rs988252817

Positions:

• chr2-47429857-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000251.3(MSH2):​c.1192G>A​(p.Ala398Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict 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. A398A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1
• Conservation: PhyloP100: 3.28

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 Likely_benign. Variant got -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.17160314).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1192G>A	p.Ala398Thr	missense_variant	7/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.1192G>A	p.Ala398Thr	missense_variant	7/16	1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461806 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727200

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Lynch syndrome 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The missense c.1192G>A(p.Ala398Thr) variant in MSH2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The p.Ala398Thr variant is novel (not in any individuals) in gnomAD Exomes and 1000 Genomes database. This variant has been reported to the ClinVar database as Uncertain significance (multiple submission). The amino acid change p.Ala398Thr in MSH2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. The amino acid Ala at position 398 is changed to a Thr changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as Variant of Uncertain Significance (VUS). -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	May 06, 2022	This missense variant replaces alanine with threonine at codon 398 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). Functional studies have shown that this variant resulted in a normal response to 6-thioguanine (PMID: 33357406). To our knowledge, this variant has not been reported in individuals affected with hereditary cancer 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. -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Dec 22, 2022	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. -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Nov 28, 2023

This missense variant replaces alanine with threonine at codon 398 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). Functional studies have shown that this variant resulted in a normal response to 6-thioguanine (PMID: 33357406). To our knowledge, this variant has not been reported in individuals affected with hereditary cancer 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

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 16, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 18822302, 21120944) -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 01, 2023

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 398 of the MSH2 protein (p.Ala398Thr). 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: 455475). 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%. 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	0.066
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Benign	0.36	T;.;.;.
Eigen	Benign	-0.12
Eigen_PC	Benign	0.10
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.94	D;D;D;D
M_CAP	Benign	0.045	D
MetaRNN	Benign	0.17	T;T;T;T
MetaSVM	Benign	-0.28	T
MutationAssessor	Benign	0.16	N;.;.;.
MutationTaster	Benign	0.97	D;D;D
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.18	N;N;.;N
REVEL	Uncertain	0.31
Sift	Benign	0.28	T;T;.;T
Sift4G	Benign	0.37	T;T;.;T
Polyphen		0.0010	B;.;.;B
Vest4		0.40
MutPred		0.27		Loss of helix (P = 0.1299);.;Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);
MVP		0.93
MPC		0.0067
ClinPred		0.56	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.20
gMVP		0.22

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

Publications

LitVar

Other links and lift over

dbSNP: rs988252817; hg19: chr2-47656996;