rs41295268
Variant summary
Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PP3_ModerateBP6_Very_Strong
The NM_000179.3(MSH6):c.1403G>A(p.Arg468His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,613,978 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★★).
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -6 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152154Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000319 AC: 8AN: 251140Hom.: 0 AF XY: 0.0000295 AC XY: 4AN XY: 135724
GnomAD4 exome AF: 0.0000198 AC: 29AN: 1461824Hom.: 0 Cov.: 34 AF XY: 0.0000234 AC XY: 17AN XY: 727204
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152154Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74338
ClinVar
Submissions by phenotype
Lynch syndrome Uncertain:1Benign:1
This missense variant replaces arginine with histidine at codon 468 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). An in vitro DNA mismatch repair assay reported this variant to have wildtype repair activity (PMID: 31965077) while a selection screen for pathogenic MSH6 variants failed to detect this variant (PMID: 28531214). This variant has been reported in at least four individuals affected with colorectal cancer (PMID: 18033691, 18809606, 34172528) and in one individual affected with Lynch syndrome (PMID: 17854147). Two of these individuals, however, exhibited clinical features inconsistent with MSH6-associated cancer such as microsatellite stability and normal MSH6 immuno-histochemistry results (PMID: 18033691, 18809606). This variant has been identified in 8/251140 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. -
Multifactorial likelihood analysis posterior probability 0.001-0.049 -
not provided Uncertain:1Benign:1
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In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate MMR proficiency in a site-directed mutagenesis assay (PMID: 28531214); This variant is associated with the following publications: (PMID: 25637381, 19389263, 17854147, 18033691, 18809606, 23621914, 21153778, 28922847, 30798936, 32926152, 34426522, 2563738, 18067074, 35980532, 17531815, 21120944, 28531214, 36243179, 34326862) -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:1
This missense variant replaces arginine with histidine at codon 468 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). Functional studies have shown that this variant to have mismatch repair activity similar to wild type (PMID: 31965077). This variant has been reported in at least four individuals affected with colorectal cancer (PMID: 18033691, 18809606, 34172528) and in one individual affected with Lynch syndrome (PMID: 17854147). Two of these individuals, however, exhibited clinical features inconsistent with MSH6-associated cancer such as microsatellite stability and normal MSH6 immuno-histochemistry results (PMID: 18033691, 18809606). This variant has been identified in 8/251140 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. -
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. -
Colorectal cancer, non-polyposis Uncertain:1
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Lynch syndrome 5 Benign:1
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not specified Benign:1
Variant summary: MSH6 c.1403G>A (p.Arg468His) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS-like, N-terminal domain 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 3.2e-05 in 253156 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1403G>A has been reported in the literature in individuals affected with colorectal cancer (example, Hampel_2008, Houlleberghs_2017). At-least one of these reported a microsatellite stable (MSS) and MLH1+/MSH2+MSH6+ IHC profile (Barneston_2008). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer/Lynch syndrome. At least one publication reports experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant on MMR (mismatch repair) protein function (Houlleberghs_2017). Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (likely benign, n=2; benign, n=1; VUS, n=1). At-least one submitter report a likely benign outcome reports a non-specified co-occurrence with mutation in same gene (phase unknown) supporting their classification and cites overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as likely benign. -
MSH6-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
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