NM_000251.3:c.163C>G

Variant names:

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

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM1 PP3 BP6

The NM_000251.3(MSH2):​c.163C>G​(p.Arg55Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000746 in 1,608,150 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R55Q) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:2
• 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: Uncertain_significance. The variant received 2 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.775
• BP6: Variant 2-47403354-C-G is Benign according to our data. Variant chr2-47403354-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 142277.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.163C>G	p.Arg55Gly	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>G	p.Arg55Gly	missense_variant	Exon 1 of 16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152238 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000129 AC: 3 AN: 232898 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000964

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000687 AC: 10 AN: 1455912 Hom.: 0 Cov.: 31 AF XY: 0.00000553 AC XY: 4 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: 0.0000235 AC: 2 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: 0.00000630 AC: 7 AN: 1110722

Other (OTH) AF: 0.0000166 AC: 1 AN: 60136

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152238 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74374

African (AFR) AF: 0.0000241 AC: 1 AN: 41470

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68050

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.0000166 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Jun 14, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

May 05, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with glycine at codon 55 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). In another functional study, this variant causes decreased mRNA and protein expression as well as a reduced DNA damage response compared to wild type (PMID: 28494185). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 4/264300 chromosomes 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. -

not specified Uncertain:1

Jun 17, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MSH2 c.163C>G (p.Arg55Gly) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS-like, N-terminal domain (IPR007695) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.3e-05 in 232898 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.163C>G has been reported in the literature in individuals affected with Lynch Syndrome, although it has been reported in at least one control individual without a personal or family history of cancer (Okawa_2023). This does not provide unequivocal conclusions about association of the variant with Lynch Syndrome. At least one experimental study reports that this variant strongly reduces mRNA and protein expression in vitro (Arora_2017). In contrast, another functional study found this variant had no damaging effect on mismatch repair activity in a massively parallel selection for mismatch repair dysfunction using 6-thioguanine (Jia_2021). The following publications have been ascertained in the context of this evaluation (PMID: 33357406, 28494185, 36243179). ClinVar contains an entry for this variant (Variation ID: 142277). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Lynch syndrome 1 Uncertain:1

Mar 09, 2024

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Lynch syndrome Uncertain:1

Nov 30, 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 arginine with glycine at codon 55 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). In another functional study, this variant causes decreased mRNA and protein expression as well as a reduced DNA damage response compared to wild type (PMID: 28494185). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 4/264300 chromosomes 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. -

not provided Uncertain:1

Jul 30, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33357406, 18822302, 21120944, 36243179, 31391288, 28494185, 33471991) -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Jan 22, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	D;.;.
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.77	D;D;D
MetaSVM	Uncertain	0.28	D
MutationAssessor	Uncertain	2.7	M;.;.
PhyloP100		2.1
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-3.7	D;.;D
REVEL	Pathogenic	0.72
Sift	Uncertain	0.0050	D;.;D
Sift4G	Uncertain	0.040	D;.;T
Polyphen		0.46	P;.;P
Vest4		0.51
MutPred		0.72		Gain of catalytic residue at A54 (P = 0.0278);Gain of catalytic residue at A54 (P = 0.0278);Gain of catalytic residue at A54 (P = 0.0278);
MVP		0.94
MPC		0.016
ClinPred		0.89	D
GERP RS		4.4
PromoterAI		0.029	Neutral
Varity_R		0.59
gMVP		0.48
Mutation Taster		=53/47	polymorphism

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;