chr7-117531047-C-A
Variant summary
Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PM2PP2PP3_StrongPP5
The NM_000492.4(CFTR):c.422C>A(p.Ala141Asp) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,613,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A141P) has been classified as Uncertain significance.
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
Publications
- cystic fibrosisInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
- congenital bilateral absence of vas deferensInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary chronic pancreatitisInheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 10 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.422C>A | p.Ala141Asp | missense_variant | Exon 4 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152120Hom.: 0 Cov.: 32 show subpopulations
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461488Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 727018 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152120Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74296 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Cystic fibrosis Pathogenic:3Uncertain:1Other:1
Variant summary: CFTR c.422C>A (p.Ala141Asp) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250646 control chromosomes. c.422C>A has been observed in individuals affected with Cystic Fibrosis including as a compound heterozygous or unknown genotype (e.g., Claustres_2000, Gouya_1997, Kambouris_2000, Petrova_2018). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately 1.7% of normal chloride channel conductance relative to wild type (e.g., Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 38388235, 10923036, 9222768, 10834512, 32429104). ClinVar contains an entry for this variant (Variation ID: 53924). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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This CFTR variant is absent from large population datasets. This variant is present in ClinVar by one submitter, however a classification was not provided. Multiple patients have been reported to carry this variant along with a second disease-causing CFTR variant; in one of these cases the variants were confirmed to be on opposite chromosomes (in trans). Of two bioinformatics tools queried, one predicts that the substitution would be possibly damaging, while the second predicts that it would be tolerated. The alanine residue at this position is highly evolutionarily conserved across most species assessed. We consider this variant likely pathogenic. -
This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 141 of the CFTR protein (p.Ala141Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 9222768, 30548586, 32429104). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 53924). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
The p.A141D variant (also known as c.422C>A), located in coding exon 4 of the CFTR gene, results from a C to A substitution at nucleotide position 422. The alanine at codon 141 is replaced by aspartic acid, an amino acid with dissimilar properties. This alteration has been identified in multiple individuals diagnosed with cystic fibrosis (Gouya L et al. Hum Mutat, 1997;10:86-7; Kambouris M et al. Eur J Pediatr, 2000 May;159:303-9; Petrova NV et al. Genes (Basel), 2020 May;11:). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at