Emery-Dreifuss muscular dystrophy- dominant type
Overview
A rare disorder characterized by slowly-progressing weakness and wasting of skeletal and heart muscles. The dominant form of the disease is associated with greater variability of symptoms.
Symptoms
* Cardiac signs * Myopathy * Muscle contractures * Stiff neck * Weak humeral muscles
Causes
Muscular dystrophy is caused by various genetic mechanisms. Duchenne’s and Becker’s muscular dystrophies are X-linked recessive disorders. Both result from defects in the gene coding for the muscle protein dystrophin; the gene has been mapped to the Xp21 locus. The incidence muscular dystrophy is about 1 in 651,450 persons in the United States. Duchenne’s and Becker’s muscular dystrophies affect males almost exclusively. Facioscapulohumeral dystrophy is an autosomal dominant disorder. Limb-girdle dystrophy is usually autosomal recessive. These two types affect both sexes about equally.