chr7-5977650-C-CA
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong
The NM_000535.7(PMS2):c.2382dupT(p.Gly795TrpfsTer29) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000668 in 149,760 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000535.7 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000668 AC: 1AN: 149760Hom.: 0 Cov.: 30
GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000138 AC: 2AN: 1454300Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 723528
GnomAD4 genome AF: 0.00000668 AC: 1AN: 149760Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0AN XY: 72932
ClinVar
Submissions by phenotype
not provided Pathogenic:2
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Lynch syndrome Pathogenic:1
The p.Gly795TrpfsX29 variant in PMS2 has been reported in 1 individual with PMS2-related cancers and segregated with disease in 2 affected relatives (Sjursen 2010 PMID: 20587412). The variant was absent from large population studies. This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 795 and leads to a premature termination codon 29 amino acids downstream. This termination codon occurs within the last exon and is, therefore, likely to escape nonsense mediated decay (NMD) and result in a truncated protein. This truncation impacts the critical MLH1 interaction domain (amino acids 675-850) and would impair protein function (Guerrette 1998 PMID: 10037723). In addition, several loss-of-function variants occuring nearby as well as downstream of this variant have been reported in individuals with PMS2-related cancers. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant hereditary non-polyposis colorectal cancer syndrome. ACMG/AMP Criteria applied: VS1_Strong, PM1, PM2_Supporting, PS4_Supporting. Please note, this variant is in a region with high homology to the PMS2 pseudogene and should be confirmed by another orthogonal assay. -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change creates a premature translational stop signal (p.Gly795Trpfs*29) in the PMS2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 68 amino acid(s) of the PMS2 protein. 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 clinical features of Lynch syndrome (PMID: 20587412, 31433215). ClinVar contains an entry for this variant (Variation ID: 480351). This variant disrupts a region of the PMS2 protein in which other variant(s) (p.Trp841Glyfs*10) have been determined to be pathogenic (PMID: 10037723, 26116798, 28218421, 30764633). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.2382dupT pathogenic mutation, located in coding exon 14 of the PMS2 gene, results from a duplication of T at nucleotide position 2382, causing a translational frameshift with a predicted alternate stop codon (p.G795Wfs*29). This alteration occurs at the 3' terminus of thePMS2 gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 68 amino acids of the protein. However, premature stop codons are typically deleterious in nature and the impacted region is critical for protein function (Ambry internal data). This mutation has been reported in multiple individuals from a family that meets Bethesda criteria for Lynch syndrome, and the tumor of at least one of these individuals was found to have absence of PMS2 via immunohistochemistry testing (Sjursen W et al. J. Med. Genet., 2010 Sep;47:579-85). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Lynch syndrome 4 Pathogenic:1
This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at