rs267608010

Positions:

• chr2-47478520-G-A
• chr2-47478520-G-C
• chr2-47478520-G-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.2458+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,702 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 Likely pathogenic (★★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MSH2 NM_000251.3 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic reviewed by expert panel P:7
• Conservation: PhyloP100: 9.49

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, Cryptic splice site detected, with MaxEntScore 6.7, offset of -10, new splice context is: cagGTgaag. 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
• PP5: Variant 2-47478520-G-A is Pathogenic according to our data. Variant chr2-47478520-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 90976.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr2-47478520-G-A is described in Lovd as [Pathogenic]. Variant chr2-47478520-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH2	NM_000251.3	c.2458+1G>A		splice_donor_variant		ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.2458+1G>A		splice_donor_variant		1	NM_000251.3	ENSP00000233146	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461702 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727160

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

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.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:7

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Apr 13, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Aug 28, 2015	This pathogenic variant is denoted MSH2 c.2458+1G>A or IVS14+1G>A and consists of a G>A nucleotide substitution at the +1 position of intron 14 of the MSH2 gene. The variant destroys a canonical splice donor site and is predicted to cause abnormal gene splicing, leading to either an abnormal message that is subject to nonsense-mediated mRNA decay or to an abnormal protein product. This variant has been reported in at least one individual with a suggestive history of Lynch syndrome (Mangold 2005). we consider this variant to be pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 02, 2021	The c.2458+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 14 of the MSH2 gene. This pathogenic mutation was previously identified in one individual whose personal and/or family history was suggestive of HNPCC/Lynch syndrome (Mangold E et al. Int. J. Cancer 2005 Sep;116:692-702). This pathogenic mutation has also been identified in several unrelated individuals whose Lynch syndrome associated tumors demonstrated loss of both MSH2/MSH6 by immunohistochemistry and one proband had a family history that met Amsterdam I criteria (Ambry internal data). In addition, this pathogenic mutation co-segregated with disease in one family tested in our laboratory (Ambry internal data). In silico splice site analysis predicts that this alteration will weaken the native splice donor site and may result in the creation or strengthening of a novel splice donor site. In addition to the clinical data from our internal cohort and 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 01, 2020	This variant causes a G to A nucleotide substitution at the +1 position of intron 14 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 an individual with personal and/or family history of Lynch syndrome-associated cancers (PMID: 15849733). 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 Likely Pathogenic. -

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. -

Lynch syndrome Pathogenic:1

Likely pathogenic, reviewed by expert panel

curation

International Society for Gastrointestinal Hereditary Tumours (InSiGHT)

Jun 21, 2019

Interrupts canonical donor splice site -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 27, 2024

This sequence change affects a donor splice site in intron 14 of the MSH2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site 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). 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: 15849733, 31615790, 35100712). ClinVar contains an entry for this variant (Variation ID: 90976). Studies have shown that disruption of this splice site is associated with inconclusive levels of altered splicing (Invitae). 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	0.36
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
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	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.45		Position offset: -11
DS_DL_spliceai		0.99		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: rs267608010; hg19: chr2-47705659;