A major obstacle looms for the drugs of the future.
Not enough doctors know how to administer them.
For just one rare neurodevelopmental disorder, known as Angelman syndrome, clinical trials are testing four cutting-edge therapies.
Twenty more research programs are under way and could yield treatments ready to move into human testing in the next several years, according to Allyson Berent-Weisse, chief scientific officer of the Foundation for Angelman Syndrome Therapeutics, or FAST, and the mother of a child with the disorder.