The Gene Doctors
In 2011, 27-year-old Sonia Vallabh learned the results of a genetic test. She carries a mutation for a rare brain disease. Barring a medical breakthrough, she is destined to develop dementia and die in her 50s. Her fate hinges on a single change among three billion DNA bases in her genome. It seemed incredible, Sonia says, “that this one change could be so dangerous.”