Lethal Neonatal Multiorgan Deficiency of Carnitine Palmitoyltransferase II

Abstract

IN adults, deficiency of carnitine palmitoyltransferase (CPT) II is a genetic disorder characterized by exercise intolerance and myoglobinuria.^{1 , 2} In newborns, it is a generalized, lethal disease with reduced CPT II activity in multiple organs, reduced concentrations of total and free carnitine, and increased concentrations of lipids and long-chain acylcarnitines.³ The clinical severity of CPT II deficiency is not determined by the degree of the reduction in CPT II activity, since this reduction is of similar magnitude in adults, young children, and newborns.^{1 2 3 4 5} However, lethal CPT II deficiency is associated with an accumulation of arrhythmogenic long-chain acylcarnitines,^{6 , 7} as in the patient whom we describe below and other fatally affected children described in the literature.^{4 , 5} Children with symptomatic CPT II deficiency might benefit if the production of long-chain acylcarnitines could be reduced by dietary change or by pharmacologic inhibition of CPT I,^{8 , 9} which catalyzes the formation of long-chain acylcarnitines.