At a glance
Also known as
Breast cancer gene 1 and 2
Why get tested?
To assess the risk of developing breast or ovarian cancer associated with inheriting mutations in the BRCA1 or BRCA2 genes
When to get tested?
Genetic testing of an unaffected person for a BRCA1 or BRCA2 mutation is generally not recommended unless a mutation has already been identified in a family member.
Genetic testing is offered only through a family cancer clinic. If a woman is referred to a family cancer clinic, the availability, limitations, potential benefits, and possible consequences of genetic testing will be discussed with her.
A blood sample drawn from a vein in the arm
Confused about genetics?
See our Genetics Information page
What is being tested?
BRCA1 and BRCA2 are two tumour suppressor . Normally, these genes help prevent cancer by producing proteins that repair damage to DNA (the genetic material in a cell). Certain changes () in these genes disrupt the function of the protein product and are associated with hereditary breast and ovarian cancers.
According to Cancer Australia, using statistics from the Australian Institute of Health and Welfare, about 17,000 women in Australia are diagnosed with breast cancer each year (15,902 in 2013 and it is estimated to be 18,000 in 2018) and about 1,500 women with ovarian cancer. In most of these women, their cancers are sporadic, but about 5-10% of these women have a familial predisposition to breast/ovarian cancer. Approximately 20% of the familial breast/ovarian cancer (i.e. 1-2% overall) are due to a harmful mutation in the BRCA1 or BRCA2 gene. Men can also inherit an increased risk of developing breast cancer, occasionally from mutations in BRCA1, but primarily from mutations in the BRCA2 gene.
The BRCA1 and BRCA2 genes are present in every cell of the body. To detect mutations in the genes, needs to be extracted from cells, and blood is the most easily accessible source of that DNA.
How is the sample collected for testing?
The test for BRCA mutations is done on a blood sample collected by needle from a vein in the arm. The test does not require surgical of breast or ovarian tissue.