NM_000251.3:c.2649T>G
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_000251.3(MSH2):c.2649T>G(p.Ile883Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,494 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. I883V) has been classified as Uncertain significance.
Frequency
Consequence
NM_000251.3 missense
Scores
Clinical Significance
Conservation
Publications
- Lynch syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
- Lynch syndrome 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- Muir-Torre syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
- mismatch repair cancer syndrome 1Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- mismatch repair cancer syndrome 2Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- ovarian cancerInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- malignant pancreatic neoplasmInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- prostate cancerInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- breast cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH2 | NM_000251.3 | c.2649T>G | p.Ile883Met | missense_variant | Exon 16 of 16 | ENST00000233146.7 | NP_000242.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MSH2 | ENST00000233146.7 | c.2649T>G | p.Ile883Met | missense_variant | Exon 16 of 16 | 1 | NM_000251.3 | ENSP00000233146.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152252Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000797 AC: 2AN: 250902 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461242Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 726908 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152252Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74390 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces isoleucine with methionine at codon 883 of the MSH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). This variant has intermediate MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold -1.32 < LOF score < 0.88, PMID: 33357406). This variant has been reported in individuals affected with Lynch syndrome (PMID: 25110875, 29442399), however, in one of these individuals this variant co-occurred with another potentially pathogenic MSH2 variant (PMID: 29442399). This variant has been identified in 3/282316 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 p.I883M variant (also known as c.2649T>G), located in coding exon 16 of the MSH2 gene, results from a T to G substitution at nucleotide position 2649. The isoleucine at codon 883 is replaced by methionine, an amino acid with highly similar properties. This alteration has been identified in an individual with an MSI-high colorectal cancer diagnosed at age 38 year and a metachronous endometrial cancer diagnosed at age 41 years showing loss of MSH2 on immunohistochemistry (Bae S et al. Korean J Obstet Gynecol 2012;55(11):870-873). This variant has also been identified in a large unselected colorectal cancer cohort (Sinn D et al. Hepatogastroenterology 2009;56(91-92):672-6), and in a cohort of 1135 Chinese patients with gastric cancer (Zhang C et al. J Med Genet, 2023 Aug;60:760-768). 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 well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear.
not specified Uncertain:1
Variant summary: MSH2 c.2649T>G (p.Ile883Met) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.1e-05 in 276876 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2649T>G has been reported in the literature in an individual affected with Lynch Syndrome (Kang 2015, Lee 2018). These reports do not provide unequivocal conclusions about association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and both laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Lynch syndrome Uncertain:1
This missense variant replaces isoleucine with methionine at codon 883 of the MSH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). This variant has intermediate MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold -1.32 < LOF score < 0.88, PMID: 33357406). This variant has been reported in individuals affected with Lynch syndrome (PMID: 25110875, 29442399), however, in one of these individuals this variant co-occurred with another potentially pathogenic MSH2 variant (PMID: 29442399). This variant has been identified in 3/282316 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.
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in individuals with MSH2-related cancers, including one individual with tumor studies consistent with pathogenic variants in this gene (Zhu 2013, Kang 2015, Lee 2018); This variant is associated with the following publications: (PMID: 19621678, 23760103, 27873144, 18822302, 9774676, 25110875, 29442399)
Muir-Torré syndrome;C2936783:Lynch syndrome 1;C5436806:Mismatch repair cancer syndrome 2 Uncertain:1
Hereditary nonpolyposis colorectal neoplasms Benign:1
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at