(CNN) -- Actress Angelina Jolie announced in a New York Times op-ed article on Tuesday that she underwent a preventive double mastectomy after learning she carries a mutation of the BRCA1 gene, which sharply increases her 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," Jolie wrote. "Once I knew that this was my reality, I decided to be proactive and to minimize the risk as much I could. I made a decision to have a preventive double mastectomy."
Jolie's mother, actress and producer Marcheline Bertrand, died of ovarian cancer in 2007 at the age of 56. Jolie is 37 years old.
In the Times op-ed, titled "My Medical Choice," Jolie said she finished three months of medical procedures at the Pink Lotus Breast Center in California on April 27 that included the mastectomies and reconstruction.
A mastectomy is an operation that removes all or part of the breast.
"I wanted to write this to tell other women that the decision to have a mastectomy was not easy. But it is one I am very happy that I made," Jolie wrote. "My chances of developing breast cancer have dropped from 87 percent to under 5 percent."
BRCA stands for breast cancer susceptibility genes -- a class of genes known as tumor suppressors, according to the National Cancer Institute.
Mutation of the BRCA1 and BRCA2 genes has been linked to hereditary breast and ovarian cancer. A blood test can determine if a woman is "highly susceptible" to the cancers.
Fellow actress Christina Applegate had a similar procedure in 2008. She also had a mutation of the BRCA1 gene.
Oscar-winning film star
Jolie may be best known for title role in the "Laura Croft" series of films, but also won an Academy Award as best supporting actress in "Girl, Interrupted." She also received a Golden Globe Award and SAG Award for the same role.
Jolie serves as a special envoy for the United Nations High Commissioner for Refugees and has visited refugee camps around the world.
The actress has been in a relationship with actor Brad Pitt since the mid-2000s, and they are engaged. The couple has three biological and three adopted children.
In telling her story, Jolie acknowledged that surgery might not be the right choice for every woman.
"For any woman reading this, I hope it helps you to know you have options," Jolie wrote. "I want to encourage every woman, especially if you have a family history of breast or ovarian cancer, to seek out the information and medical experts who can help you through this aspect of your life, and to make your own informed choices."
But for Jolie, the decision ultimately came down to her kids.
"I can tell my children that they don't need to fear they will lose me to breast cancer," she said.
It's a pain Jolie knows all too well from losing her mother to the disease.
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