2-47429942-G-T

Variant names:

• chr2-47429942-G-T
• rs267607950
• NM_000251.3:c.1276+1G>T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000251.3(MSH2):​c.1276+1G>T variant causes a splice donor, intron 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 Likely pathogenic (★★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH2 NM_000251.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:8
• Conservation: PhyloP100: 9.05

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 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-47429942-G-T is Pathogenic according to our data. Variant chr2-47429942-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 90592.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr2-47429942-G-T is described in Lovd as [Likely_pathogenic]. Variant chr2-47429942-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1276+1G>T		splice_donor_variant, intron_variant	Intron 7 of 15	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.1276+1G>T		splice_donor_variant, intron_variant	Intron 7 of 15	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:8

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2

Aug 17, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Published RNA studies show this variant activates a cryptic 5' splice site in exon 7, resulting in a deletion of 48 nucleotides from this exon (Petersen et al., 2013); This variant is associated with the following publications: (PMID: 25525159, 18566915, 12112654, 15849733, 19669161, 24090359, 16216036) -

Nov 03, 2021

Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary nonpolyposis colon cancer Pathogenic:1

Jul 01, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MSH2 c.1276+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. At least one publication reports experimental evidence that this variant abolishes normal splice site and results in the activation of a cryptic splice donor site 48 bp within exon 7, leading to an in-frame deletion of 16 amino acids in the MSH6/MSH3 interaction domain (Petersen_2013). The variant was absent in 251052 control chromosomes. c.1276+1G>T has been reported in the literature in individuals affected with Lynch Syndrome (Bisgaard_2002, Mangold_2005, Nilbert_2009, Frostberg_2021). These data indicate that the variant may be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 12112654, 34680242, 16216036, 18566915, 24090359). ClinVar contains an entry for this variant (Variation ID: 90592). Based on the evidence outlined above, the variant was classified as pathogenic. -

Lynch syndrome 1 Pathogenic:1

Aug 01, 2023

Myriad Genetics, Inc.

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Lynch syndrome Pathogenic:1

Jun 21, 2019

International Society for Gastrointestinal Hereditary Tumours (InSiGHT)

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

Interrupts canonical donor splice site -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Dec 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 7 of the MSH2 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the loss of 16 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with Lynch syndrome (PMID: 12112654, 16216036, 18566915, 24090359). It has also been observed to segregate with disease in related individuals. Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this MSH2 variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 1,370,736 individuals referred to our laboratory for MSH2 testing. ClinVar contains an entry for this variant (Variation ID: 90592). Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in exon 7 (PMID: 24090359; internal data). This variant disrupts the c.1276+1G nucleotide in the MSH2 gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 15849733, 19669161). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Dec 29, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1276+1G>T intronic pathogenic mutation results from a G to T substitution one nucleotide after coding exon 7 of the MSH2 gene. This alteration has been observed in an individual whose colorectal tumor demonstrated high microsatellite instability and loss of MSH2/MSH6 expression on immunohistochemistry (IHC), and family history met Amsterdam criteria (Ambry internal data). This alteration has also been reported in two HNPCC families (Bisgaard ML et al. Hum Mutat, 2002 Jul;20:20-7; Nilbert M et al. Fam Cancer, 2009 Jun;8:75-83) and in an individual whose colorectal tumor demonstrated high microsatellite instability and loss of MSH2 expression on IHC (Mangold E et al. J Pathol, 2005 Dec;207:385-95). This alteration was detected in a Danish family with colorectal cancer and was found to segregate with disease within the family (Petersen SM et al. BMC Med Genet, 2013 Oct;14:103). This alteration has also been demonstrated to cause aberrant splicing that leads to an in-frame deletion of 16 amino acids in the MSH6/MSH3 interaction domain of the MSH2 protein (Betz B et al. J Cancer Res Clin Oncol, 2010 Jan;136:123-34; Petersen SM et al. BMC Med Genet, 2013 Oct;14:103). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Muir-Torré syndrome;C2936783:Lynch syndrome 1;C5436806:Mismatch repair cancer syndrome 2 Pathogenic:1

May 31, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Uncertain	0.93	D
GERP RS		5.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.56		Position offset: -49
DS_DL_spliceai		1.0		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: rs267607950; hg19: chr2-47657081;