Medical Mystery: When Sleep Doesn't Come, Death Does

Carolyn and Cheryl are sisters who have lived with a mortal secret for years. A genetic mutation hangs on their family tree like poison fruit. It killed their grandfather and their uncle and, in 1999, revealed itself in their mom, Barbara. "I can remember saying, 'Mom, what's wrong? Mom, why can't you speak?'" said Carolyn. Barbara couldn't speak because she couldn't sleep — at all. Inside Barbara's brain, a genetic trip wire had been crossed, and in a matter of months, she went from being...Full Story