Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5
The NM_000251.3(MSH2):c.475dupA(p.Arg159LysfsTer19) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.
MSH2 (HGNC:7325): (mutS homolog 2) This locus is frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). When cloned, it was discovered to be a human homolog of the E. coli mismatch repair gene mutS, consistent with the characteristic alterations in microsatellite sequences (RER+ phenotype) found in HNPCC. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]
Verdict is Pathogenic. Variant got 11 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-47410201-G-GA is Pathogenic according to our data. Variant chr2-47410201-G-GA is described in ClinVar as [Pathogenic]. Clinvar id is 188513.Status of the report is no_assertion_criteria_provided, 0 stars.
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing
The p.Arg159LysfsX19 duplication was not identified in the literature but has been previously reported by our laboratory in several families with Lynch syndrome. It is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 159 and leads to a premature stop codon 19 codons downstream. This alteration is then predicted to result in a truncated or absent protein and loss of function. Loss of function variants of the MSH2 gene are an established mechanism of disease in Lynch syndrome. In summary, based on the above information, this variant is classified as pathogenic. -