Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate
The NM_001322011.2(PMS2):c.-44G>A variant causes a 5 prime UTR premature start codon gain change. The variant allele was found at a frequency of 0.0000131 in 152,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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]
Review Status: criteria provided, single submitter
Collection Method: curation
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Mar 13, 2023
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.C297Y variant (also known as c.890G>A), located in coding exon 8 of the PMS2 gene, results from a G to A substitution at nucleotide position 890. The cysteine at codon 297 is replaced by tyrosine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Lynch syndrome Uncertain:1
Dec 18, 2023
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 cysteine with tyrosine at codon 297 of the PMS2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, 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
This variant has not been reported in the literature in individuals affected with PMS2-related conditions. 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. 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) performed at Invitae indicates that this missense variant is expected to disrupt PMS2 protein function. ClinVar contains an entry for this variant (Variation ID: 455747). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 297 of the PMS2 protein (p.Cys297Tyr). -