Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate
The ENST00000265849.12(PMS2):c.1952A>G(p.Lys651Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000236 in 1,612,432 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. K651N) 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
Myriad Genetics, Inc.
Apr 04, 2023
This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -
Uncertain significance, criteria provided, single submitter
clinical testing
Baylor Genetics
Mar 05, 2024
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Uncertain significance, criteria provided, single submitter
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Nov 16, 2023
This missense variant replaces lysine with arginine at codon 651 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 been identified in 3/250440 chromosomes 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
Sep 19, 2023
The p.K651R variant (also known as c.1952A>G), located in coding exon 11 of the PMS2 gene, results from an A to G substitution at nucleotide position 1952. The lysine at codon 651 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species; however, arginine is the reference amino acid in other 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. -
Breast and/or ovarian cancer Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Sep 20, 2021
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Lynch syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
All of Us Research Program, National Institutes of Health
Dec 13, 2023
This missense variant replaces lysine with arginine at codon 651 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 been identified in 3/250440 chromosomes 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
GeneDx
Jul 04, 2024
In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as germline pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 17016615, 33004033, 32368696, 35939113, 11292842) -
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Dec 18, 2023
This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 651 of the PMS2 protein (p.Lys651Arg). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 237896). 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 not expected to disrupt PMS2 protein function with a negative predictive value of 80%. 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
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The PMS2 p.Lys651Arg variant was identified in 5 of 40 proband chromosomes (frequency: 0.125) from individuals or families with breast cancer (Balogh 2006). The variant was also identified in dbSNP (ID: rs267608167) as “With Uncertain significance allele”, ClinVar (as uncertain significance by Invitae, Ambry Genetics, and Counsyl, and as likely benign by Color). The variant was identified in control databases in 4 of 276286 chromosomes at a frequency of 0.000014 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: European (Non-Finnish) in 2 of 126486 chromosomes (freq: 0.000016), Ashkenazi Jewish in 1 of 10082 chromosomes (freq: 0.000099), and European (Finnish) in 1 of 25788 chromosomes (freq: 0.000039), while the variant was not observed in the African, Other, Latino, East Asian, and South Asian populations. The p.Lys651 residue is conserved in mammals but not in more distantly related organisms however four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; this information is not predictive enough to rule out 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. -