A woman with early-onset, slowly progressive, humeroperoneal muscle weakness had 
marked restriction of neck flexion with contracture at the elbows. She developed 
exertional dyspnea at age 25, atrial fibrillation with slow ventricular rate was 
discovered, and a cardiac pacemaker was implanted. Her father had a similar 
disorder. There is at least one other report of autosomal dominant transmission 
of this clinical picture, which had previously only been reported as 
Emery-Dreifuss muscular dystrophy with X-linked recessive inheritance. Thus, 
more than one mode of inheritance is possible for this unusual and distinctive 
form of muscular dystrophy.