It is estimated that more than 21,000 women will be diagnosed with ovarian cancer in the United States in 2009, and more than 14,000 women will die from the disease. It has also been estimated that approximately 10% of patients with ovarian cancer, the vast majority of who have epithelial tumors, carry germline variants in 1 of 2 hereditary breast and ovarian cancer genes: BRCA1 and BRCA2. BRCA1 (breast cancer gene 1, located on chromosome 17 at band q21) and BRCA2 (breast cancer gene 2, located on chromosome 13 at band q12.3) encode proteins that function in the double-strand DNA break repair pathway and behave as tumor suppressor genes. Most alterations in the BRCA1 and BRCA2 genes are frameshift, nonsense, or splice-site variants that lead to premature truncation of the protein during translation. While many of these are considered “private” variants, having been found in only 1 or a few families, common ethnic-specific variants have also been identified for some populations. Individuals carrying deleterious variants in either BRCA1 or BRCA2 are known to have an increased risk for both breast and ovarian cancer. In comparison with a lifetime risk of 1.8% for a woman in the general population, the lifetime risk of ovarian cancer is approximately 30% to 60% for BRCA1 carriers and 10% to 30% for BRCA2 carriers.