFTR gene.
Genomic Med. 2008 Jan;2(1-2):23-32. Epub 2008 May 14., [PMID:18716917]

Abstract [show]
Single Nucleotide Polymorphisms (SNPs) are being intensively studied to understand the biological basis of complex traits and diseases. The Genetics of human phenotype variation could be understood by knowing the functions of SNPs. In this study using computational methods, we analyzed the genetic variations that can alter the expression and function of the CFTR gene responsible candidate for causing cystic fibrosis. We applied an evolutionary perspective to screen the SNPs using a sequence homology-based SIFT tool, which suggested that 17 nsSNPs (44%) were found to be deleterious. The structure-based approach PolyPhen server suggested that 26 nsSNPS (66%) may disrupt protein function and structure. The PupaSuite tool predicted the phenotypic effect of SNPs on the structure and function of the affected protein. Structure analysis was carried out with the major mutation that occurred in the native protein coded by CFTR gene, and which is at amino acid position F508C for nsSNP with id (rs1800093). The amino acid residues in the native and mutant modeled protein were further analyzed for solvent accessibility, secondary structure and stabilizing residues to check the stability of the proteins. The SNPs were further subjected to iHAP analysis to identify htSNPs, and we report potential candidates for future studies on CFTR mutations.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
125 The nsSNPs which were predicted to be Table 1 List of nsSNPs that were predicted to be deleterious by SIFT and PolyPhen SNPs ID Alleles AA change Tolerance index PSIC rs1800072 G/A V11C 1.00 0.150 rs1800073 C/T R31C 0.18 2.288 rs1800074 A/T D44V 0.01 2.532 rs1800076 G/A R75Q 0.03 1.754 rs1800078 T/C L138P 0.01 2.192 rs35516286 T/C I148T 0.41 1.743 rs1800079 G/A R170H 0.05 1.968 rs1800080 A/G S182G 0.03 1.699 rs1800086 C/G T351S 0.30 1.600 rs1800087 A/C Q353H 0.03 2.093 rs4727853 C/A N417K 1.00 0.015 rs11531593 C/A F433L 0.65 0.694 rs1800089 C/T L467F 0.15 1.568 rs213950 G/A V470M 0.17 1.432 rs1800092 C/A/G I506M 0.00 1.574 rs1801178 A/G I507V 0.38 0.314 rs1800093 T/G F508C 0.00 3.031 rs35032490 A/G K532E 1.00 1.525 rs1800097 G/A V562I 0.13 0.345 rs41290377 G/C G576A 0.33 1.262 rs766874 C/T S605F 0.03 2.147 rs1800099 A/G S654G 0.03 1.611 rs1800100 C/T R668C 0.01 2.654 rs1800101 T/C F693L 0.61 0.895 rs1800103 A/G I807M 0.01 1.554 rs1800106 T/C Y903H 0.52 0.183 rs1800107 G/T S909I 0.10 1.624 rs1800110 T/C L967S 0.07 1.683 rs1800111 G/C L997F 0.24 1.000 rs1800112 T/C I1027T 0.03 1.860 rs1800114 C/T A1067V 0.04 1.542 rs36210737 T/A M1101K 0.05 2.637 rs35813506 G/A R1102K 0.52 1.589 rs1800120 G/T R1162L 0.00 2.038 rs1800123 C/T T1220I 0.22 0.059 rs34911792 T/G S1235R 0.45 1.483 rs11971167 G/A D1270N 0.12 1.739 rs4148725 C/T R1453W 0.00 2.513 Highly deleterious by SIFT and damaging by PolyPhen are indicated as bold deleterious in causing an effect in the structure and function of the protein by SIFT, PolyPhen and Pupasuite correlated well with experimental studies (Tsui 1992; Ghanem et al. 1994; Bienvenu et al. 1998) (Table 3). Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Reprod Biomed Online. 2009 Nov;19(5):685-94. Gallati S, Hess S, Galie-Wunder D, Berger-Menz E, Bohlen D
Cystic fibrosis transmembrane conductance regulator mutations in azoospermic and oligospermic men and their partners.
Reprod Biomed Online. 2009 Nov;19(5):685-94., [PMID:20021716]

Abstract [show]
The objective of this study was to investigate the contribution of cystic fibrosis transmembrane conductance regulator (CFTR) to human infertility and to define screening and counselling procedures for couples asking for assisted reproduction treatment. Extended CFTR mutation screening was performed in 310 infertile men (25 with congenital absence of the vas deferens (CAVD), 116 with non-CAVD azoospermia, 169 with severe oligospermia), 70 female partners and 96 healthy controls. CFTR mutations were detected in the majority (68%) of CAVD patients and in significant proportions in azoospermic (31%) and oligospermic (22%) men. Carrier frequency among partners of infertile men was 16/70, exceeding that of controls (6/96) significantly (P = 0.0005). Thus, in 23% of infertile couples both partners were carriers, increasing the risk for their offspring to inherit two mutations to 25% or 50%. This study emphasizes the necessity to offer extended CFTR mutation screening and counselling not only to patients with CAVD but also to azoospermic and oligozoospermic men and their partners before undergoing assisted reproduction techniques. The identification of rare and/or mild mutations will not be a reason to abstain from parenthood, but will allow adequate treatment in children at risk for atypical or mild cystic fibrosis as soon as they develop any symptoms.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
117 Based on discriminant analysis, this study predicts a high probability for the presence of CFTR mutations especially in patients with reduced ejaculate volumes (<3 ml) and structural abnormalities such as CAVD, inguinal hernia, hypotrophic testes or cryptorchidism, confirming former findings reported by Casals et al. (2000) and representing symptoms that are also frequently observed in Table 3 (continued) Couple no. Infertile male CFTR mutation Female partner CFTR mutation Offspring genotype Risk for genotype (%) 14 R31C/wt oligospermia V920M/wt R31C/V920M 25 R31C/wt 25 V920M/wt 25 wt/wt 25 15 R31C/wt azoospermia I148T/wt R31C/I148T 25 R31C/wt 25 I148T/wt 25 wt/wt 25 16 V754M/wt oligospermia V754M/wt V754M/V754M 25 V754M/wt 50 wt/wt 25 Bold = mutations associated with classic cystic fibrosis; italic = mutations associated with a mild or uncertain, unpredictable phenotype; CAVD = congenital absence of the vas deferens; wt = wildtype allele. Login to comment

[hide] Total pancreatectomy and islet cell autotransplant... Surgery. 2010 Oct;148(4):676-85; discussion 685-6. Sutton JM, Schmulewitz N, Sussman JJ, Smith M, Kurland JE, Brunner JE, Salehi M, Choe KA, Ahmad SA
Total pancreatectomy and islet cell autotransplantation as a means of treating patients with genetically linked pancreatitis.
Surgery. 2010 Oct;148(4):676-85; discussion 685-6., [PMID:20846557]

Abstract [show]
BACKGROUND: For patients with severe chronic pancreatitis, total or completion pancreatectomy with islet cell autotransplantation (IAT) can alleviate pain and avoid the complications of diabetes. Several genetic mutations, specifically, PRSS1, CFTR, and SPINK1, are associated with chronic pancreatitis. Few reports have focused on the benefit of this operation for this subset of patients. METHODS: Between February 2000 and July 2009, 118 patients were treated with total pancreatectomy and IAT for chronic pancreatitis. Patients with known genetic mutations were then selected for further analysis. RESULTS: Of the 188 patients, 16 (13.6%) patients were identified as having genetic mutations, including CFTR (n = 10), PRSS1 (n = 4), and SPINK1 (n = 2) mutations. Mean patient age was 31.4 years (range, 15-59) with an equal male-to-female ratio (50:50). Preoperatively, patients required an average of 185 +/- 60 morphine equivalents (MEQ) (median, 123 MEQ) for preoperative pain control. No patients were taking insulin before operation. After resection with IAT, patients were discharged from the hospital with a daily average of 22 +/- 4 units of insulin with 6 (38%) patients requiring fewer than 15 units of insulin at the time of discharge. At a mean follow-up of 22 months, mean insulin requirements decreased to 15 U/d (P = .0172). A total of 7 (44%) patients required 15 or fewer units daily, and 4 (25%) patients were completely insulin-independent. Average daily narcotic usage at most recent follow-up decreased to 70 MEQ (median, 0) with 10 (63%) patients currently narcotic-independent. Analyses of the 36-item short-form health survey and the McGill Pain Questionnaire demonstrated a significant improvement in quality-of-life parameters and pain assessment. CONCLUSION: In patients who suffer from genetically linked chronic pancreatitis, pancreatic resection with IAT should be considered as an early therapeutic option to decrease chronic abdominal pain while preserving endogenous endocrine function.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
117 Patient demographics Descriptive statistics Data mean (SEM) Range Age, y 32 (3) 15-59 Weight, kg 73 (6) 39-127 Body mass index, kg/m2 24 (2) 15-35 Chronic pancreatitis, y 14 (2) 3-47 Sex Male, n = 8 Female, n = 8 Previous pancreatic operations Puestow, n =3 Whipple, n = 3 Genetic mutations and loci, n (%) CFTR 10 (62.5) R297Q 2 DF508 + R117H 1 R553X + M470V 1 DF508 1 R117H 1 P750L 1 D1152H 1 R31C 1 S1235R 1 PRSS1 4 (25) R122H 3 Unknown* 1 SPINK1 2 (12.5) N34S 2 *One patient was identified as having a PRSS1 mutation, but the specific locus mutation was unknown at the time of publication. Login to comment

[hide] The etiology of acute recurrent pancreatitis in ch... Pancreas. 2011 May;40(4):517-21. Lucidi V, Alghisi F, Dall'Oglio L, D'Apice MR, Monti L, De Angelis P, Gambardella S, Angioni A, Novelli G
The etiology of acute recurrent pancreatitis in children: a challenge for pediatricians.
Pancreas. 2011 May;40(4):517-21., [PMID:21499205]

Abstract [show]
OBJECTIVES: To assess specific etiologies of acute recurrent pancreatitis at a single Italian pediatric cystic fibrosis (CF) center. METHODS: We studied, retrospectively, 78 young patients (39 female subjects; mean age at diagnosis, 8.8 +/- 5.1 years) affected by acute recurrent episodes of pancreatitis, remained etiologically undiagnosed at first-level assessment. All patients were submitted to endoscopic retrograde cholangiopancreatography to exclude biliopancreatic malformations and tested for CF by a sweat chloride test. Most patients also were studied for the research of CFTR, PRSS1, and SPINK1 gene mutations. RESULTS: A high percentage of family history for chronic pancreatitis was observed (20.5%). The sweat test identified 8 subjects (10.3%) with classic CF (2 patients) or at risk for CF (6 patients). Genetic analysis showed mutations in CFTR, SPINK1, and PRSS1 genes in 39.6%, 7.1%, and 4.5% of patients, respectively. A biliopancreatic malformation was diagnosed in 15 patients (19.2%). We also observed biliary lithiasis (5 patients [6.5%]), congenital pancreatic polycystosis (2 patients), a case of dyslipidemia, and 1 patient with a posttransplantation, drug-induced pancreatitis. CONCLUSIONS: Recurrent pancreatitis in children has several etiologies. Genetic testing confirms the high frequency of CFTR mutations. This suggests that it is of some value to identify patients with late-onset CF and CFTR-related disorders.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
46 Genetic Findings Observed in Our Study Population and Related Clinical Features CFTR PRSS1 SPINK1 Clinical CharacteristicsMutations IVS8 F508del/UN 9T/9T S181G/- NEG No respiratory symptoms 3849+10KbC9T/UN 7T/7T NEG NEG No respiratory symptoms UN/UN 7T/7T NEG N34S/- UN/UN 5T/7T NEG NEG No respiratory symptoms 1899-136T/C/UN 5T/7T NEG NEG No respiratory symptoms F508del/UN 5T/9T NEG NEG No respiratory symptoms D1152H/D1152H NEG NEG No respiratory symptoms R75Q/UN 5T/7T NEG NEG No respiratory symptoms L997F/UN 7T/9T NEG NEG No respiratory symptoms UN/UN 7T/7T NEG N34S/- W1282X/I148T 7T/9T NEG NEG No respiratory symptoms NEG N34S/- R75Q/F1052V NEG NEG No respiratory symptoms F508del/D1152H NEG NEG Bronchiectasis-CF 406-6T/C/E528E 7T/7T NEG NEG No respiratory symptoms F508del/UN 7T/9T Mild respiratory symptomsYCF L967S/L997F NEG NEG No respiratory symptoms E528E/UN 5T/7T Crohn disease, food allergy 1716 G/A/UN 7T/7T NEG NEG No respiratory symptoms 1898+1G9A/UN 7T/7T No respiratory symptoms R31C/UN No respiratory symptoms R75Q/UN 7T/7T NEG NEG No respiratory symptoms N29T;V212I; D217Y NEG F508del/UN 7T/9T NEG NEG Pancreas divisum S1235R/UN 7T/9T NEG NEG Duodenal stenosis Entries in bold font undelines the detection of mutations or polymorphisms in the studied genes. Login to comment

[hide] Complete mutational screening of the CFTR gene in ... Hum Genet. 1998 Dec;103(6):718-22. Bombieri C, Benetazzo M, Saccomani A, Belpinati F, Gile LS, Luisetti M, Pignatti PF
Complete mutational screening of the CFTR gene in 120 patients with pulmonary disease.
Hum Genet. 1998 Dec;103(6):718-22., [PMID:9921909]

Abstract [show]
In order to determine the possible role of the cystic fibrosis transmembrane regulator (CFTR) gene in pulmonary diseases not due to cystic fibrosis, a complete screening of the CFTR gene was performed in 120 Italian patients with disseminated bronchiectasis of unknown cause (DBE), chronic bronchitis (CB), pulmonary emphysema (E), lung cancer (LC), sarcoidosis (S) and other forms of pulmonary disease. The 27 exons of the CFTR gene and their intronic flanking regions were analyzed by denaturing gradient gel electrophoresis and automatic sequencing. Mutations were detected in 11/23 DBE (P = 0.009), 7/25 E, 5/27 CB, 5/26 LC, 5/8 S (P = 0.013), 1/4 tuberculosis, and 1/5 pneumonia patients, and in 5/33 controls. Moreover, the IVS8-5T allele was detected in 6/25 E patients (P = 0.038). Four new mutations were identified: D651N, 2377C/T, E826K, and P1072L. These results confirm the involvement of the CFTR gene in disseminated bronchiectasis of unknown origin, and suggest a possible role for CFTR gene mutations in sarcoidosis, and for the 5T allele in pulmonary emphysema.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
62 Five mutations (G576A, R668C, R74W, R31C, and I506V) are not thought to be the cause of CF (CFGAC website): three of them (G576A, R668C, and R74W) have been found in CBAVD patients (Anguiano et al. 1992; Chillon et al. 1995; Mercier et al. 1995; Verlingue et al. 1996), R31C was described in a DBE patient (Girodon et al. 1997), and I506V was found in the normal allele in the father of a CF child (Ghanem et al. 1994). Login to comment
64 All these mutations, except V754M and R31C, affect highly conserved residues among five species investigated: human, bovine, mouse, Xenopus, and dogfish (Tucker et al. 1992). Login to comment
88 of cases CFTR gene PolyTb status tested mutationa DBE 23 1 G576A-R668C/L997F 7/9 1 ∆F508/L997F 9/9 1 ∆F508/- 7/9 1 R1066C/- 5/7 1 3667ins4/- 5/7 1 R75Q/- 7/7 1 M1137V/- 7/7 1 -/- 5/5 3 -/- 5/7 10 -/- 7/7 2 -/- 7/9 CB 27 1 P111L/- 7/7 1 R117H/- 7/7 1 E585X/- 7/7 1 P1072L/- 7/7 1 -/- 5/7 15 -/- 7/7 6 -/- 7/9 1 -/- 9/9 E 25 1 R668C/- 7/7 6 -/- 5/7 16 -/- 7/7 6 -/- 7/9 S 8 1 E826K/- 7/7 1 ∆F508/- 7/9 1 4382delA/- 7/7 1 L997F/- 7/9 1 V754M/- 7/9 3 -/- 7/7 LC 26 1 I148T/- 5/7 1 D1270N-R74W 5/7 1 D651N/- 7/7 1 Y301C/- 7/7 1 -/- 5/7 16 -/- 7/7 5 -/- 7/9 TB 4 1 -/- 5/7 1 -/- 7/7 2 -/- 7/9 Pneumonia 5 4 -/- 7/7 1 -/- 5/7 Pnx 2 2 -/- 7/7 Controls 68 1 L997F/- 7/9 1 R31C/- 7/7 1 I506V/- 5/7 1 -/- 5/7 1 -/- 5/9 23 -/- 7/7 4 -/- 7/9 1 -/- 9/9 2 ? Login to comment
120 Three missense mutations were detected in 33 controls: L997F, which is present in two DBE and in one sarcoidosis patients; R31C, which was first described in an apparently unaffected 6-year-old child (Ghanem et al. 1994) and next in a DBE patient (Girodon et al. 1997); I506V, which was described in a healthy parent of a CF patient who bore ∆F508 on the other chromosome (Kobayashi et al. 1990). Login to comment

[hide] CFTR mutation combinations producing frequent comp... Hum Mutat. 2012 Nov;33(11):1557-65. doi: 10.1002/humu.22129. Epub 2012 Jul 2. El-Seedy A, Girodon E, Norez C, Pajaud J, Pasquet MC, de Becdelievre A, Bienvenu T, des Georges M, Cabet F, Lalau G, Bieth E, Blayau M, Becq F, Kitzis A, Fanen P, Ladeveze V
CFTR mutation combinations producing frequent complex alleles with different clinical and functional outcomes.
Hum Mutat. 2012 Nov;33(11):1557-65. doi: 10.1002/humu.22129. Epub 2012 Jul 2., [PMID:22678879]

Abstract [show]
Genotype-phenotype correlations in cystic fibrosis (CF) may be difficult to establish because of phenotype variability, which is associated with certain CF transmembrane conductance regulator (CFTR) gene mutations and the existence of complex alleles. To elucidate the clinical significance of complex alleles involving p.Gly149Arg, p.Asp443Tyr, p.Gly576Ala, and p.Arg668Cys, we performed a collaborative genotype-phenotype correlation study, collected epidemiological data, and investigated structure-function relationships for single and natural complex mutants, p.[Gly576Ala;Arg668Cys], p.[Gly149Arg;Gly576Ala;Arg668Cys], and p.[Asp443Tyr;Gly576Ala;Arg668Cys]. Among 153 patients carrying at least one of these mutations, only three had classical CF and all carried p.Gly149Arg in the triple mutant. Sixty-four had isolated infertility and seven were healthy individuals with a severe mutation in trans, but none had p.Gly149Arg. Functional studies performed on all single and natural complex mutants showed that (1) p.Gly149Arg results in a severe misprocessing defect; (2) p.Asp443Tyr moderately alters CFTR maturation; and (3) p.Gly576Ala, a known splicing mutant, and p.Arg668Cys mildly alter CFTR chloride conductance. Overall, the results consistently show the contribution of p.Gly149Arg to the CF phenotype, and suggest that p.[Arg668Cys], p.[Gly576Ala;Arg668Cys], and p.[Asp443Tyr;Gly576Ala;Arg668Cys] are associated with CFTR-related disorders. The present study emphasizes the importance of comprehensive genotype-phenotype and functional studies in elucidating the impact of mutations on clinical phenotype. Hum Mutat 33:1557-1565, 2012. (c) 2012 Wiley Periodicals, Inc.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
105 [2002C>T;3718-2477C>T] p.Gln689X 2 CSD Nasal polyposis 14 y,16 y NA, 29 p.[Gly576Ala;Arg668Cys] NI 3 IP 35-39 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] NI 1 IP Bronchitis 49 y NA p.[Gly576Ala;Arg668Cys] p.PheF508del 1 IP 42 y NA p.[Gly576Ala;Arg668Cys] p.Arg668Cys 1 IP NA NA p.[Gly576Ala;Arg668Cys] c.1210_34TG[12]T[5] 4 IP 19-69 y NA p.[Gly576Ala;Arg668Cys] NI 1 Cholestasis 60 y NA p.[Gly576Ala;Arg668Cys] c.1584G>A 33 CBAVD 27-50 y 9-82 p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Phe508del 2 CBAVD 30 y,36 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] c.2051_2052delAAinsG 1 CBAVD 34 y 72 p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Trp1282X 1 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Asn1303Lys 1 CBAVD 35 y 65-66 p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Ser549Asn 1 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] c.3605delA 1 CBAVD 30 y 41-69 p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Gln1411X 1 CBAVD 31 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Arg347His 3 CBAVD 29 y, 34 y, NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Gly542X 1 CBAVD 35 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] c.946delT 1 CBAVD 26 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] c.4242_4242+1delGGinsT 1 CBAVD 41 y 31 p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Arg117His 1 CBAVD 32 y NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Thr338Ile 1 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Glu379Lys 1 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Met1137Val 1 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Thr1246Ile 2 CBAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] NI 1 CBAVD 34 NA p.[Gly576Ala;Arg668Cys] p.Asn1303Lys 8 CBAVD 30-42 y NA p.[Gly576Ala;Arg668Cys] NI 1 CBAVD 27 y NA p.Arg668Cys p.Phe508del 1 CBAVD 30 y NA p.Arg668Cys NI 1 CUAVD NA NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Phe508del 1 CUAVD NA NA p.[Gly576Ala;Arg668Cys] NI 1 CUAVD Renal agenesis NA NA p.[Gly576Ala;Arg668Cys] NI 1 Hypofertility (not CBAVD) CF carrier`s partner NA NA p.[Gly576Ala;Arg668Cys] p.Asp1152His 1 FBA Mild CF considered possible, 2 older brothers with the same genotype, one with a very mild phenotype, the other being asymptomatic 22 wg NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Asn1303Lys 1 FBA TOP for de novo chromosomal translocation; not CF 21 wg NA p.[Asp443Tyr;Gly576Ala;Arg668Cys] p.Arg31Cys 1 FBA Not CF at birth 28 wg <30 p.[Gly576Ala;Arg668Cys] p.Phe508del 1 FBA Unknown outcome 23 wg NA p.[Gly576Ala;Arg668Cys] p.Phe508del 1 FBA Not CF at birth 21 wg <30 p.[Gly576Ala;Arg668Cys] p.Trp846X (Continued) Table 1. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
63 This child was diagnosed with atypical CF in the first week of life using molecular diagnostics (F508 del/R31C) as both parents were known heterozygous CF carriers. Login to comment
80 CFTR mutations Alleles found Percentage of total Homozygous (n) F508del a 86 68.2 30 3905insT a 4 3.2 1 G542X a 3 2.4 - R553X a 3 2.4 1 W1282X a 2 1.6 - 1717-1 GNA a 2 1.6 - N1303K a 0 0.0 - S549R 3 2.4 1 Q525X 3 2.4 - Y1092X 2 1.6 - 3120+1 GNA b 2 1.6 1 2347delG 2 1.6 - 2176insC 1 0.8 - 3659delC 1 0.8 - 3359delCTCTG 1 0.8 - W1089X 1 0.8 - 711+1 GNT 1 0.8 - D1152H 1 0.8 - G1244E 1 0.8 - R1066C 1 0.8 - R31C 1 0.8 - R347P 1 0.8 - R74W 1 0.8 - S945L 1 0.8 - T501I 1 0.8 - K68X 1 0.8 - Total 126 100.0% 34 a Seven most common CF-gene mutations in Switzerland ("Swiss panel")=79.4% (100/126) of alleles. Login to comment

[hide] Case records of the Massachusetts General Hospital... N Engl J Med. 2011 Oct 20;365(16):1528-36. Shah U, Shenoy-Bhangle AS
Case records of the Massachusetts General Hospital. Case 32-2011. A 19-year-old man with recurrent pancreatitis.
N Engl J Med. 2011 Oct 20;365(16):1528-36., [PMID:22010920]

Abstract [show]

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
146 The patient was found to have two CFTR mutations - ΔF508 and R31C. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
51 Sequences of the Primers Used for CFTR Analysis by HRM, GC Size, Amplicon Length, Number of Positive Controls Validated for Each Exon, and Positive Controls for Routine Analysis Exon Primer Sequences GC length Amplicon length (bp) Introns Number of heterozygous- positive controls Number of homozygous- positive controls Recommended control 1 LSCFE1Fmod 5Ј-CCGCCGCCGTTGAGCGGCAGGCACC-3Ј 8 200 bp 74 4 125GϾC LSCFE1Rmod 5Ј-CCGCCGCCGGCACGTGTCTTT CCGAAGCT-3Ј 8 19 M1I 2 2i5b 5Ј-CAAATCTGTATGGAGACC-3Ј 0 194 bp 39 5 R31C 2i3Љ 5Ј-CAACTAAACAATGTACATGAAC-3Ј 0 4 296ϩ1GϾT 3 LSCFe3Fmod LSCFe3Rmod 5Ј-CGCCGTTAAGGGAAATAGGACAA CTAAAATA-3Ј 5 276 bp 44 10 2 R75Q 5Ј-CCGCCGATTCACCAGATTTCGTAGTC-3Ј 6 66 G85V 4 LSCFe4FmodC 5Ј-CCGCCGCCGCCCGTGTTGAAATT CTCAGGGT-3Ј 12 361 bp 52 14 1 R117H LSCFe4RmodC 5Ј-CCGCCGCCCACATGTACGATAC AGAATATATGTGCC-3Ј 9 26 574delA 5 LSCFE5Fmod 5Ј-CCGCCGGTTGAAATTATCTAACTTTCC-3Ј 6 201 bp 13 8 624delT LSCFE5Rmod 5Ј-CCGAACTCCGCCTTTCCAGTTGT-3Ј 3 48 711ϩ1GϾT 6a LSCF6aFmod2 5Ј-CCGCCGGGGTGGAAGAT ACAATGACACCTG-3Ј 5 317 bp 25 8 C225X LSCF6aRmod2 5Ј-CCGCCGCCGCGATGCATAGAG CAGTCCTGGTT-3Ј 11 66 L206W 6b LSCFE6bFmod 5Ј-CGCGCCGCCGGATTTAC AGAGATCAGAGAG-3Ј 10 239 bp 0 2 1 R258G LSCFE6Brmod 5Ј-CCGCCGCCGAGGTGGA GTCTACCATGA-3Ј 8 66 1001ϩ11CϾT 7 LSCFE7Fmod2 5Ј-CCGCCGCCCTCTCCCTGAATTT TATTGTTATTGTTT-3Ј 13 326 bp 7 11 1078delT LSCFE7Rmod2 5Ј-CCCGCCGCCCTATAATGCAG CATTATGGT-3Ј 10 7 1248ϩ1GϾT 8 LSCFE8Fmod 5Ј-CCGGAATGCATTAATGCTAT TCTGATTC-3Ј 4 199 bp 32 7 W401X LSCFE8Rmod 5Ј-CCCGCAGTTAGGTGTTTAG AGCAAACAA-3Ј 4 18 1249-5AϾG 9 LSCFe9Fmod2 5Ј-CCGCCGCCGGGAATTATTTGAGAA AGCAAAACA-3Ј 8 279 bp 0 3 D443Y LSCFe9Rmod2 5Ј-CCGCCGCGAAAATACCTTCCAG CACTACAAACTAGAAA-3Ј 8 57 A455E 10 LSCF10FmodD 5Ј-CGCCGTTATGGGAGAACTGG AGCCTTCAGAG-3Ј 5 275 bp 0 15 1 F508del LSCF10RmodD 5Ј-CCGCAGACTAACCGATTGAAT ATGGAGCC-3Ј 4 68 E528E 11 h11i5 5Ј-TGCCTTTCAAATTCAGATTGAGC-3Ј 0 197 bp 42 13 2 G542X 11i3ter 5Ј-ACAGCAAATGCTTGCTAGACC-3Ј 0 17 G551D 12 LSCFE12Fmod 5Ј-CGCGTCATCTACACTAGATGACCAG-3Ј 4 244 bp 43 15 G576A 1898 ϩ 1GϾALSCFE12Rmod 5Ј-CCGGAGGTAAAATGCAATCTATGATG-3Ј 3 63 13 LSCF13AFmod 5Ј-CCGCCGCCGGAGACATATTG CAATAAAGTAT-3Ј 9 38 20 I601F LSCF13ARmod 5Ј-GCCTGTCCAGGAGACAGGA GCATCTC-3Ј 2 R668C LSCF13BFmod 5Ј-CCGCCGCAATCCTAACTGAG ACCTTACACCG-3Ј 2 R668C LSCF13BRmod 5Ј-CCGCCGATCAGGTTCAGGA CAGACTGC-3Ј 3 346 bp 2184insA LSCF13CFmod 5Ј-CCGCGGTGATCAGCACTGGCCC-3Ј 6 301 bp 77 L749L LSCF13CRmod 5Ј-CCGCGCGCGCGGCCAGTTTCTTG AGATAACCTTCT-3Ј 13 259 bp V754M LSCF13DFmod 5Ј-CGTGTCACTGGCCCCTCAGGC-3Ј 1 221 bp I807M LSCF13DRmof 5Ј-CCGCCGCCGCTAATCCTATGA TTTTAGTAAAT-3Ј 9 220 bp 2622ϩ1GϾA LSCf13FFmod 5Ј-CGCGGTGCAGAAAGAAGAAAT TCAATCCTAACTG-3Ј 4 R668C LSCF13FRmod 5Ј-CCGCCGTGCCATTCATTTGT AAGGGAGTCT-3Ј 6 2184insA 14a LSCF14aFmodB 5Ј-CCGACCACAATGGTGGCAT GAAACTG-3Ј 3 239 bp 35 7 1 T854T LSCF14aRmodB 5Ј-CCGCCGACTTTAAATCCAGTAAT ACTTTACAATAGAACA-3Ј 6 7 W846X 14b LSCF14bFmod 5Ј-CCGGAGGAATAGGTGAAGAT-3Ј 2 179 bp 38 4 2752-5GϾT LSCF14bRmodb 5Ј-CCGTACATACAAACATAGTGGATT-3Ј 3 59 2789ϩ5GϾT 15 LSCFE15Fmod 5Ј-CGCGCCGTGTATTGGAAA TTCAGTAAGTAACTTTGG-3Ј 7 412 bp 33 16 T908S LSCFE15Rmod 5Ј-CCGCAGCCAGCACTGCCAT TAGAAA-3Ј 4 68 S945L (table continues) phisms that we have chosen to exclude. Login to comment
171 Results of CFTR Analysis by HRM on 136 Samples of Patients with Idiopathic Chronic Pancreatitis (ICP) Exon Number of positive samples Mutations identified Variants identified New positive controls 1 14 14 125GϾC 2 1 1 R31C 3 9 1 G85E 7 R75Q 1 R74W 4 4 1 R117G 1 I148T R117G 1 R117H 1 A120T 5 1 1 L188P L188P 6a 5 1 V201M 1 A221A A221A 3 875ϩ40 AϾG 6b 27 1 M284T 26 1001ϩ11CϾT M284T 7 1 1 L320V L320V 8 0 0 9 1 1 D443Y 10 16 8 F508del 8 E528E 11 1 1 G542X 12 6 4 G576A 1 Y577Y L568F 1 L568F 13 7 1 S737F 4 R668C S737F 1 V754M L644L 1 L644L 14a 53 52 T854T T854TϩI853I 1 T854TϩI853I 14b 0 0 15 3 1 L967S T908S 1 T908S 1 S945L 16 0 0 17a 10 7 L997F 1 3271ϩ18CϾT 3271 ϩ 3AϾG 1 3271 ϩ 3 AϾG 1 Y1014C 17b 3 1 L1096L L1096L 1 H1054DϩG1069R 1 3272-33AϾG H1054DϩG1069R 3272-33AϾG 18 2 1 D1152H E1124del 1 E1124del 19 5 5 S1235R poly 20 7 1 W1282X 5 P1290P 1 D1270N 21 2 1 N1303K 1 T1299T 22 0 0 23 1 0 4374ϩ13 AϾG 24 43 40 Q1463Q 2 Y1424Y 1 Q1463QϩY1024Y ing domain of a gene brings an excellent sensitivity for heterozygote detection that is very close to 100%. Login to comment

[hide] Endocytic trafficking of CFTR in health and diseas... J Cyst Fibros. 2007 Jan;6(1):1-14. Epub 2006 Nov 13. Ameen N, Silvis M, Bradbury NA
Endocytic trafficking of CFTR in health and disease.
J Cyst Fibros. 2007 Jan;6(1):1-14. Epub 2006 Nov 13., [PMID:17098482]

Abstract [show]
The cystic fibrosis transmembrane conductance regulator (CFTR) is a Cl-selective anion channel expressed in epithelial tissues. Mutations in CFTR lead to the genetic disease cystic fibrosis (CF). Within each epithelial cell, CFTR interacts with a large number of transient macromolecular complexes, many of which are involved in the trafficking and targeting of CFTR. Understanding how these complexes regulate the trafficking and fate of CFTR, provides a singular insight not only into the patho-physiology of cystic fibrosis, but also provides potential drug targets to help cure this debilitating disease.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
680 R31C and R31L are CFTR mutations that also give rise to a mild clinical phenotype [71]. Login to comment
683 Expression of R31C and R31L CFTR leads to reduced macroscopic currents compared to expression of wt CFTR; however, since single channel records were not determined it is not possible to determine whether the reduced macroscopic currents are due to endocytic defects alone, or whether there are also altered gating kinetics. Login to comment
681 R31C and R31L are CFTR mutations that also give rise to a mild clinical phenotype [71]. Login to comment
684 Expression of R31C and R31L CFTR leads to reduced macroscopic currents compared to expression of wt CFTR; however, since single channel records were not determined it is not possible to determine whether the reduced macroscopic currents are due to endocytic defects alone, or whether there are also altered gating kinetics. Login to comment

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

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

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
66 Five sequence changes (R31C, R75Q, F508C, G576A, R1162L) were reported as ''mutations`` in the forms; however, they are listed as ''polymorphisms`` in the CFGAC (designed respectively as 223C/T, 356G/A, 1655T/G, 1859G/ C, and 3617G>T). Login to comment
109 h M1K, K14X, W19X, 211delG, G27E, R31C, 237insA, 241delAT, Q39X, 244delTA, 296+2T>C, 297-3C>T, W57X+F87L, 306delTAGA, P67L, A72D, 347delC, R75Q, 359insT, 394delT, 405+4A>G, Q98R, 457TAT>G, R117H+5T, R117H+I1027T, R117L, R117P, H139R, A141D, M152V, N186K, D192N, D192del, E193X, 711+1G>A, 711+3A>G, 712-1G>T, L206F, W216X, C225R, Q237E, G241R, 852del22, 876-14del12, 905delG, 993del5, E292K, Y304X, F311del, 1161delC, R347L, R352Q, W361R, 1215delG, S364P, S434X, D443Y, S466X, C491R, T501A, I506T, F508C, I507del+F508C, F508del+L467F, 1774delCT, R553G, 1802delC, 1806delA, A559E, Y563N, 1833delT, Y569C, Y569H, Y569X, G576X, G576A, T582I, 1898+3A>G+186-13C>G, 1918delGC, R600G, L610S, G628R, 2043delG, 2118del4, E664X, 2174insA, Q689X, K698R, K716X, L732X, 2347delG, 2372del8, R764X, 2423delG, S776X, 2634insT, 2640delT, C866Y, 2752-1G>T, W882X, Y913C, V920M, 2896insAG, H939D, H939R, D979V, D985H, D993Y, 3120G>A, I1005R, 3195del6, 3293delA, 3320ins5, W1063X, A1067T, 3359delCT, T1086I, W1089X, Y1092X+S1235R, W1098X, E1104X, R1128X, 3532AC>GTA, 3548TCAT>G, M1140del, 3600G>A, R1162L, 3667ins4, 3732delA+K1200E, S1206X, 3791delC, S1235R+5T, Q1238R, Q1238X, 3849+4A>G, T1246I, 3869insG, S1255P, R1283K, F1286S, 4005+1G>T, 4006-8T>A, 4015delA, N1303H, N1303I, 4172delGC, 4218insT, 4326delTC, Q1382X, 4375-1C>T, 4382delA, D1445N, CF40kbdel4-10, Cfdel17b. 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
106 Slippage usually results in the addition or subtraction of one repeat unit either side Table 5 CpG Dinucleotides in CFTR Gene That Have More than One Mutational Event Position Change Mutation Reference 223 ......... CT R31C Ghanem et al. 1994 224 ......... GT R31L Zielenski et al., in press 355 ........ C- >T R75X Dork et al., in press 356 ......... G--*T R75L B. Costes, personal communication 356 ......... G-aA R75Q' Zielenski et al. 1991b 481 ......... CT R117C D6rk et al., in press 482 ......... G-oA R117H Dean etal. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Cyst Fibros. 2006 Aug;5(3):159-64. Epub 2006 Mar 6. Ngiam NS, Chong SS, Shek LP, Goh DL, Ong KC, Chng SY, Yeo GH, Goh DY
Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in Asians with chronic pulmonary disease: a pilot study.
J Cyst Fibros. 2006 Aug;5(3):159-64. Epub 2006 Mar 6., [PMID:16678503]

Abstract [show]
BACKGROUND: Little is known about the relationship between cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in Asian patients and severe asthma or idiopathic bronchiectasis. We investigated this potential relationship in the Singaporean Chinese. METHODS: Twenty patients with chronic pulmonary disease, 14 with severe asthma and 6 with idiopathic bronchiectasis, were screened for CFTR mutations by direct gene sequencing. The frequencies of identified putative mutations were compared against 40 unaffected controls and 96 unselected population samples. RESULTS: Three missense mutations (I125T, I556V, and Q1352H) and 1 splice site variant (intron 8 12TG5T) were identified in a total of 10 patients, representing a combined mutant/variant allele frequency of 0.25. These alleles were also observed in the controls, but at a significantly lower allele frequency of 0.09 (P<0.01). Furthermore, the I125T mutation was significantly associated with the idiopathic bronchiectasis sub-group (P<0.05). CONCLUSIONS: The significantly higher frequency of CFTR mutations among patients with chronic pulmonary disease compared with unaffected controls suggests that these mutations may increase risk for disease. The association of I125T with idiopathic bronchiectasis alone suggests that different mutations predispose to different disease.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
121 The first description of I556V was made in a male French patient having atypical CF who was also compound heterozygous for another mutation, R31C in exon 2 [24]. Login to comment

[hide] A patient with pancreas divisum, recurrent acute p... Clin Gastroenterol Hepatol. 2013 May;11(5):579-81. doi: 10.1016/j.cgh.2013.02.012. Epub 2013 Feb 13. Montagnani M, Cazzato S, Mutignani M, Cevenini M, Guidetti E, Zvi IB, Aldini R, Saraceni G, Cavoli C, Garagnani P, Ferrari S, Mantovani V
A patient with pancreas divisum, recurrent acute pancreatitis, and homozygosity for the cystic fibrosis transmembrane regulator-associated protein 5T allele.
Clin Gastroenterol Hepatol. 2013 May;11(5):579-81. doi: 10.1016/j.cgh.2013.02.012. Epub 2013 Feb 13., [PMID:23416327]

Abstract [show]
Mutations in the gene encoding the cystic fibrosis transmembrane regulator (CFTR) have been reported to increase the risk of recurrent acute pancreatitis in patients with pancreas divisum. We assessed the CFTR gene in a young male patient with pancreas divisum and recurrent acute pancreatitis. Magnetic resonance cholangiopancreatography and computed tomography revealed that the patient had pancreas divisum, with an enlarged and tortuous pancreatic duct; he also had positive results from the cystic fibrosis sweat test. Genetic analysis did not identify any common CFTR mutations, but did show that he was homozygous for the 5T allele in intron 8 IVS8 5T-12TG (which affects splicing at intron 8). Endoscopic sphincterotomy and stenting of papilla minor was performed. The IVS8 5T-12TG variant has been associated with abnormal organ development, therefore it is possible that CFTR has an important role in the development of the pancreatic duct. We propose this patient has recurrent acute pancreatitis resulting from a developmental defect associated with a suboptimal CFTR function.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
37 Previously, Dray et al10 described 2 young female patients who carried the IVS8 5T-12TG variant of the CFTR gene in compound heterozygosity with different mutations (in 1 patient R31C, in the other patient F508del). 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
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
173 The 127 variants that met both clinical and functional criteria were designated cystic fibrosis causing; however, 32 remaining -variants Table 1ߒ Variants associated with incomplete penetrance Variant Number of alleles in CFTR2 Frequency in CFTR2 (out of 70,777 known alleles) Number that occur in trans with a CF-causing variant in fathers Number reported in 2,062 fathers Frequency in fathers (out of 4,124 alleles) Allele frequency in 1000 Genomes Project Variants that met clinical criteria but did not meet functional criteria p.Arg31Cys 13 0.00018 4 4 0.00097 0.001-0.004 p.Ile148Thra 99 0.00140 4 9 0.00218 Not available p.Met470Val 41 0.00058 Not analyzed 1,412 0.34239 0.087-0.647 p.Val754Met 9 0.00013 4 7 0.00170 0-0.003 Variants that did not meet clinical or functional criteria p.Arg75Gln 28 0.00040 48 74 0.01794 0.009-0.033 p.Gly576Alab 42 0.00059 12 20 0.00485 0.004-0.009 p.Arg668Cysc 49 0.00069 16 29 0.00703 0.004-0.009 p.Leu997Phe 28 0.00040 5 9 0.00218 0.001-0.003 p.Arg1162Leu 9 0.00013 2 6 0.00145 0.001 p.Ser1235Arg 54 0.00076 15 21 0.00509 0.005-0.016 aDoes not cause cystic fibrosis unless in cis with the known deleterious variant p.Ile1023_Val1024del66. Login to comment

[hide] Surgical outcomes after total pancreatectomy and i... Surgery. 2013 Oct;154(4):777-83; discussion 783-4. doi: 10.1016/j.surg.2013.07.003. Wilson GC, Sutton JM, Salehi M, Schmulewitz N, Smith MT, Kucera S, Choe KA, Brunner JE, Abbott DE, Sussman JJ, Ahmad SA
Surgical outcomes after total pancreatectomy and islet cell autotransplantation in pediatric patients.
Surgery. 2013 Oct;154(4):777-83; discussion 783-4. doi: 10.1016/j.surg.2013.07.003., [PMID:24074415]

Abstract [show]
BACKGROUND: This study aims to review surgical outcomes of pediatric patients undergoing total pancreatectomy with islet cell autotransplantation (TP/IAT) for the treatment of chronic pancreatitis (CP). METHODS: All pediatric patients (</=18 years old) undergoing TP/IAT over a 10-year period (December 2002-June 2012) were identified for inclusion in a single-center, observational cohort study. Retrospective chart review was performed to identify pertinent preoperative, perioperative, and postoperative data, including narcotic usage, insulin requirements, etiology of pancreatitis, previous operative interventions, operative times, islet cell yields, duration of hospital stay, and overall quality of life. Quality of life was assessed using the Short Form-36 health questionnaire. RESULTS: Fourteen pediatric patients underwent TP/IAT for the treatment of CP at the University of Cincinnati with a mean age of 15.9 years (range, 14-18) and a mean body mass index of 21.8 kg/m(2) (range, 14-37). Of the patients, 50% (n = 7) were male and 29% had undergone previous pancreatic operations (1 each of Whipple, Puestow, Frey, and Berne procedures). Etiology of pancreatitis was idiopathic for 57% (n = 8); the remainder had identified genetic mutations predisposing to pancreatitis (CFTR, n = 4; SPINK1, n = 1; PRSS1, n = 1). Mean operative time was 532 minutes (range, 360-674) with an average hospital duration of stay of 16 days (range, 7-37). Islet cell isolation resulted in mean islet cell equivalents (IEQ) of 500,443 in patients without previous pancreatic surgery versus 413,671 IEQ in patients with prior pancreatic surgery (P = .12). Median patient follow-up was 9 months from surgery (range, 1-78). Preoperatively, patients required on average 32.7 morphine equivalent mg per day (MEQ), which improved to 13.9 MEQ at most recent follow-up. Eleven patients (79%) were narcotic independent. None of the patients were diabetic preoperatively. All of the patients were discharged after the operation with scheduled insulin requirements (mean, 17 U/d). This requirement decreased to a mean of 10.1 U/d at most recent follow-up visit. Four patients (29%) progressed to insulin independence. All patients in this series achieved stable glycemic control postoperatively and there was no incidence of "brittle" diabetes. Quality-of-life surveys showed improvement in all tested modules. CONCLUSION: This study represents one of the largest series examining TP/IAT in the pediatric population. Pediatric patients benefitted from TP/IAT with a decrease in postoperative narcotic requirements, stable glycemic control, and improved quality of life.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
104 Patient demographics Patient characteristics Value Age (y), mean &#b1; SEM (range) 15.9 &#b1; 0.4 (14-18) Weight (kg), mean &#b1; SEM (range) 66.3 &#b1; 5.1 (42-116) Body mass index (kg/m2 ), mean &#b1; SEM (range) 21.8 &#b1; 1.8 (14-37) Gender (n) Male 7 Female 7 Etiology (n) Idiopathic 8 Genetic CFTR 4 DF508 2 R31C 1 L997F 1 SPINK1 1 N34S 1 PRSS1 1 N29I 1 Previous pancreatic operation (n) Pancreaticoduodenectomy 1 Puestow 1 Frey 1 Berne 1 CFTR, Cystic fibrosis transmembrane conductance regulator; PRSS1, cationic trypsinogen; SEM, standard error of the mean; SPINK1, serine protease inhibitor, Kazal type 1. 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
116 CFTR variant %Cases %Uctrls OR p-value %Cases w/N34S OR w/N34S p-value w/N34S F508C 0.5 0.3 1.58 0.21 0.0 0.00 0.67 R1162L 0.5 0.5 1.13 0.29 1.8 4.03 0.17 I1027T 0.5 0.3 1.99 0.17 0.0 0.00 0.70 R31C 0.3 0.7 0.42 0.088 0.0 0.00 0.52 I148T 0.3 0.4 0.75 0.27 0.0 0.00 0.63 R297Q 0.3 0.2 1.89 0.21 0.0 0.00 0.76 R74W 0.2 0.2 0.85 0.29 0.0 0.00 0.71 F1052V 0.1 0.2 0.63 0.27 0.0 0.00 0.76 I807M 0.1 0.1 1.26 0.30 0.0 0.00 0.83 R258G 0.1 0.1 1.26 0.30 0.0 0.00 0.83 G1069R 0.1 0.0 0.13 0.0 V201M 0.0 0.1 0.17 0.0 0.00 0.83 Of the 81 CFTR mutations tested in the cohort, 43 were observed at least once in cases or controls. Login to 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] Targeted next-generation sequencing effectively an... Dig Dis Sci. 2015 May;60(5):1297-307. doi: 10.1007/s10620-014-3476-9. Epub 2014 Dec 10. Nakano E, Masamune A, Niihori T, Kume K, Hamada S, Aoki Y, Matsubara Y, Shimosegawa T
Targeted next-generation sequencing effectively analyzed the cystic fibrosis transmembrane conductance regulator gene in pancreatitis.
Dig Dis Sci. 2015 May;60(5):1297-307. doi: 10.1007/s10620-014-3476-9. Epub 2014 Dec 10., [PMID:25492507]

Abstract [show]
BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) gene, responsible for the development of cystic fibrosis, is known as a pancreatitis susceptibility gene. Direct DNA sequencing of PCR-amplified CFTR gene segments is a first-line method to detect unknown mutations, but it is a tedious and labor-intensive endeavor given the large size of the gene (27 exons, 1,480 amino acids). Next-generation sequencing (NGS) is becoming standardized, reducing the cost of DNA sequencing, and enabling the generation of millions of reads per run. We here report a comprehensive analysis of CFTR variants in Japanese patients with chronic pancreatitis using NGS coupling with target capture. METHODS: Exon sequences of the CFTR gene from 193 patients with chronic pancreatitis (121 idiopathic, 46 alcoholic, 17 hereditary, and nine familial) were captured by HaloPlex target enrichment technology, followed by NGS. RESULTS: The sequencing data covered 91.6 % of the coding regions of the CFTR gene by >/= 20 reads with a mean read depth of 449. We could identify 12 non-synonymous variants including three novel ones [c.A1231G (p.K411E), c.1753G>T (p.E585X) and c.2869delC (p.L957fs)] and seven synonymous variants including three novel ones in the exonic regions. The frequencies of the c.4056G>C (p.Q1352H) and the c.3468G>T (p.L1156F) variants were higher in patients with chronic pancreatitis than those in controls. CONCLUSIONS: Target sequence capture combined with NGS is an effective method for the analysis of pancreatitis susceptibility genes.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
90 On average, 90.3 % of the coding region was successfully covered by C20 reads Table 2 Non-synonymous CFTR variants detected in this study Exon Non-synonymous variant Amino acid change dbSNP135 Genotype SIFT (score) PolyPhen-2 (score) Alcoholic CP (%) Idiopathic CP (%) Hereditary/ familial CP (%) 2 c.91C[T p.R31C rs1800073 CT D (0.012) PD (0.989) 0/46 (0) 3/121 (2.5) 0/26 (0) 2 c.92G[A p.R31H rs149353983 GA T (0.183) B (0.003) 0/46 (0) 1/121 (0.8) 0/26 (0) 4 c.374T[C p.I125T rs141723617 TC D (0.005) B (0.17) 0/46 (0) 2/121 (1.6) 1/26 (3.8) 10 c.1231A[G p.K411E - AG D (0.015) B (0.233) 0/46 (0) 1/121 (0.8) 0/26 (0) 11 c.1408G[A p.V470M rs213950 GA T (1) B (0) 21/46 (45.7) 65/121 (53.7) 11/26 (42.3) AA 5/46 (10.9) 19/121 (15.7) 1/26 (3.8) 12 c.1666A[G p.I556V rs75789129 AG T (0.536) B (0.334) 2/46 (4.3) 8/121 (6.6) 0/26 (0) GG 0/46 (0) 0/121 (0) 0/26 (0) 13 c.1753G[T p.E585X - GT - - 1/46 (2.2) 0/121 (0) 0/26 (0) 17 c.2869delC p.L957fs - - - 0/46 (0) 1/121 (0.8) 0/26 (0) 21 c.3468G[T p.L1156F rs139729994 GT T (0.163) PD (0.994) 2/46 (4.3) 10/121 (8.3) 2/26 (7.7) TT 1/46 (2.2) 0/121 (0) 0/26 (0) 25 c.4045G[A p.G1349S rs201686600 GA D (0) PD (1) 1/46 (2.2) 0/121 (0) 0/26 (0) 25 c.4056G[C p.Q1352H rs113857788 GC D (0) PD (1) 5/46 (10.9) 11/121 (9.1) 4/26 (15.4) CC 0/46 (0) 0/121 (0) 0/26 (0) 27 c.4357C[T p.R1453W rs4148725 CT D (0) PD (0.999) 3/46 (6.5) 6/121 (5.0) 1/26 (3.8) B benign, CP chronic pancreatitis, D damaging, PD probably damaging, T tolerated, SIFT Sorting Intolerant From Tolerant heterozygous form (Table 6). Login to comment
100 There were no significant difference for any other non-synonymous or synonymous variants detected in the exons Table 3 Comparison of the non-synonymous variant frequencies between the patients with CP and controls Amino acid change Genotype All CP (%) HGVD (%) P value (vs. HGVD) All CP Alcoholic CP Nonalcoholic CP Idiopathic CP Hereditary/ familial CP p.R31C CT 3/193 (1.6) 12/1102 (1.1) 0.48 [0.99 0.41 0.18 [0.99 p.R31H GA 1/193 (0.5) 0 - - - - - p.I125T TC 3/193 (1.6) 5/1102 (0.5) 0.11 [0.99 0.057 0.15 0.13 p.K411E AG 1/193 (0.5) 0 - - - - - p.V470M GA 97/193 (50.3) 573/1199 (47.8) 0.66 0.57 0.68 0.38 0.12 AA 25/193 (13.0) 185/1199 (15.4) p.I556V AG 10/193 (5.2) 78/1150 (6.8) 0.70 0.79 0.81 [0.99 0.45 GG 0/193 (0) 3/1150 (0.3) p.E585X GT 1/193 (0.5) 0 - - - - - p.L957fs 1/193 (0.5) 0 - - - - - p.L1156F GT 14/193 (7.3) 45/1136 (4.0) 0.04 0.06 0.07 0.11 0.30 TT 1/193 (0.5) 1/1136 (0.1) p.G1349S GA 1/193 (0.5) 4/1094 (0.4) 0.56 0.19 [0.99 [0.99 [0.99 p.Q1352H GC 20/193 (10.4) 57/1153 (4.9) 0.009 0.12 0.037 0.17 0.062 CC 0/193 (0) 1/1153 (0.1) p.R1453W CT 10/193 (5.2) 42/1144 (3.7) 0.32 0.25 0.49 0.45 [0.99 CP chronic pancreatitis, HGVB Human Genetic Variation Database P values were determined versus HGVD by the Fisher`s exact test Table 4 Synonymous variants in the exons of the CFTR gene detected in this study Exon Synonymous variant Amino acid change dbSNP135 Genotype Alcoholic CP (%) Idiopathic CP (%) Hereditary/ familial CP (%) 4 c.372C[T p.G124= - CT 0/46 (0) 1/121 (0.8) 0/26 (0) 13 c.1731C[T p.Y577= rs55928397 CT 0/46 (0) 1/121 (0.8) 0/26 (0) 15 c.2562T[G p.T854= rs1042077 TG 20/46 (43.5) 69/121 (57.0) 12/26 (46.2) GG 6/46 (13.0) 18/121 (14.9) 0/26 (0) 23 c.3723C[A p.G1241= rs185065886 CA 1/46 (2.2) 0/121 (0) 0/26 (0) 25 c.3975A[G p.R1325= - AG 0/46 (0) 1/121 (0.8) 0/26 (0) 27 c.4254G[A p.E1418= - GA 0/46 (0) 1/121 (0.8) 0/26 (0) 27 c.4389G[A p.Q1463= rs1800136 GA 1/46 (2.2) 3/121 (2.5) 0/26 (0) CP chronic pancreatitis between all patients with CP and controls (Tables 3, 5). Login to comment
114 Comprehensive analysis by targeted NGS enabled us to identify novel and Table 5 Comparison of the synonymous variant frequencies between the patients with CP and controls Synonymous variant Genotype All CP (%) HGVD (%) P value (vs. HGVD) All CP Alcoholic CP Nonalcoholic CP Idiopathic CP Hereditary/ familial CP c.C372T CT 1/193 (0.5) 0 - - - - - c.1731C[T CT 1/193 (0.5) 0 - - - - - c.2562T[G TG 101/193 (52.3) 528/1154 (45.8) 0.22 0.81 0.11 0.045 0.033 GG 24/193 (12.4) 181/1154 (15.7) c.3723C[A CA 1/193 (0.5) 3/671 (4.5) [0.99 0.23 [0.99 [0.99 [0.99 c.3975A[G AG 1/193 (0.5) 0 - - - - - c.4254G[A GA 1/193 (0.5) 0 - - - - - c.4389G[A GA 4/193 (2.1) 40/1112 (3.6) 0.48 [0.99 0.53 0.81 [0.99 AA 0/193 (0) 1/1112 (0.1) CP chronic pancreatitis, HGVD Human Genetic Variation Database P values were determined against HGVD by the Fisher`s exact test Table 6 Total CFTR sequencing results of patients carrying rare non-synonymous CFTR variants a Pancreatitis-associated mutations in the PRSS1, SPINK1, CTRC, and CPA1 genes Case# Etiology Age at onset Rare variant Additional non-synonymous variants c.1210-34TG(9_13) c.1210-12T(5_9) Mutation in other pancreatitis susceptibility genesa A1 Idiopathic 34 p.R31C/- p.R1453W/- TG11/TG11, 7T/7T - A2 Idiopathic 8 p.R31C/- - TG11/TG12, 7T/7T - A3 Idiopathic 16 p.R31C/- - TG11/TG12, 7T/7T - A4 Idiopathic 10 p.R31H/- - TG11/TG12, 7T/7T - A5 Idiopathic 16 p.I125T/- p.L1156F/- TG11/TG12, 7T/7T CTRC p.R29Q/- A6 Idiopathic 2 p.I125T/- - TG11/TG12, 7T/7T - A7 Hereditary 28 p.I125T/- p.R1453W/- TG11/TG12, 7T/7T - A8 Idiopathic 19 p.K411E/- p/L1156F/- TG11/TG12, 7T/7T - A9 Alcoholic 28 p.E585X/- p.I556V/- TG11/TG11, 7T/7T - A10 Idiopathic 21 p.L957fs/- p.Q1352H/- TG11/TG12, 7T/7T - A11 Alcoholic 40 p.G1349S/- - TG11/TG11, 7T/7T - rare variants in the CFTR gene. 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
32 [1075C>A;1079C>A] (Q359K/T360K) - - - Mutations that do not cause CF when combined with another CF-causing mutation c.1727G>C (G576A) c.3485G>T (R1162L) c.224G>A (R75Q) - - c.3080T>C (I1027T) c.91C>T (R31C) c.3705T>G (S1235R) - - c.2991G>C (L997F) c.2002C>T (R668C) c.2260G>A (V754M) - - Mutations/variants that were validated in this study are in bold. CF, cystic fibrosis. Table 1ߒContinued (http://www.hgvs.org/mutnomen/) and legacy mutation nomenclature (http://www.cftr2.org/browse.php). Login to comment

[hide] Benign outcome among positive cystic fibrosis newb... J Cyst Fibros. 2015 Nov;14(6):714-9. doi: 10.1016/j.jcf.2015.03.006. Epub 2015 Mar 29. Salinas DB, Sosnay PR, Azen C, Young S, Raraigh KS, Keens TG, Kharrazi M
Benign outcome among positive cystic fibrosis newborn screen children with non-CF-causing variants.
J Cyst Fibros. 2015 Nov;14(6):714-9. doi: 10.1016/j.jcf.2015.03.006. Epub 2015 Mar 29., [PMID:25824995]

Abstract [show]
BACKGROUND: The Clinical and Functional Translation of CFTR project (CFTR2) classified some cystic fibrosis transmembrane conductance regulator (CFTR) gene variants as non-cystic fibrosis (CF)-causing. To evaluate this, the clinical status of children carrying these mutations was examined. METHODS: We analyzed CF disease-defining variables over 2-6 years in two groups of California CF screen- positive neonates born from 2007 to 2011: (1) children with two CF-causing variants and (2) children with one CF-causing and one non-CF-causing variant, as defined by CFTR2. RESULTS: Children carrying non-CF-causing variants had significantly higher birth weight, lower immunoreactive trypsinogen and sweat chloride values, higher first year growth curves, and a lower rate of persistent Pseudomonas aeruginosa colonization compared to children with two CF-causing variants. CONCLUSIONS: The outcomes in children 2-6 years of age with the L997F, G576A, R1162L, V754M, R668C, R31C, and S1235R variants are consistent with the CFTR2 non-CF-causing classification.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
4 Conclusions: The outcomes in children 2-6 years of age with the L997F, G576A, R1162L, V754M, R668C, R31C, and S1235R variants are consistent with the CFTR2 non-CF-causing classification. Login to comment
95 Non-CF-causing variants from CF NBS in California cDNA name Number of patients identified from the CA CF NBS Mean [Cl-] conductance (as % WT-CFTR) b C/(B + C) (as % of WT-CFTR) in HeLa cellsc C/(B + C) (as % of WT-CFTR) in FRT cellsd CFTR protein quantity (as % WT-CFTR)e L997F c.1408A N G 34 22 97 104 100 G576Aa c.1727G N C 7 147 98 110 104 R1162L c.3485G N T 6 130 93 94 94 V754M c.2260G N A 4 140 98 107 102 R668Ca c.2002C N T 2 58 97 106 102 R31C c.91C N T 2 105 92 86 89 S1235R c.3705T N G 2 79 96 106 101 CA CF NBS = California Cystic Fibrosis Newborn Screening Program. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Cyst Fibros. 2015 Sep;14(5):661-7. doi: 10.1016/j.jcf.2015.03.009. Epub 2015 Apr 11. Chang MC, Jan IS, Liang PC, Jeng YM, Yang CY, Tien YW, Wong JM, Chang YT
Cystic fibrosis transmembrane conductance regulator gene variants are associated with autoimmune pancreatitis and slow response to steroid treatment.
J Cyst Fibros. 2015 Sep;14(5):661-7. doi: 10.1016/j.jcf.2015.03.009. Epub 2015 Apr 11., [PMID:25869325]

Abstract [show]
BACKGROUND: Autoimmune pancreatitis (AIP) is a distinct type of chronic pancreatitis. To date, the association of CFTR gene variants with AIP has not been studied. METHODS: The entire coding and intronic regions of the CFTR gene were examined using next-generation sequencing in 89 AIP patients. Clinical features, including imaging, histology, serology, steroid treatment response and extra-pancreatic involvement, were compared between AIP patients with and without CFTR gene variants. RESULTS: A total of 28.1% (25/89) of the AIP patients carried 26 CFTR variants, including nine with I556V, seven with 5T, four with S42F, two with I125T, and one each with R31C, R553X, S895N, and G1069R. The presence of CFTR variants and age was independent predictors of the response to steroid treatment, as shown by multivariate analysis. CONCLUSIONS: CFTR variants are associated with AIP. Because AIP patients with CFTR variants show slower and reduced steroid treatment responses, different treatments should be considered in AIP patients with CFTR variants.

Comments [show]

None has been submitted yet.

Sentences [show]
No. Sentence Comment
8 Results: A total of 28.1% (25/89) of the AIP patients carried 26 CFTR variants, including nine with I556V, seven with 5T, four with S42F, two with I125T, and one each with R31C, R553X, S895N, and G1069R. Login to comment
112 The identified variants included I556V in nine patients, 5T in seven, S42F in four, I125T in two, and R31C, R553X, S895N, and G1069R each in one patient (Table 1). Login to comment
140 AIP (n = 89) CFTR variants n = 26 % in AIP % with variant I556V 9 10.1% 34.6% 5 T 7 7.9% 26.9% S42F 4 4.5% 15.4% I125T 2 2.2% 7.7% R31C 1 1.1% 3.8% R553X 1 1.1% 3.8% S895T 1 1.1% 3.8% G1069R 1 1.1% 3.8% Table 2 Comparison of patients with and without CFTR variants in 89 patients with autoimmune pancreatitis. 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
363 [72G>C;164+2T>G] uncertain: CF-PI and/or CF-PS L24F nd; 296+2T>G nd R31C c.91C>T CFTR-RD non CF-causing p.Arg31Cys S42F c.125C>T uncertain: found only with an unknown allele in trans nd p.Ser42Phe E56G c.167G>A CBAVD nd p.Glu56Lys [R74W;V201M;D1270N] c. Login to comment
423 A similar good match may also be assumed for two mutations classified as non-CF-causing in CFTR2 [S1235R (p.Ser1235Arg) and R31C (p.Arg31Cys)] but as CFTR-RD-causing in our study, owing to the fact that CFTR2 is mainly aimed at classic CF and is more prone to a classification as non-causing for those mutations originating nonclassic clinical and biochemical phenotypes. 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