NM_000251.3:c.763A>G
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP3BP6
The NM_000251.3(MSH2):c.763A>G(p.Ser255Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000267 in 1,610,882 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).
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152164Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251290Hom.: 0 AF XY: 0.00000736 AC XY: 1AN XY: 135810
GnomAD4 exome AF: 0.0000288 AC: 42AN: 1458718Hom.: 0 Cov.: 29 AF XY: 0.0000262 AC XY: 19AN XY: 725856
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152164Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74362
ClinVar
Submissions by phenotype
Lynch syndrome Uncertain:1Benign:1
This missense variant replaces serine with glycine at codon 255 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). TThis variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold <= -1.32, PMID: 33357406). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 1/251290 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The MSH2 variant designated as NM_000251.2: c.763A>G (p.S255G) is classified as likely benign. Cosegregation analysis of one observed family was performed using analyze.myvariant.org (Rañola et al, 2018, PMID:28965303) and shows a likelihood ratio of 0.08 to 1 that this allele explains cancer in the family (Thompson, et al., 2003, PMID:2900794). Computer software prediction programs also suggest the MSH2 p.S255G change is benign. Additionally, in the observed family, the variant co-occurs with a likely pathogenic variant in the MSH6 gene (p.R1076C). Immunohistochemical studies of endometrial tumor from one family member with the variant showed loss of the MSH6 protein, but no loss of IHC staining for MSH2, which is consistent with the likely pathogenic variant in the MSH6 gene. Together, this information is not consistent with a pathogenic mutation in MSH2. Bayesian analysis integrating data (Tavtigian et al, 2018, PMID:29300386) gives less than 1% probability of pathogenicity, which is consistent with a classification of likely benign. This variant is not predicted to alter MSH2 function or modify risk for Lynch syndrome. This analysis was performed in conjunction with the family studies project as part of the University of Washington Find My Variant Study. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces serine with glycine at codon 255 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). TThis variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold <= -1.32, PMID: 33357406). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 1/251290 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Lynch syndrome 1 Benign:1
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 27363726]. -
Hereditary nonpolyposis colorectal neoplasms Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at