Nearly 10% of breast and ovarian cancers develop as a direct consequence of an inherited flaw in the genes BRCA1 and BRCA2. The protein products of these genes suppress the development of cancer, in part by repairing damage in other genes. Women who inherit a nonfunctioning copy of either BRCA1 or BRCA2 therefore have a significantly elevated lifetime risk of breast cancer, especially at an early age. Identification of hereditary breast and ovarian cancer susceptibility allows optimized medical management of an individual's increased risk of breast and ovarian cancer. Significantly, testing may also identify women in "high-risk" families who did not themselves inherit cancer susceptibility, allowing them to avoid unnecessary medical intervention. Choosing to be tested for breast and ovarian cancer risk is a complicated task, however. It takes into account concerns about insurance liability, family dynamics, and an individual's psychological needs. From the limited research, evidence suggests that for individuals in high-risk families it is more beneficial to know than not to know one's genetic status. Education and counseling may improve public perception about genetic testing for breast cancer.