7-117611637-C-T
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000492.4(CFTR):c.3196C>T(p.Arg1066Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,613,374 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1066H) has been classified as Pathogenic.
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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CFTR | NM_000492.4 | c.3196C>T | p.Arg1066Cys | missense_variant | Exon 20 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000658 AC: 10AN: 152080Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.0000319 AC: 8AN: 250882Hom.: 0 AF XY: 0.0000443 AC XY: 6AN XY: 135590
GnomAD4 exome AF: 0.0000171 AC: 25AN: 1461294Hom.: 0 Cov.: 31 AF XY: 0.0000138 AC XY: 10AN XY: 726942
GnomAD4 genome AF: 0.0000658 AC: 10AN: 152080Hom.: 0 Cov.: 31 AF XY: 0.0000269 AC XY: 2AN XY: 74278
ClinVar
Submissions by phenotype
Cystic fibrosis Pathogenic:12
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The p.R1066C pathogenic mutation (also known as c.3196C>T and 3328C>T), located in coding exon 20 of the CFTR gene, results from a C to T substitution at nucleotide position 3196. The arginine at codon 1066 is replaced by cysteine, an amino acid with highly dissimilar properties. In one study, this mutation was identified in 21 individuals with a severe phenotype, including pancreatic insufficiency and moderate to severe pulmonary disease. Nineteen individuals were compound heterozygous for a pathogenic mutation on the other allele and two unrelated individuals were homozygous for this mutation (Casals T et al. Hum. Mutat., 1997;10:387-92). This mutation results in defective biosynthesis and processing of the CFTR protein (Fanen P et al. J. Biol. Chem., 1997 Nov;272:30563-6). This mutation is associated with elevated sweat chloride levels and pancreatic insufficiency (Sosnay PR et al. Nat. Genet., 2013 Oct;45:1160-7). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
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ACMG classification criteria: PS3 supporting, PM2 supporting, PM3 very strong, PP3 supporting -
NM_000492.3(CFTR):c.3196C>T(R1066C) is classified as pathogenic in the context of cystic fibrosis and is associated with the classic form of this disease. Sources cited for classification include the following: PMID 23974870, 9375855 and 9374552. Classification of NM_000492.3(CFTR):c.3196C>T(R1066C) is based on the following criteria: This is a well-established pathogenic variant in the literature that has been observed more frequently in patients with clinical diagnoses than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
The c.3196C>T (p.Arg1066Cys) in the CFTR gene has been reported in homozygous state in individuals affected with cystic fibrosis (Alonso MJ. et al., 2007). Experimental studies have shown that this missense change severely disrupts CFTR protein processing and biosynthesis in vitro (Van Goor F. et al., 2014). This variant is reported with the allele frequency (0.003%) in the gnomad and novel in 1000 genome database. It has been submitted to ClinVar as a Pathogenic variant. The amino acid Arginine at position 1066 is changed to a Cysteine changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted to be damaging by both SIFT and PolyPhen2. The residue is conserved across species. For these reasons, this variant has been classified as Pathogenic. -
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1066 of the CFTR protein (p.Arg1066Cys). This variant is present in population databases (rs78194216, gnomAD 0.006%). This missense change has been observed in individuals with cystic fibrosis or congenital absence of the vas deferens (PMID: 10923036, 11883825, 15084222, 17331079, 21520337, 23302613, 23974870). This variant is also known as 3328C>T. ClinVar contains an entry for this variant (Variation ID: 7162). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CFTR protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects CFTR function (PMID: 8662892, 8702904, 9374552, 15480987, 23891399, 23974870). For these reasons, this variant has been classified as Pathogenic. -
Well-established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product (PMID: 9374552) - PS3. The c.3196C>T;p.(Arg1066Cys) missense change has been observed in affected individual(s) and ClinVar contains an entry for this variant (Clinvar ID 7162; PMID: 9375855; PMID: 25697318; PMID: 27022295) -PS4. The variant is present at low allele frequencies population databases (rs78194216 – gnomAD 0.0003189%; ABraOM no frequency - http://abraom.ib.usp.br.) - PM2_supporting. The p.(Arg1066Cys) was detected in trans with a pathogenic variant (PMID: 9375855) - PM3. Pathogenic missense variant in this residue have been reported (Clinvar ID 7158) - PM5. The variant co-segregated with disease in multiple affected family members (PMID: 9375855 - PP1. Multiple lines of computational evidence support a deleterious effect on the gene or gene product - PP3. In summary, the currently available evidence indicates that the variant is pathogenic -
Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -
Variant summary: The CFTR c.3196C>T (p.Arg1066Cys) missense variant located in the ABC transporter type 1, transmembrane domain (via InterPro) involves the alteration of a conserved nucleotide and is predicted to be damaging by 4/4 in silico tools.This variant was found in 9/223414 control chromosomes at a frequency of 0.0000403, which does not exceed the estimated maximal expected allele frequency of a pathogenic CFTR variant (0.0129603). In literature, this variant is recurrently reported in CF patients, primarily in compound heterozygous state with p.Phe508del and is regarded as a severe mutation with consistent clinical and functional outcome (Fanen_1992, Fanen_1997, Sosnay_2013, Van Goor_2013, Dupuis_2015). In a large study that included CF patients from Europe and North America, the allele frequency of this variant was 0.15% (122/79,392 CF chromosomes) (Sosnay_2013). It leads to defective CFTR processing and the drug, ivacaftor, was unable to increase chloride channel function in an in vitro assay (Van Goor_2013), implicating therapeutic importance in patients carrying this variant. Other missense changes at the same residue, namely R1066H, R1066S, and R1066L, have been reported in association with CF indicating that R1066 residue is a mutational hot-spot. Multiple clinical diagnostic laboratories/reputable databases have classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
not provided Pathogenic:8
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In the published literature, the variant has been reported as compound heterozygous and homozygous in individuals with classic CF (PMIDs: 32539862 (2020), 9475107 (1998), 9375855 (1997), 1379210 (1992)). Additionally, several functional studies indicated this variant causes defective CFTR protein processing and abnormal chloride channel function (PMIDs: 23891399 (2014), 15480987 (2004), 9374552 (1997), 8702904 (1996)). Based on the available information, this variant is classified as pathogenic. -
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not specified Pathogenic:1
The CFTR c.3196C>T; p.Arg1066Cys variant (rs78194216) is reported to cause pancreatic insufficient (PI) cystic fibrosis (CF) in individuals homozygous for this variant or compound heterozygous with a second PI CF-causing variant on the opposite chromosome (CFTR2 database, Casals 1997, Liang 1998). Functional analysis shows that p.Arg1066Cys results in a nonfunctional CFTR protein (Sosnay 2013). This variant is reported as pathogenic in ClinVar (Variation ID: 7162). It is found in the general population with an overall allele frequency of 0.003% (8/250882 alleles) in the Genome Aggregation Database. The arginine at codon 1066 is highly conserved and computational analyses (SIFT, PolyPhen-2) predict that this variant is deleterious. Based on available information, this variant is considered to be pathogenic. REFERENCES CFTR2 database: https://cftr2.org/ Casals T et al. 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. Liang MH et al. Cystic fibrosis in a Puerto Rican female homozygous for the R1066C mutation. J Med Genet. 1998 Jan;35(1):84-5. Sosnay PR et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet. 2013 Oct;45(10):1160-7. -
CFTR-related disorder Pathogenic:1
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Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
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Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
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Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at