NM_000251.3:c.1277-2A>T

Variant names:

• chr2-47445546-A-T
• rs267607949
• NM_000251.3:c.1277-2A>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.1277-2A>T variant causes a splice acceptor, intron change. 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: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MSH2 NM_000251.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.72

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 2-47445546-A-T is Pathogenic according to our data. Variant chr2-47445546-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 619528.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.1277-2A>T		splice_acceptor_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.1277-2A>T		splice_acceptor_variant, intron_variant	Intron 7 of 15	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1445090 Hom.: 0 Cov.: 27 AF XY: 0.00 AC XY: 0 AN XY: 720134

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: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome Pathogenic:1

May 01, 2018

University of Washington Department of Laboratory Medicine, University of Washington

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

MSH2 NM_000251.2:c.1277-2A>T has a 98.1% probability of pathogenicity based on combining prior probability from public data with a likelihood ratio of 1.56 to 1, generated from evidence of seeing this as a somatic mutation in a tumor without loss of heterozygosity at the MSH2 locus. See Shirts et al 2018, PMID 29887214. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Aug 03, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1277-2A>T intronic pathogenic mutation results from an A to T substitution two nucleotides upstream from coding exon 8 in the MSH2 gene. Using a Bayesian analysis that incorporates tumor mutation data, this variant was classified as likely pathogenic (Shirts BH et al. Am J Hum Genet, 2018 07;103:19-29). Two alterations impacting the same acceptor site (c.1277-2A>G and c.1277-1G>A) have been detected in individuals meeting either Amsterdam criteria or Bethesda guidelines for hereditary non-polyposis colorectal cancer (HNPCC)/Lynch syndrome and had colorectal tumors displaying high microsatellite instability with loss of MSH2 protein staining on immunohistochemistry (Sheng JQ et al. Chin J Dig Dis, 2006;7:197-205; Goldberg Y et al. Fam. Cancer, 2008 Apr;7:309-17; Sjursen W et al. J. Med. Genet., 2010 Sep;47:579-85; Tian W et al. Int J Cancer. 2019 Sep 1;145(5):1290-1298). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. 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	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	35
DANN	Uncertain	0.98
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
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		0.88		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: rs267607949; hg19: chr2-47672685;