Hereditary disorder characterized by progressive symmetrical wasting of skeletal muscles

No neural or sensory defects

Four main types: Duchenne’s (pseudohypertrophic), Becker’s (benign pseudohypertrophic), Landouzy-Dejerine (facioscapulohumeral), and Erb’s (limb-girdle) dystrophies

Duchenne’s beginning in early childhood; death within 10 to 15 years

Muscle fibers necrotize and regenerate in various states.

As regeneration slows down, degeneration dominates.

Fat and connective tissue replace muscle fibers, with ensuing weakness.

Duchenne’s and Becker’s X-linked recessive

Erb’s usually autosomal recessive

Landouzy-Dejerine autosomal dominant

Various genetic mechanisms (band Xp 21)