Our verdict is Likely benign. Variant got -1 ACMG points: 0P and 1B. BP4
The ENST00000265849.12(PMS2):c.1048C>T(p.Leu350Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,611,922 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L350I) has been classified 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]
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Jun 02, 2021
This missense variant replaces leucine with phenylalanine at codon 350 of the PMS2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 hereditary cancer 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. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Jan 25, 2024
The p.L350F variant (also known as c.1048C>T), located in coding exon 10 of the PMS2 gene, results from a C to T substitution at nucleotide position 1048. The leucine at codon 350 is replaced by phenylalanine, an amino acid with highly similar properties. This variant was observed in 1/3251 individuals who met eligibility criteria for hereditary breast and ovarian cancer syndrome (Lerner-Ellis J et al. J Cancer Res Clin Oncol, 2021 Mar;147:871-879). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -
Lynch syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
All of Us Research Program, National Institutes of Health
Oct 30, 2023
This missense variant replaces leucine with phenylalanine at codon 350 of the PMS2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 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 hereditary cancer 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. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Quest Diagnostics Nichols Institute San Juan Capistrano
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Dec 28, 2023
This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 350 of the PMS2 protein (p.Leu350Phe). This variant is not present in population databases (gnomAD no frequency). 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: 142991). 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. 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. -
Malignant tumor of breast Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
Department of Pathology and Laboratory Medicine, Sinai Health System
-
The PMS2 p.Leu350Phe variant was not identified in the literature. The variant was also identified in dbSNP (ID: rs587782875) as "With Uncertain significance allele" and in ClinVar (classified as uncertain significance by Invitae and Ambry Genetics). The variant was not identified in the following control databases: the Exome Aggregation Consortium (August 8th 2016) or the Genome Aggregation Database (Feb 27, 2017). The p.Leu350 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Lynch syndrome 4 Uncertain:1
Uncertain significance, criteria provided, single submitter