2-47410103-G-A
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_000251.3(MSH2):c.376G>A(p.Gly126Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,396 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 Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152132Hom.: 0 Cov.: 31
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 251056Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135676
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461264Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 726902
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152132Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74302
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
The p.G126S variant (also known as c.376G>A), located in coding exon 3 of the MSH2 gene, results from a G to A substitution at nucleotide position 376. The glycine at codon 126 is replaced by serine, an amino acid with similar properties. This alteration was detected in conjunction with a pathogenic MSH2 mutation (phase unknown) in an Italian individual meeting Amsterdam I criteria, whose tumor demonstrated microsatellite instability and loss of MSH2 protein expression (De Lellis L et al. PLoS ONE, 2013 Nov;8:e81194). This alteration has also been detected in a Hispanic patient diagnosed with a Lynch syndrome-associated cancer (Sunga AY et al. Cancer Genet. 2017 Apr;212-213:1-7). In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was reported to be functionally neutral (Jia X et al. Am J Hum Genet, 2021 01;108:163-175). 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 variant remains unclear. -
This missense variant replaces glycine with serine at codon 126 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). This 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 been reported in an individual affected with Lynch syndrome, whose tumor data demonstrated high microsatellite instability (PMID: 33357406). However, this individual also carried another MSH2 variant (phase not specified) that could explain the observed phenotype. This variant has been identified in 1/251056 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. -
Lynch syndrome 1 Uncertain:1Benign:1
This variant is considered likely benign. This variant has been observed in conjunction with multiple pathogenic variants, reducing the likelihood this variant itself is pathogenic. -
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Lynch syndrome Uncertain:1
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not provided Uncertain:1
Published functional studies suggest a neutral effect: demonstrates sensitivity to 6-TG and mismatch repair (MMR) function similar to wild-type (PMID: 33357406); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 24278394, 28449805, 18822302, 21120944, 33357406) -
Hereditary nonpolyposis colorectal neoplasms Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 126 of the MSH2 protein (p.Gly126Ser). This variant is present in population databases (rs767371843, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 24278394, 28449805). ClinVar contains an entry for this variant (Variation ID: 186849). Invitae Evidence Modeling incorporating data from in vitro experimental studies (internal data) did not meet the statistical confidence thresholds required to predict the impact of this variant on MSH2 function. 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. -
Muir-Torré syndrome;C2936783:Lynch syndrome 1;C5399763:Mismatch repair cancer syndrome 1 Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at