rs759603999

Positions:

• chr2-47410286-C-A
• chr2-47410286-C-G
• chr2-47410286-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000251.3(MSH2):​c.559C>A​(p.Leu187Ile) variant causes a missense 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. 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. L187P) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.27

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.

• PM1: In a helix (size 9) in uniprot entity MSH2_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) 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 chr2-47410287-T-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.853

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.559C>A	p.Leu187Ile	missense_variant	3/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.559C>A	p.Leu187Ile	missense_variant	3/16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 20, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 07, 2020	The p.L187I variant (also known as c.559C>A), located in coding exon 3 of the MSH2 gene, results from a C to A substitution at nucleotide position 559. The leucine at codon 187 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 26, 2019

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. This variant disrupts the p.Leu187 amino acid residue in MSH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16327991, 18951462, 17101317, 15849733). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with MSH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 483741). This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with isoleucine at codon 187 of the MSH2 protein (p.Leu187Ile). The leucine residue is highly conserved and there is a small physicochemical difference between leucine and isoleucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.64	D;D;.;.;.
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	3.0	M;.;.;.;.
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-1.4	N;N;N;.;N
REVEL	Pathogenic	0.78
Sift	Uncertain	0.029	D;D;D;.;D
Sift4G	Uncertain	0.050	T;D;T;.;D
Polyphen		1.0	D;.;.;.;D
Vest4		0.65
MutPred		0.75		Loss of disorder (P = 0.3232);.;.;Loss of disorder (P = 0.3232);Loss of disorder (P = 0.3232);
MVP		0.83
MPC		0.029
ClinPred		0.94	D
GERP RS		4.9
Varity_R		0.81
gMVP		0.59

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs759603999; hg19: chr2-47637425;