rs63750790
Variant summary
Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM5PP3
The NM_000251.3(MSH2):c.2064G>A(p.Met688Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,614,182 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. M688V) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152182Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000318 AC: 8AN: 251466Hom.: 0 AF XY: 0.0000221 AC XY: 3AN XY: 135908
GnomAD4 exome AF: 0.0000410 AC: 60AN: 1461882Hom.: 0 Cov.: 32 AF XY: 0.0000275 AC XY: 20AN XY: 727240
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152300Hom.: 0 Cov.: 32 AF XY: 0.0000268 AC XY: 2AN XY: 74488
ClinVar
Submissions by phenotype
Lynch syndrome 1 Uncertain:6
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
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not provided Uncertain:3
The frequency of this variant in the general population, 0.0021 (8/3814 chromosomes in Korean subpopulation, http://gnomad.broadinstitute.org), is higher than would generally be expected for pathogenic variants in this gene. In the published literature, the variant has been reported in individuals with polyps (PMID: 9559627 (1998)), colon cancer (PMID: 10777691 (2000), 23741719 (2013)), endometrial cancer (PMID: 14499697 (2003)), gastric cancer (PMID: 29050249 (2017)), breast cancer (PMID: 30093976 (2018), 33471991 (2021), 34570441 (2021)), and an unspecified cancer (PMID: 31386297 (2019)). Some of these individuals were suspected of hereditary non-polyposis colorectal cancer (HNPCC) (PMID: 9559627 (1998), 10777691 (2000), 14499697 (2003)), and Lynch Syndrome (PMID: 31386297 (2019)). However, this variant has also been reported in unaffected individuals (PMID: 15527911 (2004), 26332594 (2015), 33471991 (2021)). Functional studies of this variant on the effect of MSH2 protein function were inconclusive ((PMID: 17720936 (2007), 21309037 (2011), 22739024 (2012), 26951660 (2016), 33357406 (2021)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies are inconclusive: mixed results with respect to mismatch repair activity, protein stability, and binding ability (Gammie et al., 2007; Wielders et al., 2011; Martin-Lopez et al., 2012; Houlleberghs et al., 2016; Jia et al., 2020); Observed in individuals with colon cancer, gastric cancer, pancreatic, and other cancers, or hereditary non-polyposis colorectal cancer (HNPCC), as well as in healthy controls (Yuan et al., 1998; Nomura et al., 2000; Banno et al., 2004; Kim et al., 2017; Terashima et al., 2022; Scott et al., 2022; Okawa et al., 2023); This variant is associated with the following publications: (PMID: 24933000, 22039344, 29050249, 22949387, 31386297, 22739024, 17720936, 21309037, 9559627, 26951660, 23760103, 26332594, 15365995, 10777691, 23741719, 15527911, 25871441, 30093976, 31396961, 32566746, 33357406, 34570441, 34328007, 26206375, 22179786, 15075785, 14499697, 36135357, 18822302, 21120944, 36550560, 37559881, 36243179) -
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Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces methionine with isoleucine at codon 688 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. Experimental functional studies have demonstrated normal to intermediate impact in mismatch repair assays (PMID: 17720936, 21309037, 22739024, 26951660, 33357406) and normal interaction with MSH2, MSH6, and MLH1 (PMID: 21309037). This variant has been reported in individuals affected with colorectal, endometrial cancer (PMID: 9559627, 10777691, 14499697, 15365995), gastric cancer (PMID: 29050249), and esophageal cancer (PMID: 31396961) in the literature, but also in healthy individuals (PMID: 15527911). This variant has been identified in 8/251466 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 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. -
not specified Uncertain:1
Variant summary: MSH2 c.2064G>A (p.Met688Ile) results in a conservative amino acid change located in the C-terminal domain (IPR000432) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4.4e-05 in 252024 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in MSH2 causing Hereditary Nonpolyposis Colorectal Cancer (4.4e-05 vs 0.00057), allowing no conclusion about variant significance. c.2064G>A has been reported in the literature in multiple individuals/families affected with suspected Lynch Syndrome (e.g. Yuan_1998, Nomura_2000, Banno_2003, Shin_2004), but has also been reported in unaffected controls (e.g. Banno_2004, Olfson_2015). Two large case-control studies evaluating breast cancer genetic risk also reported this variant was not significantly enriched in the case cohorts (Dorling_2021, Okawa_2023). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer. At-least one co-occurrence with another pathogenic variant has been observed at our laboratory (BRCA2 c.1813delA, p.Ile605Tyrfs), providing supporting evidence for a benign role. Multiple publications report experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in an intermediate mismatch-repair phenotype in a yeast-based assay (Gammie_2007), however most subsequent reports indicate no overall damaging effects of the variant on mismatch repair function and ability to interact with its binding partner MSH6 (e.g. Wielders_2010, Martin-Lopez_2012, Houlleberghs_2016, Jia_2021). The following publications have been ascertained in the context of this evaluation (PMID: 14499697, 15527911, 30093976, 33471991, 17720936, 26951660, 33357406, 29050249, 31386297, 22739024, 10777691, 36243179, 26332594, 15365995, 21309037, 9559627, 23760103). At least one publication reports experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant. ClinVar contains an entry for this variant (Variation ID: 90875). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Lynch syndrome Uncertain:1
This missense variant replaces methionine with isoleucine at codon 688 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. Experimental functional studies have demonstrated normal to intermediate impact in mismatch repair assays (PMID: 17720936, 21309037, 22739024, 26951660, 33357406) and normal interaction with MSH2, MSH6, and MLH1 (PMID: 21309037). This variant has been reported in individuals affected with colorectal, endometrial cancer (PMID: 9559627, 10777691, 14499697, 15365995), gastric cancer (PMID: 29050249), and esophageal cancer (PMID: 31396961) in the literature, but also in healthy individuals (PMID: 15527911). This variant has been identified in 8/251466 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. -
Hereditary breast ovarian cancer syndrome Uncertain:1
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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