rs1553368707

Positions:

• chr2-47475246-A-G
• chr2-47475246-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000251.3(MSH2):​c.1981A>G​(p.Lys661Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. K661R) 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 U:3
• Conservation: PhyloP100: 3.96

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 2 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 10 benign, 16 uncertain in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.12029797).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1981A>G	p.Lys661Glu	missense_variant	12/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1981A>G	p.Lys661Glu	missense_variant	12/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jun 28, 2023

This missense variant replaces lysine with glutamic acid at codon 661 of the MSH2 protein. Computational prediction tools and conservation analyses suggest that this variant may not impact protein structure and function. Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. 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. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 29, 2023

This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 661 of the MSH2 protein (p.Lys661Glu). 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: 525622). 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 not 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

Color Diagnostics, LLC DBA Color Health

Sep 19, 2019

This missense variant replaces lysine with glutamic acid at codon 661 of the MSH2 protein. Computational prediction tools and conservation analyses suggest that this variant may not impact protein structure and function. Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Uncertain	0.071	D
BayesDel_noAF	Benign	-0.14
CADD	Benign	19
DANN	Benign	0.90
DEOGEN2	Benign	0.29	T;.;.;.
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.038
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.91	D;D;D;D
M_CAP	Benign	0.014	T
MetaRNN	Benign	0.12	T;T;T;T
MetaSVM	Benign	-0.59	T
MutationAssessor	Benign	-0.95	N;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-0.46	N;N;.;N
REVEL	Uncertain	0.34
Sift	Benign	0.87	T;T;.;T
Sift4G	Benign	0.82	T;T;.;T
Polyphen		0.0010	B;.;.;B
Vest4		0.45
MutPred		0.46		Loss of ubiquitination at K661 (P = 0.0118);.;Loss of ubiquitination at K661 (P = 0.0118);Loss of ubiquitination at K661 (P = 0.0118);
MVP		0.82
MPC		0.0059
ClinPred		0.69	D
GERP RS		6.0
Varity_R		0.31
gMVP		0.66

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: rs1553368707; hg19: chr2-47702385;