Carnitine palmityltransferase deficiency with permanent weakness.

A 16-year-old male had a history of muscle pain and exercise intolerance from the age of six years. At 14 years of age, he experienced the first episode of myoglobinuria and has had eight episodes subsequently. The longest interval between episodes was 14 months. Between attacks he manifested permanent, mild proximal limb weakness, elevated serum creatine kinase activity, and myopathic features indicated by electromyography and muscle biopsies. The muscle carnitine palmityltransferase activity was 30% of normal. This patient demonstrates that carnitine palmityltransferase deficiency can be a progressive disorder leading to permanent weakness. The need for early diagnosis and treatment is stressed.