The tests for BRCA-1 and BRCA-2 use the DNA in white blood cells to detect mutations in the BRCA genes. This test can then can tell you if you have mutations of the two genes that have been associated with the development of breast or ovarian cancer.

Individuals with a strong family history of breast cancer or ovarian cancer may want this test. They may want to use the results to help them decide whether to take steps that may prevent breast or ovarian cancer from developing. However because we don’t know how effective the options for prevention are, people who are considering taking this test should seek genetic counselling. In this way they can learn about and understanding the implications of the test (see "Is there anything else I should know?" below).

Since there are hundreds of possible mutations of BRCA genes, test results must be interpreted by taking into account a person’s family history. A genetic counsellor should explain the meaning of the results and offer advice to the individual and to other family members about options for decreasing risk. Counselling advice should be offered both before testing takes place and after receiving test results.

Your test results can affect other family members. When one member of a family is tested for BRCA mutations, issues often arise about how or whether to share this information with other family members. Seek advice from your doctor before asking for this test.