chr2-47480689-CTTATA-C

Position:

• chr2-47480689-CTTATA-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_000251.3(MSH2):​c.2459-6_2459-2del variant causes a splice acceptor, splice polypyrimidine tract, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 splice_acceptor, splice_polypyrimidine_tract, intron
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 8.61

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 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06238859 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.5, offset of 36, new splice context is: ttttgggattcatgttgcAGagc. Cryptic site results in inframe 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
• PP5: Variant 2-47480689-CTTATA-C is Pathogenic according to our data. Variant chr2-47480689-CTTATA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 428503.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.2459-6_2459-2del		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.2459-6_2459-2del		splice_acceptor_variant, splice_polypyrimidine_tract_variant, intron_variant		1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 31

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 08, 2023

This variant is considered likely 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. -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 28, 2021

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. Donor and acceptor splice site variants 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). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has not been reported in the literature in individuals with MSH2-related disease. ClinVar contains an entry for this variant (Variation ID: 428503). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in intron 14 of the MSH2 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 22, 2019

The c.2459-6_2459-2delTTATA intronic pathogenic mutation, located in intron 14 of the MSH2 gene, results from a deletion of 5 nucleotides within intron 14 of the MSH2 gene. This variant was identified as germline in a patient meeting Amsterdam criteria II with early onset colorectal cancer meeting Amsterdam criteria II whose tumor showed loss of MSH2 and MSH6 protein expression by IHC (Ambry internal data). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). These nucleotide positions are generally well conserved. Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native splice acceptor site; however, direct evidence is unavailable. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1114167841; hg19: chr2-47707828;