ABCMdb

ABCC7 p.Glu56Lys

Admin's notes:	Class II-III (maturation defect, gating defect) Veit et al.
ClinVar:	c.166G>A , p.Glu56Lys ? , not provided
CF databases:	c.166G>A , p.Glu56Lys D , CF-causing ; CFTR1: Missense mutation E56K was identified in a German CBAVD patient heterozygous for this mutation and for [delta]F508.
Predicted by SNAP2:	A: N (72%), C: N (72%), D: N (72%), F: N (72%), G: N (57%), H: N (78%), I: N (66%), K: N (61%), L: N (72%), M: N (72%), N: N (72%), P: D (53%), Q: N (82%), R: N (61%), S: N (72%), T: N (72%), V: N (78%), W: N (53%), Y: N (82%),
Predicted by PROVEAN:	A: N, C: D, D: N, F: D, G: N, H: N, I: D, K: N, L: D, M: D, N: N, P: D, Q: N, R: N, S: N, T: N, V: D, W: D, Y: N,

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

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

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

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79 The E56K mutation was found in a German CBAVD patient who carried ∆F508 on the maternal allele and E56K on the paternal allele. Login to comment
86 The V938G substitution was identified in two unrelated patients, one homozygote with unilateral ab- 368 Table 1A Frequency distribution and haplotypes of CFTR mutations in 106 CAVD patients Mutationa Nucleotide changesb Locationc Frequencyd Haplotypee Referencef 174delA deletion of A at 174 exon 1 1 D3 This study E56K G→A at 298 exon 3 1 B3 This study D58N G→A at 304 exon 3 1 C2 This study D110H G→A at 460 exon 4 2 C2 Dean et al. (1990) R117H G→A at 482 exon 4 24 B6 Dean et al. (1990) A120T G→A at 490 exon 4 1 n.p. Chillón et al. (1994) ̃L138 insertion of CTA after 546 exon 4 1 A2 This study L206W T→G at 749 exon 6a 1 B8 Claustres et al. (1993) M265R T→G at 926 exon 6b 1 A2 Schwarz et al. (pers. comm.) R297W C→T at 1021 exon 7 1 C2 This study 1078delT deletion of T at 1078 exon 7 1 C2 Claustres et al. (1992) R334W C→T at 1132 exon 7 1 B1 Gasparini et al. (1991) R334L G→T at 1133 exon 7 1 D3 This study I336K T→A at 1139 exon 7 1 A2 Cuppens et al. (1993) R347H G→A at 1172 exon 7 3 D1 Cremonesi et al. (1992) L375F A→C at 1257 exon 8 1 B3 Jézéquel et al. (1996) ∆F508 deletion of 3 bp between 1652-1655 exon 10 57 B1 Kerem et al. (1989) G542X G→T at 1756 exon 11 2 B1 Kerem et al. (1990) R553X C→T at 1789 exon 11 1 A4 Cutting et al. (1990) L568F G→T at 1836 exon 12 1 B3 This study 2184insA insertion of A at 2184 exon 13 1 D3 Dörk et al. (1994b) 2789+5 G→A G→A at 2789+5 intron 14b 4 D3 Highsmith et al. (1997) R933S A→T at 2931 exon 15 1 n.p. Login to comment
137 Complex alleles are indicated a One CF allele with R75X and 125G→C b One CBAVD allele with R75Q and R933S c One CBAVD allele with 5T and Q1352H d Two CF alleles with F508C and S1251N e One CF allele with 1716G→A and L619S f G576A and R668C were linked on two CBAVD and three CF alleles, whereas two additional CF alleles carried R668C together with the 3849+10kB C→T mutation (Dörk and Stuhrmann 1995) 371 Table 3 CFTR mutation genotypes in 106 males with CAVD Genotype PolyT Frequency Ethnic descent Diagnosis ∆F508/R117H 9/7 21 German, Austrian 20 CBAVD, 1 CUAVD ∆F508/5T 9/5 9 German, Austrian 8 CBAVD, 1 CUAVD ∆F508/F508C 9/7 3 German CBAVD ∆F508/R347H 9/9 2 German CBAVD ∆F508/1716 G→A 9/7 2 German CBAVD ∆F508/3272-26 A→G 9/7 2 German CBAVD ∆F508/E56K 9/7 1 German CBAVD ∆F508/M265R 9/7 1 German-Portuguese CBAVD ∆F508/R334W 9/9 1 German CBAVD ∆F508/T351S 9/9 1 German CBAVD ∆F508/L375F 9/7 1 Volga German CBAVD ∆F508/G576A & R668C 9/7 1 German CBAVD ∆F508/R933S 9/7 1 German CBAVD ∆F508/L997F 9/9 1 German CBAVD ∆F508/Y1032C 9/7 1 German CBAVD ∆F508/D1152H 9/7 1 German CBAVD ∆F508/K1351E 9/7 1 German CBAVD ∆F508/D1377H 9/7 1 Portuguese CBAVD ∆F508/L1388Q 9/7 1 German CBAVD ∆F508/unknown 9/7 4 German 3 CBAVD, 1 CUAVD 5T/5T 5/5 2 German CBAVD 5T/G542X 5/9 2 German, Turkish CBAVD 5T/D58N 5/7 1 Lebanese CBAVD 5T/̃L138 5/7 1 German-Polish CBAVD 5T/1078delT 5/7 1 German CBAVD 5T/R553X 5/7 1 German CBAVD 5T/2184insA 5/7 1 Turkish CBAVD 5T/D979A 5/7 1 Vietnamese CBAVD 5T/D1152H 5/7 1 Turkish CBAVD 5T/3659delC 5/7 1 German CBAVD 5T/S1235R 5/7 1 Greek CBAVD 5T/W1282X 5/7 1 German CBAVD 5T & Q1352H/ R297W & Q1352H 5/7 1 Vietnamese CBAVD 5T/unknown 5/7 1 German CBAVD R117H/L206W 7/9 1 German CBAVD R117H/2789+5 G→A 7/7 1 German CBAVD R117H/unknown 7/7 1 German CBAVD 2789+5 G→A/2789+5 G→A 7/7 1 Lebanese CBAVD 2789+5 G→A/L973F 7/7 1 German CBAVD V938G/V938G 7/7 1 Greek CBAVD V938G/174delA 7/7 1 German CBAVD D110H/D110H 7/7 1 Turkish CBAVD R334L/I336K 7/7 1 German CBAVD R347H/N1303K 9/9 1 German CBAVD L568F/D1152H 7/7 1 Turkish CBAVD 3272-26 A→G/V1153E 7/7 1 German CBAVD R75Q/unknown 7/7 1 German CBAVD A120T/unknown 9/7 1 German CBAVD 1716G→A/unknown 7/7 1 German CBAVD G576A & R668C/unknown 7/7 1 German CBAVD 2752-15 C→G/unknown 7/7 1 Iranian CBAVD Unknown/unknown 17 German, Turkish 7 CBAVD and 1 CUAVD without observed renal agenesis, 9 CBAVD with renal agenesis allele and the R297W mutation on a homozygous Q1352H background may then reduce CFTR function to a disease-causing level. Login to comment
144 Lung function tests indicated initial pulmonary deterioration in a few cases (FEV1 forced expiratory volume in 1 s, given as percent predicted) Subject Age Genotype Height Weight Sweat C1- Symptoms (years) (cm) (kg) (mM) 1 33 ∆F508/R117H 172 75 46 Dyspnoe 2 37 ∆F508/R117H 178 83 31 Nasal polyposis 3 31 ∆F508/R117H 181 91 n.d. Nasal polyposis 4 32 R117H/unknown 164 70 33 Recurrent infections 5 33 ∆F508/E56K 193 100 85 Sinusitis, recurrent bronchitis 6 31 ∆F508/M265R 192 112 59 Recurrent infections, pancreatitis 7 33 ∆F508/R334W 182 78 n.d. Recurrent infections, pneumonia 8 28 ∆F508/R347H n.d. n.d. n.d. Recurrent infections 9 32 ∆F508/F508C 192 98 32 Pneumonia 10 34 ∆F508/Y1032C n.d. n.d. n.d. Recurrent bronchitis 11 33 ∆F508/3272-26 A→G 172 82 125 Recurrent infections, maldigestion, FEVI 73% 12 28 ∆F508/unknown 185 95 n.d. Login to comment

[hide] Effect of ivacaftor on CFTR forms with missense mu... J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23. Van Goor F, Yu H, Burton B, Hoffman BJ
Effect of ivacaftor on CFTR forms with missense mutations associated with defects in protein processing or function.
J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23., [PMID:23891399]

Abstract [show]
BACKGROUND: Ivacaftor (KALYDECO, VX-770) is a CFTR potentiator that increased CFTR channel activity and improved lung function in patients age 6 years and older with CF who have the G551D-CFTR gating mutation. The aim of this in vitro study was to evaluate the effect of ivacaftor on mutant CFTR protein forms with defects in protein processing and/or channel function. METHODS: The effect of ivacaftor on CFTR function was tested in electrophysiological studies using a panel of Fischer rat thyroid (FRT) cells expressing 54 missense CFTR mutations that cause defects in the amount or function of CFTR at the cell surface. RESULTS: Ivacaftor potentiated multiple mutant CFTR protein forms that produce functional CFTR at the cell surface. These included mutant CFTR forms with mild defects in CFTR processing or mild defects in CFTR channel conductance. CONCLUSIONS: These in vitro data indicated that ivacaftor is a broad acting CFTR potentiator and could be used to help stratify patients with CF who have different CFTR genotypes for studies investigating the potential clinical benefit of ivacaftor.

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43 Mutations such as P67L-, E56K-, and A455E-CFTR exhibited intermediate levels of mature CFTR, which are consistent with less severe defects in CFTR processing (mature CFTR protein for P67L-, E56K-, and A455E-CFTR were 28.4&#b1; 6.8, 12.2&#b1;1.5, and 11.5&#b1;2.5% of normal, respectively). Login to comment
44 None M1V A46D E56K P67L R74W G85E E92K D110E D110H R117C R117H E193K L206W R334W I336K T338I S341P R347H R347P R352Q A455E L467P S492F F508del V520F A559T R560S R560T A561E Y569D D579G R668C L927P S945L S977F L997F F1052V H1054D K1060T L1065P R1066C R1066H R1066M A1067T R1070Q R1070W F1074L L1077P H1085R M1101K D1152H S1235R D1270N N1303K 0 100 200 300 400 500 600 * * * CFTR Mutation mRNA (% Normal CFTR) Fig. 1. Login to comment
64 Mutant CFTR form CFTR processing Mature/total % Normal CFTR Normal 0.89 &#b1; 0.01 100.0 &#b1; 18.5 G85E -0.05 &#b1; 0.04 -1.0 &#b1; 0.9 R560S 0.00 &#b1; 0.00 0.0 &#b1; 0.0 R1066C 0.02 &#b1; 0.01 0.0 &#b1; 0.0 S492F 0.00 &#b1; 0.00 0.1 &#b1; 0.1 R560T 0.01 &#b1; 0.01 0.2 &#b1; 0.1 V520F 0.05 &#b1; 0.03 0.3 &#b1; 0.2 M1101K 0.05 &#b1; 0.03 0.3 &#b1; 0.1 A561E 0.08 &#b1; 0.04 0.5 &#b1; 0.2 R1066M 0.02 &#b1; 0.02 0.5 &#b1; 0.4 N1303K 0.02 &#b1; 0.02 0.5 &#b1; 0.3 A559T 0.16 &#b1; 0.09 0.6 &#b1; 0.2 M1V 0.06 &#b1; 0.06 0.7 &#b1; 0.6 Y569D 0.11 &#b1; 0.04 0.6 &#b1; 0.2 R1066H 0.08 &#b1; 0.02a 0.7 &#b1; 0.2a L1065P 0.05 &#b1; 0.05 1.0 &#b1; 0.8 L467P 0.10 &#b1; 0.07 1.2 &#b1; 0.8 L1077P 0.08 &#b1; 0.04 1.5 &#b1; 0.6 A46D 0.21 &#b1; 0.08 1.9 &#b1; 0.5a E92K 0.06 &#b1; 0.05 1.9 &#b1; 1.3 H1054D 0.09 &#b1; 0.04 1.9 &#b1; 0.8 F508del 0.09 &#b1; 0.02a 2.3 &#b1; 0.5a H1085R 0.06 &#b1; 0.01a 3.0 &#b1; 0.7a I336K 0.42 &#b1; 0.05a 6.5 &#b1; 0.7a L206W 0.35 &#b1; 0.10a 6.8 &#b1; 1.7a F1074L 0.52 &#b1; 0.03a 10.9 &#b1; 0.6a A455E 0.26 &#b1; 0.10a 11.5 &#b1; 2.5a E56K 0.29 &#b1; 0.04a 12.2 &#b1; 1.5a R347P 0.48 &#b1; 0.04a 14.6 &#b1; 1.8a R1070W 0.61 &#b1; 0.04a 16.3 &#b1; 0.6a P67L 0.36 &#b1; 0.04a 28.4 &#b1; 6.8a R1070Q 0.90 &#b1; 0.01a 29.5 &#b1; 1.4a S977F 0.97 &#b1; 0.01a 37.3 &#b1; 2.4a A1067T 0.78 &#b1; 0.03a 38.6 &#b1; 6.1a D579G 0.72 &#b1; 0.02a 39.3 &#b1; 3.1a D1270N 1.00 &#b1; 0.00a,c 40.7 &#b1; 1.2a S945L 0.65 &#b1; 0.04a 42.4 &#b1; 8.9a L927P 0.89 &#b1; 0.01a,b 43.5 &#b1; 2.5a,b R117C 0.87 &#b1; 0.02a,b 49.1 &#b1; 2.9a,b T338I 0.93 &#b1; 0.03a,b 54.2 &#b1; 3.7a,b L997F 0.90 &#b1; 0.04a,b 59.8 &#b1; 10.4a,b D110H 0.97 &#b1; 0.01a,b 60.6 &#b1; 1.5a,b S341P 0.79 &#b1; 0.02a 65.0 &#b1; 4.9a,b R668C 0.94 &#b1; 0.03a,b 68.5 &#b1; 1.9a,b R74W 0.78 &#b1; 0.01a 69.0 &#b1; 2.7a,b D110E 0.92 &#b1; 0.05a,b 87.5 &#b1; 9.5a,b R334W 0.91 &#b1; 0.05a,b 97.6 &#b1; 10.0a,b K1060T 0.87 &#b1; 0.02a,b 109.9 &#b1; 28.0a,b R347H 0.96 &#b1; 0.02a,c 120.7 &#b1; 2.8a,b S1235R 0.96 &#b1; 0.00a,c 139.0 &#b1; 9.0a,b E193K 0.84 &#b1; 0.02a,b 143.0 &#b1; 17.1a,b R117H 0.86 &#b1; 0.01a,b 164.5 &#b1; 34.2a,b R352Q 0.98 &#b1; 0.01a,b 179.9 &#b1; 8.0a,c F1052V 0.90 &#b1; 0.01a,b 189.9 &#b1; 33.1a,b D1152H 0.96 &#b1; 0.02a,c 312.0 &#b1; 45.5a,b Notes to Table 1: Quantification of steady-state CFTR maturation expressed as the mean (&#b1;SEM; n = 5-9) ratio of mature CFTR to total CFTR (immature plus mature) or level of mature mutant CFTR relative to mature normal-CFTR (% normal CFTR) in FRT cells individually expressing CFTR mutations. Login to comment
74 Because the level of CFTR mRNA was similar across the panel of cell lines tested, the range in baseline activity and ivacaftor response likely reflects the severity of the functional defect and/or the 0 50 100 150 200 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L E56K P67L R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V Baseline With ivacaftor * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Chloride transport (% Normal) Mutant CFTR form 0 100 200 300 400 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L P67L E56K R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Mature CFTR (% Normal) Mutant CFTR form A B Fig. 2. Login to comment
82 Mutation Patientsa Chloride transport (bc;A/cm2 ) Chloride transport (% normal) EC50 Baseline With ivacaftor Baseline With ivacaftor Fold increase over baselineb Normal 204.5 &#b1; 33.3 301.3 &#b1; 33.8c 100.0 &#b1; 16.3 147.3 &#b1; 16.5c 1.5 266 &#b1; 42 G551D 1282 1.5 &#b1; 0.7 113.2 &#b1; 13.0c 1.0 &#b1; 0.5 55.3 &#b1; 6.3c 55.3 312 &#b1; 73 F1052V 12 177.3 &#b1; 13.7 410.2 &#b1; 11.3c 86.7 &#b1; 6.7 200.7 &#b1; 5.6c 2.3 177 &#b1; 14 S1235R ND 160.6 &#b1; 25.7 352.1 &#b1; 43.4c 78.5 &#b1; 12.6 172.2 &#b1; 21.2c 2.2 282 &#b1; 104 D1152H 185 117.3 &#b1; 23.0 282.7 &#b1; 46.9c 57.4 &#b1; 11.2 138.2 &#b1; 22.9c 2.4 178 &#b1; 67 D1270N 32 109.5 &#b1; 20.5 209.5 &#b1; 27.4c 53.6 &#b1; 10.0 102.4 &#b1; 13.4c 1.9 254 &#b1; 56 R668C 45 99.0 &#b1; 9.4 217.6 &#b1; 11.7c 48.4 &#b1; 4.6 106.4 &#b1; 5.7c 2.2 517 &#b1; 105 K1060T ND 89.0 &#b1; 9.8 236.4 &#b1; 20.3c 43.5 &#b1; 4.8 115.6 &#b1; 9.9c 2.7 131 &#b1; 73 R74W 25 86.8 &#b1; 26.9 199.1 &#b1; 16.8c 42.5 &#b1; 13.2 97.3 &#b1; 8.2c 2.3 162 &#b1; 17 R117H 739 67.2 &#b1; 13.3 274.1 &#b1; 32.2c 32.9 &#b1; 6.5 134.0 &#b1; 15.7c 4.1 151 &#b1; 14 E193K ND 62.2 &#b1; 9.8 379.1 &#b1; 1.1c 30.4 &#b1; 4.8 185.4 &#b1; 1.0c 6.1 240 &#b1; 20 A1067T ND 55.9 &#b1; 3.2 164.0 &#b1; 9.7c 27.3 &#b1; 1.6 80.2 &#b1; 4.7c 2.9 317 &#b1; 214 L997F 27 43.7 &#b1; 3.2 145.5 &#b1; 4.0c 21.4 &#b1; 1.6 71.2 &#b1; 2.0c 3.3 162 &#b1; 12 R1070Q 15 42.0 &#b1; 0.8 67.3 &#b1; 2.9c 20.6 &#b1; 0.4 32.9 &#b1; 1.4c 1.6 164 &#b1; 20 D110E ND 23.3 &#b1; 4.7 96.4 &#b1; 15.6c 11.4 &#b1; 2.3 47.1 &#b1; 7.6c 4.1 213 &#b1; 51 D579G 21 21.5 &#b1; 4.1 192.0 &#b1; 18.5c 10.5 &#b1; 2.0 93.9 &#b1; 9.0c 8.9 239 &#b1; 48 D110H 30 18.5 &#b1; 2.2 116.7 &#b1; 11.3c 9.1 &#b1; 1.1 57.1 &#b1; 5.5c 6.2 249 &#b1; 59 R1070W 13 16.6 &#b1; 2.6 102.1 &#b1; 3.1c 8.1 &#b1; 1.3 49.9 &#b1; 1.5c 6.2 158 &#b1; 48 P67L 53 16.0 &#b1; 6.7 88.7 &#b1; 15.7c 7.8 &#b1; 3.3 43.4 &#b1; 7.7c 5.6 195 &#b1; 40 E56K ND 15.8 &#b1; 3.1 63.6 &#b1; 4.4c 7.7 &#b1; 1.5 31.1 &#b1; 2.2c 4.0 123 &#b1; 33 F1074L ND 14.0 &#b1; 3.4 43.5 &#b1; 5.4c 6.9 &#b1; 1.6 21.3 &#b1; 2.6c 3.1 141 &#b1; 19 A455E 120 12.9 &#b1; 2.6 36.4 &#b1; 2.5c 6.3 &#b1; 1.2 17.8 &#b1; 1.2c 2.8 170 &#b1; 44 S945L 63 12.3 &#b1; 3.9 154.9 &#b1; 47.6c 6.0 &#b1; 1.9 75.8 &#b1; 23.3c 12.6 181 &#b1; 36 S977F 9 11.3 &#b1; 6.2 42.5 &#b1; 19.1c 5.5 &#b1; 3.0 20.8 &#b1; 9.3c 3.8 283 &#b1; 36 R347H 65 10.9 &#b1; 3.3 106.3 &#b1; 7.6c 5.3 &#b1; 1.6 52.0 &#b1; 3.7c 9.8 280 &#b1; 35 L206W 81 10.3 &#b1; 1.7 36.4 &#b1; 2.8c 5.0 &#b1; 0.8 17.8 &#b1; 1.4c 3.6 101 &#b1; 13 R117C 61 5.8 &#b1; 1.5 33.7 &#b1; 7.8c 2.9 &#b1; 0.7 16.5 &#b1; 3.8c 5.7 380 &#b1; 136 R352Q 46 5.5 &#b1; 1.0 84.5 &#b1; 7.8c 2.7 &#b1; 0.5 41.3 &#b1; 3.8c 15.2 287 &#b1; 75 R1066H 29 3.0 &#b1; 0.3 8.0 &#b1; 0.8c 1.5 &#b1; 0.1 3.9 &#b1; 0.4c 2.6 390 &#b1; 179 T338I 54 2.9 &#b1; 0.8 16.1 &#b1; 2.4c 1.4 &#b1; 0.4 7.9 &#b1; 1.2c 5.6 334 &#b1; 38 R334W 150 2.6 &#b1; 0.5 10.0 &#b1; 1.4c 1.3 &#b1; 0.2 4.9 &#b1; 0.7c 3.8 259 &#b1; 103 G85E 262 1.6 &#b1; 1.0 1.5 &#b1; 1.2 0.8 &#b1; 0.5 0.7 &#b1; 0.6 NS NS A46D ND 2.0 &#b1; 0.6 1.1 &#b1; 1.1 1.0 &#b1; 0.3 0.5 &#b1; 0.6 NS NS I336K 29 1.8 &#b1; 0.2 7.4 &#b1; 0.1c 0.9 &#b1; 0.1 3.6 &#b1; 0.1c 4 735 &#b1; 204 H1054D ND 1.7 &#b1; 0.3 8.7 &#b1; 0.3c 0.8 &#b1; 0.1 4.2 &#b1; 0.1c 5.3 187 &#b1; 20 F508del 29,018 0.8 &#b1; 0.6 12.1 &#b1; 1.7c 0.4 &#b1; 0.3 5.9 &#b1; 0.8c 14.8 129 &#b1; 38 M1V 9 0.7 &#b1; 1.4 6.5 &#b1; 1.9c 0.4 &#b1; 0.7 3.2 &#b1; 0.9c 8.0 183 &#b1; 85 E92K 14 0.6 &#b1; 0.2 4.3 &#b1; 0.8c 0.3 &#b1; 0.1 2.1 &#b1; 0.4c 7.0 198 &#b1; 46 V520F 58 0.4 &#b1; 0.2 0.5 &#b1; 0.2 0.2 &#b1; 0.1 0.2 &#b1; 0.1 NS NS H1085R ND 0.3 &#b1; 0.2 2.1 &#b1; 0.4 0.2 &#b1; 0.1 1.0 &#b1; 0.2 NS NS R560T 180 0.3 &#b1; 0.3 0.5 &#b1; 0.5 0.1 &#b1; 0.1 0.2 &#b1; 0.2 NS NS L927P 15 0.2 &#b1; 0.1 10.7 &#b1; 1.7c 0.1 &#b1; 0.1 5.2 &#b1; 0.8c 52.0 313 &#b1; 66 R560S ND 0.0 &#b1; 0.1 -0.2 &#b1; 0.2 0.0 &#b1; 0.0 -0.1 &#b1; 0.1 NS NS N1303K 1161 0.0 &#b1; 0.0 1.7 &#b1; 0.3 0.0 &#b1; 0.0 0.8 &#b1; 0.2 NS NS M1101K 79 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1077P 42 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066M ND 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066C 100 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1065P 25 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS Y569D 9 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS A561E ND 0.0 &#b1; 0.1 0.0 &#b1; 0.1 0.0 &#b1; 0.0 0.0 &#b1; 0.1 NS NS A559T 43 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S492F 16 0.0 &#b1; 0.0 1.7 &#b1; 1.2 0.0 &#b1; 0.0 0.8 &#b1; 0.6 NS NS L467P 16 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R347P 214 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S341P 9 0.0 &#b1; 0.0 0.2 &#b1; 0.2 0.0 &#b1; 0.0 0.1 &#b1; 0.1 NS NS a Number of individuals with the individual mutation in the CFTR-2 database (www.CFTR2.org). Login to comment
86 For example, the baseline level of chloride transport and ivacaftor response was higher for mutant CFTR forms associated with mild defects in CFTR processing (e.g., E56K, P67L, L206W, A455E, D579G, S945L, S977F, A1067T, R1070Q, R1070W, F1074L, and D1270N) than for those associated with severe defects in CFTR processing (e.g., F508del, H1054D, R1066H). Login to comment
92 Mutant CFTR forms that did not significantly respond to ivacaftor under the experimental conditions used in this study were generally associated with severe defects in CFTR processing A B C D E F 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 S1235R D1152H F1052V D1270N ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R668C K1060T R74W R117H ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 E193K A1067T L997F R1070Q ivacaftor [Log M] Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 D110E D579G D110H R1070W ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F1074L E56K P67L A455E ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R347H S945L L206W S977F ivacaftor [Log M] 0 100 200 300 400 -8 -6 -4 0 T338I R1066H R117C R352Q ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K ivacaftor [Log M] 0 5 10 15 20 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K R1066H T338I ivacaftor [Log M] G H I Fig. 3. Login to comment

[hide] VX-809 corrects folding defects in cystic fibrosis... Mol Biol Cell. 2013 Oct;24(19):3016-24. doi: 10.1091/mbc.E13-05-0240. Epub 2013 Aug 7. Ren HY, Grove DE, De La Rosa O, Houck SA, Sopha P, Van Goor F, Hoffman BJ, Cyr DM
VX-809 corrects folding defects in cystic fibrosis transmembrane conductance regulator protein through action on membrane-spanning domain 1.
Mol Biol Cell. 2013 Oct;24(19):3016-24. doi: 10.1091/mbc.E13-05-0240. Epub 2013 Aug 7., [PMID:23924900]

Abstract [show]
Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domain, and its channel assembly requires multiple interdomain contacts. The most common CF-causing mutation, F508del, occurs in NBD1 and results in misfolding and premature degradation of F508del-CFTR. VX-809 is an investigational CFTR corrector that partially restores CFTR function in people who are homozygous for F508del-CFTR. To identify the folding defect(s) in F508del-CFTR that must be repaired to treat CF, we explored the mechanism of VX-809 action. VX-809 stabilized an N-terminal domain in CFTR that contains only MSD1 and efficaciously restored function to CFTR forms that have missense mutations in MSD1. The action of VX-809 on MSD1 appears to suppress folding defects in F508del-CFTR by enhancing interactions among the NBD1, MSD1, and MSD2 domains. The ability of VX-809 to correct F508del-CFTR is enhanced when combined with mutations that improve F508del-NBD1 interaction with MSD2. These data suggest that the use of VX-809 in combination with an additional CFTR corrector that suppresses folding defects downstream of MSD1 may further enhance CFTR function in people with F508del-CFTR.

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60 There are several CF-associated mutations in MSD1 that cause defects in CFTR processing and function: N-terminal tail (E56K and P67L), TM1 (E92K), TM2 (L206W), and TM4 (V232D) (Figure 4, A-E). Login to comment
196 D. E92K F508 -B C -B C VX-809 0 3 10 30 M CFTR CFTR B17 15 14 17 C0 25 66 95 B18 30 28 27 C 1 8 9 8 % Norm VX-809 0 3 10 30 M C-100 1 81 1 83 N.D. 24 5 78 100 N.D. 15 B14 4 6 4 7 1 1 6 12 16 3 2 C. B11 10 11 12 C 1 1 1 7 VX-809 0 3 10 30 M -B C F508 CFTR E92K % Norm % Norm E. VX-809 0 50 100 150 200 250 -10 -9 -8 -7 -6 -5 -4 Chloride Transport ( A/cm 2 ) VX-809 (Log M) E92K-CFTR Normal 0 50 100 150 200 250 DMSO VX-809 Corr-4a Chloride Transport ( A/cm2) E92K-CFTR 0 100 200 300 400 E56K P67L E92K L206W V232V dF508 I SC ( A/cm 2 ) DMSO VX-809 Normal VX-809 on MSD1 has potential to promote high-level functional correction of CFTR in people with CF who harbor mutations other than F508del (Bobadilla et al., 2002). Login to comment

[hide] Ivacaftor: a review of its use in patients with cy... Drugs. 2013 Sep;73(14):1595-604. doi: 10.1007/s40265-013-0115-2. Deeks ED
Ivacaftor: a review of its use in patients with cystic fibrosis.
Drugs. 2013 Sep;73(14):1595-604. doi: 10.1007/s40265-013-0115-2., [PMID:24030637]

Abstract [show]
Ivacaftor (Kalydeco) is a potentiator of the cystic fibrosis transmembrane conductance regulator (CFTR) and is the first drug that treats an underlying cause of cystic fibrosis to be licensed for use. Ivacaftor increases the open probability (i.e. gating) of CFTR channels with the G551D mutation, thus enhancing chloride transport, and is indicated in a number of countries for the treatment of cystic fibrosis in patients aged >/=6 years who carry this mutation. This review focuses on pharmacological, clinical efficacy and tolerability data relevant to the use of ivacaftor in this indication. In two 48-week, double-blind, phase III trials in patients aged >/=12 (STRIVE) or 6-11 (ENVISION) years with cystic fibrosis and the G551D mutation, oral ivacaftor 150 mg every 12 h significantly improved lung function relative to placebo, when used in combination with standard care. Significant improvements in pulmonary exacerbation risk (in STRIVE) as well as bodyweight and some aspects of health-related quality of life (both studies) were also seen with the drug versus placebo. Moreover, the beneficial effects of ivacaftor on parameters such as lung function and bodyweight were maintained over up to 96 weeks of treatment in an ongoing open-label extension of these studies. Ivacaftor was generally well tolerated, with headache, oropharyngeal pain, upper respiratory tract infection and nasal congestion being among the most common adverse events. Thus, ivacaftor expands the current treatment options for patients with cystic fibrosis who have the G551D mutation. Its potential for use in patients with other CFTR mutations is also of interest.

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36 Further in vitro data suggest that other CFTR proteins with residual function may also be potentiated by ivacaftor, including those with mutations that affect conductance (e.g. R117H, D110H), mildly affect CFTR processing (e.g. E56K, P67L) or have uncharacterized effects (e.g. D110E, S1235R) [5, 16]. 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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363 [72G>C;164+2T>G] uncertain: CF-PI and/or CF-PS L24F nd; 296+2T>G nd R31C c.91C>T CFTR-RD non CF-causing p.Arg31Cys S42F c.125C>T uncertain: found only with an unknown allele in trans nd p.Ser42Phe E56G c.167G>A CBAVD nd p.Glu56Lys [R74W;V201M;D1270N] c. Login to comment