The BRCA1 gene is a gene which acts as a tumor suppressor gene, or a gene which prevents tumor cells from growing. A mutation in the BRCA1 gene can lead to an increased risk for breast or ovarian cancer, since it is the gene that prevents the development of breast cancers.
BRCA1 genes are able to repair damaged dna, and ensure the stability of the genetic information.
Even if you have the BRCA1 mutation, it doesn’t mean that you will develop breast cancer. It puts you at a higher risk for cancer, but does not guarantee it.
Certain risk factors such as family history may lead to increased risk for breast cancer, which means that you may want to consider getting tested for the disease.