Primary features of a recently described syndrome include choreo-athetosis, mental retardation, self-destructive biting of the lower lip and finger tips, and hyperuricemia. Onset in early childhood, even in the neonatal period, follows an uneventful birth and apparently normal development. Self-mutilation may extend to the nasal septum and tongue. Early symptoms are developmental retardation, abnormal muscle tone, choreo-athetosis, hyperuricemia observed first as "sand" or orange precipitate hematuria, and then uric acid crystalluria. Without treatment the condition is usually progessive, and results eventually in complete helplessness accompanied by spastic or rigid quadriplegia.
The serum uric acid level is elevated, reported as high as 18.5 mg/100 cc. More important is the extremely high turnover rate of the uric acid pool, determined to be approximately six times that found in adults with gout. In addition, the incorporation of intravenously administered glycine labeled with radioactive carbon (14C) into urinary uric acid is 200 times