rs864622340

chr2-47416374-CT-C

Variant summary

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

The NM_000251.3(MSH2):c.1023del(p.Val342LeufsTer15) variant causes a frameshift change involving the alteration of a 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. L341L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 7.87

Genes affected

MSH2 (HGNC:7325): (mutS homolog 2) This locus is frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). When cloned, it was discovered to be a human homolog of the E. coli mismatch repair gene mutS, consistent with the characteristic alterations in microsatellite sequences (RER+ phenotype) found in HNPCC. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

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 2-47416374-CT-C is Pathogenic according to our data. Variant chr2-47416374-CT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 220006.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1023del	p.Val342LeufsTer15	frameshift_variant	6/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1023del	p.Val342LeufsTer15	frameshift_variant	6/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 21, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Jul 31, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 11, 2019	The variant results in a shift of the reading frame, and is therefore predicted to result in the loss of a functional protein. Found in at least one symptomatic patient, and not found in general population data. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 22, 2020	Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (Lek 2016); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Observed in individuals with breast cancer (Roberts 2018); This variant is associated with the following publications: (PMID: 29345684) -

Hereditary nonpolyposis colon cancer Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Feb 05, 2019

Variant summary: The variant, MSH2 c.1023delT (p.Val342LeufsX15) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (eg. c.1030C>T (p.Gln344X), c.1221_1222delCT(p.Tyr408fsX8), and c.1226_1227delAG (p.Gln409fsX7)). The variant was absent in 246218 control chromosomes (gnomAD). To our knowledge, no occurrence of c.1023delT in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 28, 2023

This sequence change creates a premature translational stop signal (p.Val342Leufs*15) in the MSH2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MSH2 are known to be pathogenic (PMID: 15849733, 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 MSH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 220006). 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

Dec 27, 2023

The c.1023delT pathogenic mutation, located in coding exon 6 of the MSH2 gene, results from a deletion of one nucleotide at nucleotide position 1023, causing a translational frameshift with a predicted alternate stop codon (p.V342Lfs*15). 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

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs864622340; hg19: chr2-47643513;