NM_000251.3:c.1013G>T

Variant names:

• chr2-47416366-G-T
• rs587779065
• NM_000251.3:c.1013G>T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_000251.3(MSH2):​c.1013G>T​(p.Gly338Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G338E) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 9.81

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 11 ACMG points.

• PM1: In a helix (size 11) in uniprot entity MSH2_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47416366-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 2-47416366-G-T is Pathogenic according to our data. Variant chr2-47416366-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 568928.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1013G>T	p.Gly338Val	missense_variant	Exon 6 of 16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.1013G>T	p.Gly338Val	missense_variant	Exon 6 of 16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Lynch syndrome 1 Pathogenic:1

Jul 31, 2023

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely pathogenic. Functional studies indicate this variant impacts protein function [PMID: 33357406]. This variant is expected to disrupt protein structure [Myriad internal data]. -

not provided Pathogenic:1

Apr 29, 2015

Clinical Genetics and Genomics, Karolinska University Hospital

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Aug 05, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G338V pathogenic mutation (also known as c.1013G>T), located in coding exon 6 of the MSH2 gene, results from a G to T substitution at nucleotide position 1013. The glycine at codon 338 is replaced by valine, an amino acid with dissimilar properties. In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was determined to be functionally deleterious (Jia X et al. Am J Hum Genet, 2021 01;108:163-175). In another functional study that measured the mutation rate of MSH2 alterations in yeast, this alteration demonstrated a 7.98-fold increase in mutation rate compared to MSH2 wild-type, which was considered potentially pathogenic (Ollodart AR et al. Genetics, 2021 Jun;218:iyab058). Based on internal structural analysis using published crystal structures, G338V is strongly destabilizing to the MSH2 MutS domain III (Warren JJ et al. Mol Cell, 2007 May;26:579-92; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Apr 30, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with MSH2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with valine at codon 338 of the MSH2 protein (p.Gly338Val). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.77	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	3.5	H;.;.;.
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-8.8	D;D;.;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;.;D
Sift4G	Pathogenic	0.0010	D;D;.;D
Polyphen		1.0	D;.;.;D
Vest4		0.99
MutPred		0.95		Gain of MoRF binding (P = 0.0911);.;Gain of MoRF binding (P = 0.0911);Gain of MoRF binding (P = 0.0911);
MVP		0.98
MPC		0.032
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.99
gMVP		0.85

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: rs587779065; hg19: chr2-47643505; COSMIC: COSV51875790;