Angelina Jolie is a carrier of a gene mutation known as BRCA 1. Carriers of this gene mutation have an 80% lifetime risk of developing breast cancer. The only known prevention is double mastectomy. Angelina wrote an opinion piece in the New York Times today explaining that she underwent double mastectomy to minimize her risk of developing breast cancer.
BRCA 1 and 2 genes are normal genes found in the body. The typical role of these genes is to keep DNA stable and prevent cells from growing out of control, or mutating. Mutations of either BRCA 1 or BRCA 2 genes can lead to loss of cell control and the development of various cancers, among which breast and ovarian cancers are most prevalent.
BRCA 1 and 2 mutations can be passed on to children leading to hereditary breast and ovarian cancer in multiple generations. The chances of inheriting a BRCA 1 or 2 mutation are somewhat high. In order for an egg to be fertilized by sperm, it must discard half of its chromosomes. Since the BRCA mutation is typically found on one chromosome, there is a 50% chance that the mutation will be randomly discarded by the egg. If the gene is not discarded, it will pass to the child who will also be a BRCA mutation carrier. In other words, there is a 50% chance of passing the mutation to a child.
Dr. John Jain and his colleague, Dr. Dagan Wells of Oxford University, are currently conducting a study aimed at identifying eggs that have successfully discarded the BRCA mutation, and studying what makes those particular eggs more resilient. If experts can effectively identify the mutation-resistant eggs, then these healthy eggs can be used to create embryos, ultimately eliminating hereditary breast and ovarian cancer from future generations.
Learn more about genetic screening for BRCA 1 & 2 here.