[Myopathy in the course of carnitine palmitoyltransferase II deficiency]

Congenital deficiency of carnitine palmitoyltransferase (CPT) II is a disease with an autosomal recessive inheritance of phenotypic variability which depends on age at the onset of symptoms. Three entities associated with deficiency of CPT II are known: the perinatal, the infantile and the adult form. The perinatal disease is the most severe form and is invariably fatal. On the other hand, the adult CPT II clinical phenotype is benign and requires additional external triggers such as high-intensity exercise to provoke myopathic symptoms. We report a case of adult CPT II deficiency presenting with the subtle symptoms of myopathy. A 32-year-old man was admitted to the hospital complaining of muscle pain after exercise. Athletic appearance drew attention, because the patient denied practicing sport. Neurological examination revealed marked tiredness during the single-leg hop test without other abnormalities. Electromyography (EMG) and serum biochemistry were not typical for myopathy. Routine histopathological examination did not reveal any abnormalities of structure of muscle fibers. Diagnosis was established after ultrastructural and biochemical analysis which revealed changes typical for CPT II deficiency.