Diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency in the neonatal period by measurement of medium-chain fatty acids in plasma and filter paper blood samples

Medium-chain acyl-coenzyme A dehydrogenase is an enzyme necessary for the breakdown of certain fatty acids, a process which is part of normal body reactions. Medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) is inheritable only when both parents have the same gene, and it can result in encephalopathy, brain dysfunction, or in sudden infant death syndrome. A simple test for MCADD would facilitate diagnosis, and is important because relatively simple therapy may prevent illness and death, once MCADD is identified. A test is described in which blood collected in tubes or on filter paper can be processed to determine if accumulation of two fatty acids, indicative of MCADD, has occurred in a patient. In both a three-year-old patient and his newborn brother, the sum of the levels of the two fatty acids greatly exceeded that expected in healthy subjects. Urinary levels of metabolites confirmed the diagnosis of MCADD in the two patients. The results suggest that this simple procedure would facilitate identification of young children with MCADD. The two children in this case, plus a third child born after the initial diagnoses, have grown normally; treatment has consisted of avoiding fasting. More extensive studies would be desirable to show the range of normal values for blood levels of fatty acids within a large population. (Consumer Summary produced by Reliance Medical Information, Inc.)