ORE THAN 10 YEARS AFTER BRCA1 AND BRCA2 werediscoveredasmajorbreastcancersusceptibility genes, the medical community is just beginningtogetaglimpseofhowgermlinemutations in these genes might be distributed among racial/ethnic minority populations in the United States. While a growing body of evidence documents the benefits of preventive measureshavingminimalriskforwomenwithidentifiableBRCA1 andBRCA2mutations,genetictestingservicesremainunderutilized by minority women. In this issue of JAMA, John and colleagues 1 provide information regarding the prevalence of pathogenic BRCA1 mutations in a population-based study among5USracial/ethnicgroupsinNorthernCalifornia.PrevalencewasparticularlyhighamongyoungAfricanAmericans, a group that has long been recognized as having a disproportionate burden of aggressive young-onset breast cancer. With more than 200000 women estimated to be diagnosed with breast cancer and more than 40000 deaths from the disease each year, 2 a renewed emphasis on prevention for control of breast cancer is warranted. Women with germline mutations in BRCA1 and BRCA2 genes face dramatically increased risks of breast and ovarian cancers. The decision to pursue genetic testing for BRCA1 and BRCA2, with its associated costs, depends on 2 prerequisites: valid mutation detection methods for the test and effective cancer prevention strategies for mutation carriers. Regarding the first prerequisite, the specificity of genetic testing for BRCA mutations is believed to be 100% and sensitivity is estimated at 85%, 3 although recent studies have shown that analysis of genomic rearrangements,whichwasnotperformedintheUnitedStates until2006,maysignificantlyincreasesensitivity. 4,5 Forthesecond prerequisite, mutation carriers now have the option of choosingfromaspectrumofevidence-basedpreventionstrategies,includingintensivebreastcancersurveillanceusingmag