Inborn Errors of Metabolism with Myopathy: Defects of Fatty Acid Oxidation and the Carnitine Shuttle System

Pediatr Clin North Am. 2018 Apr;65(2):317-335. doi: 10.1016/j.pcl.2017.11.006. Epub 2017 Dec 28.


Fatty acid oxidation disorders (FAODs) and carnitine shuttling defects are inborn errors of energy metabolism with associated mortality and morbidity due to cardiomyopathy, exercise intolerance, rhabdomyolysis, and liver disease with physiologic stress. Hypoglycemia is characteristically hypoketotic. Lactic acidemia and hyperammonemia may occur during decompensation. Recurrent rhabdomyolysis is debilitating. Expanded newborn screening can detect most of these disorders, allowing early, presymptomatic treatment. Treatment includes avoiding fasting and sustained extraneous exercise and providing high-calorie hydration during illness to prevent lipolysis, and medium-chain triglyceride oil supplementation in long-chain FAODs. Carnitine supplementation may be helpful. However, conventional treatment does not prevent all symptoms.

Keywords: Cardiomyopathy; Carnitine shuttling defects; Fatty acid oxidation defects; Rhabdomyolysis.

Publication types

  • Review

MeSH terms

  • Carnitine / metabolism*
  • Fatty Acids / metabolism*
  • Humans
  • Infant
  • Infant, Newborn
  • Metabolism, Inborn Errors / complications
  • Metabolism, Inborn Errors / diagnosis*
  • Metabolism, Inborn Errors / therapy
  • Muscular Diseases / etiology*
  • Muscular Diseases / therapy
  • Neonatal Screening / methods*
  • Oxidation-Reduction


  • Fatty Acids
  • Carnitine