The intermediate form of maple syrup disease

A severely retarded and tetraspastic child died at the age of four years upon a respiratory infection with acidosis, disturbances of serum electrolytes and lactic aciduria. Brain autopsy showed a spongy degeneration and led to suspect an inborn error of amino-acid metabolism. These findings corresponded with the results of computer-tomography and were supported by post mortem amino-acid analysis. An intermediate variant of leucinosis was detected in an younger sister at the age of five months after cerebral convulsions and opisthotonic posture. The activity of the branched chain ketoacid decarboxylase in fibroblasts was reduced to 3-4% of normal. A protein restricted diet allowed a nearly normal cerebral development and improvement of computer-tomographic results. The similarity of clinical and biochemical data in both children indicate that a maple syrup urine disease was most likely the underlying disease in the older sister. Later performed electron-microscopical examinations of the older sister indicate that spongy degeneration of the central nervous system in leucinoisis is caused by a spongy myelinopathy, which is different from the alterations found in Canavan's disease, what could be pointed out for the first time.