Do you need to know if your DNA is imbedded with disease-causing mutations?
The answer is, it depends.
In May, actor Angelina Jolie announced in an article in The New York Times that she had a double mastectomy, or the surgical removal of both her breasts. She wrote that she chose this path because of a heightened risk of breast cancer given her family history and because her DNA carries breast cancer-related mutations in the BRCA1 and BRCA2 genes.
It is no surprise then that mutations in these genes—basically errors in their blueprint—predispose us to cancer. Mutations in these genes prevent damaged DNA from being repaired and this DNA damage over successive replications can result in the cell growing uncontrollably and the tissue becoming cancerous.
All cancers are caused, in part, by mutations to the DNA, but only 5-10% of all cancers are caused by mutations inherited from our parents. As we age we tend to accumulate mutations as a natural part of ageing and these mutations can result in cancer. But these mutations are not inheritable, which is why in most people cancer appears later in the lives.
Vijay Haribhakti, consultant surgical oncologist, Jaslok Hospital and Research Centre, Mumbai, worries about Jolie’s decision and the impact it can have. “Some women in India may choose to undergo a preventive double mastectomy when they do not need to,” he says. According to him, 80% of his efforts in surgery are on breast conservation and his advice is that a double mastectomy followed by reconstructive surgery is not something to take lightly. “It is a major surgery with risks of complications at several junctures. Also, latest research shows that compared with a double mastectomy, a double mastectomy combined with an oophorectomy, or the removal of the ovaries, is even better at risk reduction if that is the end-point being considered,” he adds. However, an oophorectomy has its own side-effects of accelerated ageing and accelerated osteoporosis. Read More
Sujata Kelkar Shetty, PhD, writes on public health issues and is a research scientist trained at the National Institutes of Health in Bethesda, US.