BRCA1

Chr 17ADAR

BRCA1 DNA repair associated

Also known as: BRCAI, BRCC1, BROVCA1, FANCS, IRIS, PNCA4, PPP1R53, PSCP

The BRCA1 protein functions as an E3 ubiquitin ligase that facilitates DNA repair by forming polyubiquitin chains and coordinating cellular responses to DNA damage through homologous recombination. Heterozygous mutations cause autosomal dominant familial breast-ovarian cancer syndrome and increase susceptibility to pancreatic cancer, while biallelic mutations result in autosomal recessive Fanconi anemia complementation group S. The pathogenic mechanism involves loss of DNA repair capacity leading to genomic instability and increased cancer risk in the heterozygous state, or severe DNA repair deficiency causing bone marrow failure and developmental abnormalities in the homozygous state.

Summary from RefSeq, OMIM, UniProt

Primary Disease Associations & Inheritance

{Breast-ovarian cancer, familial, 1}MIM #604370
AD
{Pancreatic cancer, susceptibility to, 4}MIM #614320
Fanconi anemia, complementation group SMIM #617883
AR
UniProtBreast cancer
UniProtPancreatic cancer 4
12
Active trials
1693
Pubs (1 yr)
122
P/LP submissions
0%
P/LP missense
0.92
LOEUF
LOF*
Mechanism· G2P
Clinical SummaryBRCA1
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Gene-Disease Validity (ClinGen)
BRCA1-related cancer predisposition · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

2 total gene-disease associations curated

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
120 unique Pathogenic / Likely Pathogenic· 209 VUS of 500 total submissions
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Clinical Trials
12 active or recruiting trials — potential therapeutic options may be available
📖
GeneReview available — BRCA1
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.92LOEUF
pLI 0.000
Z-score 2.16
OE 0.73 (0.590.92)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.58Z-score
OE missense 0.95 (0.901.00)
891 obs / 941.3 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.73 (0.590.92)
00.351.4
Missense OE0.95 (0.901.00)
00.61.4
Synonymous OE0.96
01.21.6
LoF obs/exp: 55 / 75.2Missense obs/exp: 891 / 941.3Syn Z: 0.51
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
strongBRCA1-related Fanconi anemiaLOFAR
definitiveBRCA1-related cancerLOFAD
DN
0.6356th %ile
GOF
0.4085th %ile
LOF
0.56top 25%

This gene has evidence for multiple mechanisms of pathogenicity (loss-of-function and dominant-negative). The Badonyi & Marsh model scores dominant-negative highest among its predictions, but genomic evidence (constraint, ClinVar variant spectrum, and literature) most strongly supports loss-of-function (haploinsufficiency). Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

LOF1 literature citation · 71% of P/LP variants are LoF
DNprediction above median · 1 literature citation

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNAll of these treatments were found to induce substantial levels of apoptosis in the presence of wild-type BRCA1, whereas dominant negative BRCA1 truncation mutants diminished the apoptotic response.PMID:10938285
LOFVan der Merwe et al. (2020) used MLPA and NGS to evaluate 744 patients with breast cancer or ovarian cancer in a South African cohort. 7 individuals were found to have large genomic rearrangements of BRCA1 (1.1% of total patients).PMID:32375709

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

500 submitted variants in ClinVar

Classification Summary

Pathogenic97
Likely Pathogenic23
VUS209
Likely Benign140
Benign1
Conflicting4
97
Pathogenic
23
Likely Pathogenic
209
VUS
140
Likely Benign
1
Benign
4
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
70
0
27
0
97
Likely Pathogenic
15
0
8
0
23
VUS
5
176
24
4
209
Likely Benign
0
11
60
69
140
Benign
0
0
1
0
1
Conflicting
4
Total9018712073474

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

BRCA1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

Pancreatic Adenocarcinoma MetastaticBRCA1 MutationBRCA2 Mutation

SHARON: A Clinical Trial for Metastatic Cancer Using Chemotherapy and Patients' Own Stem Cells

RECRUITING
NCT04150042Phase PHASE1General Oncology, Inc.Started 2021-01-13
MelphalanBCNUVitamin B12B
Advanced Solid TumorsEwing SarcomaHepatocellular Carcinoma (HCC)

A Phase 1/1B Study of ST-01156, a Small Molecule RBM39 Degrader, in Patients With Advanced Solid Malignancies

RECRUITING
NCT07197554Phase PHASE1SEED Therapeutics, Inc.Started 2025-12-01
ST-01156
Stage I Breast CancerStage II Breast CancerStage III Breast Cancer

Niraparib + Dostarlimab In BRCA Mutated Breast Cancer

ACTIVE NOT RECRUITING
NCT04584255Phase PHASE2Dana-Farber Cancer InstituteStarted 2020-12-18
NiraparibDostarlimab
Advanced Malignant Solid NeoplasmAnn Arbor Stage III Non-Hodgkin LymphomaAnn Arbor Stage IV Non-Hodgkin Lymphoma

Targeted Therapy Directed by Genetic Testing in Treating Pediatric Patients With Relapsed or Refractory Advanced Solid Tumors, Non-Hodgkin Lymphomas, or Histiocytic Disorders (The Pediatric MATCH Screening Trial)

ACTIVE NOT RECRUITING
NCT03155620Phase PHASE2National Cancer Institute (NCI)Started 2017-07-31
Biopsy ProcedureBiospecimen CollectionBone Marrow Aspiration and Biopsy
Metastatic Pancreatic Cancer

Olaparib and Durvalumab (MEDI4736) in Patients with Metastatic Pancreatic Cancer and DNA Damage Repair Genes Alterations

ACTIVE NOT RECRUITING
NCT05659914Phase PHASE2Spanish Cooperative Group for the Treatment of Digestive Tumours (TTD)Started 2022-11-28
olaparib+durvalumab
Advanced Breast Cancer

FUnctional Selection of Advanced Breast Cancer Patients for Talazoparib Treatment Using the REpair Capacity (RECAP) Test

RECRUITING
NCT06193525Phase PHASE2Erasmus Medical CenterStarted 2019-09-16
Talazoparib
Advanced Solid TumorMetastatic Solid TumorGBM

Study of LP-184 in Patients With Advanced Solid Tumors

RECRUITING
NCT05933265Phase PHASE1, PHASE2Lantern Pharma Inc.Started 2023-06-09
LP-184SpironolactoneOlaparib
Breast CarcinomaGenetic Predisposition to CancerBRCA Mutation

MEASUREMENT OF CIRCULATING MUTATION BURDEN

RECRUITING
NCT06792721Centre Francois BaclesseStarted 2025-07-04
Mutation Burden cfMB analysis
Metastatic Triple Negative Breast Cancer

To Assess Safety and Efficacy of Agents Targeting DNA Damage Repair With Olaparib Versus Olaparib Monotherapy.

ACTIVE NOT RECRUITING
NCT03330847Phase PHASE2AstraZenecaStarted 2018-03-07
Olaparib Continuous (28-Day cycle) 300 mg BD.Ceralasertib 160 mg OD + olaparib continuous 300 mg BD (28-day cycle).Adavosertib 150 mg BD + olaparib 200 mg BD (21-day cycle).
Breast NeoplasmsGermline BRCA1 Gene MutationGermline BRCA2 Gene Mutation

Prospective Study of MAstectomy With Reconstruction Including Robot Endoscopic Surgery

ACTIVE NOT RECRUITING
NCT04585074Severance HospitalStarted 2020-04-08
Robotic or endoscopic nipple sparing mastectomyConventional mastectomy (including nipple sparing mastectomy, skin sparing mastectomy)
BRCA1 MutationBRCA2 Mutation

BRCA Mutation Carriers' Platform a Multicenter Study

RECRUITING
NCT07253051Fondazione Policlinico Universitario Agostino Gemelli IRCCSStarted 2025-04-05
Registration of clinical datas in the platform
Triple Negative Breast CancerBreast Cancer

Serial Circulating Tumor DNA (ctDNA) Monitoring During Adjuvant Capecitabine in Early Triple-negative Breast Cancer

RECRUITING
NCT04768426Phase PHASE2Stanford UniversityStarted 2021-02-03
Capecitabine
Clinical Literature
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