rs200429136

chr2-47429936-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PM5

The NM_000251.3(MSH2):c.1271A>G(p.His424Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,592 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. H424Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 6.53

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 8 benign, 14 uncertain 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 chr2-47429935-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1271A>G	p.His424Arg	missense_variant	7/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1271A>G	p.His424Arg	missense_variant	7/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461592 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727126

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Feb 27, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Mar 24, 2023	This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 27, 2023	The p.H424R variant (also known as c.1271A>G), located in coding exon 7 of the MSH2 gene, results from an A to G substitution at nucleotide position 1271. The histidine at codon 424 is replaced by arginine, an amino acid with highly similar properties. This alteration has been identified in a cohort of 572 atherosclerosis patients with no clinical history of cancer (Pinard A et al. Hum Mutat, 2016 Dec;37:1299-1307). In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was reported to be functionally neutral (Jia X et al. Am J Hum Genet, 2021 Jan;108:163-175). This amino acid position is poorly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 02, 2022	This missense variant replaces histidine with arginine at codon 424 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). This variant has intermediate MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold -1.32 < LOF score < 0.88, PMID: 33357406). This variant has not been reported in individuals affected with hereditary cancer 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. -

not provided Uncertain:1

Uncertain significance, no assertion criteria provided

research

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Jul 13, 2012

- -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 17, 2023

Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 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. ClinVar contains an entry for this variant (Variation ID: 41642). This variant has not been reported in the literature in individuals affected with MSH2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 424 of the MSH2 protein (p.His424Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
Cadd	Benign	21
Dann	Benign	0.97
DEOGEN2	Uncertain	0.68	D;.;.;.
Eigen	Benign	0.17
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.87	D;D;D;D
M_CAP	Benign	0.080	D
MetaRNN	Uncertain	0.56	D;D;D;D
MetaSVM	Uncertain	0.37	D
MutationAssessor	Uncertain	2.2	M;.;.;.
MutationTaster	Benign	0.74	D;D;D
PrimateAI	Benign	0.41	T
PROVEAN	Uncertain	-3.3	D;D;.;D
REVEL	Uncertain	0.55
Sift	Benign	0.31	T;T;.;T
Sift4G	Benign	0.32	T;T;.;T
Polyphen		0.044	B;.;.;B
Vest4		0.51
MutPred		0.43		Loss of ubiquitination at K423 (P = 0.0382);.;Loss of ubiquitination at K423 (P = 0.0382);Loss of ubiquitination at K423 (P = 0.0382);
MVP		0.93
MPC		0.011
ClinPred		0.83	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.58
gMVP		0.41

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: rs200429136; hg19: chr2-47657075;