Long-Chain Fatty Acid Beta-Oxidation Defects: A Case Series and Literature Review

Fatty acid beta-oxidation defects (FAOD) are a subgroup of lipid myopathies with heterogeneous presentations. Clinical presentation may manifest as muscular weakness, cramps, postexercise myalgias, and episodic rhabdomyolysis in children or adults. Our objective was to describe the clinical manifestations, biochemical, anatomopathological, and molecular results in a series of adult patients diagnosed with FAOD during adolescence or adulthood at five centers in Argentina. A total of seven patients with carnitine palmitoyltransferase-2 (CPT II), very-long-chain acyl-CoA dehydrogenase (VLCAD), and long-chain 3-hydroxyacyl-CoA dehydrogenase LCHAD deficiency were reported. The definite diagnosis of metabolic myopathies due to FAOD requires an understanding of clinical, biochemical, neurophysiological, and muscular imaging/biopsy patterns. All patients in this series consulted pediatricians, general practitioners, rheumatologists, and orthopedists for years, underscoring the need to disseminate these presentation patterns across various medical specialties. Early diagnosis and treatment using traditional diets and new pharmacological strategies not only enhance the quality of life, but also improve survival in these patients.