Defect Detector: Plugging holes in a breast cancer–gene screen

A European genetic test catches mutations that are missed by the sole test commercially available in the United States to screen the so-called breast cancer genes, a new study shows.

The genes, called BRCA1 and BRCA2, normally encode proteins that suppress rampant cell growth. But when these genes are mutated, they can yield defective proteins that leave a person vulnerable to cancer.