2-47403328-A-C

Position:

• chr2-47403328-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000251.3(MSH2):​c.137A>C​(p.His46Pro) 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. 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. H46Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.54

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]

MSH2 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47403329-C-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.137A>C	p.His46Pro	missense_variant	1/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.137A>C	p.His46Pro	missense_variant	1/16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 13, 2022

This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 46 of the MSH2 protein (p.His46Pro). 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: 525765). 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. 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 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 05, 2024

The p.H46P variant (also known as c.137A>C), located in coding exon 1 of the MSH2 gene, results from an A to C substitution at nucleotide position 137. The histidine at codon 46 is replaced by proline, an amino acid with similar 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 neutral (Jia X et al. Am J Hum Genet, 2021 Jan;108:163-175). 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 available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	29
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.88	D;.;.
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.85	T;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	0.80	D
MutationAssessor	Pathogenic	3.6	H;.;.
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-8.4	D;.;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D;.;D
Sift4G	Uncertain	0.0030	D;.;D
Polyphen		1.0	D;.;D
Vest4		0.92
MutPred		0.91		Loss of catalytic residue at H46 (P = 0.0257);Loss of catalytic residue at H46 (P = 0.0257);Loss of catalytic residue at H46 (P = 0.0257);
MVP		0.98
MPC		0.028
ClinPred		1.0	D
GERP RS		4.3
Varity_R		0.99
gMVP		0.89

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: rs1553348822; hg19: chr2-47630467;