rs267607943

chr2-47429740-A-Cchr2-47429740-A-Gchr2-47429740-A-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000251.3(MSH2):c.1077-2A>C variant causes a splice acceptor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 8.36

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 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.7, offset of 11, new splice context is: ttatttccgattgaatttAGtgg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-47429740-A-C is Pathogenic according to our data. Variant chr2-47429740-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 90528.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr2-47429740-A-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH2	NM_000251.3	c.1077-2A>C		splice_acceptor_variant		ENST00000233146.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH2	ENST00000233146.7	c.1077-2A>C		splice_acceptor_variant		1	NM_000251.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

Lynch syndrome 1 Pathogenic:2

Pathogenic, reviewed by expert panel	research	International Society for Gastrointestinal Hereditary Tumours (InSiGHT)	Oct 10, 2014	Multifactorial likelihood analysis posterior probability >0.99 -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Jul 31, 2023	This variant is considered pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. This variant is strongly associated with more severe personal and family histories of cancer, typical for individuals with pathogenic variants in this gene [PMID: 27363726]. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 23, 2023	The c.1077-2A>C intronic pathogenic mutation results from an A to C substitution two nucleotides upstream from coding exon 7 in the MSH2 gene. This variant has been identified in probands who met Amsterdam I/II criteria for Lynch syndrome or had loss of MSH2 and MSH6 protein expression in their Lynch syndrome-associated tumors by immunohistochemistry (IHC) (Ambry internal data). Also, this variant was previously reported in one family fulfilling Amsterdam I criteria (De Lellis L, PLoS ONE 2013 ; 8(11):e81194) and in another family of Italian descent suspected of having HNPCC/Lynch syndrome (Ponz de Leon M, Br. J. Cancer 2004 Feb; 90(4):882-7). Tumor testing in both reported families showed loss of MSH2 protein expression by IHC and high microsatellite instability (MSI-H). 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. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. RNA studies have demonstrated this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 01, 2020	This variant causes an A to C nucleotide substitution at the -2 position of intron 6 of the MSH2 gene. Splice site prediction tools suggest that this variant may have a significant impact on RNA splicing. Although this prediction has not been confirmed in published RNA studies, this variant is expected to result in an absent or disrupted protein product. This variant has been reported in individuals affected with Lynch syndrome (PMID: 14970868, 24278394). Microsatellite instability and loss of MSH2 protein expression have been demonstrated in tumor samples from these individuals. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of MSH2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

not specified Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

May 28, 2021

This variant is located in a canonical splice-acceptor site and interferes with normal MSH2 mRNA splicing. The variant has been reported in individuals with personal or family history of hereditary non-polyposis colorectal cancer (HNPCC) and urinary tract cancer in the published literature (PMID: 31615790 (2020), 24278394 (2013), 15849733 (2005), 14970868 (2004)). This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

May 07, 2022

This sequence change affects an acceptor splice site in intron 6 of the MSH2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. 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: 14970868, 24278394, 31615790). This variant is also known as IVS6-2A>C. ClinVar contains an entry for this variant (Variation ID: 90528). Studies have shown that disruption of this splice site results in activation of a cryptic splice site and introduces a premature termination codon (Invitae). The resulting mRNA is expected to undergo nonsense-mediated decay. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.27
Cadd	Pathogenic	35
Dann	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.99		Position offset: 13
DS_AL_spliceai		1.0		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: rs267607943; hg19: chr2-47656879;