Could a Drug Reverse Mental Retardation?

Can a genetic disorder that derails brain development be cured with a drug? A clinical trial announced today represents the first step towards testing a drug therapy for Fragile X syndrome, the most common inherited cause of intellectual disability. The trial will enroll healthy volunteers and assess the safety of a drug that blocks a type of glutamate receptor thought to be overactive in people with Fragile X. Experts have long assumed that once the brain is wired wrong during development that it can't be fixed by simply giving someone a drug.