BRCA1

About BRCA1

BRCA1 Breast Cancer 1 is a tumor suppressor gene on chromosome 17q21.31. Its protein partners with BRCA2 and PALB2 in homologous recombination, the high fidelity pathway that repairs DNA double strand breaks, and it also takes part in cell cycle checkpoint control and transcriptional regulation. Inherited pathogenic variants are inherited in an autosomal dominant pattern and substantially raise lifetime risk of breast cancer, often at younger ages than in the general population, and of ovarian cancer. BRCA1 associated breast tumors are frequently triple negative. Certain founder variants, including 185delAG and 5382insC, are relatively common in Ashkenazi Jewish populations. The gene was mapped to chromosome 17 by Mary-Claire King and colleagues in 1990 and cloned in 1994. Testing may involve targeted founder variant analysis or full gene sequencing as part of multigene panels. People found to carry a pathogenic variant are typically offered genetic counseling, enhanced screening, and discussion of risk reducing options. PARP inhibitors exploit synthetic lethality in BRCA deficient cancers, which rely on alternative repair pathways.