what is the brca gene

The BRCA genes are two genes that are important in fighting cancer and are sometimes called tumor suppressor genes. They produce proteins that are used by the cell in an enzymatic pathway that makes very precise, perfectly matched repairs to DNA molecules that have double-stranded breaks. When they work normally, these genes help keep breast, ovarian, and other types of cells from growing and dividing too rapidly or in an uncontrolled way. However, certain mutations in the BRCA genes can make cells more likely to divide and change rapidly, which can lead to cancer. Everyone has two copies of each of these genes, one inherited from each parent. A harmful variant in BRCA1 or BRCA2 can be inherited from either parent, and each child of a parent who carries any mutation in one of these genes has a 50% chance of inheriting the mutation. Inherited mutations are present from birth in all cells in the body, and even if someone has inherited a harmful variant in BRCA1 or BRCA2 from one parent, they would have inherited a normal copy of that gene from the other parent. However, the normal copy can be lost or change in some cells in the body during that person’s lifetime, which is called a somatic alteration. Not every woman who has a BRCA1 or BRCA2 gene mutation will get breast or ovarian cancer, but having a gene mutation puts you at an increased risk for these cancers.