Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
 2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lesch-Nyhan syndrome is a rare genetic disorder, caused by a mutation in the gene coding for the enzyme hypoxanthine-guanine phosphoribosyltransferase, which is characterized by hyperuricemia and its associated symptoms along with motor disorders and compulsive self-mutilation. We show that the temporal difference learning algorithm that has been often used to interpret dopaminergic activity in the basal ganglia offers an explanation for the self-mutilation behaviors. We propose that a dysfunctional dopamine signal inadvertently reinforces early, accidental injurious behavior that is initially caused by clumsiness owing to the motor disorders. Simulations of this model reproduce findings on the results of behavioral treatments for dealing with self-mutilation behaviors.
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PMID:A model of behavioral treatments for self-mutilation behavior in Lesch-Nyhan syndrome. 1828 46

Lesch-Nyhan disease is a neurogenetic disorder caused by deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase. The classic form of the disease is described by a characteristic syndrome that includes overproduction of uric acid, severe generalized dystonia, cognitive disability and self-injurious behaviour. In addition to the classic disease, variant forms of the disease occur wherein some clinical features are absent or unusually mild. The current studies provide the results of a prospective and multi-centre international study focusing on neurological manifestations of the largest cohort of Lesch-Nyhan disease variants evaluated to date, with 46 patients from 3 to 65 years of age coming from 34 families. All had evidence for overproduction of uric acid. Motor abnormalities were evident in 42 (91%), ranging from subtle clumsiness to severely disabling generalized dystonia. Cognitive function was affected in 31 (67%) but it was never severe. Though none exhibited self-injurious behaviours, many exhibited behaviours that were maladaptive. Only three patients had no evidence of neurological dysfunction. Our results were compared with a comprehensive review of 78 prior reports describing a total of 127 Lesch-Nyhan disease variants. Together these results define the spectrum of clinical features associated with hypoxanthine-guanine phosphoribosyltransferase deficiency. At one end of the spectrum are patients with classic Lesch-Nyhan disease and the full clinical phenotype. At the other end of the spectrum are patients with overproduction of uric acid but no apparent neurological or behavioural deficits. Inbetween are patients with varying degrees of motor, cognitive, or behavioural abnormalities. Recognition of this spectrum is valuable for understanding the pathogenesis and diagnosis of all forms of hypoxanthine-guanine phosphoribosyltransferase deficiency.
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PMID:Attenuated variants of Lesch-Nyhan disease. 2062 15