Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000535.7(PMS2):c.2239A>T(p.Arg747*) variant causes a stop gained change involving the alteration of a non-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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
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 Pathogenic. Variant got 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-5978632-T-A is Pathogenic according to our data. Variant chr7-5978632-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 504753.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.Arg747X variant in PMS2 has not been previously reported in individuals wi th Lynch syndrome or in large population studies. This nonsense variant leads to a premature termination codon at position 747, which is predicted to lead to a truncated or absent protein. Heterozygous loss of function of the PMS2 gene is a n established disease mechanism in Lynch syndrome. In summary, this variant meet s criteria to be classified as pathogenic for Lynch syndrome in an autosomal dom inant manner based upon its predicted impact on the protein and absence in contr ols. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change creates a premature translational stop signal (p.Arg747*) in the PMS2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PMS2 are known to be pathogenic (PMID: 21376568, 24362816). The frequency data for this variant in the population databases (gnomAD) is considered unreliable due to the presence of homologous sequence, such as pseudogenes or paralogs, in the genome. This premature translational stop signal has been observed in individual(s) with Lynch syndrome (PMID: 30729418). ClinVar contains an entry for this variant (Variation ID: 504753). For these reasons, this variant has been classified as Pathogenic. -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.R747* pathogenic mutation (also known as c.2239A>T), located in coding exon 13 of the PMS2 gene, results from an A to T substitution at nucleotide position 2239. This changes the amino acid from an arginine to a stop codon within coding exon 13. This mutation has been reported in an individual from colorectal cancer cohort suspicious for Lynch syndrome (Clarke EV et al. Fam Cancer 2019 07;18(3):317-325). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Lynch syndrome 4 Pathogenic:1
Sep 22, 2023
Myriad Genetics, Inc.
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant is considered pathogenic. This variant creates a termination codon and is predicted to result in premature protein truncation. -