Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate
The ENST00000265849.12(PMS2):c.320G>C(p.Arg107Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R107W) has been classified as Likely pathogenic.
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]
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-6003724-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 127789.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=5, Pathogenic=1, Uncertain_significance=1}.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.917
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Oct 31, 2018
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Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Sep 22, 2022
The p.R107P variant (also known as c.320G>C), located in coding exon 4 of the PMS2 gene, results from a G to C substitution at nucleotide position 320. The arginine at codon 107 is replaced by proline, an amino acid with 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. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
Sep 01, 2016
This variant is denoted PMS2 c.320G>C at the cDNA level, p.Arg107Pro (R107P) at the protein level, and results in the change of an Arginine to a Proline (CGG>CCG). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. PMS2 Arg107Pro 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 Arginine and Proline differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. PMS2 Arg107Pro occurs at a position that is conserved across species and is located within the ATPase domain (Guarne 2001, Fukui 2011). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether PMS2 Arg107Pro is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -