Mary-Claire King

By Krista Shaw

The National Cancer Institute states that up to sixty-five percent of woman with a mutation in their BRCA1 or BRCA2 gene develop breast cancer before reaching the age of seventy. BRCA1 and BRCA2 genes suppress tumor formation and mutations to their gene sequences can inhibit this function. By proving the genes that can predict a person’s susceptibility to breast cancer exist, Mary-Claire King paved the way for the development of tests for BRCA gene mutations. These tests give women the opportunity to choose a course of preventative treatment by identifying dangerous BRCA mutations.   

When King began research in the 1970s, causes for cancer were poorly understood. Noticing that breast cancer clusters in some families, King hypothesized that the disease, at least in some cases, is inherited. In an interview with the DNA Learning Center (DNALC), King said that she searched for segments of protein and DNA that were present in all women in a family who developed breast cancer but absent in women in the same family who had not developed breast cancer. Through this technique King found the region of the chromosome that contains a gene which projects breast cancer risk. In 1990, King’s team announced the existence of this gene, which came to be known as BRCA1.   

As King recalled in a New York Times interview: “My paper triggered a race in public and private laboratories, including my own, to clone the gene.”  The National Center for Biotechnology Information records show that Myriad Genetics ultimately won the race in 1994 by finding the gene on chromosome 17 and by determining its sequence. In 1995 Myriad applied for a patent of the gene sequence. When Myriad was granted the patent the following year, it attained sole rights to use of the gene. A second breast cancer indicating gene (BRCA2) was also identified and patented by Myriad.  

Many researchers, King prominent among them, spoke out against these patents because the early tests that Myriad developed failed to identify all mutations of breast cancer related genes. Additionally, King fought Myriad’s monopoly because the costs of their tests posed financial burdens to poor and uninsured people. After a lengthy period of court battles, King’s hopes were realized in the 2013 Supreme Court case Association for Molecular Pathology v. Myriad Genetics, Inc., which decided that “a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated.” Because of this court decision, and in part because of King’s research and outspoken support of an accurate and accessible test, women today can easily learn their risk of breast cancer and determine a treatment course. 

King has an impressive record of work supporting human rights. DNALC reports that she left her Ph.D. work, for a time, to study the effects of pesticides on farmers and that she eventually used her Ph.D. in genetics to reunite Argentinian families separated by the country’s civil war. Now, King continues to advocate for the broad administration of BRCA1 and BRCA2 testing to all women above the age of thirty because there is a risk of mutation even in women who have no family history of breast cancer.  

King is currently a professor and a Phi Beta Kappa Senator for the University of Washington. She is the recipient of numerous awards including the Clowes Award for Basic Research from the American Association for Cancer Research, the Brinker Award from the Komen Foundation, and the Albert and Mary Lasker Foundation Award.  

Krista Shaw is a senior at the University of Dallas majoring in English. The University of Dallas is home to the Eta of Texas Chapter of Phi Beta Kappa.