rs774132884

Positions:

• chr2-47410161-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM5

The NM_000251.3(MSH2):​c.434T>C​(p.Ile145Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,774 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. I145M) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: MSH2 NM_000251.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 4.74

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 2 ACMG points.

• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-47410162-T-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.434T>C	p.Ile145Thr	missense_variant	3/16	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.434T>C	p.Ile145Thr	missense_variant	3/16	1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251430 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135892

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: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461774 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 727190

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: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Alfa AF: 0.000142 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.0000165 AC: 2

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:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 21, 2023	This missense variant replaces isoleucine with threonine at codon 145 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 has intermediate MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold -1.32 < LOF score < 0.88, PMID: 33357406). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 1/251430 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 21, 2023	The p.I145T variant (also known as c.434T>C), located in coding exon 3 of the MSH2 gene, results from a T to C substitution at nucleotide position 434. The isoleucine at codon 145 is replaced by threonine, an amino acid with similar properties. In a massively parallel cell-based functional assay testing susceptibility to a DNA damaging agent, 6-thioguanine (6-TG), this variant was reported to be functionally neutral (Jia X et al. Am J Hum Genet, 2021 01;108:163-175). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Mar 25, 2023

- -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jul 10, 2023

This missense variant replaces isoleucine with threonine at codon 145 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 has intermediate MSH2 function in a 6-thioguanine sensitivity assay in haploid human cells (internally defined LOF score threshold -1.32 < LOF score < 0.88, PMID: 33357406). This variant has not been reported in individuals affected with MSH2-related disorders in the literature. This variant has been identified in 1/251430 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

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 31, 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; Published functional studies suggest no impact on mismatch repair function (Jia et al., 2020); This variant is associated with the following publications: (PMID: 18822302, 21120944, 33357406) -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 03, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	20
DANN	Benign	0.27
DEOGEN2	Benign	0.28	T;T;.;.;.
Eigen	Benign	-0.50
Eigen_PC	Benign	-0.33
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.92	D;D;D;D;D
M_CAP	Benign	0.040	D
MetaRNN	Uncertain	0.48	T;T;T;T;T
MetaSVM	Uncertain	-0.019	T
MutationAssessor	Benign	1.1	L;.;.;.;.
MutationTaster	Benign	0.71	D;N;N
PrimateAI	Benign	0.40	T
PROVEAN	Benign	-0.50	N;N;N;.;N
REVEL	Uncertain	0.48
Sift	Benign	0.19	T;T;T;.;T
Sift4G	Benign	0.45	T;T;T;.;T
Polyphen		0.0	B;.;.;.;B
Vest4		0.61
MutPred		0.86		Loss of stability (P = 0.0019);.;.;Loss of stability (P = 0.0019);Loss of stability (P = 0.0019);
MVP		0.99
MPC		0.0061
ClinPred		0.082	T
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.093
gMVP		0.63

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: rs774132884; hg19: chr2-47637300;