rs876659906

chr2-47445598-C-Achr2-47445598-C-Gchr2-47445598-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_000251.3(MSH2):c.1327C>A(p.Leu443Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,202 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. L443V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 4.05

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 3 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 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=0.40976328).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1327C>A	p.Leu443Ile	missense_variant	8/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1327C>A	p.Leu443Ile	missense_variant	8/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461202 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 726946

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.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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	Jun 15, 2023	This missense variant replaces leucine with isoleucine at codon 443 of the MSH2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MSH2-related disorders 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 25, 2023	The p.L443I variant (also known as c.1327C>A), located in coding exon 8 of the MSH2 gene, results from a C to A substitution at nucleotide position 1327. The leucine at codon 443 is replaced by isoleucine, an amino acid with highly 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. -

Lynch syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 443 of the MSH2 protein (p.Leu443Ile). 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: 408497). 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 with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
Cadd	Benign	22
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.43	T;.;.;.
Eigen	Benign	0.12
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.85	T;T;T;T
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.41	T;T;T;T
MetaSVM	Uncertain	0.13	D
MutationAssessor	Benign	1.2	L;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-0.97	N;N;.;N
REVEL	Uncertain	0.42
Sift	Benign	0.11	T;T;.;T
Sift4G	Benign	0.16	T;T;.;T
Polyphen		0.022	B;.;.;P
Vest4		0.35
MutPred		0.38		Gain of catalytic residue at S445 (P = 0.1664);.;Gain of catalytic residue at S445 (P = 0.1664);Gain of catalytic residue at S445 (P = 0.1664);
MVP		0.82
MPC		0.0072
ClinPred		0.72	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.58
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs876659906; hg19: chr2-47672737;