Genetic Information

Gene & Transcript Details

Gene
BRCA2
Transcript
NM_000059.3 MANE Select
Total Exons
Reference Sequence
NC_000013.10
Alternative Transcripts
IDStatusDetails
NM_000059.4 MANE Select 11954 nt | 200–10456
NM_000059.2 Alternative 11386 nt | 228–10484
NM_000059.3 RefSeq Select 11386 nt | 228–10484

Variant Details

HGVS Notation
NM_000059.3:c.794-2A>G
Protein Change
Splice
Location
Exon 9 (Exon 9 of )
9
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.0 in 100,000
Extremely Rare
ACMG Criteria Applied PM2
This variant is absent or extremely rare in population databases (PM2 criteria applies).

ClinVar

Open
Classification
Likely Pathogenic
4 publications
Publications List
PMID: 33471991

The c.794-2A>G intronic variant results from an A to G substitution two nucleotides upstream from coding exon 9 in the BRCA2 gene. In one study, this variant was reported in 1/60,466 breast cancer cases and in 0/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and may result in the creation or strengthening of a novel splice acceptor site. The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNAdecay. RNA studies have demonstrated that this alteration results in a transcript predicted to lead to a protein with an in-frame deletion of 372 amino acids; however, the exact functional impact of the deleted amino acids is unknown at this time (Ambry internal data). This nucleotide position is highly conserved in available vertebrate species. Based on the available evidence, the clinical significance of this variant remains unclear.

PMID: 16199547

This sequence change affects an acceptor splice site in intron 9 of the BRCA2 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 BRCA2 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 568479). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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.

Clinical Statement

"This variant has been reported in ClinVar as Likely pathogenic (4 clinical laboratories) and as Uncertain significance (2 clinical laboratories) and as Likely Pathogenic (1 clinical laboratories) and as Pathogenic (1 clinical laboratories) and as Uncertain Significance by ClinGen ENIGMA BRCA1 and BRCA2 Variant Curation Expert Panel, ClinGen expert panel."

COSMIC Somatic Evidence

Open
COSMIC ID
Recurrence
0 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
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Functional Impact & Domains

Functional Domain

Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain.
Related Variants in This Domain
No evidence of other pathogenic variants at this position in gene BRCA2.

Functional Studies & Therapeutic Relevance

Functional Summary

Error in OpenAI Consolidation. OncoKB: BRCA2SpliceBRCA2SpliceSomaticNCBI Gene:675|Show additional gene information Variant OverviewBRCA2, a tumor suppressor involved in the DNA damage response, is mutated in various cancer types.The BRCA2 splice alteration has not specifically been reviewed by the OncoKB team, and therefore its biological significance is unknown. JAX-CKB: No results found

Database Previews
OncoKB
OncoKB Preview
JAX-CKB
JAX-CKB Preview

Click on previews to view full database entries. External databases may require institutional access.

Computational Analysis

Pathogenicity Predictions

SpliceAI
Predictor Consensus
Mixed/VUS
PP3 Applied
Yes
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.99 2 bp
- Donor Loss (DL) 0.01 174 bp
+ Acceptor Gain (AG) 0.31 20 bp
+ Donor Gain (DG) 0.0 20 bp
High impact (≥0.5) Medium impact (0.2-0.49) Low impact (<0.2)

VCEP Guidelines

Applied ACMG/AMP Criteria (VCEP Specific)

Filter Criteria:
PVS1

PVS1 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PM2

PM2 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PP3

PP3 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PP5

PP5 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)