3-Hydroxydicarboxylic aciduria--a fatty acid oxidation defect with severe prognosis.

We describe five patients with a suspected defect in the beta-oxidation of fatty acids characterized by a massive excretion of 3-hydroxydicarboxylic acids in the urine and accumulation of 3-hydroxy fatty acids in serum during acute illness. Long-chain and medium-chain acyl-coenzyme A dehydrogenases in fibroblasts were normal in all patients. Four of them died of cardiomyopathy and liver insufficiency at 3 to 14 months of age. Two of the patients had elder siblings who had died unexpectedly in early infancy. These patients differ from previously described patients with beta-oxidation defects.