ABCMdb

ABCC7 p.Val562Ile

ClinVar:	c.1684G>A , p.Val562Ile ? , Uncertain significance c.1684G>C , p.Val562Leu ? , not provided
CF databases:	c.1684G>A , p.Val562Ile (CFTR1) D , V562I was detected by DGGE and direct sequencing. The patient was born in Morocco and is homozygous for the mutation and reported to have severe CF with pancreatic insufficiency. The G to A change at 1816 was previously reported to the database as a polymorphism (1816G/A) by Fanen et al. in 1992 c.1684G>C , p.Val562Leu (CFTR1) ? , V562L was detected by DGGE analysis, followed by direct fluorescent sequencing. It was detected in one patient from 220 in Northern Ireland. The other CF allele is presently unknown.
Predicted by SNAP2:	A: D (75%), C: D (63%), D: D (91%), E: D (91%), F: D (85%), G: D (91%), H: D (91%), I: N (57%), K: D (95%), L: N (87%), M: D (80%), N: D (91%), P: D (91%), Q: D (91%), R: D (95%), S: D (85%), T: D (85%), W: D (95%), Y: D (91%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: N, K: D, L: N, M: N, N: D, P: D, Q: D, R: D, S: D, T: D, W: D, Y: D,

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[hide] Determination of the relative contribution of thre... Eur J Hum Genet. 2002 Feb;10(2):100-6. Audrezet MP, Chen JM, Le Marechal C, Ruszniewski P, Robaszkiewicz M, Raguenes O, Quere I, Scotet V, Ferec C
Determination of the relative contribution of three genes-the cystic fibrosis transmembrane conductance regulator gene, the cationic trypsinogen gene, and the pancreatic secretory trypsin inhibitor gene-to the etiology of idiopathic chronic pancreatitis.
Eur J Hum Genet. 2002 Feb;10(2):100-6., [PMID:11938439]

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In the last 5 years, mutations in three genes, the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the cationic trypsinogen (PRSS1) gene, and the pancreatic secretory trypsin inhibitor (PSTI) gene, have been found to be associated with chronic pancreatitis (CP). In this study, using established mutation screening methods, we systematically analysed the entire coding sequences and all exon/intron junctions of the three genes in 39 patients with idiopathic CP (ICP), with a view to evaluating the relative contribution of each gene to the aetiology of the disease. Our results demonstrate that, firstly, 'gain-of-function' mutations in the PRSS1 gene may occasionally be found in an obvious ICP subject. Secondly, presumably 'loss-of-function' mutations in the PSTI gene appear to be frequent, with a detection rate of at least 10% in ICP and, finally, abnormal CFTR alleles are common: at least 20% of patients carried one of the most common CFTR mutations, and about 10% of patients were compound heterozygotes, having at least one 'mild' allele. Thus, in total, about 30% of ICP patients carried at least one abnormal allele in one of the three genes, and this is the most conservative estimate. Moreover, a trans-heterozygous state with sequence variations in the PSTI/CFTR genes was found in three patients. However, an association between the 5T allele in intron 8 of the CFTR gene and ICP remains unproven.

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56 `Gain-of-function' PRSS1 mutations are rare in ICP While PRSS1 mutations are often found in patients with hereditary pancreatitis, they can also be identified in subjects with ICP, albeit with an exceptionally low Table 1 Sequence variations identified in the PRSS1, PSTI, and CFTR genes in 39 patients with ICP CFTR Patient PRSS1 PSTI Mutant PolyT 1 ± a ± ± 7T/7T 2 ± ± F508del/R352Q 9T/7T 3 ± ± F508del/P5L 9T/7T 4 ± ± c.4575+2G4A 9T/7T 5 ± ± ± 7T/7T 6 ± N34Sb ± 7T/7T 7 ± ± ± 7T/5T 8 ± ± F508del/Q1476X 9T/7T 9 ± ± ± 7T/7T 10 ± ± ± 7T/7T 11 ± ± ± 7T/7T 12 ± ± ± 7T/7T 13 ± ± V562I 7T/5T 14 ± ± 2C4A W1282X 7T/5T 15 ± ± IVS3-6T4C 7T/7T 16 R122H ± ± 7T/7T 17 ± ± ± 9T/7T 18 ± ± ± 7T/5T 19 ± ± ± 7T/7T 20 ± N34S/N34S ± 7T/7T 21 ± ± ± 9T/5T 22 ± ± ± 7T/7T 23 ± ± E217G/A1136T 9T/7T 24 ± ± ± 7T/7T 25 ± ± ± NDc 26 ± ± ± ND 27 ± N34S IVS18 ± 20T4C 9T/7T 28 ± ± F508del 9T/7T 29 ± ± ± 7T/7T 30 ± ± N1303K ND 31 ± ± G542X 9T/7T 32 ± ± ± 7T/5T 33 ± ± F508del 9T/7T 34 ± ± 41G4Ad ± 7T/7T 35 ± ± ± 9T/7T 36 ± ± ± 9T/7T 37 ± ± ± 7T/7T 38 ± N34S L967S 7T/7T 39 ± ± ± 7T/5T a Indicates two wild alleles. Login to comment
85 Firstly, we found a total of 10 additional alleles (R352Q, P5L, c.4575+2G4A, V562I, IVS3-6T4C, E217G/A1136T, IVS18-20T4C, and L967S; Table 1) that would have been missed by the conventional genotyping method. Login to comment

[hide] Characterization of cystic fibrosis conductance tr... Hum Reprod. 2004 Nov;19(11):2502-8. Epub 2004 Aug 27. Grangeia A, Niel F, Carvalho F, Fernandes S, Ardalan A, Girodon E, Silva J, Ferras L, Sousa M, Barros A
Characterization of cystic fibrosis conductance transmembrane regulator gene mutations and IVS8 poly(T) variants in Portuguese patients with congenital absence of the vas deferens.
Hum Reprod. 2004 Nov;19(11):2502-8. Epub 2004 Aug 27., [PMID:15333598]

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BACKGROUND: Cystic fibrosis conductance transmembrane regulator (CFTR) gene mutations and IVS8 poly(T) variants in Portuguese patients with bilateral (CBAVD) and unilateral (CUAVD) congenital absence of the vas deferens remain to be evaluated. METHODS: Patient screening was carried out by PCR, denaturing gradient gel electrophoresis and DNA sequencing. RESULTS: CFTR mutations were found in 18 out of 31 (58.1%) CBAVD and in three of four (75%) CUAVD patients. The most frequent mutations were F508del and R334W in CBAVD and G542X in CUAVD, with the allelic frequencies of R334W (6.5%) and G542X (25%) being particular to the Portuguese population. The 5T allelic frequency was 3.5% in the fertile male population, 25% in CUAVD and 27.4% in CBAVD patients. The combined frequency of mutations (CFTR+5T) was increased in CBAVD to 22 out of 31 (71%). The frequency of CFTR mutations was compared with that of patients with secondary obstructive azoospermia (OAZ; one out of 16, 6.3%) and non-obstructive azoospermia (NOAZ; two out of 22, 9.1%) with conserved spermatogenesis, which were similar to the general population. However, whereas the 5T allelic frequency in OAZ was similar to that of the general population (3.1%), it was increased in NOAZ cases (14.3%). CONCLUSIONS: Data confirm that CFTR+5T mutations represent the most common genetic abnormality in CAVD, and suggest that cases of NOAZ may be associated with the 5T allele.

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92 The frequency of the other mutations was: four of 62 (6.5%) for R334W, two of 62 (3.2%) for R117H, P205S and G576A, and one of 62 (1.6%) for D614G, V562I, R668C, 2789-5G ! Login to comment
104 Of the 22 NOAZ patients with conserved spermatogenesis and normal renal development, there were seven (31.8%) Table I. CFTR mutations and IVS8-5T variants found in 77 Portuguese azoospermic patients Syndromes Mutations n CFTR mutations IVS8 poly(T) variants Two mutations One mutation CBAVD F508del/R117H 1 1 - 7/9 F508del/D614G 1 1 - 7/9 R334W/R334W 1 1 - 7/7 R334W/V562I 1 1 - 5/7 R117H/P205S 1 1 - 7/7 2789 þ 5G ! Login to comment
109 Studies in a CBAVD patient with the R334W/V562I and 5T/7T mutations. Login to comment
114 (a) CAVD patient with mutation V562I (heterozygote); (b) a normal individual. Login to comment

[hide] The role of cystic fibrosis gene mutations in dete... Gastroenterol Clin North Am. 2004 Dec;33(4):817-37, vii. Cohn JA, Mitchell RM, Jowell PS
The role of cystic fibrosis gene mutations in determining susceptibility to chronic pancreatitis.
Gastroenterol Clin North Am. 2004 Dec;33(4):817-37, vii., [PMID:15528020]

Abstract [show]
This article reviews current concepts regarding the pathobiology of cystic fibrosis pancreatic disease. It summarizes recent studies on the relationship between CFTR mutations and pancreatitis, and it reviews several unresolved issues in the field.

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78 The European data Table 1 Abnormal CFTR and PSTI genotypes detected in two studies of idiopathic chronic pancreatitis* CFTR genotype category N Genotypes detected in individual subjects US study (Noone et al [47]) CFsev / CFm-v compound heterozygotes 8 DF508 / R117H-7T**; DF508 / 5T; DF508 / 5T; DF508 / D1152H; DF508 / D1152H; DF508 / P574H; DF508 / 3120G>A; 621þ1G>T/G1069R CFm-v / CFm-v compound heterozygotes 1 5T / 5T** CFsev / - (CF carriers) 1 N1303K / - CFm-v / - 7 R117H-7T / -; 5T / -**; 5T / -; 5T / -; 5T / -; 5T / -; 5T / - Normal (- / -) CFTR genotype 22 1 was homozygous for the N34S PSTI mutation; 5 were N34S carriers European study (Audrezet et al [50]) CFsev / CFm-v compound heterozygotes 4 DF508/R352Q; DF508/P5L; DF508/Q1476X; W1282X/5T*** CFm-v / CFm-v compound heterozygotes 2 V562I/5T; E217G/A1136T CFsev / - (CF carriers)**** 3 DF508 / -; DF508 / -; G542X / - CFm-v / - 9 L967S/-**; IVS18-20T>C/-**; c.4575þ2G>A/-; IVS3-6T>C; 5T/-; 5T/-; 5T/-; 5T/-; 5T/- Normal (- / -) CFTR genotype 17 1 was homozygous for the N34S PSTI mutation; 1 was a N34S carrier * CFTR mutations were classified as causing either severe (CFsev ) or mild-variable loss-of-function (CFm-v ) [18,47]; all detected CFsev mutations are CF-causing mutations according to current consensus criteria [79]. Login to comment

[hide] The impact of cystic fibrosis and PSTI/SPINK1 gene... Clin Lab Med. 2005 Mar;25(1):79-100. Cohn JA, Mitchell RM, Jowell PS
The impact of cystic fibrosis and PSTI/SPINK1 gene mutations on susceptibility to chronic pancreatitis.
Clin Lab Med. 2005 Mar;25(1):79-100., [PMID:15749233]

Abstract [show]
This article reviews current concepts regarding the pathobiology of cystic fibrosis pancreatic disease. It summarizes recent studies on the relationship between CFTR mutations and pancreatitis, and it reviews several unresolved issues in the field.

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90 Table 1 Abnormal CFTR and PSTI genotypes detected in two studies of idiopathic chronic pancreatitis* CFTR genotype category N Genotypes detected in individual subjects US study (Noone et al [47]) CFsev / CFm-v compound heterozygotes 8 DF508 / R117H-7T**; DF508 / 5T; DF508 / 5T; DF508 / D1152H; DF508 / D1152H; DF508 / P574H; DF508 / 3120G>A; 621þ1G>T/G1069R CFm-v / CFm-v compound heterozygotes 1 5T / 5T** CFsev / - (CF carriers) 1 N1303K / - CFm-v / - 7 R117H-7T / -; 5T / -**; 5T / -; 5T / -; 5T / -; 5T / -; 5T / - Normal (- / -) CFTR genotype 22 1 was homozygous for the N34S PSTI mutation; 5 were N34S carriers European study (Audrezet et al [50]) CFsev / CFm-v compound heterozygotes 4 DF508/R352Q; DF508/P5L; DF508/Q1476X; W1282X/5T*** CFm-v / CFm-v compound heterozygotes 2 V562I/5T; E217G/A1136T CFsev / - (CF carriers)**** 3 DF508 / -; DF508 / -; G542X / - CFm-v / - 9 L967S/-**; IVS18-20T>C/-**; c.4575þ2G>A/-; IVS3-6T>C; 5T/-; 5T/-; 5T/-; 5T/-; 5T/- Normal (- / -) CFTR genotype 17 1 was homozygous for the N34S PSTI mutation; 1 was a N34S carrier * CFTR mutations were classified as causing either severe (CFsev ) or mild-variable loss-of-function (CFm-v ) [18,47]; all detected CFsev mutations are CF-causing mutations according to current consensus criteria [79]. Login to comment

[hide] Reduced CFTR function and the pathobiology of idio... J Clin Gastroenterol. 2005 Apr;39(4 Suppl 2):S70-7. Cohn JA
Reduced CFTR function and the pathobiology of idiopathic pancreatitis.
J Clin Gastroenterol. 2005 Apr;39(4 Suppl 2):S70-7., [PMID:15758663]

Abstract [show]
Idiopathic chronic pancreatitis (ICP) is the leading cause of chronic pancreatitis in children and nonalcoholic adults. The risk of developing ICP is increased in individuals who have mutations of the cystic fibrosis gene (CFTR) and of a trypsin inhibitor gene (PSTI). In studies from the United States and France, the risk of ICP is increased about 40-fold by having two abnormal copies of the CFTR gene, about 14-fold by having the N34S PSTI mutation, and about 500-fold by having both. When ICP patients have two abnormal copies of the CFTR gene, there is also evidence of reduced residual CFTR protein function in extrapancreatic tissues based on clinical findings and nasal ion transport responses. Thus, pancreatitis risk is highest in individuals who have abnormalities in both the pancreatic ducts (CFTR) and acini (PSTI). These findings indicate that PSTI is a modifier gene for CFTR-related ICP and have implications for the diagnosis and pathogenesis of pancreatitis.

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69 Abnormal CFTR and PSTI Genotypes Detected in Two Studies of ICP CFTR Genotype Category* N Genotypes Detected in Individual Subjects U.S. study (Noone et al47 ) CFsev / CFm-v compound heterozygotes 8 DF508 / R117H-7T †; DF508 / 5T; DF508 / 5T; DF508 / D1152H; DF508 / D1152H; DF508 / P574H; DF508 / 3120G.A; 621 + 1G.T/G1069R CFm-v / CFm-v compound heterozygotes 1 5T / 5T † CFsev / 2 (CF carriers) 1 N1303K / 2 CFm-v / 2 7 R117H-7T / 2; 5T / 2 †; 5T / 2; 5T / 2; 5T / 2; 5T / 2; 5T / 2 Normal (2 / 2) CFTR genotype 22 1 was homozygous for the N34S PSTI mutation; 5 were N34S carriers French study (Audrezet et al50 ) CFsev / CFm-v compound heterozygotes 4 DF508/R352Q; DF508/P5L; DF508/Q1476X; W1282X/5T‡ CFm-v / CFm-v compound heterozygotes 2 V562I/5T; E217G/A1136T CFsev / 2 (CF carriers)§ 3 DF508 / 2; DF508 / 2; G542X / 2 CFm-v / 2 9 L967S/2 †; IVS18-20T.C/ 2†; c.4575+2G.A/2; IVS3-6T.C; 5T/2; 5 /2; 5T/ 2; 5T/2; 5T/ 2 Normal (2 / 2) CFTR genotype 17 1 was homozygous for the N34S PSTI mutation; 1 was a N34S carriers *Mutations of the cystic fibrosis (CF) gene (CFTR) were classified as causing either severe (CFsev ) or mild-variable loss-of-function (CFm-v )18,47 ; all detected CFsev mutations are CF-causing mutations according to current consensus criteria.68 In the U.S. study, most patients were tested for rare mutations by DNA sequencing47 ; in the French study, most patients were tested by dHPL.50 †These patients were also carriers for the N34S mutation of a trypsin inhibitor gene (PSTI). Login to comment

[hide] Extensive sequencing of the CFTR gene: lessons lea... Hum Genet. 2005 Dec;118(3-4):331-8. Epub 2005 Sep 28. McGinniss MJ, Chen C, Redman JB, Buller A, Quan F, Peng M, Giusti R, Hantash FM, Huang D, Sun W, Strom CM
Extensive sequencing of the CFTR gene: lessons learned from the first 157 patient samples.
Hum Genet. 2005 Dec;118(3-4):331-8. Epub 2005 Sep 28., [PMID:16189704]

Abstract [show]
Cystic fibrosis (CF) is one of the most common monogenic diseases affecting Caucasians and has an incidence of approximately 1:3,300 births. Currently recommended screening panels for mutations in the responsible gene (CF transmembrane regulator gene, CFTR) do not detect all disease-associated mutations. Our laboratory offers extensive sequencing of the CFTR (ABCC7) gene (including the promoter, all exons and splice junction sites, and regions of selected introns) as a clinical test to detect mutations which are not found with conventional screening. The objective of this report is to summarize the findings of extensive CFTR sequencing from our first 157 consecutive patient samples. In most patients with classic CF symptoms (18/24, 75%), extensive CFTR sequencing confirmed the diagnosis by finding two disease-associated mutations. In contrast, only 5 of 75 (7%) patients with atypical CF had been identified with two CFTR mutations. A diagnosis of CF was confirmed in 10 of 17 (58%) newborns with either positive sweat chloride readings or positive immunoreactive trypsinogen (IRT) screen results. We ascertained ten novel sequence variants that are potentially disease-associated: two deletions (c.1641AG>T, c.2949_2853delTACTC), seven missense mutations (p.S158T, p.G451V, p.K481E, p.C491S, p.H949L, p.T1036N, p.F1099L), and one complex allele ([p.356_A357del; p.358I]). We ascertained three other apparently novel complex alleles. Finally, several patients were found to carry partial CFTR gene deletions. In summary, extensive CFTR gene sequencing can detect rare mutations which are not found with other screening and diagnostic tests, and can thus establish a definitive diagnosis in symptomatic patients with previously negative results. This enables carrier detection and prenatal diagnosis in additional family members.

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76 Meconium peritonitis;pseudocyst; volvulus 6 p.W1282X/p.S492F 2 months M IRT positive 57, 78, 75, 80, 81 Dx of CF, symptomatic 7 DF508/p.F1099Lb 2 months M IRT positive 48, 52 Asymptomatic at this point 8 DF508/[p.R352W; pP750L]c 1.5 months M IRT positive 1 nl, 44 Followed in CF clinic, being treated prophylactically, neg. elastase 9 DF508/c.1154insTC 4 days M Meconium ileus at birth Not done CF, two affected sibs 10 DF508/c.2789+2insA 2 months F IRT positive 58,57,53 Dx of CF a Concentrations >60 mmol/l on repeated analysis are diagnostic for cystic fibrosis b Novel CFTR mutation c Complex CFTR allele with two different mutations Table 4 Complex CFTR alleles observed in a series of 157 patient samples after extensive sequencing Subject Genotype Phenotype Age Sweat chloride concentration (mmol/l) 1 [p.G576A;p.R668C]/wta Chronic cough, sinusitis, and recurrent pneumonia 3 years Normal 2 p.R1158X/[p.V562I;p.A1006E] Mild CF 40 years 115 3 DF508/[p.R352W;p.P750L] Abnormal newborn screen 49 days 44 4 [c.1198_1203delTGGGCT;c.1204G>A]/wt Mild CF (respiratory symptoms) 12 years 110, 115 a This complex allele has been previously described in a patient with disseminated bronchiectasis with L997F on the other allele (Pignatti et al. 1995) Table6NovelCFTRvariantsfoundinaseriesof157patientsamplesafterextensivesequencing SubjectMutation type LocationNucleotidechangeEffectonproteinCFTRdomaina Mutationonother allele Phenotype 1MissenseExon4c.605G>Cp.S158TL1Nonedetected4-month-oldmale,abnormalnewbornscreen; 3borderlinesweattestresults 2ComplexalleleExon7[c.1198_1203delTGGGCT; c.1204G>A] [p.W356_A357del; p.V358I] AfterTM6and beforeNBD1 Nonedetected12-year-oldmale,meconiumilleusatbirth, respiratorysymptomsofCF;positivesweatchlorides (110,115mmol/l).Motheralsocarriescomplexallele 3MissenseExon9c.1484G>Tp.G451VNBD1DF50819-year-oldmale,diagnosisofCF 4MissenseExon10c.1573A>Gp.K481ENBD1Nonedetected15-year-oldmale,atypicalCF,asthma,2borderline sweatchlorides(low60s) 5MissenseExon10c.1604G>Cp.C491SNBD1NonedetectedNoabnormalsymptoms;sisterofCFpatientthat carriesp.P67L/DF508.Probablebenign variantascertainedduring singleexonsequencingofexon10 6DeletionExon10c.1641AG>Tp.K503NfsX23NBD1p.H609R22-year-oldmale,classicCF,PI,positivesweat chloride(>100mmol/l) 7DeletionExon15c.2949_2953delTACTCp.H939fsX32L3DF5083-month-oldfemale,diagnosisofCF,positivesweat chloride(105mmol/l) 8MissenseExon15c.2978A>Tp.H949LL3Nonedetected, but5Tpositive 12-year-oldmale,atypicalCF,sinusproblems. Login to comment
53 Finally, one CF patient with mild symptoms carried a complex allele [p.V562I; p.A1006E] and a nonsense mutation (p.R1158X) on the other allele. Login to comment
74 DF508/c.546insCTA CF; lung symptoms; PS; 2 sibs with CF NG Pos p.R1066C/c.3272-26 A>G Mild CF 40 115 [p.V562I;p.A1006E]b /p.R1158X CF, FTT 6 Not done DF508/c.1716G>A Classic CF 21 Not done p.R785X/c.2732insA Classic CF, PI 4 Not done DF508/p.R117C Classic CF 2 Not done DF508/p.R75X CF 19 Pos DF508/p.G451Va Mild CF 23 Pos DF508/p.L206W Classic CF 9 150s DF508/p.G542Xc Classic CF 15 Pos p.T1036N/p.T1036Na CF, PS 9 Pos DF508/c.3272-26 A>G Classic CF 33 Not done DF508/p.R117Hc Classic CF 35 Not done DF508/p.A455Ec CF 3 Pos p.G551D/p.Y275X a Novel CFTR variant b Complex CFTR allele c Both mutations are on the ACMG/ACOG panel Table 5 Diagnosis of CF in infants/newborns with abnormal newborn screening results Patient number Genotype Age at sequencing Sex Newborn screen result Sweat chloride concentration (mmol/l)a Phenotype 1 DF508/c.2789+2insA 3 months F Positive sweat test 88,96,89,84 Dx of CF, being treated prophylactically 2 DF508/c.2949del5b 3 months F IRT positive 105 Dx of CF 3 p.G551D/c.1259insA 14 months M Positive sweat test ?

In reference to DF508 and 1716G>A. Does this mean these two mutation have resulted in "classic CF"? Does this mean 1716G>A is disease causing?
Gibson75 on 2013-08-12 07:00:25

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103 The last two samples were from affected siblings and were found to be positive for three previously described CFTR mutations: p.V562I, p.A1006E, and p.R1158X. 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.

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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] 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.

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1 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. Login to comment
3 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. Login to comment
4 Biochemical studies revealed that 4RK generates higher steady-state levels of mature CFTR (band C) for wtand V562I-CFTR than does G550E. Login to comment
37 47 ͉ 17891-17896 and 4RK act by different mechanisms. To explore this possibility, we tested the effects of G550E and 4RK on three additional CF mutations within NBD1: R560T, A561E, and V562I.ʈ We selected for study these CF mutants because (i) these residues constitute a hot spot for disease-causing mutations (seven mutations are associated with these three residues࿣ ); (ii) A561E and R560T are the second and fourth most frequent mutations among Portuguese and Irish CF patients, respectively (28); (iii) like G550E and R555K (one of the 4RK mutants), these mutations affect residues located between the LSGGQ and Walker B motifs of NBD1, which are highly conserved across species; and (iv) they all lie within the same ␣-helix (H5; G550-Y563) within the ATP-binding cassette ␣-subdomain of NBD1 (29, 30). Login to comment
38 To test the hypothesis that G550E and 4RK act by different mechanisms, we used biochemical and functional assays to investigate how these revertants rescue F508del-, R560T-, A561E-, and V562I-CFTR. Login to comment
39 Results R560T, but Not V562I, Disrupts the Processing of CFTR. Like F508del-CFTR, many CF mutations disrupt the processing of CFTR and its delivery to the cell surface. Login to comment
41 For the reasons outlined in the Introduction, we chose to analyze the CF mutations R560T, A561E, and V562I. Login to comment
43 Therefore, we first investigated the processing of R560T and V562I by using Western blot (WB). Login to comment
45 In contrast, band B and a diffuse Ϸ180 kDa band (band C) were observed for both V562I-CFTR and wt-CFTR (Fig. 1A). Login to comment
46 These data suggest that R560T, disrupts the trafficking of CFTR, whereas V562I-CFTR is delivered to the cell surface. Login to comment
58 Fig. 1A demonstrates that steady-state levels of band C for both wtand V562I-CFTR were increased by 4RK but not by G550E, most strikingly for V562I-CFTR. Login to comment
61 To investigate this, we examined the turnover rate of band B and the efficiency of its processing into band C for wt-, F508del- and V562I-CFTR alone or in cis with the revertants by pulse-chase analysis, followed by IP (Fig. 2 A-C). Login to comment
65 For V562I-CFTR, the turnover rate of V562I-G550E was slightly, but not significantly (P Ͼ 0.05), reduced compared with those of V562I- and V562I-4RK-CFTR (Fig. 2F). Login to comment
66 Furthermore, the efficiency of processing of V562I-4RK (dotted line, Fig. 2I) was slightly increased relative to those of V562I and V562I-G550E (solid and dashed lines, Fig. 2I, respectively). Login to comment
67 Finally, Fig. 2 shows that the turnover rates of V562I- and wt-CFTR were equivalent (slope of solid lines in D and F; P Ͼ 0.05), whereas the processing of V562I- was slightly faster than that of wt-CFTR (solid lines in G and I).࿣The CFTR Mutation Database: http://www.sickkids.on.ca/cftr. Login to comment
70 (A) WB of total protein (30 ␮g) from BHK cells stably expressing wt-, F508del-, R560T-, A561E-, or V562I-CFTR, alone or in cis with 4RK and G550E. Login to comment
75 (D) BHK cells expressing F508del-, R560T-, or A561E-CFTR alone or in cis with the revertants 4RK and G550E were analyzed by CFTR IP after pulse-labeling for 3 h. Labeled arrows indicate the positions of bands A, B, and C. Thus, the higher steady-state levels of band C for 4RK variants of both wtand V562I-CFTR (Fig. 1A) are explained only in part by a slight (but not significant) increase in the efficiency of processing band B to band C. Surprised that the revertants did not exert stronger effects on the processing of CFTR, we wondered how they might influence CFTR Cl-channel function. Login to comment
76 WTand V562I-CFTR Have Equivalent Functions. Login to comment
79 Consistent with the biochemical data (Fig. 1), these agonists had no effect on F508del-, R560T-, or A561E-CFTR (Fig. 3 B-D) but evoked a striking efflux of I- from V562I-CFTR (Fig. 3E), which has a time course equivalent to that of wt-CFTR and 1.3-fold greater (Fig. 3F). Login to comment
80 A likely explanation for this enhanced efflux of I- from V562I-CFTR-expressing cells is their greater membrane abundance of CFTR (Fig. 1A). Login to comment
85 Interestingly, V562I-G550E generated an efflux of I- equivalent in magnitude and time-course to that of V562I-CFTR (Fig. 3 E and F) despite its lower steady-state levels of band C. However, 4RK, which generated higher steady-state levels of band Fig. 2. Login to comment
86 Turnover and processing of wt-, F508del-, and V562I-CFTR alone or in cis with 4RK and G550E. Login to comment
87 (A-C) BHK cells expressing wt-, G550E- and 4RK-CFTR (A); F508del-, F508del-4RK-, and F508del-G550E-CFTR (B); and V562I-, V562I-4RK-, and V562I-G550E-CFTR (C) were pulse-labeled for 20 min with 100 ␮Ci͞ml [35S]methionine and then chased for 0, 0.5, 1, 3, and 5 h. Login to comment
88 (D-F) Turnover of band B for wt- (D), F508del- (E), and V562I-CFTR (F) in the absence and presence of revertant mutations. Login to comment
91 (G and I) Efficiency of processing into band C for wt-CFTR (G) and V562I-CFTR (I) in the absence and presence of revertant mutations and for revertants of F508del-CFTR (H). Login to comment
96 (A-E) Time courses of I-efflux from BHK cells stably expressing wt- (A), F508del- (B), R560T- (C), A561E- (D), and V562I- (E) CFTR in the absence and presence of the 4RK and G550E mutations. Login to comment
102 C (Fig. 1A), decreased the magnitude of the V562I-evoked I-efflux to a level equivalent to that of wt-CFTR (Fig. 3 E and F). Login to comment
103 Taken together, our iodide efflux data strongly suggest that the increased steady-state levels of band C (and the slight increase in CFTR processing efficiency) observed for the 4RK variants of wtand V562I-CFTR (Figs. 1 and 2) do not result in increased CFTR channel activity. Login to comment
104 In contrast, the data suggest that G550E compensates for a decreased steady-state level of band C by enhancing the channel activity of wtand V562I-CFTR. Login to comment
107 To test the idea that the revertant G550E enhances the Cl-channel function of wt and CF mutants, we used the patch-clamp technique to study the single-channel behavior of wt-, V562I-, and F508del-CFTR in the absence and presence of the revertants. Login to comment
108 Fig. 4 demonstrates that the single-channel properties of V562I-CFTR were identical to those of wt-CFTR. Login to comment
109 Like wt-CFTR (2), the gating behavior of V562I-CFTR was characterized by bursts of channel openings interrupted by brief flickery closures and separated by longer closures between bursts (Fig. 4A). Login to comment
110 Strikingly, V562I-CFTR had the same open probability (Po), mean burst duration (MBD), interburst interval (IBI), and ATP-dependence [V562I, ATP concentration for half maximal activation (Km) ϭ 252 ␮M; wt, Km ϭ 210 ␮M] as wt-CFTR (Fig. 4 B-D and data not shown). Login to comment
111 Together with our observation that V562I-CFTR does not affect the efficiency of CFTR processing (Figs. 1 and 2), these data raise the possibility that V562I is not a disease-causing mutation. Login to comment
118 Like their effects on wt-CFTR, 4RK and G550E enhanced V562I-CFTR channel gating and rescued that of F508del-CFTR with different efficacies (Fig. 4). Login to comment
127 Like F508del, R560T and A561E disrupt CFTR processing, whereas V562I traffics normally to the cell surface, forming a Cl-channel with properties indistinguishable from those of wt-CFTR. Login to comment
136 Single-channel activity of wt-, V562I-, and F508del-CFTR alone and in cis with 4RK and G550E. Login to comment
140 Columns and error bars are means Ϯ SEM (wt: n ϭ 6 for all data; 4RK: Po, n ϭ 2; MBD and IBI, n ϭ 1; G550E: Po, n ϭ 3; MBD and IBI, n ϭ 1; V562I: Po, n ϭ 5; MBD and IBI, n ϭ 2; V562I-4RK: Po, n ϭ 4; MBD and IBI, n ϭ 3; V562I-G550E: Po, n ϭ 8; MBD and IBI, n ϭ 3; F508del: n ϭ 10 for all data; F508del-4RK: Po, n ϭ 13; MBD and IBI, n ϭ 10; F508del-G550E: Po, n ϭ 5; MBD and IBI, n ϭ 4). Login to comment
144 Surprisingly, our data demonstrate that V562I-CFTR is processed as efficiently as wt-CFTR (Fig. 2) and forms a Cl-channel functionally equivalent to wt-CFTR (Fig. 4). Login to comment
145 Indeed, our structural model predicts that V562I is without effect on the tertiary structure of NBD1. Login to comment
146 Based on these data, we do not consider V562I-CFTR to be a CF-causing variant. Login to comment
182 However, the opposite effect was observed for both wtand V562I-CFTR when in cis with 4RK; therefore, the effects observed with the R31 mutants must result from the loss of a stabilizing role played by the N terminus rather than from interference with an AFT. Login to comment
205 When compared with both wtand F508del-CFTR, clones expressing V562I- and R560T-CFTR expressed higher and lower levels of protein, respectively, precluding studies on cell lines with equivalent amounts of CFTR protein. Login to comment

[hide] Detection of cystic fibrosis transmembrane conduct... Hum Reprod. 2007 May;22(5):1285-91. Epub 2007 Feb 28. Ratbi I, Legendre M, Niel F, Martin J, Soufir JC, Izard V, Costes B, Costa C, Goossens M, Girodon E
Detection of cystic fibrosis transmembrane conductance regulator (CFTR) gene rearrangements enriches the mutation spectrum in congenital bilateral absence of the vas deferens and impacts on genetic counselling.
Hum Reprod. 2007 May;22(5):1285-91. Epub 2007 Feb 28., [PMID:17329263]

Abstract [show]
BACKGROUND: Mutations in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene have been widely detected in infertile men with congenital bilateral absence of the vas deferens (CBAVD). Despite extensive analysis of the CFTR gene using varied screening methods, a number of cases remain unsolved and could be attributable to the presence of large gene rearrangements, as recently shown for CF patients. METHODS: We carried out a complete CFTR gene study in a group of 222 CBAVD patients with strict diagnosis criteria and without renal anomaly, and searched for rearrangements using a semi-quantitative assay in a subgroup of 61 patients. RESULTS: The overall mutation detection rate was 87.8%, and 82% of patients carried two mutations. Ten out of the 99 different mutations accounted for 74.6% of identified alleles. Four large rearrangements were found in patients who already carried a mild mutation: two known partial deletions (exons 17a to 18 and 22 to 23), a complete deletion and a new partial duplication (exons 11 to 13). The rearrangements accounted for 7% of the previously unknown alleles and 1% of all identified alleles. CONCLUSIONS: Screening for rearrangements should be part of comprehensive CFTR gene studies in CBAVD patients and may have impacts on genetic counselling for the patients and their families.

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53 In five out of the 14 patients carrying the (TG)11(T)5 allele, V562I was also identified, probably in cis as documented in two of these cases and in other patients who do not have CBAVD (Girodon et al., unpublished data). Login to comment
69 Frequent cystic fibrosis transmembrane conductance regulator (CFTR) defects found in congenital bilateral absence of the vas deferens (CBAVD) patients (above 1% among the identified alleles) Mutation No. of alleles % of the 390 identified alleles F508dela 119 30.5 IVS8(T)5a,b 107 27.4 (TG)12(T)5 82 (TG)13(T)5 16 (TG)11(T)5b 9 R117Ha 25 6.4 R668C 9 2.3 [D443Y;G576A;R668C] 6 [G576A;R668C] 2 R668C 1 L206W 7 1.8 D1152H 6 1.5 W1282Xa 5 1.3 [V562I;(TG)11(T)5] 5 1.3 [R74W;D1270 N] 4 1.0 [R74W;D1270 N] 3 [R74W;V201M;D1270 N] 1 Q1352H(G . Login to comment
71 b Do not include the [V562I;(TG)11(T)5] complex alleles that are indicated below. Login to comment
142 (TG)11(T)5 penetrance reaching only 11% (Groman et al., 2004), we systematically investigated the whole CFTR gene to look for other cis mutations in the 14 patients carrying this variant and we found V562I in five of them. Login to comment
144 Although V562I has been considered a severe CF mutation, a series of arguments question its severe deleterious effect: its presence in trans of the severe W1282X mutation, the case of a V562I homozygous CF patient who carried in cis the frameshift 2347delG (Girodon et al., unpublished data), and the fact that residue V562 is not conserved in other proteins containing the ATP-binding cassette motif. Login to comment
145 We suggest reconsidering V562I as a mild and CBAVD-associated mutation. Login to comment

[hide] Molecular characterization of the cystic fibrosis ... Genet Med. 2007 Mar;9(3):163-72. Grangeia A, Sa R, Carvalho F, Martin J, Girodon E, Silva J, Ferraz L, Barros A, Sousa M
Molecular characterization of the cystic fibrosis transmembrane conductance regulator gene in congenital absence of the vas deferens.
Genet Med. 2007 Mar;9(3):163-72., [PMID:17413420]

Abstract [show]
PURPOSE: Approximately 20% of patients with congenital absence of the vas deferens remain without two mutations identified. We applied a strategy of serial screening steps to 45 patients with congenital absence of the vas deferens and characterized cystic fibrosis transmembrane conductance regulator gene mutations in all cases. METHODS: DNA samples of 45 patients with congenital absence of the vas deferens were screened by successive different molecular genetics approaches. RESULTS: Initial screening for the 31 most frequent cystic fibrosis mutations, IVS8 poly(TG)m, poly(T)n, and M470V polymorphisms, identified 8 different mutations in 40 patients (88.9%). Extensive cystic fibrosis transmembrane conductance regulator gene analysis by denaturing gradient gel electrophoresis, denaturing high-performance liquid chromatography, and DNA sequencing detected 17 further mutations, of which three were novel. Cystic fibrosis transmembrane conductance regulator gene rearrangements were searched by semiquantitative fluorescent multiplex polymerase chain reaction, which detected a CFTRdele2,3 (21 kb) large deletion and confirmed two homozygous mutations. Overall, 42 patients (93.3%) had two mutations and 3 patients (6.7%) had one mutation detected. CONCLUSIONS: The present screening strategy allowed a higher mutation detection rate than previous studies, with at least one cystic fibrosis transmembrane conductance regulator gene mutation found in all patients with congenital absence of the vas deferens.

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93 DeltaF508 was the second most common mutation, representing 21 (23.3%) of total alleles, followed by R334W (6, Table 1 CFTR gene mutations and polymorphisms in patients with congenital absence of the vas deferens Mutation Location Nucleotide alteration Effect Method 1 CFTRdele2,3 Exons 2-3 Deletion of exons 2 and 3 Frameshift QFM-PCR 2 R117H Exon 4 G¡A at 482 AA substitution 31 mutation panel 3 P205S Exon 6a C¡T at 745 AA substitution DGGE/dHPLC 4 L206W Exon 6a T¡G at 749 AA substitution DGGE/dHPLC 5 R258G Exon 6b A¡G at 904 AA substitution DGGE/dHPLC 6 R334W Exon 7 C¡T at 1132 AA substitution 31 mutation panel 7 T5 allele Intron 8 Deletion of 2T at 1342-12 to -6 Aberrant splicing DGGE/DNA sequencing 8 P439S Exon 9 C¡T at 1447 AA substitution DGGE/dHPLC 9 D443Ya Exon 9 G¡T at 1459 AA substitution DGGE/dHPLC 10 I507del Exon 10 Deletion of 3 bp at 1648-1653 AA deletion 31 mutation panel 11 DeltaF508 Exon 10 Deletion of 3 bp at 1652-1655 AA deletion 31 mutation panel 12 G542X Exon 11 G¡T at 1756 Truncation 31 mutation panel 13 V562I Exon 12 G¡A at 1816 AA substitution DGGE/dHPLC 14 G576Aa Exon 12 G¡C at 1859 Aberrant splicing DGGE/dHPLC 15 D614G Exon 13 A¡G at 1973 AA substitution DGGE/dHPLC 16 R688Ca Exon 13 C¡T at 2134 AA substitution DGGE/dHPLC 17 V754M Exon 13 G¡A at 2392 AA substitution DGGE/dHPLC 18 E831X Exon 14a G¡T at 2623 Truncation DGGE/dHPLC 19 3272-26AϾG Intron 17a A¡G at 3272-26 Aberrant splicing DGGE/dHPLC 20 2789ϩ5G¡A Intron 14b G¡A at 2789ϩ5 Aberrant splicing 31 mutation panel 21 V1108L Exon 17b G¡C at 3454 AA substitution DGGE/dHPLC 22 L1227S Exon 19 T¡C at 3812 AA substitution DGGE/dHPLC 23 S1235R Exon 19 T¡G at 3837 AA substitution DGGE/dHPLC 24 P1290S Exon 20 C¡T at 4000 AA substitution DGGE/dHPLC 25 N1303K Exon 21 C¡G at 4041 AA substitution 31 mutation panel 26 E1401K Exon 23 G¡A at 4333 AA substitution DGGE/dHPLC Polymorphisms 1 TG repeats Intron 8 9-13 copies at 1342-12 to -35 Sequence variation DGGE/DNA sequencing 2 M470V Exon 10 A or G at 1540 Sequence variation DNA sequencing 3 125G/C Exon 1 G¡C at 125 Sequence variation DGGE/dHPLC 4 1001ϩ11T/C Intron 6b C¡4T at 1001ϩ11 Sequence variation DGGE/dHPLC 5 1716G/A Exon 10 G¡A at 1716 Sequence variation DGGE/dHPLC 6 1899-136T/G Intron 12 T¡G at 1899-136 Sequence variation DGGE/dHPLC 7 T854T Exon 14a T¡G at 2694 Sequence variation DGGE/dHPLC 8 3601-65C/A Intron 18 C¡A at 3601-65 Sequence variation DGGE/dHPLC 9 4521G/A Exon 24 G¡A at 4521 Sequence variation DGGE/dHPLC QFM-PCR, semiquantitative fluorescent multiplex polymerase chain reaction; bp, base pair; DGGE, denaturing gradient gel electrophoresis; dHPLC, denaturing high-performance liquid chromatography. Login to comment
101 The missense M470V polymorphism was evaluated in all 45 pa- tientswithCAVD(Table2).TheallelicfrequencyoftheM470variant Table 2 CFTR genotypes identified in patients with congenital absence of the vas deferens CFTR mutation genotypes [(TG)mTn] genotype M470V Patients N % DeltaF508 (TG)10T9 (TG)12T5 M V 11 24.4 DeltaF508 (TG)10T9 (TG)11T5 M M 1 2.2 DeltaF508 R117H (TG)10T9 (TG)10T7 M M 2 4.4 G542X (TG)10T9 (TG)12T5 M V 2a 4.4 DeltaF508 R334W (TG)10T9 (TG)11T7 M V 1 2.2 DeltaF508 D443Y-G576A-R668C (TG)10T9 (TG)10T7 M M 1 2.2 DeltaF508 D614G (TG)10T9 (TG)11T7 M V 1 2.2 DeltaF508 E831X (TG)10T9 (TG)11T7 M V 1 2.2 DeltaF508 L1227S (TG)10T9 (TG)11T7 M M 1 2.2 DeltaF508 E1401K (TG)10T9 (TG)11T7 M V 1 2.2 I507del D614G (TG)11T7 (TG)10T7 M V 1 2.2 N1303K L206W (TG)10T9 (TG)9T9 M M 1 2.2 R117H P205S (TG)11T7 (TG)10T7 M V 1 2.2 R117H R334W (TG)10T7 (TG)11T7 M V 1 2.2 R334W P439S (TG)11T7 (TG)11T7 M V 1 2.2 R334W R334Wb (TG)11T7 (TG)11T7 V V 1 2.2 R334W V562I (TG)11T7 (TG)11T5 V M 1 2.2 D443Y-G576A-R668C 3272-26A¡G (TG)10T7 (TG)10T7 M M 1 2.2 G576A-R668C V754Mb (TG)10T7 (TG)11T7 M M 1 2.2 S1235R S1235Rb (TG)13T5 (TG)13T5 M M 1 2.2 2789ϩ5G¡A S1235Rb (TG)10T7 (TG)13T5 M M 1 2.2 3272-26A¡G P1290S (TG)11T7 (TG)10T7 M V 1 2.2 P205S (TG)11T7 (TG)12T5 V V 1 2.2 G576A-R668C b (TG)10T7 (TG)11T5 M M 1 2.2 V1108L b (TG)11T7 (TG)11T5 V M 1 2.2 N1303K (TG)10T9 (TG)12T5 M V 1 2.2 3272-26A¡G b (TG)10T7 (TG)12T5 M V 1 2.2 CFTRdele2,3 b (TG)11T7 (TG)13T5 V M 1 2.2 b (TG)11T5 (TG)12T5 M V 1 2.2 b (TG)13T5 (TG)12T5 M V 1 2.2 DeltaF508 - (TG)10T9 (TG)11T7 M V 1a 2.2 L206W -b (TG)9T9 (TG)11T7 M V 1 2.2 R258G -b (TG)11T7 (TG)11T7 V V 1 2.2 a CUAVD. Login to comment
110 Large Table 3 Allelic frequencies of CFTR mutations in patients with congenital absence of the vas deferens CBAVD CUAVD Total Patients 42 3 45 Alleles 84 6 90 Mutations N % N % N % 1 T5 allele 26a 31 2 33.3 28 31.1 2 DeltaF508 20 23.8 1 16.7 21 23.3 3 R334W 6a 7.1 0 0 6 6.7 4 R117H 4 4.8 0 0 4 4.4 5 G576A 4b 4.8 0 0 4 4.4 6 R688C 4b 4.8 0 0 4 4.4 7 S1235R 3a 3.6 0 0 3 3.3 8 3272-26A¡G 3 3.6 0 0 3 3.3 9 P205S 2 2.4 0 0 2 2.2 10 L206W 2 2.4 0 0 2 2.2 11 D443Y 2b 2.4 0 0 2 2.2 13 D614G 2 2.4 0 0 2 2.2 14 N1303K 2 2.4 0 0 2 2.2 12 G542X 0 0 2 33.3 2 2.2 15 R258G 1 1.2 0 0 1 1.1 16 P439S 1 1.2 0 0 1 1.1 17 I507del 1 1.2 0 0 1 1.1 18 V562I 1 1.2 0 0 1 1.1 19 V754M 1 1.2 0 0 1 1.1 20 E831X 1 1.2 0 0 1 1.1 21 2789ϩ5G¡A 1 1.2 0 0 1 1.1 22 V1108L 1 1.2 0 0 1 1.1 23 L1227S 1 1.2 0 0 1 1.1 24 P1290S 1 1.2 0 0 1 1.1 25 E1401K 1 1.2 0 0 1 1.1 26 CFTRdele2,3 1 1.2 0 0 1 1.1 CBAVD, congenital bilateral absence of the vas deferens; CUAVD, congenital unilateral absence of the vas deferens. Login to comment

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

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

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

[hide] 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.

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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] Independent contribution of common CFTR variants t... Pancreas. 2010 Mar;39(2):209-15. de Cid R, Ramos MD, Aparisi L, Garcia C, Mora J, Estivill X, Farre A, Casals T
Independent contribution of common CFTR variants to chronic pancreatitis.
Pancreas. 2010 Mar;39(2):209-15., [PMID:19812525]

Abstract [show]
OBJECTIVE: We have assessed whether CFTR gene has a major impact on chronic pancreatitis (CP) pathogenesis than that provided by the CFTR mutations. For this aim, we have evaluated clinical parameters, CFTR mutations, and 3 potential regulatory CFTR variants (coding single-nucleotide polymorphisms): c.1540A>G, c.2694T>G, and c.4521G>A. METHODS: CFTR gene analysis was performed in a cohort of 136 CP patients and 93 controls from Spanish population using current scanning techniques (single-strand conformation polymorphism/heteroduplex, denaturing gradient gel electrophoresis, and denaturing high-performance liquid chromatography) and direct sequencing. RESULTS: A higher frequency of CFTR mutations were observed in patients (39%) than in controls (15%; P < or = 0.001), differences being mostly attributable to the prevalence of the cystic fibrosis (CF)-causing mutations (P = 0.009). The analysis of variants has shown statistically significant differences between patients and controls for c.4521G>A (Pcorrected = 0.036). Furthermore, the multi-marker analysis revealed that the 1540A;2694G;4521A (AGA) haplotype was more prevalent in CP than controls (Pcorrected = 0.042). Remarkably, this association was unrelated to CF-causing mutations (P = 0.006). CONCLUSIONS: Our results corroborate the higher susceptibility of CF carriers to CP and, furthermore, suggest that the AGA haplotype could contribute to an increased risk in the development of CP irrespective of other CF-causing mutations.

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81 CFTR Genotypes in Chronic Pancreatitis Patients and General Population Pt/Phenotype CFTR Genotype Pt/Phenotype CFTR Genotype 1/ACP F508del† , I1027T/j 19/ACP* R668C/j 2/ACP* F508del† /j 20/ACP D836Y/j 3/ACP F508del† , I1027T/Y1014C 21/ACP* L997F† /j 4/ACP F508del† /1716G9A 22/ACP* R1162L/j 5/ACP* F508del† /1716G9A 23/ACP 5T-11TG/j 6/ACP* F508del† /S1235R 24/ACP 5T-11TG/j 7/ACP G542X† /j 25/ACP 5T-11TG/j 8/ACP* W1282X† /j 26/ACP* 5T-11TG/j 9/ACP 5T-12TG† /5T-11TG 27/ACP* 5T-11TG/j 10/ACP* 5T-12TG† /j 28/ACP 1716G9A/4374+13A9G 11/ACP R75Q/j 29/ACP 1716G9A/j 12/ACP R75Q/j 30/ACP 1716G9A/j 13/ACP Y122C/Y122C 31/ACP 1716G9A/j 14/ACP* R170C/j 32/ACP 1716G9A/j 15/ACP* R258G/j 33/ACP* 1716G9A/j 16/ACP* M281T/j 34/ACP 2377C9T/j 17/ACP* R297Q† /- 35/ACP* 2377C9T/j 18/ACP T351S/- 36/ACP 3499+37G9A/j 1/ICP F508del† /- 10/ICP* 1716G9A/j 2/ICP D443Y,G576A,R668C† /j 11/ICP* 1716G9A/j 3/ICP* D443Y,G576A,R668C† /j 12/ICP 1716G9A/j 4/ICP* P205S† /j 13/ICP* 1716G9A/j 5/ICP* L997F† /j 14/ICP* 1716G9A/j 6/ICP* R170H/1716G9A 15/ICP* 1716G9A/j 7/ICP 109A9G/j 16/ICP* 1716G9A/j 8/ICP* 5T-11TG/j 17/ICP 1716G9A/j 9/ICP* 5T-11TG/j 1/GP 5T-12TG† /j 8/GP 1716G9A/j 2/GP 5T-12TG† /j 9/GP 1716G9A/j 3/GP A534E† /j 10/GP 1716G/A/j 4/GP 5T-11TG/V562I 11/GP 1716G9A/j 5/GP 5T-11TG/j 12/GP 1716G9A/j 6/GP 5T-11TG/j 13/GP 3690A9G/j 7/GP 1716G9A/j 14/GP 3690A9G/j Corresponding mutation nomenclature (Human Genome Variation Society and Cystic Fibrosis Mutation Data Base): c.1584G9A (1716G9A), c.1210-7_1210-6delTT (5T), 1210-34_1210-13TG (11TG), g.-23A9G (109A9G), c.4242+13A9G (4374+13A9G), c.2245C9T (2377C9T), c.3367+ 37G9A (3499+37G9A), and c.3558A9G (3690A9G). Login to comment

[hide] Molecular and functional characterization of the c... J Comp Physiol B. 2010 Apr;180(4):545-61. Epub 2009 Dec 12. Demmers KJ, Carter D, Fan S, Mao P, Maqbool NJ, McLeod BJ, Bartolo R, Butt AG
Molecular and functional characterization of the cystic fibrosis transmembrane conductance regulator from the Australian common brushtail possum, Trichosurus vulpecula.
J Comp Physiol B. 2010 Apr;180(4):545-61. Epub 2009 Dec 12., [PMID:20012660]

Abstract [show]
Unlike eutherian mammals, the colon of the Australian common brushtail possum, Trichosurus vulpecula, a metatherian mammal, is incapable of electrogenic Cl(-) secretion and has elevated levels of electrogenic Na(+) absorption, while the ileum secretes HCO (3) (-) rather than Cl(-). In eutherian mammals, the cystic fibrosis transmembrane conductance regulator (CFTR) is essential for both Cl(-) and HCO (3) (-) secretion and the regulation of Na(+) absorption. Therefore, we have sequenced possum (p)CFTR, described its distribution and characterized the properties of cloned pCFTR expressed in Fischer rat thyroid (FRT) cells. pCFTR (GenBank accession No. AY916796) has a 1,478 amino acid open reading frame, which has >90% identity with CFTR from other marsupials and >80% identity with non-rodent eutherian mammals. In pCFTR, there is a high level of conservation of the transmembrane and nucleotide binding domains although, with the exception of other marsupials, there is considerable divergence from other species in the R domain. FRT cells transfected with pCFTR express mature CFTR protein which functions as a small Cl(-) channel activated by cAMP-dependent phosphorylation. In whole-cell recordings it has a linear, time and voltage-independent conductance, with a selectivity sequence P(Br) > P(Cl) > P(I) > P(HCO)(3) >> P(Gluconate). pCFTR transcript is present in a range of epithelia, including the ileum and the colon. The presence of pCFTR in the ileum and its measured HCO (3) (-) permeability suggest that it may be involved in ileal HCO (3) (-) secretion. Why the possum colon does not secrete Cl(-) and has elevated electrogenic Na(+) absorption, despite the apparent expression of CFTR, remains to be determined.

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136 The only difference was seen in the Walker B motif of NBD1, where there was a valine to isoleucine substitution at amino acid 562. Login to comment
212 Although this is in a ''hot spot`` for mutations that affect CFTR function and result in CF in humans (Roxo-Rosa et al. 2006), this particular mutation (V562I) has no effect on either the trafficking or function of human CFTR (Roxo-Rosa et al. 2006). Login to comment

[hide] Association of cystic fibrosis genetic modifiers w... Fertil Steril. 2010 Nov;94(6):2122-7. Epub 2010 Jan 25. Havasi V, Rowe SM, Kolettis PN, Dayangac D, Sahin A, Grangeia A, Carvalho F, Barros A, Sousa M, Bassas L, Casals T, Sorscher EJ
Association of cystic fibrosis genetic modifiers with congenital bilateral absence of the vas deferens.
Fertil Steril. 2010 Nov;94(6):2122-7. Epub 2010 Jan 25., [PMID:20100616]

Abstract [show]
OBJECTIVE: To investigate whether genetic modifiers of cystic fibrosis (CF) lung disease also predispose to congenital bilateral absence of the vas deferens (CBAVD) in association with cystic fibrosis transmembrane conductance regulator (CFTR) mutations. We tested the hypothesis that polymorphisms of transforming growth factor (TGF)-beta1 (rs 1982073, rs 1800471) and endothelin receptor type A (EDNRA) (rs 5335, rs 1801708) are associated with the CBAVD phenotype. DESIGN: Genotyping of subjects with clinical CBAVD. SETTING: Outpatient and hospital-based clinical evaluation. PATIENT(S): DNA samples from 80 subjects with CBAVD and 51 healthy male controls from various regions of Europe. This is one of the largest genetic studies of this disease to date. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Genotype analysis. RESULT(S): For single nucleotide polymorphism (SNP) rs 5335, we found increased frequency of the CC genotype among subjects with CBAVD. The difference was significant among Turkish patients versus controls (45.2% vs. 19.4%), and between all cases versus controls (36% vs. 15.7%). No associations between CBAVD penetrance and polymorphisms rs 1982073, rs 1800471, or rs 1801708 were observed. CONCLUSION(S): Our findings indicate that endothelin receptor type A polymorphism rs 5335 may be associated with CBAVD penetrance. To our knowledge, this is the first study to investigate genetic modifiers relevant to CBAVD.

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68 Portuguese CFTR alleles Spanish CFTR alleles Turkish CFTR alleles 5T 22 F508del 11 5T 20 F508del 14 5T 9 D1152H 14 R334W 5 D443Ya 3 D110H 3 R117H 3 G576Aa 3 F508del 2 S1235R 3 R668Ca 3 3041-11del7 2 N1303K 2 G542X 2 1767del6 2 P205S 2 R117H 2 2789þ5G>A 2 D614G 2 V232D 2 CFTRdele2(ins186) 2 G542X 1 L997F 1 3120þ1G>A 1 L206W 1 H609R 1 G1130A 1 V562I 1 N1303H 1 M952I 1 I507del 1 L206W 1 365insT 1 3272-26A>G 1 3272-26A/G 1 E585X 1 2789þ5G>A 1 L15P 1 2752-15C>G 1 G576Aa 1 R347H 1 R334Q 1 R668Ca 1 2689insG 1 R347H 1 CFTRdele2,3 1 R1070W 1 E831X 1 L1227S 1 I 1027T 1 R1070W 1 E831X 1 3272-26A>G 1 L997F 1 I853F 1 A349V 1 6T 1 Note: CFTR ¼ cystic fibrosis transmembrane conductance regulator. Login to comment

[hide] Folding and rescue of a cystic fibrosis transmembr... J Biol Chem. 2010 Aug 27;285(35):27033-44. Epub 2010 Jun 15. Da Paula AC, Sousa M, Xu Z, Dawson ES, Boyd AC, Sheppard DN, Amaral MD
Folding and rescue of a cystic fibrosis transmembrane conductance regulator trafficking mutant identified using human-murine chimeric proteins.
J Biol Chem. 2010 Aug 27;285(35):27033-44. Epub 2010 Jun 15., 2010-08-27 [PMID:20551307]

Abstract [show]
Impairment of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel causes cystic fibrosis, a fatal genetic disease. Here, to gain insight into CFTR structure and function, we exploited interspecies differences between CFTR homologues using human (h)-murine (m) CFTR chimeras containing murine nucleotide-binding domains (NBDs) or regulatory domain on an hCFTR backbone. Among 15 hmCFTR chimeras analyzed, all but two were correctly processed, one containing part of mNBD1 and another containing part of mNBD2. Based on physicochemical distance analysis of divergent residues between human and murine CFTR in the two misprocessed hmCFTR chimeras, we generated point mutations for analysis of respective CFTR processing and functional properties. We identified one amino acid substitution (K584E-CFTR) that disrupts CFTR processing in NBD1. No single mutation was identified in NBD2 that disrupts protein processing. However, a number of NBD2 mutants altered channel function. Analysis of structural models of CFTR identified that although Lys(584) interacts with residue Leu(581) in human CFTR Glu(584) interacts with Phe(581) in mouse CFTR. Introduction of the murine residue (Phe(581)) in cis with K584E in human CFTR rescued the processing and trafficking defects of K584E-CFTR. Our data demonstrate that human-murine CFTR chimeras may be used to validate structural models of full-length CFTR. We also conclude that hmCFTR chimeras are a valuable tool to elucidate interactions between different domains of CFTR.

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287 This raises the interesting possibility that P1290T might be a sequence variation (polymorphism) like V562I (24). Login to comment

[hide] Clinical hallmarks and genetic polymorphisms in th... Clin Invest Med. 2010 Aug 1;33(4):E234-9. Tomaiuolo AC, Alghisi F, Petrocchi S, Surace C, Roberti MC, Bella S, Lucidi V, Angioni A
Clinical hallmarks and genetic polymorphisms in the CFTR gene contribute to the disclosure of the A1006E mutation.
Clin Invest Med. 2010 Aug 1;33(4):E234-9., [PMID:20691141]

Abstract [show]
Since the identification of the Cystic Fibrosis transmembrane conductance regulator (CFTR) gene in 1989, many genetic mutations have been found in cystic fibrosis (CF) patients. Dysfunctions of the CFTR gene are responsible for the highly variable clinical presentation ranging from severe CF, disseminated bronchiectasis, idiopathic chronic pancreatitis and congenital bilateral absence of vas deferens (CBAVD). Linkage disequilibrium studies have shown that some mutations are stringently coupled with polymorphisms in a genetic complex called haplotype. From a familial study of a patient with CBAVD, carrier of the A1006E mutation, we have observed its strict association with the polymorphism 5T-TG11. In order to speed up the genetic diagnosis and to correlate the clinical setting to this genetic feature, we have directly investigated the exon 17a, where the A1006E mutation is located, of five cystic fibrosis patients belonging to two unrelated families. All patients had the 5T-TG11 tract, F508del and one unknown mutation. One more family with two affected individuals carrying the Q220X/A1006E mutations was investigated for the poly-T polymorphism. All the members were found to have the A1006E mutation and the 5T-TG11 in the same DNA strand, demonstrating that this strategy is a reliable and inexpensive method for genotyping the CFTR gene. A detailed description of the clinical presentation and follow-up are provided in order to highlight common phenotypic features useful to improve the management of cystic fibrosis patients.

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57 Exon 10 was also analyzed in order to complete the haplotype feature: M470 was homozygous in each individual while the V562I sequence variation was present in all but one patient. Login to comment
61 A similar rate has been observed in the Spanish population, while, surprisingly, this mutation was not detected among the Hispanics of the Latin American populations.11 The same study identified its association with the V562I and the IVS8-5T in a complex allele that is now updated including the TG11 polymorphism reported from our investigations. Login to comment
68 Moreover, all but one case (Pt1) show the V562I revealing a weaker association between this sequence variation and the previously described haplotype. Login to comment
73 TABLE 1. Allelic genotyping of the patients with CFTR geneTABLE 1. Allelic genotyping of the patients with CFTR geneTABLE 1. Allelic genotyping of the patients with CFTR geneTABLE 1. Allelic genotyping of the patients with CFTR geneTABLE 1. Allelic genotyping of the patients with CFTR geneTABLE 1. Allelic genotyping of the patients with CFTR gene Patients Haplotype Mutations Tn-TGm Sequence variations Sequence variations Pt1 Strand 1 F508del 9T-TG10 M470V Strand 2 A1006E 5T-TG11 M470V - Pts2-3 Strand 1 Q220X 7T-TG11 M470V Strand 2 A1006E 5T-TG11 M470V V562I Pts4-7 Strand 1 F508del 9T-TG10 M470V Strand 2 A1006E 5T-TG11 M470V V562I TABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR geneTABLE 2. Phenotypic features of patients with CFTR gene Pts Age at diagnosis Sweat test Current clinical statusCurrent clinical statusCurrent clinical statusCurrent clinical statusCurrent clinical status (years) (mmol/L) Age (years) X-Ray Lung Assessment FEV1% PS ARP 1 35 Cl: 84 36 Bronchiectasis 61 - - 2 21 Cl: 74 36 Bronchiectasis 76 - + 3 14 Cl: 76 29 Bronchiectasis 73 + - 4 IRT + Na: 76 18 Bronchial thickening 110 + - 5 16 Na: 121 34 Initial bronchiectasis 86 + - 6 14 Na: 119 32 Bronchiectasis; lobe excision 74 - + 7 13 Na: 97 31 Bronchial thickening 91 + - IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` IRT: Immunoreactive Trypsinogen Test FEV1: Forced Expiratory Volume in 1 second PS: Pancreatic Sufficiency ARP: Acute Recurrent Pancreatitis ` agnosis of 16.2 ± 10.5 years, median age of 14 years) the course of the disease leads to a complete phenotypic expression. Login to comment

[hide] A new complex allele of the CFTR gene partially ex... Genet Med. 2010 Sep;12(9):548-55. Lucarelli M, Narzi L, Pierandrei S, Bruno SM, Stamato A, d'Avanzo M, Strom R, Quattrucci S
A new complex allele of the CFTR gene partially explains the variable phenotype of the L997F mutation.
Genet Med. 2010 Sep;12(9):548-55., [PMID:20706124]

Abstract [show]
PURPOSE: To evaluate the role of complex alleles, with two or more mutations in cis position, of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in the definition of the genotype-phenotype relationship in cystic fibrosis (CF), and to evaluate the functional significance of the highly controversial L997F CFTR mutation. METHODS: We evaluated the diagnosis of CF or CFTR-related disorders in 12 unrelated subjects with highly variable phenotypes. According to a first CFTR mutational analysis, subjects appeared to be compound heterozygotes for a classic mutation and the L997F mutation. A further CFTR mutational analysis was conducted by means of a protocol of extended sequencing, particularly suited to the detection of complex alleles. RESULTS: We detected a new [R117L; L997F] CFTR complex allele in the four subjects with the highest sweat test values and CF. The eight subjects without the complex allele showed the most varied biochemical and clinical outcome and were diagnosed as having mild CF, CFTR-related disorders, or even no disease. CONCLUSIONS: The new complex allele partially explains the variable phenotype in CF subjects with the L997F mutation. CFTR complex alleles are likely to have a role in the definition of the genotype-phenotype relationship in CF. Whenever apparently identical CFTR-mutated genotypes are found in subjects with divergent phenotypes, an extensive mutational search is mandatory.

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103 In vivo findings and, in some cases, in vitro functional characterizations have been reported for [F508C; S1251N],38 [R347H; D979A],39,40 [R74W; D1270N],41 [G628R; S1235R],42,43 [M470V; S1235R],42 [S912L; G1244V],44 [R117H; (TG)mTn],45-47 [R117C; (TG)mTn],46 [S1235R; (TG)mT5],48 [G576A; R668C],10,49 [V562I; A1006E],49 [R352W; P750L],49 [1198_1203del TGGGCT; 1204GϾA],49 [V754M; CFTRdele3_10,14b_16],50 and [F508del; I1027T].51 These complex alleles have been found in patients with either CF or CFTR-RD, although more often in the former. Login to comment

[hide] Orphan missense mutations in the cystic fibrosis t... J Mol Diagn. 2011 Sep;13(5):520-7. Epub 2011 Jun 25. Fresquet F, Clement R, Norez C, Sterlin A, Melin P, Becq F, Kitzis A, Thoreau V, Bilan F
Orphan missense mutations in the cystic fibrosis transmembrane conductance regulator a three-step biological approach to establishing a correlation between genotype and phenotype.
J Mol Diagn. 2011 Sep;13(5):520-7. Epub 2011 Jun 25., [PMID:21708286]

Abstract [show]
More than 1860 mutations have been found within the human cystic fibrosis transmembrane conductance regulator (CFTR) gene sequence. These mutations can be classified according to their degree of severity in CF disease. Although the most common mutations are well characterized, few data are available for rare mutations. Thus, genetic counseling is particularly difficult when fetuses or patients with CF present these orphan variations. We describe a three-step in vitro assay that can evaluate rare missense CFTR mutation consequences to establish a correlation between genotype and phenotype. By using a green fluorescent protein-tagged CFTR construct, we expressed mutated proteins in COS-7 cells. CFTR trafficking was visualized by confocal microscopy, and the cellular localization of CFTR was determined using intracellular markers. We studied the CFTR maturation process using Western blot analysis and evaluated CFTR channel activity by automated iodide efflux assays. Of six rare mutations that we studied, five have been isolated in our laboratory. The cellular and functional impact that we observed in each case was compared with the clinical data concerning the patients in whom we encountered these mutations. In conclusion, we propose that performing this type of analysis for orphan CFTR missense mutations can improve CF genetic counseling.

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40 The exception was p.[Val562Ile] (V562I), which we encountered in two unrelated families with distinct genotypes. Login to comment
66 [274-6TϾC(ϩ)1210-12T(5)(ϩ)1684GϾ A] (equaling V562I). Login to comment
97 Sequences of Site-Directed Mutagenesis Primers Mutation Sense oligonucleotide sequences L102P 5=-GTACAGCCTCTCTTACCGGGAAGAATCATAGCTTCC-3= L167R 5=-AAGAAGACTTTAAAGCGGTCAAGCCGTGTTCTAG-3= P574S 5=-GCTGATTTGTATTTATTAGACTCTTCTTTTGGATACCTAGATG-3= V562I 5=-AGAATTTCTTTAGCAAGAGCAATATACAAAGATGCTGATTTG-3= K696R 5=-CAGACTGGAGAGTTTGGGGAAAGAAGGAAGAATTCTATTCTC-3= P841R 5=-GATATGGAGAGCATACGAGCAGTGACTACATGG-3= CFTR Missense Mutation Biological Assay 3 JMD Month 2011, Vol. xx, No. Login to comment
116 The lowered maturation of P574S suggests an attenuated class II mutation. Login to comment
124 [274-6TϾC(ϩ)1210-12T(5) (ϩ)1684GϾA (ϭp.[Val562Ile])] Infertility, no CBAVD, previously treated bilateral cryptorchidism Ø Ø Ø In the genotype column, the amino acid substitutions that we investigated are boldfaced. Login to comment
137 Normal Phenotype for the V562I CFTR Variant The controversial V562I substitution lies inside nucleotide-binding domain 1. Login to comment
139 By using Western blot analysis, the maturation process of V562I-CFTR appears similar to the one visualized for WT-CFTR (Figure 4B). Login to comment
142 In our cell model, according to the three techniques that we used, V562I substitution behaves like a polymorphism with no evidence for cellular or functional impact. Login to comment
145 This confirms that V562I substitution should be a polymorphism with no structural or functional impact on the CFTR protein. Login to comment
173 This finding is in accordance with the dramatically reduced activity that we found for L102P-CFTR protein in cell culture. Login to comment
199 A B C V562I actin mergeV562I actin merge % of maximal activation ns 0 50 100 WT V562I % of maximal activation ns 0 50 100 WT V562I % of maximal activation ns 0 50 100 WT V562I B CFTR NaKATPase C WT F508del V562I B CFTR NaKATPase C WT F508del V562I Figure 4. Login to comment
200 The V562I amino acid substitution does not alter CFTR phenotype. Login to comment
214 His genotype was p.[Pro841Arg] ϩ [Arg74Trp;Val201Met; Asp1270Asn]. Login to comment
218 We found the V562I missense variation in a case of male infertility (genotype previously given). Login to comment
224 Our results are concordant with those previously obtained in baby hamster kidney cells overexpressing CFTR23 (by using Western blot analysis, iodide effluxes, and inside-out patch-clamp experiments in which the V562I mutant behaves like WT CFTR). Login to comment
225 However, V562I, which was first reported as a polymorphism,24 has been reassigned as a non-CF-causing mutation, notably implicated in the CBAVD phenotype.20 Because the V562I-CFTR protein appears unaffected, the mutation could only elicit dysfunction at the RNA level. Login to comment
60 Sequences of Site-Directed Mutagenesis Primers Mutation Sense oligonucleotide sequences L102P 5=-GTACAGCCTCTCTTACCGGGAAGAATCATAGCTTCC-3= L167R 5=-AAGAAGACTTTAAAGCGGTCAAGCCGTGTTCTAG-3= P574S 5=-GCTGATTTGTATTTATTAGACTCTTCTTTTGGATACCTAGATG-3= V562I 5=-AGAATTTCTTTAGCAAGAGCAATATACAAAGATGCTGATTTG-3= K696R 5=-CAGACTGGAGAGTTTGGGGAAAGAAGGAAGAATTCTATTCTC-3= P841R 5=-GATATGGAGAGCATACGAGCAGTGACTACATGG-3= was presented. Login to comment
67 [274-6TϾC(ϩ)1210-12T(5)(ϩ)1684GϾ A] [c.1684GϾA equaling p.Val562Ile (V562I)]. Login to comment
83 [274-6TϾC(ϩ)1210-12T(5) (ϩ)1684GϾA (ϭp.[Val562Ile])] Infertility, no CBAVD, previously treated bilateral cryptorchidism Ø Ø Ø In the genotype column, the amino acid substitutions that we investigated are boldfaced. Login to comment
117 The V562I amino acid substitution does not alter CFTR phenotype. Login to comment
165 Normal Phenotype for the V562I CFTR Variant The controversial V562I substitution lies inside nucleotide-binding domain 1. Login to comment
167 By using Western blot analysis, the maturation process of V562I-CFTR appears similar to the one visualized for WT-CFTR (Figure 4B). Login to comment
170 In our cell model, according to the three techniques that we used, V562I substitution behaves like a polymorphism with no evidence for cellular or functional impact. Login to comment
220 Our results are concordant with those previously obtained in baby hamster kidney cells overexpressing CFTR23 (by using Western blot analysis, iodide effluxes, and inside-out patch-clamp experiments in which the V562I mutant behaves like WT-CFTR). Login to comment
221 However, V562I, which was first reported as a polymorphism,24 has been reassigned as a non-CF-causing mutation, notably implicated in the CBAVD phenotype.20 Because the V562I-CFTR protein appears unaffected, the mutation could only elicit dysfunction at the RNA level. Login to comment

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

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

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45 (%) p.F508del # E.10 1009 (51.74) p.G542X # E.11 150 (7.69) p.N1303K # E.21 57 (2.92) c.1811 + 1.6kbA > G I.11 36 (1.84) p.R334W # E.7 35 (1.79) p.L206W E.6a 32 (1.64) c.711 + 1G > T # I.5 31 (1.58) p.Q890X E.15 28 (1.43) p.R1162X # E.19 25 (1.28) c.2789 + 5G > A # I.14b 24 (1.23) p.R1066C E.17b 23 (1.18) p.I507del # E.10 21 (1.07) c.1609delCA E.10 18 (0.92) c.712-1G > T I.5 18 (0.92) c.3272-26A > G I.17a 18 (0.92) c.2183AA > G # E.13 16 (0.82) p.G85E # E.3 15 (0.77) c.2869insG E.15 15 (0.77) p.W1282X # E.20 15 (0.77) p.V232D E.6a 14 (0.71) p.A1006E * E.17a 12 (0.61) c.2184insA E.13 11 (0.56) p.K710X E.13 11 (0.56) TOTAL (n = 23) 1,634 (83.72) * , the complex allele [p.A1006E; p.V562I; IVS8-6(5T)] #, CF mutations identified with the Celera Diagnosis Cystic Fibrosis v2 genotyping assay and the Inno-Lipa CFTR12, CFTR17 + Tn Samples with microsatellite haplotypes 16/45-46-47 (IVS8CA/IVS17bTA) were submitted to direct analysis of the c.1811 + 1.6kbA > G mutation, which was found mainly associated with the 16-46 haplotype. Login to comment
70 The major complexity detected is attributable to the polyvariant [p.A1006E; p.V562I; IVS8-6(5T)], which was observed in all patients with the p.A1006E mutation (Table 1). Login to comment

[hide] Measurements of CFTR-Mediated Cl(-) Secretion in H... PLoS One. 2012;7(10):e47708. doi: 10.1371/journal.pone.0047708. Epub 2012 Oct 17. Sousa M, Servidoni MF, Vinagre AM, Ramalho AS, Bonadia LC, Felicio V, Ribeiro MA, Uliyakina I, Marson FA, Kmit A, Cardoso SR, Ribeiro JD, Bertuzzo CS, Sousa L, Kunzelmann K, Ribeiro AF, Amaral MD
Measurements of CFTR-Mediated Cl(-) Secretion in Human Rectal Biopsies Constitute a Robust Biomarker for Cystic Fibrosis Diagnosis and Prognosis.
PLoS One. 2012;7(10):e47708. doi: 10.1371/journal.pone.0047708. Epub 2012 Oct 17., [PMID:23082198]

Abstract [show]
BACKGROUND: Cystic Fibrosis (CF) is caused by approximately 1,900 mutations in the CF transmembrane conductance regulator (CFTR) gene encoding for a cAMP-regulated chloride (Cl(-)) channel expressed in several epithelia. Clinical features are dominated by respiratory symptoms, but there is variable organ involvement thus causing diagnostic dilemmas, especially for non-classic cases. METHODOLOGY/PRINCIPAL FINDINGS: To further establish measurement of CFTR function as a sensitive and robust biomarker for diagnosis and prognosis of CF, we herein assessed cholinergic and cAMP-CFTR-mediated Cl(-) secretion in 524 freshly excised rectal biopsies from 118 individuals, including patients with confirmed CF clinical diagnosis (n = 51), individuals with clinical CF suspicion (n = 49) and age-matched non-CF controls (n = 18). Conclusive measurements were obtained for 96% of cases. Patients with "Classic CF", presenting earlier onset of symptoms, pancreatic insufficiency, severe lung disease and low Shwachman-Kulczycki scores were found to lack CFTR-mediated Cl(-) secretion (<5%). Individuals with milder CF disease presented residual CFTR-mediated Cl(-) secretion (10-57%) and non-CF controls show CFTR-mediated Cl(-) secretion >/=30-35% and data evidenced good correlations with various clinical parameters. Finally, comparison of these values with those in "CF suspicion" individuals allowed to confirm CF in 16/49 individuals (33%) and exclude it in 28/49 (57%). Statistical discriminant analyses showed that colonic measurements of CFTR-mediated Cl(-) secretion are the best discriminator among Classic/Non-Classic CF and non-CF groups. CONCLUSIONS/SIGNIFICANCE: Determination of CFTR-mediated Cl(-) secretion in rectal biopsies is demonstrated here to be a sensitive, reproducible and robust predictive biomarker for the diagnosis and prognosis of CF. The method also has very high potential for (pre-)clinical trials of CFTR-modulator therapies.

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103 As to the 5 individuals showing inconclusive Ussing chamber measurements, one individual had one CF-disease causing mutation (G542X) and two individuals had RD- related mutations (V562I and G576A). Login to comment

[hide] CFTR mutations in the Algerian population. J Cyst Fibros. 2008 Jan;7(1):54-9. Epub 2007 Jun 14. Loumi O, Ferec C, Mercier B, Creff J, Fercot B, Denine R, Grangaud JP
CFTR mutations in the Algerian population.
J Cyst Fibros. 2008 Jan;7(1):54-9. Epub 2007 Jun 14., [PMID:17572159]

Abstract [show]
The nature and frequency of the major CFTR mutations in the North African population remain unclear, although a small number of CFTR mutation detection studies have been done in Algeria and Tunisia, showing largely European mutations such as F508del, G542X and N1303K, albeit at different frequencies, which presumably emerged via population admixture with Caucasians. Some unique mutations were identified in these populations. This is the first study that includes a genetic and clinical evaluation of CF patients living in Algeria. In order to offer an effective diagnostic service and to make accurate risk estimates, we decided to identify the CFTR mutations in 81 Algerian patients. We carried out D-HPLC, chemical-clamp denaturing gradient gel electrophoresis, multiplex amplification analysis of the CFTR gene and automated direct DNA sequencing. We identified 15 different mutations which account for 58.5% of the CF chromosomes. We used a quantitative PCR technique (quantitative multiplex PCR short fragment fluorescence analysis) to screen for deletion/duplication in the 27 exons of the gene. Taking advantage of the homogeneity of the sample, we report clinical features of homozygous CF patients. As CFTR mutations have been detected in males with infertility, 46 unrelated Algerian individuals with obstructive azoospermia were also investigated.

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90 Table 1 CFTR mutations detected in 36 Algerian patients (N=72 CF chromosomes) Mutations Substitution nucleotide Substitution amino acid Localisation N % Cum. fr. hF508del del CTT Del phe 507/508 Exon 10 12 16.7 16.7 N1303K C→G 4041 Asn→Lys 1303 Exon 21 6 8.3 25.0 711+1G→T G→T711+1 MRNA splicing defect Intron 5 6 8.3 33.3 2183AA/G del A2184 Frameshift Exon 13 3 4.2 37.5 A→G 2183 1609delCA delCA Frameshift Exon 10 2 2.8 40.3 1812-1G→A G→A 1812-1 mRNA splicing defect Intron 11 2 2.8 43.1 V562I G→A 1816 Val→Ile 562 Exon 12 2 2.8 45.9 V754M G→A 2392 Val→Met 754 Exon 13 1 1.4 47.3 W1282X G→A 3978 Trp→Stop 1282 Exon 20 3 4.2 51.5 621+3A/Ga A→G 621+3 mRNA splicing defect Intron 4 1 1.4 52.9 4332delTGa delTG4332 Frameshift Exon 23 G542X G→T 1756 Gly→Stop 542 Exon 11 1 1.4 54.3 4271delC del A 4271 Frameshift Exon 23 1 1.4 55.7 S977F C→T 3062 Ser→Phe 97 Exon 16 1 1.4 57.1 21Kb del 21-kb del Del AA E2-E3 1 1.4 58.5 R74W C→T 352 Arg→Trp 74 Exon 3 0 0 D1270N G→A 3940 Asp→Asn 1270 Exon 20 0 0 Total 43 58.5 N=number of chromosomes; Cum. fr.=cumulative frequency. Login to comment
94 The duplication of 11 bases [1716+(51→61)] was only found in the father of a compound heterozygote V562I/S997F CF patient. Login to comment

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

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

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108 g D44G, 300delA, W57X, 405+1G>A, D110H, E116K, 541del4, 542del7, L137R, 621+2T>G, I175V, H199R, H199Y, C225X, V232D, Q290X, E292X, G314V, T338I, 1221delCT, W401X, Q452P, I502T, 1716+2T>C, G544S, R560S, A561E, V562I, Y569D, 1898+3A>G, 1898+5G>A, G628R(G>A), 2143delT, G673X, R851X, Q890X, S977F, 3129del4, 3154delG, 3271+1G>A, G1061R, R1066L, R1070W, 3601-17T>C, S1196X, 3732delA, G1249R, 3898insC, 4374+1G>A, del25kb. Login to comment
140 Non-F508del Mutations Found as Homozygous in a Sample of 3,710 Patients With Cystic Fibrosis Mutation n 711+1G>T 8 G542X 7 N1303K 7 2183delAA>G 5 W1282X 4 G551D 3 3905insT 3 R334W 2 R347P 2 1078delT 2 1811+1.6kbA>G 2 2113delA 2 Y1092X 2 R1162X 2 306insA 1 E92K 1 G178R 1 L227R 1 1677delTA 1 1717-1G>A 1 1717-8G>A 1 R553X 1 S549R(T>G) 1 R560S 1 V562I 1 Y569D 1 2711delT 1 S945L 1 R1158X 1 I1234V 1 3849+10kbC>T 1 Q1313X 1 del25kb 1 E831X 1 I175V 1 G314V 1 L1077P 1 produce a small quantity of functional protein as a result of a variable proportion of normal CFTR mRNA transcripts in addition to the abnormal ones (class V); 3) they are located in sites known to generate less severe mutants (external loops, residues lining the pore); and/or 4) they have been observed in CF with pancreatic sufficiency, CBAVD, and/or CF-related attenuated phenotypes only. Login to comment

[hide] Increased frequency of cystic fibrosis deltaF508 m... Eur Respir J. 1999 Jun;13(6):1281-7. Puechal X, Fajac I, Bienvenu T, Desmazes-Dufeu N, Hubert D, Kaplan JC, Menkes CJ, Dusser DJ
Increased frequency of cystic fibrosis deltaF508 mutation in bronchiectasis associated with rheumatoid arthritis.
Eur Respir J. 1999 Jun;13(6):1281-7., [PMID:10445602]

Abstract [show]
This study investigated the clinical characteristics and the possible involvement of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in patients with symptomatic diffuse bronchiectasis (DB) associated with rheumatoid arthritis (RA). Twenty-six patients with both RA and DB (group RA+DB) and control groups of 29 consecutive patients with RA but no bronchiectasis (group RA) and 29 patients with symptomatic DB of unknown origin (group DB) were prospectively studied. Among the patients of the RA+DB group, four (15.4%) were heterozygous for the CFTR gene deltaF508 mutation, whereas no deltaF508 mutation was found in patients of the RA and the DB groups (both, p<0.05). This frequency of deltaF508 mutation was also higher than the expected frequency (2.8%) in the general European population (p<0.04). Sweat chloride values and nasal potential differences were normal in three out of four patients carrying the deltaF508 mutation. In the RA+DB group, those with deltaF508 mutation had more frequent chronic sinusitis (p<0.05), a trend toward a more severe pulmonary involvement, and a lower value of nasal potential differences (p<0.01) whereas their rheumatic features had no particularity. In the RA+DB group, patients with adult-onset bronchiectasis (including two with deltaF508 mutation) had a greater reduction in total lung capacity (p<0.05) and lower nasal potential differences (p<0.005) than those with childhood-onset bronchiectasis. This study suggests a possible deleterious effect of the cystic fibrosis transmembrane conductance regulator mutated protein in the airways which may predispose to the development and severity of bronchiectasis in patients suffering from rheumatoid arthritis.

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83 mmol.L-1 mV gene mutation 1 F 67 51 Yes II II 0401/1401 51 20 P. aeruginosa 48 -24 DF508/- 2{ F 52 29 Yes IV IV 0406/0416 35 50 P. aeruginosa ND -31 DF508/- 3 F 35 16 II II 0311/1302 4 82 H. influenzae 18 -21 DF508/- 4 F 52 42 II II 03011/1001 4 79 ND 55 -21.0 DF508/- 5 F 56 48 II III 0101/0401 12 90 Normal flora 40 -15.3 R668C/- 6 F 59 49 III III 0401/0405 4 14 P. aeruginosa 57 ND S1235R/- 7 F 55 53 II I 0101/1001 2 92 Normal flora 42 -17.3 -/- 8 F 55 46 III III 0101/1302 3 83 Normal flora 60 -18.7 -/- 9{ F 66 20 III IV 0101/0401 4 78 P. mirabilis 35 -15.8 -/- 10 M 71 61 II III 0701/1001 67 60 Normal flora 34 -19.2 V562I/- 11 M 59 34 II III 0101/0408 53 94 H. influenzae 62 -20.8 -/- 12 F 56 30 Yes III III 0101/0311 10 89 Normal flora 53 -11.1 -/- 13 F 46 43 Yes II III 0101/0405 9 73 H. influenzae 29 -21.3 -/- 14 F 47 41 II III 03011/0401 9 80 Normal flora 86 -16.5 -/- 15 F 54 44 II II 0401/0401 1 67 Normal flora 50 -13 -/- 16 F 59 37 III III 0101/0401 3 53 H. influenzae 70 -16.8 -/- 17 F 49 47 I I 03011/1401 10 58 H. parainfluenzae 79 -18.5 -/- 18{ F 65 37 Yes III III 03011/1501 56 43 Normal flora 35 -33.8 -/- 19 F 65 54 Yes II III 0101/1101 10 91 ND 64 -9.6 -/- 20 F 70 55 III III 0101/0401 4 80 Normal flora 38 -13.5 -/- 21 F 69 53 IV IV 0101/1501 4 35 P. aeruginosa 35 ND -/- 22 M 66 63 II II 0401/1104 63 97 Normal flora 36 -20.2 -/- 23 F 61 56 I I 03011/0701 4 76 Flavobacterium spp. Login to comment
164 Although the V562I and S1235R mutations have been described in CF patients, the putative detrimental effect of these mutations is disputable. Login to comment
163 Although the V562I and S1235R mutations have been described in CF patients, the putative detrimental effect of these mutations is disputable. Login to comment

[hide] Spectrum of CFTR mutations in the Middle North of ... Hum Mutat. 1999;14(1):89. Telleria JJ, Alonso MJ, Calvo C, Alonso M, Blanco A
Spectrum of CFTR mutations in the Middle North of Spain and identification of a novel mutation (1341G-->A). Mutation in brief no. 252. Online.
Hum Mutat. 1999;14(1):89., [PMID:10447267]

Abstract [show]
We have analyzed 39 unrelated cystic fibrosis (CF) families by denaturing gradient gel electrophoresis (DGGE) and direct sequencing in order to determine the spectrum of CF mutations in our population. This approach has allowed us to detect 72 out of the 78 CF chromosomes (92.3%). The DF508 mutation was found to be present in 51/78 (65.4%) CF chromosomes, in accordance with the predicted Northwest-Southeast gradient within the European population. Another 14 known mutations, and the novel 1341G-->A mutation were identified. Nine out of fifteen non DF508 mutations were present in a single chromosome. The 1341G-->A mutation, found in 2 unrelated patients, is a new mutation associated to severe phenotype, causing pancreatic insufficiency and chronic lung infections. Our data suggest a different distribution of non-DF508 mutations in our population when compared with previous studies carried out in Spanish CF families. Six out of the 14 non-F508 in our study were not present in a recent study carried out in 640 Spanish families with CE These six mutations account for 29.6% non DF508 chromosomes in our sample.

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33 Spectrum of CFTR Mutations Table 1 Spectrum of CFTR mutations identified in the present study compared with data published by Casals et al. (Casals et al. 1997) This study Casals et al. Mutation Exon/Intron n % n % ∆F508 E 10 51 65.4 681 53.2 711+1G→T I 5 3 3.8 22 1.7 G542X E 11 3 3.8 108 8.43 1213delT E 7 2 2.6 0 0 1341G→A E 8 2 2.6 0 0 R1066C E 17b 2 2.6 14 1.09 1717-1G→A I 10 1 1.3 1 0.08 S549R E 11 1 1.3 0 0 V562I E 12 1 1.3 0 0 G576A E 12 1 1.3 0 0 2183AA→G E13 1 1.3 5 0.39 2789+5G→A I 14b 1 1.3 11 0.86 Q890X E 15 1 1.3 13 1.01 3849+1G→A I 19 1 1.3 0 0 N1303K E 21 1 1.3 34 2.65 Other 0 0 391 30.5 Known mutations 72 92.3 1155 90.23 Unknown mutations 6 7.7 125 9.7 DISCUSSION The knowledge of the spectrum of mutations causing CF in any specific geographic region provide useful information to design the best approach in pre and postnatal diagnosis of CF; for the screening of mutations in the population at risk; to stimate the genetic risk etc. Moreover, the response to different therapeutic approaches could vary depending on the CF mutations in any case. Login to comment

[hide] Novel CFTR variants identified during the first 3 ... J Mol Diagn. 2013 Sep;15(5):710-22. doi: 10.1016/j.jmoldx.2013.05.006. Epub 2013 Jun 28. Prach L, Koepke R, Kharrazi M, Keiles S, Salinas DB, Reyes MC, Pian M, Opsimos H, Otsuka KN, Hardy KA, Milla CE, Zirbes JM, Chipps B, O'Bra S, Saeed MM, Sudhakar R, Lehto S, Nielson D, Shay GF, Seastrand M, Jhawar S, Nickerson B, Landon C, Thompson A, Nussbaum E, Chin T, Wojtczak H
Novel CFTR variants identified during the first 3 years of cystic fibrosis newborn screening in California.
J Mol Diagn. 2013 Sep;15(5):710-22. doi: 10.1016/j.jmoldx.2013.05.006. Epub 2013 Jun 28., [PMID:23810505]

Abstract [show]
California uses a unique method to screen newborns for cystic fibrosis (CF) that includes gene scanning and DNA sequencing after only one California-40 cystic fibrosis transmembrane conductance regulator (CFTR) panel mutation has been identified in hypertrypsinogenemic specimens. Newborns found by sequencing to have one or more additional mutations or variants (including novel variants) in the CFTR gene are systematically followed, allowing for prospective assessment of the pathogenic potential of these variants. During the first 3 years of screening, 55 novel variants were identified. Six of these novel variants were discovered in five screen-negative participants and three were identified in multiple unrelated participants. Ten novel variants (c.2554_2555insT, p.F1107L, c.-152G>C, p.L323P, p.L32M, c.2883_2886dupGTCA, c.2349_2350insT, p.K114del, c.-602A>T, and c.2822delT) were associated with a CF phenotype (42% of participants were diagnosed at 4 to 25 months of age), whereas 26 were associated with CFTR-related metabolic syndrome to date. Associations with the remaining novel variants were confounded by the presence of other diseases or other mutations in cis or by inadequate follow-up. These findings have implications for how CF newborn screening and follow-up is conducted and will help guide which genotypes should, and which should not, be considered screen positive for CF in California and elsewhere.

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165 Participant 3 was identified with novel variant c.-837T>C (found to be in cis with p.V562I after parent testing) and p.F508del on the opposite chromosome. Login to comment

[hide] A Genotypic-Oriented View of CFTR Genetics Highlig... Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229. Lucarelli M, Bruno SM, Pierandrei S, Ferraguti G, Stamato A, Narzi F, Amato A, Cimino G, Bertasi S, Quattrucci S, Strom R
A Genotypic-Oriented View of CFTR Genetics Highlights Specific Mutational Patterns Underlying Clinical Macrocategories of Cystic Fibrosis.
Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229., [PMID:25910067]

Abstract [show]
Cystic fibrosis (CF) is a monogenic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The genotype-phenotype relationship in this disease is still unclear, and diagnostic, prognostic and therapeutic challenges persist. We enrolled 610 patients with different forms of CF and studied them from a clinical, biochemical, microbiological and genetic point of view. Overall, there were 125 different mutated alleles (11 with novel mutations and 10 with complex mutations) and 225 genotypes. A strong correlation between mutational patterns at the genotypic level and phenotypic macrocategories emerged. This specificity appears to largely depend on rare and individual mutations, as well as on the varying prevalence of common alleles in different clinical macrocategories. However, 19 genotypes appeared to underlie different clinical forms of the disease. The dissection of the pathway from the CFTR mutated genotype to the clinical phenotype allowed to identify at least two components of the variability usually found in the genotype-phenotype relationship. One component seems to depend on the genetic variation of CFTR, the other component on the cumulative effect of variations in other genes and cellular pathways independent from CFTR. The experimental dissection of the overall biological CFTR pathway appears to be a powerful approach for a better comprehension of the genotype-phenotype relationship. However, a change from an allele-oriented to a genotypic-oriented view of CFTR genetics is mandatory, as well as a better assessment of sources of variability within the CFTR pathway.

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215 The Q779X (p.Gln779*) mutation was found in a CF-PS brother and sister with a [(TG)11T5; V562I; A1006E]/Q779X (c. Login to comment
288 The V562I (p.Val562Ile) and the A1006E (p.Ala1006Glu) were only found within the complex allele. Login to comment
377 [1210-14TG[11];1210-12T[5];1684G>A;3017C>A] CF-PS,CFTR-RD T5 varying clinical consequence; V562I nd; A1006E nd K442X c.1324A>T CF-PI nd p.Lys442* T465N c.1394C>A CF-PI nd p.Thr465Asn [S466X(TGA);R1070Q] c. Login to comment