Genetic Variant MSH2:c.1277-2A>G (chr2-47445546-A-G) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000251.3(MSH2):c.1277-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000692 in 1,445,090 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 33)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

MSH2
NM_000251.3 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic reviewed by expert panel P:5

Conservation

PhyloP100: 6.72

Variant links:

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]

MSH2 links:

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ACMG classification

Classification made for transcript

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 2-47445546-A-G is Pathogenic according to our data. Variant chr2-47445546-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 90605.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr2-47445546-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3 link	c.1277-2A>G		splice_acceptor_variant, intron_variant	Intron 7 of 15	ENST00000233146.7	NP_000242.1	P43246-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7 link	c.1277-2A>G		splice_acceptor_variant, intron_variant	Intron 7 of 15	1	NM_000251.3	ENSP00000233146.2		P43246-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.92e-7

AC:

AN:

1445090

Hom.:

Cov.:

AF XY:

0.00000139

AC XY:

AN XY:

720134

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000189

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

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

Sep 05, 2013

International Society for Gastrointestinal Hereditary Tumours (InSiGHT)

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: research

Splicing aberration, >2 tumours with MSH2 immunoloss, co-segregation with disease & absent in 1000 genomes -

Lynch-like syndrome

Pathogenic:1

Jul 01, 2019

Constitutional Genetics Lab, Leon Berard Cancer Center

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Gastric cancer

Pathogenic:1

Jul 01, 2021

Laboratory for Genotyping Development, RIKEN

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Jul 19, 2017

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1277-2A>G intronic pathogenic mutation results from an A to G substitution two nucleotides upstream from coding exon 8 in the MSH2 gene. This alteration has been reported in an individual with an MSI-high and MSH2 IHC absent colorectal cancer at age 33 (Overbeek LI et al. Br. J. Cancer, 2007 May;96:1605-12). This alteration has also been reported in two Norwegian families with an aggregation of colorectal cancers and was shown to give rise to aberrant splicing, specifically out of frame exon 8 skipping (Sjursen W et al. J. Med. Genet., 2010 Sep;47:579-85). This alteration has been classified as pathogenic using the following lines of evidence: in silico prediction models, segregation with disease, clinical phenotype including tumor characteristics, mutation co-occurrence, and functional studies (Thompson BA et al. Hum. Mutat. 2013 Jan;34:200-9; Thompson BA et al. Nat. Genet. 2014 Feb;46:107-15; available at [www.insight-group.org/variants/classifications/]). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.15

CADD

Pathogenic

DANN

Benign

0.97

Eigen

Pathogenic

0.97

Eigen_PC

Pathogenic

0.79

FATHMM_MKL

Pathogenic

0.99

GERP RS

4.2

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.92

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.76

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over