The onset is in adolescence. The course is slower and
more benign than the other dystrophies. Features involve the eyes and ears (sensorineural
hearing loss, eyelid drooping, retinal detachments, and telangiectasia),
cardiac system (atrial tachycardia, cor pulmonale), thoracic system (restrictive lung disease, winged
scapula), and neuromuscular system (facial, scapular, and humeral muscular dystrophy, abdominal
wall weakness; inability to raise the arms is an early feature and facial
weakness is characteristic). The lower limbs are affected later.