Submissions for variant NM_000179.3(MSH6):c.233G>A (p.Arg78Lys)

gnomAD frequency: 0.00001  dbSNP: rs864622425

Total submissions: 6

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Invitae	RCV000203940	SCV000260605	uncertain significance	Hereditary nonpolyposis colorectal neoplasms	2023-01-29	criteria provided, single submitter	clinical testing	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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MSH6 protein function. ClinVar contains an entry for this variant (Variation ID: 220220). This variant has not been reported in the literature in individuals affected with MSH6-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 78 of the MSH6 protein (p.Arg78Lys).
Ambry Genetics	RCV000561944	SCV000676110	uncertain significance	Hereditary cancer-predisposing syndrome	2022-09-21	criteria provided, single submitter	clinical testing	The p.R78K variant (also known as c.233G>A), located in coding exon 1 of the MSH6 gene, results from a G to A substitution at nucleotide position 233. The arginine at codon 78 is replaced by lysine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Cancer Genomics Group, Japanese Foundation For Cancer Research	RCV001030487	SCV001193641	uncertain significance	Hereditary breast ovarian cancer syndrome	2019-05-01	criteria provided, single submitter	research
Illumina Laboratory Services, Illumina	RCV001139580	SCV001299753	uncertain significance	Lynch syndrome 5	2018-01-12	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV001174583	SCV001337762	uncertain significance	not specified	2020-01-10	criteria provided, single submitter	clinical testing	Variant summary: MSH6 c.233G>A (p.Arg78Lys) results in a conservative amino acid change located in the PWWP domain (IPR000313) of the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 60512 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.233G>A in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two 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.
All of Us Research Program, National Institutes of Health	RCV003997624	SCV004837701	uncertain significance	Lynch syndrome	2023-11-02	criteria provided, single submitter	clinical testing	This missense variant replaces arginine with lysine at codon 78 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MSH6-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.