The BRCA2 gene is a gene associated with early onset breast cancer and an increased risk of developing breast and other cancers. It is also known as the breast cancer susceptibility gene or the early onset breast cancer gene, among other names. Along with BRCA1, a related gene, it can be tested in a patient to see if the patient is at increased risk for developing breast cancer. The outcome of the test may be used to develop a treatment plan including prophylactic treatment.
This gene is located on the 13th chromosome. It is one of the genes involved in regulating the process of DNA repair. When the BRCA2 gene has a deleterious mutation, errors in DNA can accumulate through multiple cell divisions and lead to the development of cancer in the patient. This gene may also play a role in cell division, another way it can contribute to the development of cancers.
In genetic testing, the BRCA2 gene can be examined to see if it has a mutation. Some people have benign or even beneficial mutations, a result of natural genetic variation. Others have mutations known to be deleterious, found in patients with an increased chance of developing breast cancer. Testing can also identify an unknown or ambiguous mutation, a mutation with an unknown link to breast cancer. In patients with an ambiguous result, surveillance may be recommended to identify signs of cancer early, in case the mutation is harmful.
In women, deleterious mutations in the BRCA2 gene increase the chances of developing breast cancer at an early age. Susceptibility to other cancers like ovarian, pancreatic, and kidney cancers can also be increased. People with mutations in both BRCA1 and 2 can develop anemia and be at risk for cancers like leukemia. Men with mutated BRCA2 genes have an increased risk of breast, prostate, and pancreatic cancers.
Genetic testing can provide important information for people making decisions about their long term care. If people have several close relatives with a history of breast cancer, especially with an early onset, they may be advised to receive genetic testing. Likewise, people in populations like the Ashkenazi Jewish community and the Icelandic community are at higher risk of having BRCA2 mutations and could benefit from genetic testing.
Counseling is usually offered with BRCA2 gene testing. In counseling, patients can discuss the implications of the test results and their options moving forward. These options include increased surveillance for the early signs of breast cancer, preventative surgery, and chemopreventative drug treatments.