2-47478383-T-G

Position:

• chr2-47478383-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PM5 PP3

The NM_000251.3(MSH2):​c.2322T>G​(p.Ile774Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I774F) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.689

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 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47478381-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 408475.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Likely_pathogenic=4, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.759

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.2322T>G	p.Ile774Met	missense_variant	14/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.2322T>G	p.Ile774Met	missense_variant	14/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Apr 10, 2023

This missense variant replaces isoleucine with methionine at codon 774 of the MSH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 07, 2023

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 774 of the MSH2 protein (p.Ile774Met). 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: 1354604). This variant disrupts the p.Ile774 amino acid residue in MSH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 28765196; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.80	D;.;.;.
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.45
FATHMM_MKL	Benign	0.14	N
LIST_S2	Uncertain	0.86	D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.76	D;D;D;D
MetaSVM	Uncertain	0.47	D
MutationAssessor	Uncertain	2.6	M;.;.;.
MutationTaster	Benign	0.77	D;D;D
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-2.8	D;D;.;D
REVEL	Pathogenic	0.65
Sift	Uncertain	0.0010	D;D;.;D
Sift4G	Uncertain	0.0020	D;D;.;D
Polyphen		1.0	D;.;.;D
Vest4		0.82
MutPred		0.66		Loss of methylation at K773 (P = 0.0339);.;Loss of methylation at K773 (P = 0.0339);Loss of methylation at K773 (P = 0.0339);
MVP		0.88
MPC		0.033
ClinPred		0.98	D
GERP RS		-6.4
Varity_R		0.94
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-47705522;