A heightened risk of breast cancer in older women has been linked to a gene, according to a new study. The new results, reported in the August 6 edition of the New England Journal of Medicine, indicate that women who have mutations in the PALB2 gene average a one in three chance of developing breast cancer by the age of 70.

The study, which was led by the University of Cambridge, focused on data from 154 families lacking BRCA1 or BRCA2 mutations, including 362 family members with mutations in the PALB2 genes.

Results from the study show that women with rare mutations in the PALB2 gene generally had a 35 percent chance of developing breast cancer by the age of 70. The risks largely depended on family history of breast cancer, in which case carriers with higher numbers of relatives affected by breast cancer were at an increased risk.

Study leader Dr. Marc Tischkowitz of the Department of Medical Genetics at the University of Cambridge, said in a statement, “Since the BRCA1 and BRCA2 mutations were discovered in the mid-90s, no other genes of similar importance have been found and the consensus in the scientific community if more exist we would have found them by now. PALB2 is a potential candidate to be ‘BRCA3’. As mutations in this gene are uncommon, obtaining accurate risk figures is only possible through large international collaborations like this.”

According to cancer.org, approximately one in eight women, or 12 percent, in the U.S. will develop invasive breast cancer during their lifetime.