rs869312796

chr2-47466806-C-Gchr2-47466806-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000251.3(MSH2):c.1659C>G(p.Asn553Lys) variant causes a missense, splice region 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. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. N553S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MSH2 NM_000251.3 missense, splice_region
• Scores: Splicing: ADA: 0.2984
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.46

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.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 benign, 15 uncertain in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.821

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1659C>G	p.Asn553Lys	missense_variant, splice_region_variant	10/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1659C>G	p.Asn553Lys	missense_variant, splice_region_variant	10/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

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

Invitae

Jul 14, 2023

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 553 of the MSH2 protein (p.Asn553Lys). 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: 645899). An algorithm developed specifically for the MSH2 gene suggests that this missense change is likely to be deleterious (PMID: 23690608). 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

Aug 26, 2020

The p.N553K variant (also known as c.1659C>G), located in coding exon 10 of the MSH2 gene, results from a C to G substitution at nucleotide position 1659. The asparagine at codon 553 is replaced by lysine, an amino acid with similar properties. This amino acid position is highly 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.0
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;.;.;.
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.82	D;D;D;D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Uncertain	2.9	M;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-4.2	D;D;.;D
REVEL	Pathogenic	0.72
Sift	Uncertain	0.017	D;D;.;D
Sift4G	Uncertain	0.026	D;D;.;D
Polyphen		0.99	D;.;.;D
Vest4		0.90
MutPred		0.64		Gain of ubiquitination at N553 (P = 0.0247);.;Gain of ubiquitination at N553 (P = 0.0247);Gain of ubiquitination at N553 (P = 0.0247);
MVP		0.93
MPC		0.032
ClinPred		1.0	D
GERP RS		3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.30
dbscSNV1_RF	Benign	0.37
SpliceAI score (max)		0.14		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: rs869312796; hg19: chr2-47693945;