rs773790621
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2
The NM_000492.4(CFTR):c.766A>G(p.Ser256Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000256 in 1,599,070 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S256S) has been classified as Likely benign.
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: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CFTR | NM_000492.4 | c.766A>G | p.Ser256Gly | missense_variant | Exon 7 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152220Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000520 AC: 12AN: 230864 AF XY: 0.0000803 show subpopulations
GnomAD4 exome AF: 0.0000276 AC: 40AN: 1446850Hom.: 0 Cov.: 31 AF XY: 0.0000376 AC XY: 27AN XY: 718730 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152220Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74364 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Cystic fibrosis Uncertain:2
The p.S256G variant (also known as c.766A>G), located in coding exon 7 of the CFTR gene, results from an A to G substitution at nucleotide position 766. The serine at codon 256 is replaced by glycine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This sequence change replaces serine, which is neutral and polar, with glycine, which is neutral and non-polar, at codon 256 of the CFTR protein (p.Ser256Gly). This variant is present in population databases (rs773790621, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with CFTR-related conditions. ClinVar contains an entry for this variant (Variation ID: 582520). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
CFTR-related disorder Uncertain:1
- -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at