Maple syrup urine disease: An uncommon cause for neonatal metabolic distress.

Maple Syrup Urine Disease is an autosomal recessive disorder caused by a deficiency in the activity of the branched-chain α-ketoacid dehydrogenase complex. This rare disorder represents one of the causes of acute neonatal illness which results in devastating disturbances of neurological development. On investigation of 1750 infants with neurological impairment for inborn errors of amino acid metabolism, 4 neonates with classical maple syrup urine disease were detected. These otherwise normal neonates presented in the first week after birth with seizures, lethargy and refusal of feeds, hypoglycemia and metabolic acidosis. The plasma and urine concentrations of the branched-chain amino acids were increased and there was ketoaciduria. Two of these neonates expired before specific treatment could be instituted. Routine biochemical screening of neonates with acute illness could unearth many cases of this rare inherited metabolic disease.