ABCMdb

ABCC7 p.Ile175Val

ClinVar:	c.523A>G , p.Ile175Val ? , not provided
CF databases:	c.523A>G , p.Ile175Val (CFTR1) D , This mutation was detected by DGGE in exon 5 in a CF patient from Southern France.
Predicted by SNAP2:	A: N (61%), C: D (53%), D: D (71%), E: D (63%), F: N (66%), G: D (63%), H: D (53%), K: N (53%), L: N (82%), M: N (53%), N: D (53%), P: D (66%), Q: N (57%), R: D (53%), S: N (66%), T: N (82%), V: N (87%), W: D (80%), Y: N (66%),
Predicted by PROVEAN:	A: N, C: N, D: N, E: N, F: N, G: N, H: N, K: N, L: N, M: N, N: N, P: N, Q: N, R: N, S: N, T: N, V: N, W: N, Y: N,

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Publications
[hide] Mutation-specific potency and efficacy of cystic f... J Pharmacol Exp Ther. 2009 Sep;330(3):783-91. Epub 2009 Jun 2. Caputo A, Hinzpeter A, Caci E, Pedemonte N, Arous N, Di Duca M, Zegarra-Moran O, Fanen P, Galietta LJ
Mutation-specific potency and efficacy of cystic fibrosis transmembrane conductance regulator chloride channel potentiators.
J Pharmacol Exp Ther. 2009 Sep;330(3):783-91. Epub 2009 Jun 2., [PMID:19491324]

Abstract [show]
Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel. The mutations G551D and G1349D, which affect the nucleotide-binding domains (NBDs) of CFTR protein, reduce channel activity. This defect can be corrected pharmacologically by small molecules called potentiators. CF mutations residing in the intracellular loops (ICLs), connecting the transmembrane segments of CFTR, may also reduce channel activity. We have investigated the extent of loss of function caused by ICL mutations and the sensitivity to pharmacological stimulation. We found that E193K and G970R (in ICL1 and ICL3, respectively) cause a severe loss of CFTR channel activity that can be rescued by the same potentiators that are effective on NBD mutations. We compared potency and efficacy of three different potentiators for E193K, G970R, and G551D. The 1,4-dihydropyridine felodipine and the phenylglycine PG-01 [2-[(2-1H-indol-3-yl-acetyl)-methylamino]-N-(4-isopropylphenyl)-2-phenylac etamide] were strongly effective on the three CFTR mutants. The efficacy of sulfonamide SF-01 [6-(ethylphenylsulfamoyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid cycloheptylamide], another CFTR potentiator, was instead significantly lower than felodipine and PG-01 for the E193K and G970R mutations, and almost abolished for G551D. Furthermore, SF-01 modified the response of G551D and G970R to the other two potentiators, an effect that may be explained by an allosteric antagonistic effect. Our results indicate that CFTR potentiators correct the basic defect caused by CF mutations residing in different CFTR domains. However, there are differences among potentiators, with felodipine and PG-01 having a wider pharmacological activity, and SF-01 being more mutation specific. Our observations are useful in the prioritization and development of drugs targeting the CF basic defect.

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No. Sentence Comment
91 To this respect, we considered I148T, I175V, Q179K, and E193K in ICL1 (Seibert et al., 1997) and G970R in ICL3 (Seibert et al., 1996). Login to comment
100 This discrepancy was even more striking for I175V, which was associated with an anion transport rate greater than wild-type CFTR. Login to comment
120 The activity of I175V was also not significantly affected by potentiators, a behavior that further indicates that this protein is already totally activated with maximal forskolin and therefore behaves essentially as the normal protein. Login to comment
225 I175V may be another benign variant because its activity was comparable with or even higher than that of the native protein. Login to comment
228 Therefore, it is possible that some mutations such as I175V and I148T have a more profound effect on CFTR as a regulator of other proteins (Schreiber et al., 1999). Login to comment

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

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

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68 of chromosomes (frequency %) p.M1V 1 1 (0.23) p.M1K 1 1 (0.23) c.300delA 3 1 (0.23) p.P67L 3 1 (0.23) c.359insT 3 1 (0.23) p.G85E 3 3 (0.70) c.394delTT 3 1 (0.23) p.Q98R 4 1 (0.23) p.R117H 4 2 (0.47) p.Y122X 4 2 (0.47) p.Y161N 4 1 (0.23) c.621+1GNT intron 4 1 (0.23) c.621+2TNG intron 4 1 (0.23) p.I175V 5 2 (0.47) c.711+1GNT intron 5 5 (1.16) p.L206W 6 3 (0.70) p.Q220X 6 1 (0.23) p.L227R 6 1 (0.23) c.1078delT 7 2 (0.47) p.R334W 7 7 (1.63) p.R347P 7 2 (0.47) c.1215delG 7 1 (0.23) c.T5 intron 8 1 (0.23) p.D443Y 9 1 (0.23) p.I506T 10 1 (0.23) p.I507del 10 4 (0.93) p.F508del 10 259 (60.23) p.F508C 10 1 (0.23) c.1677delTA 10 1 (0.23) c.1717-8GNA intron 10 1 (0.23) c.1717-1GNA intron 10 6 (1.40) p.G542X 11 23 (5.35) p.S549R 11 1 (0.23) p.G551D 11 2 (0.47) p.R553X 11 1 (0.23) c1811+1.6kbANG intron 11 4 (0.93) c.1812-1GNA intron 11 1 (0.23) p.T582I 12 1 (0.23) p.E585X 12 2 (0,47) c.1898+1GNA intron 12 1 (0.23) [c.1898+5GNA ;p.E725K] intron 12 1 (0.23) c.1898+73TNG intron 12 1 (0.23) c.2183AANG 13 4 (0.93) c.2184insA 13 1 (0.23) p.K710X 13 4 (0.93) c.2423delG 13 1 (0.23) p.S776X 13 1 (0.23) c.2493ins8 13 1 (0.23) p.R792X 13 1 (0.23) p.K830X 13 1 (0.23) p.D836Y 14a 1 (0.23) p.W846X1 14a 1 (0.23) c.2711delT 14a 1 (0.23) c.2789+5GNA intron 14b 3 (0.70) p.S945L 15 3 (0.70) p.D993Y 16 1 (0.23) c.3129del4 17a 1 (0.23) c.3195del6 17a 1 (0.23) c.3272-26ANG intron 17a 1 (0.23) [c.3395insA ;pI148T] 17b/4 1 (0,23) p.Y1092X 17b 3 (0.70) Table 1 (continued) Mutation Location exon/intron No. Login to comment

[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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Sentences [show]
No. Sentence Comment
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] Disease-associated mutations in cytoplasmic loops ... Biochemistry. 1997 Sep 30;36(39):11966-74. Seibert FS, Jia Y, Mathews CJ, Hanrahan JW, Riordan JR, Loo TW, Clarke DM
Disease-associated mutations in cytoplasmic loops 1 and 2 of cystic fibrosis transmembrane conductance regulator impede processing or opening of the channel.
Biochemistry. 1997 Sep 30;36(39):11966-74., [PMID:9305991]

Abstract [show]
Since little is known about the contribution to function of the N-terminal cytoplasmic loops (CL1, residues 139-194; CL2, residues 242-307) of cystic fibrosis transmembrane conductance regulator (CFTR), all nine point mutations identified in CLs 1 and 2 from patients with cystic fibrosis were reconstructed in the expression vector pcDNA3-CFTR and expressed transiently in COS-1 and HEK-293 cells and stably in Chinese hamster ovary (CHO) cells. Four amino acid substitutions retarded production of mature, fully glycosylated CFTR, suggesting that misprocessing of the channel causes the disease symptoms in the affected patients. Protein maturation could not be promoted by cell culture conditions of reduced temperature (26 degrees C). When properly processed mutants were evaluated for functional defects by the iodide efflux method, the G178R- and E193K-CFTR-expressing cell lines showed impaired anion translocation activities. Patch-clamp studies of single channels revealed that E193K variants had a significantly decreased open probability, which resulted from an increase in the mean closed time of the channels. This contrasted with a previous study of disease-associated point mutations in CL3 that mainly affected the mean open time. None of the maturation-competent CL 1 and 2 mutants had altered conductance. Thus, the N-terminal CLs appear not to contribute to the anion translocation pathway of CFTR; rather, mutations in CL1 can impede transition to the open state. Interestingly, the ability of the non-hydrolyzable ATP analogue adenylyl imidodiphosphate (AMP-PNP) to lock the channel into open bursts was abolished by the I148T and G178R amino acid substitutions.

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Sentences [show]
No. Sentence Comment
106 However, only the mutations I148T, I175V, G178R, E193K, and R297Q allowed wild-type-like maturation of the protein to the fully glycosylated 170 kDa species (band C). Login to comment
120 In accordance with reduced levels of processing, the H139R, G149R, D192G, and R258G mutations significantly decreased the anion translocation capability of CFTR, whereas the properly processed I148T, I175V, and R297Q variants allowed iodide movement comparable to that of wild type. Login to comment
190 I148T, I175V, and R297Q did not adversely affect the processing, gating, or conductance of CFTR. Login to comment
199 The entire CFTR gene was not sequenced in patients with mutations I148T, I175V, or R297Q when these mutations were published. Login to comment

[hide] Missense mutation R1066C in the second transmembra... Hum Mutat. 1997;10(5):387-92. Casals T, Pacheco P, Barreto C, Gimenez J, Ramos MD, Pereira S, Pinheiro JA, Cobos N, Curvelo A, Vazquez C, Rocha H, Seculi JL, Perez E, Dapena J, Carrilho E, Duarte A, Palacio AM, Nunes V, Lavinha J, Estivill X
Missense mutation R1066C in the second transmembrane domain of CFTR causes a severe cystic fibrosis phenotype: study of 19 heterozygous and 2 homozygous patients.
Hum Mutat. 1997;10(5):387-92., [PMID:9375855]

Abstract [show]
We report the clinical features of 21 unrelated cystic fibrosis (CF) patients from Portugal and Spain, who carry the mutation R1066C in the CFTR gene. The current age of the patients was higher in the R1066C/any mutation group (P < 0.01), as compared to the deltaF508/deltaF508 group. Poor values for lung radiological involvement (Chrispin-Norman) and general status (Shwachman-Kulcycki) were observed in the R1066C/any mutation group (P < 0.005 and P < 0.0004). A slightly, but not significantly worse lung function was found in the R1066C/any mutation group when compared with the deltaF508/deltaF508 patients. No significant differences were detected regarding the age at diagnosis, sweat Cl-values, or percentiles of height and weight between the two groups. Neither were significant differences observed regarding sex, meconium ileus (4.7% vs. 11.1%), dehydration (10.5% vs. 14.7%), or pancreatic insufficiency (PI) (100% vs. 97.8%). The proportion of patients with lung colonization by bacterial pathogens was slightly, but not significantly higher in the R1066C/any mutation group (70.0%), as compared with the deltaF508/deltaF508 group (57.5%). Other clinical complications were significantly more frequent in the R1066C/any mutation patients(P < 0.02) than in the deltaF508/deltaF508 group. The two homozygous R1066C/R1066C patients died at the ages of 3 months and 7 years. The data presented in this study clearly demonstrate that the R1066C mutation is responsible for a severe phenotype similar to that observed in homozygous deltaF508 patients. The poor clinical scores and complications of patients with the R1066C mutation are probably related to their slightly longer survival.

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No. Sentence Comment
60 (Strong et al., 1991), E92K (Nunes et al., 1993), S549N (Curtis et al., 1993), I175V (Romey et al., 1994), A559T (McDowell et al., 1995), and G85E (Vázquez et al., 1996). Login to comment

[hide] Homozygosity for a novel missense mutation (I175V)... Hum Mol Genet. 1994 Apr;3(4):661-2. Romey MC, Desgeorges M, Malzac P, Sarles J, Demaille J, Claustres M
Homozygosity for a novel missense mutation (I175V) in exon 5 of the CFTR gene in a family of Armenian descent.
Hum Mol Genet. 1994 Apr;3(4):661-2., [PMID:7520799]

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10 Direct asymmetric sequencing of exon 5 using dideoxynucleotide chain termination method revealed an A to G transition at nucleotide 655 (Fig. lb), that replaces isoleucine by valine at codon 175 (1175V). Login to comment
17 Detection and identification of the substitution I175V. Login to comment
18 a. DGGE analysis of exon 5 of CFTR, showing the familial segregation of mutation I175V: the parents (lanes 2 and 3) are heterozygous (presence of heteroduplexes formed between complementary strands of the two alleles); the two affected daughters (lanes 4 and 5) arc homozygous for the mutated allele, which is situated at a lower position in the denaturing gel than the normal allele (lane 1, control DNA). Login to comment

[hide] Comparative ex vivo, in vitro and in silico analys... J Cyst Fibros. 2015 Feb 27. pii: S1569-1993(15)00039-9. doi: 10.1016/j.jcf.2015.02.002. Ramalho AS, Clarke LA, Sousa M, Felicio V, Barreto C, Lopes C, Amaral MD
Comparative ex vivo, in vitro and in silico analyses of a CFTR splicing mutation: Importance of functional studies to establish disease liability of mutations.
J Cyst Fibros. 2015 Feb 27. pii: S1569-1993(15)00039-9. doi: 10.1016/j.jcf.2015.02.002., [PMID:25735457]

Abstract [show]
The Cystic Fibrosis p.Ile1234Val missense mutation actually creates a new dual splicing site possibly used either as a new acceptor or donor. Here, we aimed to test the accuracy of in silico predictions by comparing them with in vitro and ex vivo functional analyses of this mutation for an accurate CF diagnosis/prognosis. To this end, we applied a new in vitro strategy using a CFTR mini-gene which includes the complete CFTR coding sequence plus intron 22 (short version) which allows the assessment of alternatively spliced mRNA levels as well as the properties of the resulting abnormal CFTR protein regarding processing, intracellular localization and function. Our data demonstrate that p.Ile1234Val leads to usage of the alternative splicing donor (but not acceptor) resulting in alternative CFTR transcripts lacking 18nts of exon 22 which produce a truncated CFTR protein with residual Cl- channel function. These results recapitulate data from native tissues of a CF patient. In conclusion, the existing in silico prediction models have limited application and ex vivo functional assessment of mutation effects should be made. Alternatively the in vitro strategy adopted here can be applied to assess the disease liability of mutations for an accurate CF diagnosis/prognosis.

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No. Sentence Comment
297 For these mutations we performed an analysis with the NNS software and found that 3 of these sites were recognized as splice sites, but only 2 (the GU created by the I175V and the GU created by I1234V) had higher scores than the normal splice site (see Table S14). Login to comment