Duchenne Muscular Dystrophy (DMD) is the most common neuromuscular disease in child, affecting approximately one in every 3,500 male births. It is caused by mutations in the gene for dystrophin, which corresponds to a protein that has an extremely important role in muscle fiber integrity and function.
It is characterized by general, progressive, irreversible and severe loss of muscle function. By about the age of 10 to 13, sufferers become unable to walk and, by the time they reach adolescence, they require respiratory assistance. Survival can also be threatened by heart muscle involvement. Every year, 150 to 200 young boys in France are diagnosed with Duchenne muscular dystrophy.
Today Genethon is piloting, a program based on the utilization of an AAV (Adeno-Associated Virus) vector which carries a transgene coding for a microdystrophin, together with the Institut de Myologie (Paris), Atlantic Gene Therapies (Nantes), and in collaboration with Professor George Dickson of the University of London (Royal Holloway). Due to the very large size of the dystrophin gene (or DMD gene), the complete DNA of the gene cannot be used in in this type of vector. For this reason, the therapeutic strategy consists of using a gene coding for a shortened but functional gene for this protein (micro- or mini[dystrophin).
The production of this micro-dystrophin gene in the muscles of the patient will make it possible to treat all the boys affected with Duchenne muscular dystrophy.