Submissions for variant NM_000251.3(MSH2):c.433A>G (p.Ile145Val)

dbSNP: rs876659264

Total submissions: 8

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Ambry Genetics	RCV000221599	SCV000275515	likely benign	Hereditary cancer-predisposing syndrome	2022-04-06	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	RCV000465648	SCV000548200	uncertain significance	Hereditary nonpolyposis colorectal neoplasms	2023-10-23	criteria provided, single submitter	clinical testing	This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 145 of the MSH2 protein (p.Ile145Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MSH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 231613). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 80%. Experimental studies have shown that this missense change does not substantially affect MSH2 function (PMID: 33357406). 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.
GeneDx	RCV000483760	SCV000573440	uncertain significance	not provided	2017-02-17	criteria provided, single submitter	clinical testing	This variant is denoted MSH2 c.433A>G at the cDNA level, p.Ile145Val (I145V) at the protein level, and results in the change of an Isoleucine to a Valine (ATT>GTT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MSH2 Ile145Val was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Isoleucine and Valine share similar properties, this is considered a conservative amino acid substitution. MSH2 Ile145Val occurs at a position that is not conserved and is located in the connector domain (Lützen 2008). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether MSH2 Ile145Val is a pathogenic or benign variant. We consider it to be a variant of uncertain significance.
Counsyl	RCV000662917	SCV000785860	uncertain significance	Lynch syndrome 1	2017-12-19	criteria provided, single submitter	clinical testing
Color Diagnostics, LLC DBA Color Health	RCV000221599	SCV000904859	uncertain significance	Hereditary cancer-predisposing syndrome	2023-02-01	criteria provided, single submitter	clinical testing	This missense variant replaces isoleucine with valine at codon 145 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). To our knowledge, this variant has not been reported in individuals affected with MSH2-related disorders in the literature. 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.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000780457	SCV000917720	uncertain significance	not specified	2018-11-30	criteria provided, single submitter	clinical testing	Variant summary: MSH2 c.433A>G (p.Ile145Val) results in a conservative amino acid change in the encoded protein sequence. Four of four in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 246238 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.433A>G in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
Myriad Genetics, Inc.	RCV000662917	SCV004018228	uncertain significance	Lynch syndrome 1	2023-03-16	criteria provided, single submitter	clinical testing	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.
All of Us Research Program, National Institutes of Health	RCV003997912	SCV004830244	uncertain significance	Lynch syndrome	2023-06-28	criteria provided, single submitter	clinical testing	This missense variant replaces isoleucine with valine at codon 145 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). To our knowledge, this variant has not been reported in individuals affected with MSH2-related disorders in the literature. 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.