2-47482870-A-T
Variant summary
Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP6
The NM_000251.3(MSH2):c.2726A>T(p.Lys909Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,318 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. K909Q) has been classified as Likely benign.
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: Likely_benign. The variant received -1 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  0.00000657  AC: 1AN: 152234Hom.:  0  Cov.: 33 show subpopulations 
GnomAD4 exome  AF:  0.00000821  AC: 12AN: 1461084Hom.:  0  Cov.: 31 AF XY:  0.00000963  AC XY: 7AN XY: 726798 show subpopulations 
Age Distribution
GnomAD4 genome  0.00000657  AC: 1AN: 152234Hom.:  0  Cov.: 33 AF XY:  0.00  AC XY: 0AN XY: 74372 show subpopulations  ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. 
ClinVar
Submissions by phenotype
Lynch syndrome 1    Uncertain:2Benign:1 
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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]. -
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
Hereditary cancer-predisposing syndrome    Uncertain:1Benign:1 
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. -
This missense variant replaces lysine with isoleucine at codon 909 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). Functional studies have shown that this variant does not affect MSH2 mismatch repair activity in an in vitro mismatch repair efficiency assay (PMID: 22581703) and 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 individuals affected with colorectal cancer, with tumor samples showing microsatellite instability (PMID: 15872200, 22581703) and with one individual having normal MSH2 and MSH6 protein expression but lack of MLH1 protein expression via immunohistochemistry (PMID: 22581703). This variant has not been identified 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 specified    Uncertain:1 
Variant summary: MSH2 c.2726A>T (p.Lys909Ile) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250502 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2726A>T has been reported in the literature at least one individual affected with colorectal cancer (e.g. Hampel_2005, Kantelinen_2012). These report(s) do not provide unequivocal conclusions about association of the variant with Lynch Syndrome. At least two publications report experimental evidence evaluating an impact on protein function (Kantelinen_2012, Jia_2020) and both showed no damaging effect of this variant on mismatch repair capability versus the WT protein. The following publications have been ascertained in the context of this evaluation (PMID: 22581703, 33357406, 15872200). ClinVar contains an entry for this variant (Variation ID: 216359). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Lynch syndrome    Uncertain:1 
This missense variant replaces lysine with isoleucine at codon 909 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). Functional studies have shown that this variant does not affect MSH2 mismatch repair activity in an in vitro mismatch repair efficiency assay (PMID: 22581703) and 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 individuals affected with colorectal cancer, with tumor samples showing microsatellite instability (PMID: 15872200, 22581703) and with one individual having normal MSH2 and MSH6 protein expression but lack of MLH1 protein expression via immunohistochemistry (PMID: 22581703). This variant has not been identified 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 
Published functional studies demonstrate no damaging effect (Kantelinen et al., 2012; Jia et al., 2020); Not observed in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Observed in an individual with colorectal cancer who also carried an MSH6 variant and whose tumor displayed microsatellite instability (MSI-H), absence of MLH1 protein and presence of MSH2 and MSH6 proteins by immunohistochemistry (IHC) (Hampel et al., 2005); This variant is associated with the following publications: (PMID: 19389263, 22581703, 22179786, 18822302, 21120944, 27873144, 9774676, 30267214, 15872200, 33357406) -
Hereditary nonpolyposis colorectal neoplasms    Uncertain:1 
This sequence change replaces lysine, which is basic and polar, with isoleucine, which is neutral and non-polar, at codon 909 of the MSH2 protein (p.Lys909Ile). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with colorectal cancer (PMID: 15872200, 22581703). ClinVar contains an entry for this variant (Variation ID: 216359). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect MSH2 function (PMID: 22581703). 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. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at