NM_000251.3:c.998G>T

Variant names:

• chr2-47416351-G-T
• rs63750828
• NM_000251.3:c.998G>T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000251.3(MSH2):​c.998G>T​(p.Cys333Phe) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C333R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• 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 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47416350-T-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 2-47416351-G-T is Pathogenic according to our data. Variant chr2-47416351-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 638846.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.998G>T	p.Cys333Phe	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.998G>T	p.Cys333Phe	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: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 1 Pathogenic:2

May 04, 2022

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 28, 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]. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Feb 25, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with phenylalanine at codon 333 of the MSH2 protein (p.Cys333Phe). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and phenylalanine. This variant has been reported in individuals in the Leiden Open-source Variation Database (PMID: 21520333). ClinVar contains an entry for this variant (Variation ID: 638846). 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 expected to disrupt MSH2 protein function. This variant disrupts the p.Cys333 amino acid residue in MSH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12624141, 15849733, 16175654, 21642682, 28769567, 25559809, 26681312, 18951462, 17101317, 26951660, 17720936). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Jan 02, 2019

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.C333F variant (also known as c.998G>T), located in coding exon 6 of the MSH2 gene, results from a G to T substitution at nucleotide position 998. The cysteine at codon 333 is replaced by phenylalanine, an amino acid with highly dissimilar properties. A likely pathogenic variant (p.C333R) and a pathogenic mutation (p.C333Y) have been been described at the same codon, and both have been identified in individuals meeting Amsterdam criteria with tumors demonstrating absent MSH2 and MSH6 by IHC (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). In addition, this alteration is predicted to be deleterious by in silico analysis. In addition, this alteration is predicted to be deleterious by MAPP-MMR in silico analyses (Chao EC et al. Hum. Mutat. 2008 Jun;29:852-60). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.91	D;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	H;.;.;.
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-10	D;D;.;D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0010	D;D;.;D
Sift4G	Pathogenic	0.0010	D;D;.;D
Polyphen		1.0	D;.;.;D
Vest4		0.91
MutPred		0.95		Loss of methylation at K332 (P = 0.0289);.;Loss of methylation at K332 (P = 0.0289);Loss of methylation at K332 (P = 0.0289);
MVP		0.97
MPC		0.026
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.99
gMVP		0.80

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: rs63750828; hg19: chr2-47643490;