2-47445623-A-G

Position:

• chr2-47445623-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000251.3(MSH2):​c.1352A>G​(p.Gln451Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 4.88

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 Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a helix (size 18) in uniprot entity MSH2_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1352A>G	p.Gln451Arg	missense_variant	8/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.1352A>G	p.Gln451Arg	missense_variant	8/16	1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Jun 14, 2021

DNA sequence analysis of the MSH2 gene demonstrated a sequence change, c.1352A>G, in exon 8 that results in an amino acid change, p.Gln451Arg. This sequence change has not been described in known population databases (dbSNP rs878853801). The p.Gln451Arg change affects a moderately conserved amino acid residue located in a domain of the MSH2 protein that is known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Gln451Arg substitution. This sequence change does not appear to have been previously described in patients with MSH2-related disorders. Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Gln451Arg change remains unknown at this time. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 12, 2024

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Published functional studies demonstrate sensitivity to 6-thioguanine, suggesting intact mismatch repair function (PMID: 33357406); This variant is associated with the following publications: (PMID: 18822302, 21120944, 33357406) -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 14, 2022

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 451 of the MSH2 protein (p.Gln451Arg). 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: 237366). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MSH2 protein function. 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. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 22, 2021

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
CADD	Uncertain	23
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.61	D;.;.;.
Eigen	Benign	0.12
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Benign	0.041	D
MetaRNN	Uncertain	0.45	T;T;T;T
MetaSVM	Uncertain	0.15	D
MutationAssessor	Uncertain	2.1	M;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-2.2	N;N;.;N
REVEL	Uncertain	0.55
Sift	Benign	0.098	T;T;.;T
Sift4G	Benign	0.16	T;T;.;T
Polyphen		0.045	B;.;.;B
Vest4		0.63
MutPred		0.44		Gain of ubiquitination at K449 (P = 0.0773);.;Gain of ubiquitination at K449 (P = 0.0773);Gain of ubiquitination at K449 (P = 0.0773);
MVP		0.97
MPC		0.0069
ClinPred		0.78	D
GERP RS		5.6
Varity_R		0.72
gMVP		0.62

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: rs878853801; hg19: chr2-47672762;