Over the past 5 years, tests for germline (heritable) gene mutations associated with high risk of chronic diseases, such as breast cancer, have become increasingly available. Appropriately used, tests for such mutations could lead to reductions in disease morbidity and mortality. Population screening has been proposed for some cancer-related mutations; however, not all populations are suitable for such screening. The benefits of screening and preventive treatments for individuals with cancer-related mutations in different populations depend on the prevalence and penetrance of the mutation, the mortality associated with the disease, the age of the person screened at testing, and the potential effects of preventive measures on risk of developing the disease, quality of life, and costs. The criteria normally used to assess cancer screening tests can be applied, with some modifications, to tests for cancer-related genetic mutations and can help physicians, insurance companies, and health-policy makers to decide whether or not specific genetic tests should be used to screen specific populations