maple syrup urine disease [AS, mapul + Ar, sharab + Gk, ouron, urine] , an inherited metabolic disorder in which an enzyme necessary for the breakdown of the amino acids valine, leucine, and isoleucine is lacking. The disease is usually diagnosed in infancy. It is recognized by the characteristic maple syrup odor of the urine and by hyperreflexia. Stress, fever, and infection aggravate the condition. Treatment includes a diet avoiding these amino acids and occasionally dialysis to remove excess protein. Also called branched-chain ketoaciduria.
