Eighty-four reports that described the Tests to detect mutations in BReast CAncer clinical outcomes in prophylactic or therapeutic studies susceptibility genes BRCA1 and BRCA2 were identified and synthesized to assess the benefit and harm of testing. [...] Genetic testing for these mutations is available in Counselling reduces the perceived risk and the Canada, and can be accessed as a clinical laboratory associated anxiety, and increases the uptake of service or through a research study. [...] In BRCA1 mutation carriers, the lifetime risk of developing breast or ovarian cancer is as high as 85% and 42% to 63% respectively.5 In BRCA2 carriers, the lifetime risk of developing breast or ovarian cancer is as high as 86% and 27% respectively. [...] There is evidence that a dozen other ethnic groups have a higher prevalence of specific BRCA mutations (up to eight times that of the general population).7 Factors that increase the likelihood of inherited breast or ovarian cancer include multiple cases of breast or ovarian cancer in a family, diagnosis of breast cancer before age 35, presence of male breast cancer in the family, or a combination [...] The clinical significance of some variants is uncertain, and there are advantages and disadvantages to each of the molecular methods that are used to detect mutations.