2-47416375-T-G

Variant names:

• chr2-47416375-T-G
• rs63751147
• NM_000251.3:c.1022T>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000251.3(MSH2):​c.1022T>G​(p.Leu341Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,334 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. L341F) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.87
• Publications: 11 publications found

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 Gene-Disease associations (from GenCC):

• Lynch syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
• Lynch syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• Muir-Torre syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, G2P
• mismatch repair cancer syndrome 1

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• mismatch repair cancer syndrome 2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• ovarian cancer

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• malignant pancreatic neoplasm

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• prostate cancer

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• rhabdomyosarcoma

  Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
• breast cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
• hereditary breast carcinoma

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 38 uncertain 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 chr2-47416375-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 90507.Status of the report is reviewed_by_expert_panel, 3 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.982

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000251.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MSH2	NM_000251.3	MANE Select	c.1022T>G	p.Leu341Arg	missense	Exon 6 of 16	NP_000242.1
	MSH2	NM_001406674.1		c.1022T>G	p.Leu341Arg	missense	Exon 6 of 18	NP_001393603.1
	MSH2	NM_001406631.1		c.1022T>G	p.Leu341Arg	missense	Exon 6 of 18	NP_001393560.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MSH2	ENST00000233146.7	TSL:1 MANE Select	c.1022T>G	p.Leu341Arg	missense	Exon 6 of 16	ENSP00000233146.2
	MSH2	ENST00000406134.5	TSL:1	c.1022T>G	p.Leu341Arg	missense	Exon 6 of 16	ENSP00000384199.1
	MSH2	ENST00000645506.1		c.1022T>G	p.Leu341Arg	missense	Exon 6 of 17	ENSP00000495455.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460334 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 726642

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86234

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1110602

Other (OTH) AF: 0.0000166 AC: 1 AN: 60340

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00131091), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

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

Apr 05, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L341R variant (also known as c.1022T>G), located in coding exon 6 of the MSH2 gene, results from a T to G substitution at nucleotide position 1022. The leucine at codon 341 is replaced by arginine, an amino acid with dissimilar 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.

Feb 20, 2024

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces leucine with arginine at codon 341 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant does not impact MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold <= -1.32, PMID: 33357406). 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). A different variant affecting the same codon, c.1022T>C (p.Leu341Pro), is considered to be disease-causing (ClinVar variation ID: 90507), suggesting this position is important for the protein function. 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.

Lynch syndrome Uncertain:1

Aug 23, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces leucine with arginine at codon 341 of the MSH2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, 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.

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Jan 15, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 341 of the MSH2 protein (p.Leu341Arg). 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: 491742). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 95%. 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.49	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		7.9
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-5.9	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.87		Gain of MoRF binding (P = 0.0193)
MVP		0.97
MPC		0.030
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.94
gMVP		0.86
Mutation Taster		=5/95	disease causing

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

Other links and lift over

dbSNP: rs63751147; hg19: chr2-47643514;