Familial carnitine transporter defect: A treatable cause of cardiomyopathy in children☆
Section snippets
Patient 1
A 6-and-a-half-year-old boy, who had a history of asthma, was admitted to the hospital for evaluation of cardiomegaly and congestive heart failure. Two years previously, a chest radiograph revealed that his heart size was at the upper limits of normal (Figure 1, A ).During the 6 weeks before admission, he had increasing fatigue and dyspnea. A chest radiograph showed severe cardiomegaly (Figure 1, B ). There was no family history of cardiac disease or sudden death, and the parents were not
Discussion
Long-chain fatty acids are an important energy substrate for the myocardium and other muscle tissue. Long-chain fatty acid metabolism depends on carnitine availability. Carnitine forms acylcarnitine esters with long-chain fatty acids and facilitates their transport across the inner mitochondrial membrane (Figure 9).Once inside the mitochondria, the long-chain fatty acids can undergo β-oxidation, thereby providing a critical source of energy for cardiac and skeletal muscle.[3], [11]
Carnitine
Conclusions
The low survival rate of children with dilated cardiomyopathy suggests that pediatricians and pediatric cardiologists need to take active measures to identify underlying causes so that appropriate treatment can be instituted. In the case of patients 1 and 2, the identification of their severe plasma and muscle carnitine deficiency was essential to the selection of L-carnitine therapy. For patient 1, the L-carnitine therapy was lifesaving and produced dramatic resolution of his severe congestive
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Cited by (0)
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Supported in part by the Ray and Hattie Anderson Center for the Study of Hereditary Cardiac Disease (Dr Pierpont), the Variety Club Association Gunshoots Program (Dr Pierpont), and the National Institutes of Health R01-DK-43841 and M01- RR00240 (Dr Stanley).