Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_000251.3(MSH2):c.2458+3A>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).
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]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change falls in intron 14 of the MSH2 mRNA. It does not directly change the encoded amino acid sequence of the MSH2 protein. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a MSH2-related disease. Algorithms developed to predict the effect of nucleotide changes on mRNA splicing suggest that this intronic variant may alter mRNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, this is a novel intronic change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. -