Good news for families with a history of breast cancer. Scientists have found a gene that causes a hereditary form of the disease, the first step toward developing an early test for the malady. Unfortunately, only 1 in 20 breast-cancer cases is inherited. Still, scientists believe the breakthrough is likely to help develop a way to check for other forms of the disease as well, according to TIME reporter Allison Park. The gene found today -- BRCA1 -- may also raise the risk of contracting ovarian cancer.