At-Home Cancer-Risk Test Opens New—and Fraught—Field

WASHINGTON—Federal health officials this week allowed a genetic testing firm to sell kits to consumers to test whether they carry gene mutations that put them at higher risk for breast and ovarian cancer.

The action, part of a broader regulatory shift, is the first time the Food and Drug Administration has allowed a company—in this case 23andMe Inc.—to market such a cancer-risk test directly to the public.

It...