2-47410374-T-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_000251.3(MSH2):c.645+2T>C variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 splice_donor
• Scores: Splicing: ADA: 0.9898
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.88

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 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.09910873 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_addAF computational evidence supports a deleterious effect, 0.625
• PP5: Variant 2-47410374-T-C is Pathogenic according to our data. Variant chr2-47410374-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 450032.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-47410374-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.645+2T>C		splice_donor_variant		ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.645+2T>C		splice_donor_variant		1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 20, 2022	Canonical splice site variant predicted to result in an in-frame deletion of the adjacent exon; Not observed at significant frequency in large population cohorts (gnomAD); Identified in a large cohort of predominantly healthy individuals being evaluated by multi-gene panel (eMERGE Consortium 2019); This variant is associated with the following publications: (PMID: 21120944, 18822302, 31447099) -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2020	- -

Lynch syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Dec 21, 2016

The c.645+2T>C variant in MSH2 has not been previously reported in individuals w ith Lynch Syndrome or in large population studies. This variant occurs in the in variant region (+/- 1,2) of the splice consensus sequence and is predicted to ca use altered splicing leading to an abnormal or absent protein. Heterozygous loss of function of the MSH2 gene is an established disease mechanism in individuals with Lynch syndrome. In summary, this variant meets criteria to be classified a s pathogenic for Lynch syndrome in an autosomal dominant manner based upon absen ce from the general population and predicted impact to the protein. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 24, 2024

This sequence change affects a donor splice site in intron 3 of the MSH2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MSH2 are known to be pathogenic (PMID: 15849733, 24362816). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 16884359). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 450032). Studies have shown that disruption of this splice site is associated with altered splicing resulting in multiple RNA products (Invitae). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 26, 2023

The c.645+2T>C intronic variant results from a T to C substitution two nucleotides after coding exon 3 in the MSH2 gene. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. In silico splice site analysis for this alteration is inconclusive; however, RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). The resulting transcript is in-frame and is not expected to trigger nonsense-mediated mRNAdecay; however, direct evidence is unavailable. The exact functional effect of the altered amino acid sequence is unknown; however, the impacted region is critical for protein function (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This nucleotide position is highly conserved in available vertebrate species. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.15
Cadd	Uncertain	25
Dann	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Benign	0.61
SpliceAI score (max)		0.24		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.24		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs876658996; hg19: chr2-47637513;