Maple syrup urine disease variant

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Maple syrup urine disease (branched-chain ketoaciduria), a genetic disorder with a well-defined biochemical defect, was first described as a clinical syndrome by Menkes et al in 1954.1 It is characterized by an accumulation of three keto acids corresponding to a partial breakdown of leucine, isoleucine, and valine which occur in excess in urine, blood, and other body fluids. The symptoms of anorexia, vomiting, hypertonicity, mental retardation, and occasionally convulsions appear early in life. The clinically diagnostic feature is a maple syrup odor in the urine.2, 3

Patients and their families have been described with transient episodes of neurologic signs associated with elevations of branched-chain amino acids. The late onset of symptoms and the fact that the children appear to be normal between attacks are strikingly different from the classic picture of maple syrup urine disease. Enzyme activity of the peripheral leukocytes in the affected children showed a significant reduction, and decarboxylase activity of the branched-chain keto acids was not as severe as the classic form of maple syrup urine disease.4

Maple syrup urine disease after chronic infection has been reported by one of us.5 In the case reported here the association with trauma appears to be significant. We review the central nervous system manifestations commonly associated with this disease.

Case report

A 9-year-old girl was admitted to the Cleveland Clinic Hospital on January 5, 1970, with a diagnosis of encephalopathy of undetermined etiology. One month before admission an inner ear infection developed, and the patient reported that three weeks before . . .



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