A Case of Adult-Onset VLCAD Deficiency

Mitochondrial fatty acid β-oxidation disorders are autosomal recessive disorders that impair mitochondrial β-oxidation and transport of fatty acids. These disorders have diverse clinical presentations. The neonatal-onset form presents with hyperammonemia, transient hypoglycemia, metabolic acidosis, cardiomyopathy, and sudden death. The Late-onset form presents with neuropathy, myopathy, and retinopathy. We report a case of a 25-year-old man who presented with episodic weakness, exercise intolerance, myalgia, and rhabdomyolysis. Whole-exome sequencing identified a pathogenic variant in acyl-Coenzyme A dehydrogenase very long chain gene, confirming a diagnosis of very long-chain acyl-Coenzyme A dehydrogenase deficiency (autosomal recessive).