In 1990, her laboratory zeroed in on chromosome 17q21 to prove that breast cancer is genetically inherited in some families. The scientists working with Mary-Claire King, PhD, called this particular genetic mutation BRCA1. Soon after, another mutation, called BRCA2, was identified.

Today the mutations are known not only for significantly increasing the risk of breast cancer in women but for putting men at risk for prostate and pancreatic cancer, too.

King spoke to a scientific crowd at Upstate‘s Presidential Symposium last fall. She explained that determining who is at increased risk for breast cancer remains tricky.

About half of the people who are found to have a BRCA mutation are surprised, because they have no cases of breast cancer in their families.

Also, BRCA1 and BRCA2 are not the only genes involved in hereditary breast cancer. King said there are “breast cancer families” whose members have no BRCA mutations.

This article appears in the winter 2017 issue of Cancer Care magazine.