NM_000251.3:c.295A>C

Variant names:

• chr2-47408484-A-C
• rs63750230
• NM_000251.3:c.295A>C

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6 BP7

The NM_000251.3(MSH2):​c.295A>C​(p.Arg99Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,132 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R99R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MSH2 NM_000251.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 1.27
• 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_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.65).
• BP6: Variant 2-47408484-A-C is Benign according to our data. Variant chr2-47408484-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 91057.
• BP7: Synonymous conserved (PhyloP=1.27 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.295A>C	p.Arg99Arg	synonymous_variant	Exon 2 of 16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.295A>C	p.Arg99Arg	synonymous_variant	Exon 2 of 16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251342 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000992

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460132 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726492

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

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86176

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110520

Other (OTH) AF: 0.00 AC: 0 AN: 60336

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000439 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Apr 17, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.295A>C variant (also known as p.R99R), located in coding exon 2 of the MSH2 gene, results from an A to C substitution at nucleotide position 295. This nucleotide substitution does not change the arginine at codon 99. This variant has been reported in a Chinese family that meets Amsterdam II criteria (Wang CF et al. Zhonghua Yi Xue Yi Chuan Xue Za Zhi, 2006 Feb;23:32-6). This nucleotide position is not well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will not have any significant effect on splicing; however, direct evidence is unavailable. Based on the available evidence, the clinical significance of this variant remains unclear. -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Mar 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.65
CADD	Benign	11
DANN	Benign	0.48
PhyloP100		1.3
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs63750230; hg19: chr2-47635623;