Genetic Information

Gene & Transcript Details

Gene
BRCA2
Transcript
NM_000059.4 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_000059.4:c.4005dup
Protein Change
F1336Ifs*2
Location
Exon 11 (Exon 11 of )
11
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
Pathogenic
1 publications
Publications List
PMID: 24156927

The c.4005dupA pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from a duplication of A at nucleotide position 4005, causing a translational frameshift with a predicted alternate stop codon (p.F1336Ifs*2). This alteration has been reported in multiple large studies of BRCA1/2 mutation positive families (Tea MK et al. Maturitas, 2014 Jan;77:68-72; Palmero EI et al. Sci Rep, 2018 06;8:9188; Rebbeck TR et al. Hum. Mutat., 2018 05;39:593-620). This alteration, designated 4232insA, has also been reported in a Hungarian male breast cancer patient (Ramus SJ et al. Am. J. Hum. Genet., 1997 May;60:1242-6). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation.

PMID: 20104584

This sequence change creates a premature translational stop signal (p.Phe1336Ilefs*2) in the BRCA2 gene. It is expected to result in an absent or disrupted protein product. 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 premature translational stop signal has been observed in individual(s) with a personal and/or family history of breast and/or ovarian cancer (PMID: 9150174, 24156927, 29446198, 29907814). This variant is also known as 4232insA. ClinVar contains an entry for this variant (Variation ID: 51581). For these reasons, this variant has been classified as Pathogenic.

Clinical Statement

"This variant has been reported in ClinVar as Pathogenic (3 clinical laboratories) and as Pathogenic by Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) expert panel."

COSMIC Somatic Evidence

Open
COSMIC ID
Recurrence
0 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC 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

The BRCA2 F1336Ifs*2 variant is a truncating mutation that results in the loss of critical protein domains, including the C-terminal DNA binding domain, nuclear localization signal, and CDK2 phosphorylation site. Functional studies indicate that such truncating mutations impair the nuclear localization of BRCA2, disrupting its role in maintaining homologous recombination during DNA damage response. This functional impairment supports a damaging effect of the variant.

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
Unknown
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.0 111 bp
- Donor Loss (DL) 0.0 -453 bp
+ Acceptor Gain (AG) 0.0 52 bp
+ Donor Gain (DG) 0.01 -157 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)

PS3

PS3 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PM2

PM2 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PP5

PP5 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)