An x-linked inherited syndrome caused by mutations in the gene that encodes the enzyme hypoxanthine-guanine phosphoribosyltransferase, resulting in accumulation of uric acid in the body.(menkes, textbook of child neurology, 5th ed, pp127) Elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. Intellectual impairment may also occur but is typically not severe. Self-destructive behaviors such as biting of fingers and lips are seen frequently. Affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. An inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism hypoxanthine phosphoribosyltransferase.Mental retardation is common but normal intelligence occurs in some cases. Associated disorders include spastic cerebral palsy, choreoathetosis, renal uric acid calculi, gouty tophi, and uric acid nodules.
Patients are normal at birth but begin to show hypertonicity at about 4 months and irritability and other neurological symptoms become apparent during the second year of life, the child becoming gradually more aggressive and self-destructive, banging his head, biting the lower lip and, less commonly, the upper lip, cheeks, fingers, and hands, sometimes using the fingers to mutilate his ears and nose. An inborn error of metabolism resulting from a deficiency of hypoxanthine-guanine phosphoribosyltransferase (ec 2.4.2.8) with increased conversion of glycine to uric acid with excessive purine synthesis and hyperuricemia.combined immunodeficiency disorders ( D81.-)ĭisorders of purine and pyrimidine metabolism.
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