ABSTRACT
The genetically determined disorders of fatty acid oxidation represent a recently rapidly growing group of inborn errors of metabolism. Myopathic carnitine palmitoyl transferase deficiency was known for some time earlier, but considered among myopathies not a forerunner of expansive growth of knowledge, and HMG CoA lyase deficiency had been described but considered to be an organic acidemia. Disorders of fatty acid oxidation may present with myopathy or cardiomyopathy. They may also present with sudden infant death syndrome, but often the initial presentation is with a Reye-like episode of hypoketotic hypoglycemia, often with elevated blood concentrations of creatine kinase, and uric acid, as well as transaminases. The normal response to fasting and the oxidation of fat begins with lipolysis, which releases free-fatty acids. In patients with disorders of fatty acid oxidation, concentrations of free-fatty acids are usually higher than those of 3-hydroxybutyrate in blood at times of illness and metabolic stress.
