Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_000535.7(PMS2):c.1876G>C(p.Ala626Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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]
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This missense variant replaces alanine with proline at codon 626 of the PMS2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with PMS2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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. This variant has not been reported in the literature in individuals affected with PMS2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 626 of the PMS2 protein (p.Ala626Pro). ClinVar contains an entry for this variant (Variation ID: 91319). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on PMS2 protein function. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.A626P variant (also known as c.1876G>C), located in coding exon 11 of the PMS2 gene, results from a G to C substitution at nucleotide position 1876. The alanine at codon 626 is replaced by proline, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -