2-47403390-A-G

Variant names:

• chr2-47403390-A-G
• rs768824654
• NM_000251.3:c.199A>G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_Strong PS1_Moderate PM2 PP3_Moderate

The NM_001258281.1(MSH2):​c.1A>G​(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000312 in 1,601,220 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).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: MSH2 NM_001258281.1 start_lost
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: -0.540

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 Pathogenic. Variant got 10 ACMG points.

• PVS1: Start lost variant, next in-frame start position is after 6 pathogenic variants. Next in-frame start position is after 17 codons. Genomic position: 47408436. Lost 0.019 part of the original CDS.
• PS1: Another start lost variant in NM_001258281.1 (MSH2) was described as [Pathogenic] in Lovd
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.199A>G	p.Met67Val	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.199A>G	p.Met67Val	missense_variant	Exon 1 of 16	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000276 AC: 4 AN: 1449038 Hom.: 0 Cov.: 31 AF XY: 0.00000417 AC XY: 3 AN XY: 719050

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: 0.0000194

Gnomad4 NFE exome AF: 0.00000271

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74342

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.00000833 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Oct 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 methionine with valine at codon 67 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). 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). To our knowledge, 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. -

Mar 29, 2021

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. -

not specified Uncertain:1

Jan 19, 2023

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.199A>G (p.Met67Val) results in a conservative amino acid change located in the DNA mismatch repair protein MutS-like, N-terminal domain (IPR007695) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4.4e-06 in 228538 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.199A>G in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Three ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance and one ClinVar submitter (evaluation after 2014) cites it as likely benign. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Lynch syndrome Uncertain:1

Oct 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 methionine with valine at codon 67 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). 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). To our knowledge, 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. -

not provided Uncertain:1

Nov 27, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek 2016); While protein-based in silico analysis supports that this missense variant does not alter protein structure/function, splice predictors support a deleterious effect. In the absence of RNA or functional studies, the actual effect of this sequence change is unknown.; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Jul 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 67 of the MSH2 protein (p.Met67Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with breast cancer (PMID: 35449176). ClinVar contains an entry for this variant (Variation ID: 216347). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33357406) indicates that this missense variant is not expected to disrupt MSH2 function with a negative predictive value of 80%. Experimental studies have shown that this missense change does not substantially affect MSH2 function (PMID: 33357406). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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	0.066	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	21
DANN	Benign	0.83
DEOGEN2	Uncertain	0.51	D;T;.;.;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.34	N
LIST_S2	Benign	0.85	D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.14	T;T;T;T;T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	0.99	L;.;.;.;.
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.92	N;N;N;.;N
REVEL	Uncertain	0.41
Sift	Uncertain	0.017	D;T;D;.;D
Sift4G	Uncertain	0.012	D;T;D;.;D
Polyphen		0.0	B;.;.;.;B
Vest4		0.14
MutPred		0.68		Loss of helix (P = 0.2022);.;.;Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);
MVP		0.95
MPC		0.0065
ClinPred		0.24	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.75
gMVP		0.33

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.89		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.89		Position offset: -5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs768824654; hg19: chr2-47630529;