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?
If you have a strong family history of breast or ovarian cancer, or are of Ashkenazi Jewish ancestry, following appropriate pre-test genetic counselling
A blood sample drawn from a vein in the arm
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, about 15,000 women in Australia are diagnosed with breast cancer each year and about 1,400 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, DNA 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.