BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are genes that every woman and man carries from birth. These genes, when functioning normally, are involved in preventing the development of cancer. A congenital change in one of these genes, also called a "gene mutation" or "mutation", impairs the repair function of these genes. This results in a greatly increased risk of developing breast and ovarian cancer.

According to current knowledge, women who carry a mutation in the BRCA1 or BRCA2 gene have a 50-80% risk of developing breast cancer and up to 53% risk of developing ovarian cancer.

With this greatly increased risk of these cancers, preventive removal of the breast gland and, if necessary, preventive removal of the ovaries is usually recommended. However, the individual situation of the woman, her age, her willingness to take risks, her desire to have children, her desire to breastfeed and other points must always be taken into account in the decision or recommendation.

Probably the best known patient with this disease is Angelina Jolie.