Submissions for variant NM_000251.3(MSH2):c.1484C>T (p.Thr495Ile)

gnomAD frequency: 0.00001  dbSNP: rs756516114

Total submissions: 5

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Ambry Genetics	RCV000164768	SCV000215444	likely benign	Hereditary cancer-predisposing syndrome	2022-04-27	criteria provided, single submitter	clinical testing	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.
Invitae	RCV000167935	SCV000218583	likely benign	Hereditary nonpolyposis colorectal neoplasms	2023-12-29	criteria provided, single submitter	clinical testing
GeneDx	RCV000486548	SCV000566431	uncertain significance	not provided	2015-04-30	criteria provided, single submitter	clinical testing	This variant is denoted MSH2 c.1484C>T at the cDNA level, p.Thr495Ile (T495I) at the protein level, and results in the change of a Threonine to an Isoleucine (ACA>ATA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MSH2 Thr495Ile was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Threonine and Isoleucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. MSH2 Thr495Ile occurs at a position that is not conserved and is located within the clamp domain (Lutzen 2008). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available information, it is unclear whether MSH2 Thr495Ile is pathogenic or benign. We consider it to be a variant of uncertain significance.
Color Diagnostics, LLC DBA Color Health	RCV000164768	SCV001343690	uncertain significance	Hereditary cancer-predisposing syndrome	2023-04-26	criteria provided, single submitter	clinical testing	This missense variant replaces threonine with isoleucine at codon 495 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 a Lynch syndrome family, however, a pathogenic variant in MSH6 was also identified that could explain the observed phenotype (PMID: 27601186). This variant has been identified in 2/251298 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.
All of Us Research Program, National Institutes of Health	RCV003995363	SCV004833452	uncertain significance	Lynch syndrome	2023-06-26	criteria provided, single submitter	clinical testing	This missense variant replaces threonine with isoleucine at codon 495 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 a Lynch syndrome family, however, a pathogenic variant in MSH6 was also identified that could explain the observed phenotype (PMID: 27601186). This variant has been identified in 2/251298 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.