Senior Medical Correspondent Elizabeth Cohen explains Angelina Jolie's cancer gene mutation that increased her risk for breast cancer

CNN's Elizabeth Cohen weighs in on Angelina Jolie's revelation about her double mastectomy. She explains the health risks behind having an abnormal mutation to the BRCA1 gene, which can increase a women's risk for breast and ovarian cancer.

In her op-ed piece Angelina Jolie writes, "I carry a 'faulty' gene, BRCA1, which sharply increases my risk of developing breast cancer and ovarian cancer. My doctors estimated that I had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer, although the risk is different in the case of each woman."

Given this diagnosis Jolie, "decided to be proactive and to minimize the risk as much I could. I made a decision to have a preventive double mastectomy."