BRCA1 and BRCA2 are genes which normally help to prevent breast cancer by making proteins which inhibit abnormal cellular growth. While a woman with an average risk for breast cancer has a 10% chance of developing the disease sometime in her lifetime, a woman who has either the BRCA1 or BRCA2 has an estimated 50-87% chance of developing breast cancer by the age of 70.

Breast Cancer is the most common cancer in women.

What are the options for women who test positive? More aggressive screening Chemoprevention Prophylactic Surgery ( removal of breasts or ovaries) Some studies have shown that removal of both ovaries can even significantly reduce the risk of breast cancer in this group of patients.

Most genetic tests are performed on a blood sample.

Available tests and the associated cancers: BRCA1 BRCA1, for cancers of Breast, Colon, Ovaries, Prostate BRCA2 BRCA2, for cancers of Breast, Colon, Ovaries, Prostate p53 p53, for cancers of Breast, Bone, Leukemia, Brain Tumor APC APC, for Colon cancer RET RET, for Medulary Thyroid cacnner VHL VHL, Von Hipple Lindau NF1 NF1, for Neurofibrosarcoma RB1 RB1, for Retinoblastoma BLM BLM, for cancers of Colon, Esophaeal, Tongue, Leukemia and Wilms Tumor

In addition to a possible increased susceptibility to breast cancer, BRCA1and BRCA2 mutations are thought to contribute to earlier onset of the disease. Breast cancers caused by BRCA1 or BRCA2 mutations usually occur before menopause, whereas most non-genetic breast cancers usually occur after menopause. In addition to a possible increased susceptibility to breast cancer, BRCA1and BRCA2 mutations are thought to contribute to earlier onset of the disease. Breast cancers caused by BRCA1 or BRCA2 mutations usually occur before menopause, whereas most non-genetic breast cancers usually occur after menopause.

BRCA1; located on chromosome 17 BRCA2; located on chromosome 13