BRCA1

BRCA1 is best understood as part of the cell's DNA repair crew. Imagine a maintenance team whose job is to fix the worst kind of damage, a clean break across both strands of the DNA. BRCA1 helps organize that careful, accurate repair so the cell's genetic blueprint stays intact.

BRCA1 is a tumor-suppressor gene; its protein works in homologous recombination, a precise method of mending double-strand breaks using the matching chromosome as a template. When BRCA1 is missing or broken, the cell falls back on sloppier repair, errors pile up, and the genome becomes unstable, raising the chance that a cell turns cancerous.

Inheriting one harmful BRCA1 variant substantially raises lifetime risk of breast and ovarian cancer, and to a lesser degree some other cancers. Risk is high but not certain; it is a strong predisposition, not a diagnosis. This knowledge supports screening choices and, importantly, sits at the heart of genetic counseling rather than self-directed alarm.