rs1060501990

chr2-47476384-A-Gchr2-47476384-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000251.3(MSH2):c.2023A>G(p.Lys675Glu) 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K675Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 8.95

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 9 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 14 uncertain in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant 2-47476384-A-G is Pathogenic according to our data. Variant chr2-47476384-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 408453.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr2-47476384-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.2023A>G	p.Lys675Glu	missense_variant	13/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.2023A>G	p.Lys675Glu	missense_variant	13/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 07, 2020

The p.K675E variant (also known as c.2023A>G), located in coding exon 13 of the MSH2 gene, results from an A to G substitution at nucleotide position 2023. The lysine at codon 675 is replaced by glutamic acid, an amino acid with similar properties. This alteration has been reported in the germline of an individual diagnosed with MSI-H colorectal cancer and was also identified as somatic in a MSI-H colorectal tumor (InSiGHT database; Ambry internal data). Based on internal structural analysis, this variant is anticipated to disrupt the ATP binding site (Walker JE et al. EMBO J., 1982;1:945-51). An in vitro complementation assay showed that p.K675E results in less than 25% MMR activity when compared to wild-type (Drost M et al. Genet Med 2019 07;21(7):1486-1496). This alteration has been classified as pathogenic using the following lines of evidence: in silico prediction models, segregation with disease, clinical phenotype including tumor characteristics, mutation co-occurrence, and functional studies (Thompson BA et al. Hum. Mutat. 2013 Jan;34:200-9; Thompson BA et al. Nat. Genet. 2014 Feb;46:107-15; available at [www.insight-group.org/variants/classifications/]). 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 majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 24, 2022

This missense change has been observed in individual(s) with clinical features of MSH2-related conditions (PMID: 21520333). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 675 of the MSH2 protein (p.Lys675Glu). ClinVar contains an entry for this variant (Variation ID: 408453). 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. Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is expected to disrupt MSH2 protein function. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	30
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	D;.;.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D;D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	5.0	H;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-3.7	D;D;.;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;.;D
Sift4G	Pathogenic	0.0	D;D;.;D
Polyphen		1.0	D;.;.;D
Vest4		0.98
MutPred		0.93		Loss of ubiquitination at K675 (P = 0.0233);.;Loss of ubiquitination at K675 (P = 0.0233);Loss of ubiquitination at K675 (P = 0.0233);
MVP		0.99
MPC		0.031
ClinPred		1.0	D
GERP RS		6.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.99

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: rs1060501990; hg19: chr2-47703523;