—BRCA1 and BRCA2 are uncommon. They are thought to account for about 5 per cent to 10 per cent of all breast cancers, and about 15 per cent of ovarian cancers.
—If a number of family members have had breast or ovarian cancer, particularly at a younger age, the U.S. Preventive Services Task Force says women should discuss with a health professional if they're at increased risk, too. A genetic counsellor can help high-risk women decide whether to have a blood test to see if they inherited the genes.
—Doctors advise women with faulty BRCA genes to undergo frequent screenings for breast cancer, and to consider having their ovaries removed at some point between ages 35 and 40 or when childbearing is complete. A new study suggests BRCA1 carriers might benefit from surgery at the earlier age.