BRCA 1 & 2

BRCA1 and BRCA2 are the two most commonly involved genes in familial breast cancer, and also increase the risk of ovarian, prostate, and various other tumours. BRCA1 mutations are more likely to cause malignancy in general.


Both BRCA1 and BRCA2 are involved in homologous recombination (the 'accurate' double strand DNA break repair mechanism.

Syndrome Features

Patients have:

  • A 70% risk of breast cancer by age 70 (BRCA1), 40% for BRCA2
    • BRCA1 associated breast cancer is commonly of triple negative ductal type
  • A 25% risk of ovarian cancer by age 70 (both)
  • An elevated risk of pancreatic cancer
  • An elevated risk of prostate cancer
  • Elevated risks of other tumours such as cervical cancer

Patients often have first degree relatives with breast or ovarian cancers which prompts genetic testing.