rs587779264
Variant summary
Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PP3_StrongPP5_Very_Strong
The NM_000179.3(MSH6):c.3469G>A(p.Gly1157Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,822 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 pathogenic (★★).
Frequency
Consequence
NM_000179.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461822Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 727220
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Lynch syndrome 5 Pathogenic:1
This variant is considered likely pathogenic. Functional studies indicate this variant impacts protein function [PMID: 32849802]. This variant is expected to disrupt protein structure [Myriad internal data]. -
Inherited MMR deficiency (Lynch syndrome) Pathogenic:1
PS3_Supporting,PM2_Supporting,PP3,PP4_Strong -
not provided Pathogenic: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; Published functional studies demonstrate significant decrease in mismatch repair activity (Thompson et al., 2020); This variant is associated with the following publications: (PMID: 23621914, 24323032, 17531815, 21120944, 32849802) -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1157 of the MSH6 protein (p.Gly1157Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of MSH6-related conditions and/or colon cancer (PMID: 24323032, 32849802; internal data). ClinVar contains an entry for this variant (Variation ID: 89393). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MSH6 protein function with a positive predictive value of 95%. This variant disrupts the p.Gly1157 amino acid residue in MSH6. Other variant(s) that disrupt this residue have been determined to be pathogenic (internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The p.G1157S variant (also known as c.3469G>A), located in coding exon 6 of the MSH6 gene, results from a G to A substitution at nucleotide position 3469. The glycine at codon 1157 is replaced by serine, an amino acid with similar properties. This variant has been identified in a proband whose Lynch syndrome-associated tumor demonstrated normal mismatch repair protein expression by immunohistochemistry (IHC); however, this variant has also been identified in multiple probands whose Lynch syndrome-associated tumor demonstrated loss of MSH6 expression by IHC (Buchanan DD et al. J Clin Oncol, 2014 Jan;32:90-100; Ambry internal data; External laboratory data). In a functional study, this variant demonstrated deficient mismatch repair activity in an in vitro complementation assay (Thompson BA et al. Front Genet, 2020 Jul;11:798; Drost M et al. Genet Med, 2020 05;22:847-856). Based on internal structural analysis, G1157S is highly destabilizing to the local structure (Warren JJ et al. Mol Cell, 2007 May;26:579-92; Ambry internal data). Another alteration at the same codon, p.G1157C (c.3469G>T), has been identified in several individuals whose Lynch-associated tumor demonstrated high microsatellite instability (MSI-H) and/or isolated loss of MSH6 protein expression on IHC (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Lynch syndrome 4 Pathogenic:1
The MSH6 c.3469G>A (p.Gly1157Ser) variant has been reported in at least two individuals affected with colon and endometrial cancers (Buchanan DD et al., PMID: 24323032; Thompson BA et al., PMID: 32849802). This variant is absent from the general population (gnomAD v.2.1.1), indicating it is not a common variant. Functional studies show a decrease in mismatch repair activity, indicating that this variant impacts protein function (Thompson BA et al., PMID: 32849802). Furthermore, examination of protein expression by immunohistochemistry shows loss of MSH6 with this variant (Buchanan DD et al., PMID: 24323032). Other variants at this same codon, c.3470G>A (p.Gly1157Asp) and c.3469G>T (p.Gly1157Cys), have been reported in affected individuals in internal databases at Invitae and Ambry (ClinVar Variation IDs: 619540, 142773). Computational predictors indicate that the variant is damaging, evidence that correlates with impact to MSH6 function. Based on available information and the ACMG/AMP guidelines for variant interpretation (Richards S et al., PMID: 25741868), this variant is classified as likely pathogenic. -
not specified Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at