Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong
The NM_000535.7(PMS2):c.1450C>T(p.Pro484Ser) 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. 15/21 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]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant is denoted PMS2 c.1450C>T at the cDNA level, p.Pro484Ser (P484S) at the protein level, and results in the change of a Proline to a Serine (CCT>TCT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PMS2 Pro484Ser was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Proline and Serine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. PMS2 Pro484Ser occurs at a position that is not conserved and is not located in a known functional domain (Guarne 2001, Fukui 2011). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether PMS2 Pro484Ser is pathogenic or benign. We consider it to be a variant of uncertain significance. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.P484S variant (also known as c.1450C>T), located in coding exon 11 of the PMS2 gene, results from a C to T substitution at nucleotide position 1450. The proline at codon 484 is replaced by serine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -