Onset is in late childhood and progression is slow. Males and females are equally affected. Pseudohypertrophy is not a feature. This condition is sometimes mimicked by Kugelberg Welander syndrome or polymyositis. Facioscapulohumeral dystrophy is an autosomal dominant disorder that affects face, shoulder girdle and upper ann, as the name implies.
Onset is in adolescence with very slow progression and generally normal life span.
There is often congenital absence of some muscles. A variant is accompanied by anterior compartment wasting in the lower extremities and is sometimes mistaken for Charcot-Marie Tooth. Myotonic dystrophy, an autosomal dominant disorder, differs from the other dystrophies in that a clinical dystrophy or wasting is a late feature and there is striking involvement of endocrine system, heart smooth muscle and eye. The characteristic feature is delayed relaxation of percussed muscles and presence of slow relaxation after gripping. The tongue is often involved with resultant slowing of speech.