rs755587950
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_000179.3(MSH6):c.2372G>A(p.Arg791His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.00000398 AC: 1AN: 250954Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135616
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461854Hom.: 0 Cov.: 34 AF XY: 0.00000413 AC XY: 3AN XY: 727230
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces arginine with histidine at codon 791 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/250954 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.R791H variant (also known as c.2372G>A), located in coding exon 4 of the MSH6 gene, results from a G to A substitution at nucleotide position 2372. The arginine at codon 791 is replaced by histidine, an amino acid with highly similar properties. This alteration was detected in a cohort of 72 cases of hereditary breast/ovarian cancer and 57 hereditary non-polyposis colorectal cancer patients in Spain (Velázquez C et al. J Transl Med, 2020 Jun;18:232). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
not specified Uncertain:1
Variant summary: MSH6 c.2372G>A (p.Arg791His) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS, core domain (IPR007696) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250954 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2372G>A has been reported in the literature in an individual who went through panel testing (35 genes) for inherited cancer (example: Valazquez_2020). This individual also had a pathogenic co-occurrence (PMS2 c.137G>T, p.Ser46Ile), providing supporting evidence for a benign role (example: Valazquez_2020). This report does 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. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all 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 arginine with histidine at codon 791 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/250954 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 has a deleterious effect on protein structure/function; Co-occurred with a pathogenic PMS2 variant in an individual with either hereditary breast/ovarian cancer or hereditary non-polyposis colorectal cancer (PMID: 32522261); This variant is associated with the following publications: (PMID: 32522261, 17531815, 21120944) -
Hereditary nonpolyposis colorectal neoplasms Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at