rs755501968

chr2-47463133-A-Gchr2-47463133-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PP3_Moderate BP6

The NM_000251.3(MSH2):c.1489A>G(p.Ile497Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/23 in silico tools predict a benign 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. I497M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:2
• Conservation: PhyloP100: 0.520

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 Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 12 benign, 15 uncertain in NM_000251.3
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• BP6: Variant 2-47463133-A-G is Benign according to our data. Variant chr2-47463133-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 230562.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=6, Benign=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1489A>G	p.Ile497Val	missense_variant	9/16	ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1489A>G	p.Ile497Val	missense_variant	9/16	1	NM_000251.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152226 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251298 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135838

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461678 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727146

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.0000994

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152226 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74378

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

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

Alfa AF: 0.000141 Hom.: 0

Bravo AF: 0.0000378

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Apr 06, 2018	This variant is denoted MSH2 c.1489A>G at the cDNA level, p.Ile497Val (I497V) at the protein level, and results in the change of an Isoleucine to a Valine (ATA>GTA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MSH2 Ile497Val was not observed at a significant allele frequency in large population cohorts (Lek 2016). This variant is located in the Clamp domain and the region of interaction with MSH6 and MSH3 (Guerrette 1998, L?tzen 2008, Kansikas 2011). While protein-based in silico analyses predict that this variant is unlikely to alter protein structure or function, multiple splicing models predict that this variant may create a cryptic splice donor site upstream of the natural splice donor, leading to abnormal splicing. However, in the absence of RNA or functional studies, the actual effect of this variant is unknown. Based on currently available evidence, it is unclear whether MSH2 Ile497Val is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 02, 2018	- -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 17, 2023	This missense variant replaces isoleucine with valine at codon 497 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 been identified in 2/251298 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. -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 22, 2019	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

Uncertain significance, criteria provided, single submitter

clinical testing

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

Dec 21, 2023

Variant summary: MSH2 c.1489A>G (p.Ile497Val) results in a conservative amino acid change located in the DNA mismatch repair protein MutS, core domain (IPR007696) of the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251298 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1489A>G has been reported in the literature as a VUS in a report that aimed at assessing the prevalence of secondary findings in 19 NCCN designated genes within a cohort of 400 individuals without a cancer diagnosis undergoing whole exome sequencing (WES) analysis (example, Kraemer_2019). This report does not provide unequivocal conclusions about association of the variant with Hereditary Nonpolyposis Colorectal Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 31422574). Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=4) and benign/likely benign (n=2). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Lynch syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Dec 13, 2023

This missense variant replaces isoleucine with valine at codon 497 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 been identified in 2/251298 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. -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 19, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Benign	-0.030	T
BayesDel_noAF	Benign	-0.18
Cadd	Benign	19
Dann	Benign	0.65
DEOGEN2	Benign	0.34	T;.;.;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.68	T;T;T;T
M_CAP	Benign	0.040	D
MetaRNN	Benign	0.089	T;T;T;T
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	0.34	N;.;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	0.26	N;N;.;N
REVEL	Uncertain	0.38
Sift	Benign	0.28	T;T;.;T
Sift4G	Benign	0.29	T;T;.;T
Polyphen		0.0	B;.;.;B
Vest4		0.23
MutPred		0.39		Gain of disorder (P = 0.1703);.;Gain of disorder (P = 0.1703);Gain of disorder (P = 0.1703);
MVP		0.86
MPC		0.0069
ClinPred		0.019	T
GERP RS		-6.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.056
gMVP		0.13

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.96		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs755501968; hg19: chr2-47690272;