Gene therapy for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is the most common genetic muscle disorder, affecting 23,000 boys in the US each year. The disease results from a mutation in the gene that encodes dystrophin — the largest gene discovered to date. Adeno-associated viruses have proven the safest and most effective vehicles for delivering therapeutic genes into the muscle tissue but they are too small to carry a dystrophin gene. Now, the development of dystrophin 'mini-genes' might have resolved that problem.

In a study published in the 5 December issue of Proceedings of the National Academy of Sciences, Dr Xiao Xiao and colleagues from the University of Pittsburgh created miniature versions of dystrophin genes that were one-third the normal size. Adeno-associated viral 'packages' carrying truncated dystrophin genes were injected into the calf muscle of mice unable to produce the dystrophin protein. Functional dystrophin protein was expressed in about 90% of the muscle tissue...