http://www.ninds.nih.gov/disorders/md/md.htm
National Institute of Neurological Disorders and Stroke, National Institutes of Health
Muscular dystrophy (MD) refers to a group of genetic diseases characterized by progressive weakness and degeneration of the skeletal or voluntary muscles which control movement. The major forms of MD include myotonic, Duchenne, Becker, limb-girdle, facioscapulohumeral, congenital, oculopharyngeal, distal and Emery-Dreifuss.