chr7-6005892-C-CAATT

Position:

• chr7-6005892-C-CAATT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The ENST00000265849.12(PMS2):​c.162_163insAATT​(p.Asp55AsnfsTer2) variant causes a frameshift, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. I54I) has been classified as Uncertain significance. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PMS2 ENST00000265849.12 frameshift, splice_region
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 1.63

Genes affected

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]

ACMG classification

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 7-6005892-C-CAATT is Pathogenic according to our data. Variant chr7-6005892-C-CAATT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 484246.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PMS2	NM_000535.7	c.162_163insAATT	p.Asp55AsnfsTer2	frameshift_variant, splice_region_variant	2/15	ENST00000265849.12	NP_000526.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PMS2	ENST00000265849.12	c.162_163insAATT	p.Asp55AsnfsTer2	frameshift_variant, splice_region_variant	2/15	1	NM_000535.7	ENSP00000265849	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 4 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	May 31, 2024	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 20, 2023	- -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 16, 2023

This sequence change creates a premature translational stop signal (p.Asp55Asnfs*2) 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). This variant is not present in population databases (gnomAD no frequency). 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: 484246). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 21, 2017

The c.162_163insAATT pathogenic mutation, located in coding exon 2 of the PMS2 gene, results from an insertion of 4 nucleotides at position 162, causing a translational frameshift with a predicted alternate stop codon (p.D55Nfs*2). 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1554306288; hg19: chr7-6045523;