Presence of mutations in either their BRCA1 or BRCA2 genes increases a woman's risk of developing breast or ovarian cancer.
Identifying such women provides them with an opportunity to take preventive measures such as surgery to remove their breasts. One caveat to identifying such women by simply sequencing their BRCA1 and BRCA2 genes and detecting mutations is that not all mutations are harmful. However, Shyam Sharan and colleagues, at the National Cancer Institute at Frederick, have now developed an assay to distinguish harmful BRCA1 mutations from those that are not. As discussed by the authors and, in an accompanying commentary, Roger Greenberg, this assay has immense clinical potential to identify those patients that might benefit from treatments to prevent breast cancer.