Genes are the "blueprints" for our bodies. Some people are born with an abnormal copy ("mutation") of a gene. These people may have a higher chance of getting a disease. Different mutations in different genes cause different diseases. Some women get breast cancer because they are born with an abnormal copy of a gene called BRCA1 or BRCA2. These women also have a higher chance of getting ovary cancer. Women with breast cancer and an abnormal copy of BRCA1 or BRCA2 also have a higher chance of getting a second breast cancer in their other breast. Because of this, women who might have a mutation may have genetic testing soon after their breast cancer diagnosis to learn about their risks of getting another cancer.