muscular dystrophy

Although it’s still unclear what killed the 27-year-old, his death is raising questions about the experiment and the overall prospect of what one ethicist calls designer genetic therapies.

Gene therapy has helped a 9-year-old boy regain enough muscle strength to run. If successful in others, the treatment could change the lives of thousands of children with Duchenne muscular dystrophy.

H. Lee Sweeney, a world leader in research on neuromuscular diseases, has agreed to move to University of Florida next year to lead an institute…