Twins' Cure A First Victory For Genome Testing

For years, scientists have predicted that knowing the whole human genetic code would pay off huge dividends in diagnosing and treating disease. The promise has largely remained just that. Now, a pair of 14-year-old twins has become among the first to benefit from a whole-genome test. NPR health and science correspondent Richard Knox talks to host Scott Simon about the breakthrough that essentially cured the twins' disease within days.