maple syrup urine disease

maple syrup urine disease [mā′pəl sĭr′əp, sûr′-] n.

1. A hereditary metabolic disorder due to a deficiency of decarboxylase enzyme that leads to elevated concentrations of leucine, isoleucine, and valine in the blood and urine, characterized by the urine having an odor similar to that of maple syrup, severe mental retardation, and seizures.branched chain ketoaciduria