Familial systemic carnitine deficiency.

Two sisters with systemic carnitine deficiency showed the heterogenicity of this condition and a lack of correlation between measurable carnitine levels and clinical manifestations. One child experienced recurrent metabolic encephalopathy, which was diagnosed as Reye's syndrome. The older child, despite lower carnitine concentrations, was asymptomatic. Lipid inclusion myopathy was shown in both children. Serum, muscle, and liver carnitine levels were reduced. The parents had normal serum carnitine concentrations. Both children had significantly abnormal renal handling of carnitine, and their mother, a mild alteration. This family provided evidence for genetic transmission and presumed autosomal recessive inheritance in this disease. Both children were treated with carnitine without clear benefit; no side effects were noted. Previously reported cases of systemic carnitine deficiency were reviewed.