Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The ENST00000265849.12(PMS2):c.537+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000693 in 1,442,700 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar 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 Pathogenic. Variant got 18 ACMG points.
PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-6002452-C-T is Pathogenic according to our data. Variant chr7-6002452-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 215994.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
The PMS2 c.537+1G>A variant is predicted to disrupt the GT donor site and interfere with normal splicing. This variant was reported in an individual with colorectal cancer (Wang et al. 2020. PubMed ID: 31992580). This variant is reported in 0.0029% of alleles in individuals of Latino descent in gnomAD. This variant has been interpreted as likely pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/215994/). Variants that disrupt the consensus splice donor site in PMS2 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -
not provided Pathogenic:1
Likely pathogenic, criteria provided, single submitter
clinical testing
GeneDx
May 07, 2024
Observed in an individual with colorectal cancer (PMID: 31992580); Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 20587412, 29922827, 31992580) -
Lynch syndrome 4;C5436817:Mismatch repair cancer syndrome 4 Pathogenic:1
Likely pathogenic, criteria provided, single submitter
Likely pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jul 26, 2023
In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 215994). Disruption of this splice site has been observed in individual(s) with colorectal cancer (PMID: 20587412, 31992580). This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change affects a donor splice site in intron 5 of the PMS2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PMS2 are known to be pathogenic (PMID: 21376568, 24362816). -
Likely pathogenic, criteria provided, single submitter
clinical testing
Ambry Genetics
Feb 26, 2021
The c.537+1G>A intronic variant results from a G to A substitution one nucleotide after coding exon 5 of the PMS2 gene. This nucleotide position is highly conserved in available vertebrate species. This variant is reported in an individual diagnosed with MSI-H colorectal cancer at age 55 (Wang Q et al. J Med Genet, 2020 07;57:487-499). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -
Lynch syndrome 4 Pathogenic:1
Likely pathogenic, criteria provided, single submitter
clinical testing
Myriad Genetics, Inc.
Sep 19, 2023
This variant is considered likely pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. -