Miyoshi dystrophy, caused by a gene defect on chromosome 2, is autosomal recessive and affects the back of the lower legs first. In general, the distal dystrophies are less severe, progress more slowly and involve fewer muscles than the other dystrophies, although spread to other muscles can occur. Walking can be improved with orthopedic devices that support the foot. Muscle weakness and wasting generally start in the shoulders, upper arms and lower legs. Weakness may later spread to involve the muscles of the chest and pelvic area.
Contractures appear early in the disease, usually involving the ankle and elbow.
Unlike other forms of muscular dystrophy, contractures in Emery-Dreifuss dystrophy often appear before the person experiences significant muscle weakness. Physical therapy is beneficial in minimizing the contractures. Life-threatening heart problems are a common part of this disorder. These problems can even occur in females who don't have the disease but are carriers, so sisters and mothers of boys with Emery-Dreifuss should be examined. The skeletal muscle weakness is less severe than it is in some other dystrophies, such as Duchenne.