The autosomal dominant condition becomes apparent even though the affected person has only one abnormal gene. Facioscapulohumoral MD, myotonic dystrophy, and oculopharyngeal or ocular MD are dystrophies that can occur due to this condition. Progressive muscle weakness may lead to several disabilities depending on which muscle groups are affected. One of the first muscle groups affected are the muscles used for standing and walking. The facial muscles, if they are affected, may change the expression in a person's face.
Muscular dystrophy can cause arrhythmias, an irregular heartbeat.
Other problems can be drooping eyelids, drooling, bone deformities, mental impairment, clawfoot, and clawhand. The symptoms are almost identical, with muscle weakness affecting the pelvis, upper arms, and upper legs. These diseases will eventually affect all the voluntary muscles. Duchenne's MD usually occurs in boys between the ages of 2 to 6 years old. Boys with Duchenne's MD lack muscle protein, dystrophin, which is important for maintaining the structure of the muscle cells.