Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The self-injurious movements of Lesch-Nyhan patients are considered extremely severe and currently intractable. Lesch-Nyhan syndrome is a genetic disorder of purine metabolism resulting in several abnormalities, one of which is elevated levels of xanthine. The author reasons that elevated plasma xanthine sets off a chain of events that produce excessive endogenous convulsants and diminished endogenous anticonvulsants. Treatment is proposed for self-injury in Lesch-Nyhan that entails reducing production of two endogenous convulsants (kynurenine and quinolinic acid) and enhancing two endogenous anticonvulsants (serotonin and gamma aminobutyric acid).
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PMID:Serotonin-GABA treatment is hypothesized for self-injury in Lesch-Nyhan syndrome. 149 33

Lesch-Nyhan syndrome is a hereditary disorder of purine metabolism causing overproduction of uric acid and neurological problems including spasticity, choreoathetosis, mental retardation, and compulsive self-mutilation. The syndrome is caused by a defect in the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT), which converts guanine and hypoxanthine to the nucleotides GMP and IMP. There is evidence that the neurological problems are due to an adverse effect of the HPRT deficiency on the survival and/or development of dopaminergic neurons, specifically. Here we report that HPRT-deficient PC12 mutants that have a normal or near normal dopamine content (55-97% of that of wild-type cells) fail to undergo neuronal differentiation induced by nerve growth factor (NGF) when the de novo pathway of purine synthesis is partially inhibited. However, nerve growth factor-induced differentiation is near normal under these conditions in PC12 HPRT-deficient mutants containing much lower dopamine levels (<8% of that of wild type cells), indicating a neurotoxic effect of the endogenous dopamine in the mutants. The degree of inhibition of the de novo pathway of purine synthesis was the same in both classes of HPRT-deficient mutants. Expression of BCl-2 in a PC12 mutant that has a normal dopamine content allowed partial NGF-induced differentiation suggesting that the apoptotic pathway might be involved in the failure of differentiation when the de novo pathway of purine synthesis is partially inhibited.
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PMID:Impaired differentiation of HPRT-deficient dopaminergic neurons: a possible mechanism underlying neuronal dysfunction in Lesch-Nyhan syndrome. 967 Sep 94

Lesch-Nyhan syndrome is a genetic disorder resulting in hyperuricemia, choreoathetosis, mental retardation, and self-mutilation. The most salient feature of this disorder is the self-injurious behavior (SIB). Although the utility of behavioral interventions with SIB has been well documented, behavioral interventions with Lesch-Nyhan syndrome have been limited in number and long-term success. This article reviews the behavioral treatments that have been used in treating individuals with Lesch-Nyhan syndrome and discusses the strengths and weaknesses of these methods. Suggestions for future directions in the use of behavioral interventions for controlling SIB in Lesch-Nyhan syndrome are provided.
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PMID:A review of behavioral treatments used for Lesch-Nyhan syndrome. 1080 80

Lesch-Nyhan syndrome is a rare genetic disorder characterized by mental retardation, self-mutilation, choreoathetosis, and hyperuricemia. The disease is caused by a mutation in the hypoxanthine-guanine phosphoribosyltransferase gene and is transmitted as a sex-linked recessive disorder. Since hyperuricemia is the primary metabolic problem caused by a hypoxanthine-guanine phosphoribosyltransferase mutation, urologic evaluation and treatment is often necessary for children with this disease. We report a 3-year-old boy who presented with anuric renal failure secondary to bilateral obstructing uric acid calculi. The evaluation of T lymphocytes revealed a hypoxanthine-guanine phosphoribosyltransferase mutation consistent with Lesch-Nyhan syndrome. The diagnosis and urologic management of this disorder is discussed.
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PMID:Lesch-Nyhan syndrome presenting as acute renal failure secondary to obstructive uropathy. 1111 62

Lesch-Nyhan disease (LND) is a rare, X-linked genetic disorder that involves the nearly complete absence of an enzyme (hypoxanthine-guanine phosphoribosyltransferase, or HPRT) that is essential for purine salvage. In addition to hyperuricemia, all patients with classic LND suffer from movement disorder and compulsive self-injury, and most have mental retardation. Patients with partial HPRT deficiency (variants) always have hyperuricemia and often have neurologic abnormalities, but do not self-injure and usually are described as having normal intelligence. Here we compare 15 patients with LND to 9 variants and 13 normal adolescents and adults. Testing revealed unambiguous and qualitatively similar cognitive deficits in both patient groups. The variants produced scores that were intermediate between those of patients with LND and normal participants on nearly every cognitive measure. We discuss these findings in terms of what is known about the neuropathology of LND.
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PMID:Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency. 1177 23

Lesch-Nyhan syndrome (LNS) is an X-linked hereditary disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase. Patients with this syndrome are characterized by hyperuricemia, self-mutilation, developmental retardation, and movement disorders such as spasticity and dystonia. The authors performed bilateral chronic stimulation of the globus pallidus internus for control of dystonic movements in a 19-year-old man with LNS. His self-mutilating behavior unexpectedly disappeared after chronic stimulation. This is the first case of LNS that has been successfully treated with deep brain stimulation. The findings indicate that neurobehavioral features of this syndrome are either mediated in the basal ganglia pathways or secondary to the dystonia.
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PMID:Disappearance of self-mutilating behavior in a patient with lesch-nyhan syndrome after bilateral chronic stimulation of the globus pallidus internus. Case report. 1259 32

Lesch-Nyhan syndrome (LNS), first described in 1964 by Lesch and Nyhan, is a rare X-linked genetic disorder involving (near) absence of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HPRT). It occurs in 1:100,000 to 380,000 live births (1, 2). The deficiency of HPRT activity leads to an excessive uric acid production resulting in neurological, renal and musculoskeletal manifestations. Death usually occurs in the second or third decade from infection or renal failure. Clinical presentation is characterized by mental retardation, choreoathetosis, spasticity, hyperuricemia and cerebral palsy. A characteristic feature of LNS is the appearance of intractable self-injurious behaviour (SIB), usually in the form of severe lip and finger biting, gouging of eyes, face scratching and head banging requiring extreme management techniques such as the application of restraints and or extraction of teeth at an early age. In this case report a unique approach of SIB in LNS is presented.
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PMID:Self-mutilation behaviour in Lesch-Nyhan syndrome. 1613 97

Lesch-Nyhan disease (LND) is a rare X-linked recessive genetic disorder caused by a deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) enzyme. The classic clinical condition is characterized by cognitive impairment, hypotonia at rest, choreoathetosis, hyperuricaemia and the hallmark symptom of severe and involuntary self-mutilation. We describe a man with LND who was initially thought to have suffered from a dyskinetic cerebral palsy after an uncomplicated inguinal herniorrhaphy under general anaesthesia at 5 1/2 months of age. In the absence of overt self-injurious behaviour, the diagnosis was not considered for nearly two decades. The diagnosis of LND was established at 20 years of age through clinical review, biochemical examinations and molecular analysis. HPRT haemolysate activity was 7.6% of the normal control, suggesting that he had a milder variant of the disease. Mutation analysis of the HPRT gene revealed a novel missense mutation, c.449T > G in exon 6 (p.V150G). Cascade testing of family members revealed that the mother was heterozygous for the mutation but two siblings (a brother and a sister) did not carry the sequence mutation. Whether the onset of neurological abnormalities in this particular case can be attributed to the general anaesthesia is discussed.
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PMID:Lesch-Nyhan disease in a 20-year- old man incorrectly described as developing 'cerebral palsy' after general anaesthesia in infancy. 1682 47

Lesch-Nyhan syndrome (LNS) is an X-linked genetic disorder resulting in hyperuricemia, choreoathetosis, mental retardation, and self-injurious behavior. It is caused by loss of activity of the ubiquitous enzyme hypoxanthine-guanine-phosphoribosyltransferase (HPRT). The biochemical analysis of residual HPRT activity in patients' red blood cells is the first step in LNS diagnosis, and it precedes molecular study to discover the specific mutation. Unfortunately, biochemical diagnosis of healthy carriers is difficult because HPRT enzymatic activity in blood cells is similar in LNS carriers and in healthy people; genetic tests can help reveal mutations at the genomic or cDNA level, whereas gross deletions involving the first or last exons of HPRT gene are not detectable. Until now, a test based on 6-thioguanine-resistant phenotype of HPRT mutant cells from LNS patients is the only method accepted for the diagnosis of any kind of mutation in carriers. In this work, we introduce a new approach to identify carriers of large deletions in HPRT gene using real-time PCR. Results were validated in a blinded manner with a linkage study and with results obtained in Italian families previously analyzed with selective medium test. Real-time PCR analysis clearly confirmed the results obtained by selective medium; linkage data strengthened real time results, allowing us to follow the allele with the mutated HPRT through the family pedigree. We hope that the real-time PCR approach will provide a useful and reliable method to diagnose LNS carriers of large deletions in HPRT gene.
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PMID:Real-time PCR and linkage studies to identify carriers presenting HPRT deleted gene. 1722 73

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


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