Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000535.7(PMS2):c.58C>T(p.Arg20Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000546 in 1,610,668 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. R20Q) has been classified as Benign.
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
Counsyl
Nov 09, 2016
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Uncertain significance, criteria provided, single submitter
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Sep 19, 2023
This missense variant replaces arginine with tryptophan at codon 20 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 been reported in individuals affected with Lynch syndrome-associated cancer and/or colon polyps (PMID: 25980754), breast cancer (PMID: 30093976), and gastric cancer (PMID: 36627197). This variant has been identified in 13/277000 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
Mar 31, 2023
The p.R20W variant (also known as c.58C>T), located in coding exon 2 of the PMS2 gene, results from a C to T substitution at nucleotide position 58. The arginine at codon 20 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration was identified in a cohort of 1260 individuals undergoing panel testing for Lynch syndrome due to having a diagnosis of a Lynch-associated cancer and/or polyps (Yurgelun MB et al. Gastroenterology, 2015 Sep;149:604-13.e20). This alteration was also identified in an Asian individual diagnosed with 2 or more primary cancers (Chan GHJ et al. Oncotarget, 2018 Jul;9:30649-30660). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Nov 03, 2017
Variant summary: The PMS2 c.58C>T (p.Arg20Trp) variant involves the alteration of a conserved nucleotide. 4/4 in silico tools predict a damaging outcome for this variant (SNPsandGO not captured due to low reliability index). This variant was found in 13/271264 control chromosomes at a frequency of 0.0000479, which does not exceed the estimated maximal expected allele frequency of a pathogenic PMS2 variant (0.0001136). The variant was reported in one patient undergoing genetic testing for Lynch syndrome without strong evidence for or against pathogenicity (Yurgelun_2015). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. Taken together, this variant is classified as VUS. -
PMS2-related disorder Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
PreventionGenetics, part of Exact Sciences
Feb 13, 2024
The PMS2 c.58C>T variant is predicted to result in the amino acid substitution p.Arg20Trp. This variant has been reported in an individual with breast cancer and an individual undergoing Lynch syndrome genetic testing (Table S2, Chan et al. 2018. PubMed ID: 30093976; Table S2, Yurgelan et al. 2015. PubMed ID: 25980754). This variant is reported in 0.030% of alleles in individuals of South Asian descent in gnomAD and is interpreted as uncertain significance in ClinVar (https://preview.ncbi.nlm.nih.gov/clinvar/variation/216461/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Lynch syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
All of Us Research Program, National Institutes of Health
Oct 06, 2023
This missense variant replaces arginine with tryptophan at codon 20 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 been reported in individuals affected with Lynch syndrome-associated cancer and/or colon polyps (PMID: 25980754), breast cancer (PMID: 30093976), and gastric cancer (PMID: 36627197). This variant has been identified in 13/277000 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
Sep 05, 2023
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Identified in patients with Lynch syndrome-associated cancers/polyps or breast cancer (Yurgelun et al., 2015; Chan et al., 2018; Zhang et al., 2023); This variant is associated with the following publications: (PMID: 25980754, 30093976, 11574484, 18768816, 36627197, 21239990) -
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Nov 08, 2023
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 20 of the PMS2 protein (p.Arg20Trp). This variant is present in population databases (rs573374779, gnomAD 0.03%). This missense change has been observed in individual(s) with hereditary breast and ovarian cancer syndrome and/or suspected Lynch syndrome (PMID: 25980754, 30093976). ClinVar contains an entry for this variant (Variation ID: 216461). 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 with a positive 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. -