Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4
The NM_000535.7(PMS2):c.2506G>C(p.Glu836Gln) variant causes a missense change. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
PMS2 (HGNC:9122): (PMS1 homolog 2, mismatch repair system component) The protein encoded by this gene is a key component of the mismatch repair system that functions to correct DNA mismatches and small insertions and deletions that can occur during DNA replication and homologous recombination. This protein forms heterodimers with the gene product of the mutL homolog 1 (MLH1) gene to form the MutL-alpha heterodimer. The MutL-alpha heterodimer possesses an endonucleolytic activity that is activated following recognition of mismatches and insertion/deletion loops by the MutS-alpha and MutS-beta heterodimers, and is necessary for removal of the mismatched DNA. There is a DQHA(X)2E(X)4E motif found at the C-terminus of the protein encoded by this gene that forms part of the active site of the nuclease. Mutations in this gene have been associated with hereditary nonpolyposis colorectal cancer (HNPCC; also known as Lynch syndrome) and Turcot syndrome. [provided by RefSeq, Apr 2016]
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing
DNA sequence analysis of the PMS2 gene demonstrated a sequence change, c.2506G>C, in exon 15 that results in an amino acid change, p.Glu836Gln. This sequence change does not appear to have been previously described in individuals with PMS2-related disorders and has also not been described in population databases such as ExAC and gnomAD. The p.Glu836Gln change affects a moderately conserved amino acid residue located in a domain of the PMS2 protein that is not known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Glu836Gln substitution. Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Glu836Gln change remains unknown at this time. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 836 of the PMS2 protein (p.Glu836Gln). The frequency data for this variant in the population databases (gnomAD) is considered unreliable due to the presence of homologous sequence, such as pseudogenes or paralogs, in the genome. This variant has not been reported in the literature in individuals affected with PMS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 2443220). Invitae Evidence Modeling incorporating data from in vitro experimental studies (internal data) indicates that this missense variant is not expected to disrupt PMS2 function with a negative predictive value of 95%. 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. -