NM_000251.3:c.2634+5G>A

Variant names:

• chr2-47480876-G-A
• NM_000251.3:c.2634+5G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000251.3(MSH2):​c.2634+5G>A variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 31)
• Consequence: MSH2 NM_000251.3 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 6.24

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 2-47480876-G-A is Pathogenic according to our data. Variant chr2-47480876-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1172006.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH2	NM_000251.3	c.2634+5G>A		splice_region_variant, intron_variant	Intron 15 of 15	ENST00000233146.7	NP_000242.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH2	ENST00000233146.7	c.2634+5G>A		splice_region_variant, intron_variant	Intron 15 of 15	1	NM_000251.3	ENSP00000233146.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1 Uncertain:1

Jul 15, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a G to A nucleotide substitution at the +5 position of intron 15 of the MSH2 gene. Splice site prediction tools predict that this variant may have a significant impact on RNA splicing. Two other single nucleotide substitutions with similar predicted splicing impact, c.2634+5G>C and c.2634+5G>T, have been shown to cause exon 15 skipping in patient RNA samples (PMID: 11074494, 18033691) and in minigene splicing assay (PMID: 18561205), respectively. To our knowledge, this variant has not been reported in functional studies nor in individuals affected with hereditary cancer in the literature. However, the two other variants at this position, c.2634+5G>C and c.2634+5G>T, have been reported in multiple Lynch syndrome families with DNA mismatch repair-deficient colorectal cancer (PMID: 11074494, 15713769, 16807412, 18561205, 31101557). In one family, the c.2634+5G>C variant segregated in 5 affected family members (PMID: 18033691). 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. -

Apr 29, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2634+5G>A intronic variant results from a G to A substitution 5 nucleotides after coding exon 15 in the MSH2 gene. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis for this alteration is inconclusive; however, direct evidence is insufficient at this time (Ambry internal data). Based on the available evidence, the clinical significance of this variant remains unclear. -

Hereditary nonpolyposis colon cancer Pathogenic:1

Feb 25, 2025

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MSH2 c.2634+5G>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Two predict the variant abolishes a 5' splicing donor site. One predict the variant weakens a 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 251350 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2634+5G>A has been reported in the literature in at least one individual affected with Hereditary Nonpolyposis Colorectal Cancer. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 35430768). ClinVar contains an entry for this variant (Variation ID: 1172006). In addition, other variants affecting this nucleotide (c.2634+5G>T, c.2634+5G>C) have been reported to associate with Hereditary Nonpolyposis Colorectal Cancer. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Jul 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 15 of the MSH2 gene. It does not directly change the encoded amino acid sequence of the MSH2 protein. It affects a nucleotide within the consensus splice site. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with clinical features of MSH2-related conditions (PMID: 35430768). ClinVar contains an entry for this variant (Variation ID: 1172006). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant is associated with inconclusive levels of altered splicing (Invitae). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.60
CADD	Uncertain	26
DANN	Benign	0.84

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.10		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-47708015;