Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate
The NM_000251.3(MSH2):c.367-5C>G variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,459,802 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to 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]
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Mar 02, 2023
Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. ClinVar contains an entry for this variant (Variation ID: 142907). This variant has not been reported in the literature in individuals affected with MSH2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 2 of the MSH2 gene. It does not directly change the encoded amino acid sequence of the MSH2 protein. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
May 21, 2024
The c.367-5C>G intronic variant results from a C to G substitution 5 nucleotides upstream from coding exon 3 in the MSH2 gene. This nucleotide position is not well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. RNA studies have demonstrated that this alteration results in an incomplete splice defect; the clinical impact of this abnormal splicing is unknown at this time (Ambry internal data). Based on the available evidence, the clinical significance of this variant remains unclear. -