Most affected males die by the third decade of respiratory or cardiac muscle involvement. Becker's dystrophy is also X-linked recessive and resembles Duchennes in terms of pseudohypertrophy of calves and proximal muscle weakness. Onset, however, is later, sometimes in the teens, and progression is less rapid. Cardiac involvement is not usual. Limb girdle dystrophy is usually autosomal recessive, although out, dominant cases have been reported.
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.