Ethylmalonic adipic aciduria--a treatable hepatomuscular disorder in two adult brothers.

An adult male presented at 28 years of age with muscle weakness and liver dysfunction. His brother had died suddenly 2 years earlier after presenting with Reye's syndrome. Urine organic acid analysis and muscle and cultured fibroblast fatty acid oxidation studies confirmed a diagnosis of ethylmalonic/adipic aciduria-an inherited defect of fatty acid oxidation. The patient responded favourably to treatment with a low fat/high carbohydrate diet supplemented with riboflavin. This case highlights the importance of considering inborn errors of metabolism, in particular fatty acid oxidation defects, in adults with liver disease, muscle disease or Reye's syndrome.