2-47403354-C-T

Variant names:

• chr2-47403354-C-T
• rs587782354
• NM_000251.3:c.163C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000251.3(MSH2):​c.163C>T​(p.Arg55Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,455,912 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. R55G) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.07
• Publications: 4 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 33 benign, 37 uncertain in NM_000251.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.885

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.163C>T	p.Arg55Trp	missense_variant	Exon 1 of 16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.163C>T	p.Arg55Trp	missense_variant	Exon 1 of 16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1455912 Hom.: 0 Cov.: 31 AF XY: 0.00000276 AC XY: 2 AN XY: 723818

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

American (AMR) AF: 0.00 AC: 0 AN: 43982

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25838

East Asian (EAS) AF: 0.00 AC: 0 AN: 39514

South Asian (SAS) AF: 0.00 AC: 0 AN: 84950

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51860

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5470

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1110722

Other (OTH) AF: 0.00 AC: 0 AN: 60136

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 1 Uncertain:1

Apr 27, 2019

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Sep 03, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 55 of the MSH2 protein (p.Arg55Trp). 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: 638302). Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is 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

Aug 05, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R55W variant (also known as c.163C>T), located in coding exon 1 of the MSH2 gene, results from a C to T substitution at nucleotide position 163. The arginine at codon 55 is replaced by tryptophan, an amino acid with dissimilar properties. In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was determined to be functionally deleterious (Jia X et al. Am J Hum Genet, 2021 Jan;108:163-175). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.54
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;.;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.88	D;D;D
MetaSVM	Uncertain	0.61	D
MutationAssessor	Uncertain	2.7	M;.;.
PhyloP100		2.1
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-4.7	D;.;D
REVEL	Pathogenic	0.77
Sift	Uncertain	0.0010	D;.;D
Sift4G	Uncertain	0.0020	D;.;D
Polyphen		1.0	D;.;D
Vest4		0.63
MutPred		0.75		Gain of catalytic residue at A54 (P = 0.0169);Gain of catalytic residue at A54 (P = 0.0169);Gain of catalytic residue at A54 (P = 0.0169);
MVP		0.90
MPC		0.033
ClinPred		1.0	D
GERP RS		4.4
PromoterAI		-0.015	Neutral
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.8
Varity_R		0.72
gMVP		0.59
Mutation Taster		=50/50

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: rs587782354; hg19: chr2-47630493;