Who's Your Daddy? DNA Tests May Shock You

A simple DNA test is enough to rend a family apart, the Los Angeles Times reports. As more people take genetic tests to uncover medical data or trace family roots, more are discovering that their biological father is someone else. It's an old issue in medicine—blood types, after all, can reveal non-paternity—but "it's going to be more and more of a problem," one doctor says.

Common medical practice is to tell the mother alone—in some cases for her own safety—but ethical quandaries arise when a child suffers from a disorder due to genes from both parents. An uninformed husband could falsely believe he carries a genetic disorder. "Non-paternity is one of the issues that genetic counselors dread but at some point in their careers will have to deal with," one counselor says.
(More genetic testing stories.)