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Bozano A, Schiaffino A, Spessa A, Valeriani F, Mancinelli R, Micheli V, Dolcetta D. Description of the Lesch-Nyhan neurobehavioral disorder and its management through participant observation of three young individuals. JIMD Rep 2020; 52:63-71. [PMID: 32154061 PMCID: PMC7052696 DOI: 10.1002/jmd2.12100] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/09/2020] [Accepted: 01/21/2020] [Indexed: 11/12/2022] Open
Abstract
Background Lesch-Nyhan disease (LND; OMIM 300322), caused by virtually absent hypoxanthine-guanine phosphoribosyltransferase activity, in its classic form is characterised by hyperuricemia, variable cognitive impairment, severe motor disorder and a characteristic behavioural disorder (Lesch-Nyhan Behavior, LNB), typically described as self-injurious behavior (SIB) and "self-mutilation." This work focuses on the latter aspect with the aim of exploring and broadening it. Methods The participant observation method was used to follow three children diagnosed with LND individually, in different contexts of daily life, always with their usual restraints and in the presence of a caregiver. Results 60 observational sessions, for over 90 total hours, led to the description of 292 LNBs, interfering with different aspects of life. Harmful behaviors could be classified into different categories, based on the life aspect affected and type of harm provoked. Antecedent conditions, consequent reactions, and emotions of the child and different management of the caregiver were recorded for each LNB. We confirmed that patients normally feel pain. Most common emotional reactions are regret and shock. As a consequence of a LNB, increased anxiety was always recorded, never satisfaction. Caregiver strategies most commonly used to stop the LNB and preventing recurrences are reported and discussed. Conclusions We are proposing a wider LNB description, beyond the classical Self-injurious behavior (SIB), stating that it is widespread and pervasive, involving every facet of the patients' life. Caregivers and operators should be aware that they might face different LNBs, and have to recognize them to find the better way to manage patients.
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Affiliation(s)
| | | | | | | | | | - Vanna Micheli
- Università di Siena and "LND Famiglie Italiane" Siena Italy
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2
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Torres RJ. Current understanding of Lesch-Nyhan disease and potential therapeutic targets. Expert Opin Orphan Drugs 2019. [DOI: 10.1080/21678707.2019.1652597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Rosa J. Torres
- Department of Biochemistry, La Paz University Hospital, IdiPaz, Madrid, Spain and Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
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3
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Khasnavis T, Torres RJ, Sommerfeld B, Puig JG, Chipkin R, Jinnah HA. A double-blind, placebo-controlled, crossover trial of the selective dopamine D1 receptor antagonist ecopipam in patients with Lesch-Nyhan disease. Mol Genet Metab 2016; 118:160-166. [PMID: 27179999 DOI: 10.1016/j.ymgme.2016.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 04/22/2016] [Accepted: 04/22/2016] [Indexed: 01/04/2023]
Abstract
Lesch-Nyhan disease (LND) is a genetic disorder that has characteristic metabolic, neurologic, and behavioral features. There are multiple behavioral problems including impulsivity, aggressiveness, and severe recurrent self-injurious behavior (SIB). This last behavior varies considerably across subjects and may encompass self-biting, self-hitting, scratching, head banging, and other injurious actions. Current treatments for SIB involve behavioral extinction, sedatives, physical restraints, and removal of teeth. Because these interventions do not reliably control SIB, better treatments are urgently needed. Animal studies have suggested that D1-dopamine receptor antagonists such as ecopipam may suppress SIB. These observations have led to proposals that such drugs might provide effective treatment for in LND. The current study describes the results of a double-blind, three-period, crossover trial of a single dose of ecopipam in subjects with LND. The study was designed for 20 patients, but it was terminated after recruitment of only 10 patients, because interim analysis revealed unanticipated side effects. These side effects were most likely related to starting with a single large dose without any titration phase. Despite the limited data due to early termination, the drug appeared to reduce SIB in most cases. Subjects who completed the trial were eligible to continue the drug in an open-label extension phase lasting a year, and one patient who elected to continue has maintained a striking reduction in SIB for more than a year with no apparent side effects. These results suggest ecopipam could be a useful treatment for SIB in, but further studies are needed to establish an appropriate dosing regimen.
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Affiliation(s)
- Tanya Khasnavis
- Department of Neurology, Emory University, Atlanta, GA 30322, USA
| | - Rosa J Torres
- Department of Clinical Biochemistry, La Paz University Hospital, IdiPaz, Madrid, Spain; Center for Biomedical Network Research on Rare Diseases, ISCIII, Madrid, Spain
| | | | - Juan Garcia Puig
- Department Internal Medicine, La Paz University Hospital, IdiPaz, Madrid, Spain
| | - Richard Chipkin
- Psyadon Pharmaceuticals, 20451 Seneca Meadows Parkway, Germantown, MD, 20876, USA
| | - H A Jinnah
- Department of Neurology, Emory University, Atlanta, GA 30322, USA; Department of Human Genetics, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University, Atlanta, GA 30322, USA.
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4
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Khasnavis T, Reiner G, Sommerfeld B, Nyhan WL, Chipkin R, Jinnah HA. A clinical trial of safety and tolerability for the selective dopamine D1 receptor antagonist ecopipam in patients with Lesch-Nyhan disease. Mol Genet Metab 2016; 117:401-6. [PMID: 26922636 DOI: 10.1016/j.ymgme.2016.02.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/16/2016] [Accepted: 02/16/2016] [Indexed: 10/22/2022]
Abstract
Lesch-Nyhan disease (LND) is an inherited metabolic disorder characterized by the overproduction of uric acid and distinct behavioral, cognitive, and motor abnormalities. The most challenging clinical problem is self-injurious behavior (SIB), which includes self-biting, self-hitting, self-abrasion, and other features. Currently, these behaviors are managed by behavioral extinction, sedatives, physical restraints, and removal of teeth. More effective treatments are needed. Pre-clinical studies have led to the hypothesis that D1-dopamine receptor antagonists may provide useful treatments for SIB in LND. Ecopipam is one such selective D1-dopamine receptor antagonist. This report summarizes results of a dose-escalation study of the safety and tolerability of ecopipam in 5 subjects with LND. The results suggest that ecopipam is well tolerated, with sedation being the most common dose-limiting event. Several exploratory measures also suggest ecopipam might reduce SIB in this population. These results support the hypothesis that D1-dopamine receptor antagonists may be useful for suppressing SIB in LND, and encourage further studies of efficacy.
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Affiliation(s)
- Tanya Khasnavis
- Department of Neurology, Emory University, Atlanta, GA 30322, USA
| | - Gail Reiner
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | | | - William L Nyhan
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Richard Chipkin
- Psyadon Pharmaceuticals, 20451 Seneca Meadows Parkway, Germantown, MD 20876, USA
| | - H A Jinnah
- Department of Neurology, Emory University, Atlanta, GA 30322, USA; Department of Human Genetics, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University, Atlanta, GA 30322, USA.
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5
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Fu R, Sutcliffe D, Zhao H, Huang X, Schretlen DJ, Benkovic S, Jinnah HA. Clinical severity in Lesch-Nyhan disease: the role of residual enzyme and compensatory pathways. Mol Genet Metab 2015; 114:55-61. [PMID: 25481104 PMCID: PMC4277921 DOI: 10.1016/j.ymgme.2014.11.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/01/2014] [Accepted: 11/01/2014] [Indexed: 01/01/2023]
Abstract
Mutations in the HPRT1 gene, which encodes the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGprt), cause Lesch-Nyhan disease (LND) and more mildly affected Lesch-Nyhan variants. Prior studies have suggested a strong correlation between residual hypoxanthine recycling activity and disease severity. However, the relevance of guanine recycling and compensatory changes in the de novo synthesis of purines has received little attention. In the current studies, fibroblast cultures were established for 21 healthy controls and 36 patients with a broad spectrum of disease severity related to HGprt deficiency. We assessed hypoxanthine recycling, guanine recycling, steady-state purine pools, and de novo purine synthesis. There was a strong correlation between disease severity and either hypoxanthine or guanine recycling. Intracellular purines were normal in the HGprt-deficient fibroblasts, but purine wasting was evident as increased purine metabolites excreted from the cells. The normal intracellular purines in the HGprt-deficient fibroblasts were likely due in part to a compensatory increase in purine synthesis, as demonstrated by a significant increase in purinosomes. However, the increase in purine synthesis did not appear to correlate with disease severity. These results refine our understanding of the potential sources of phenotypic heterogeneity in LND and its variants.
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Affiliation(s)
- Rong Fu
- Department of Neurology, Emory University, Atlanta, GA, USA
| | - Diane Sutcliffe
- Department of Neurology, Emory University, Atlanta, GA, USA; Department of Human Genetics, Emory University, Atlanta, GA, USA; Department of Pediatrics, Emory University, Atlanta, GA, USA
| | - Hong Zhao
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA
| | - Xinyi Huang
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA
| | - David J Schretlen
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steve Benkovic
- Department of Chemistry, Pennsylvania State University, University Park, PA, USA
| | - H A Jinnah
- Department of Neurology, Emory University, Atlanta, GA, USA; Department of Human Genetics, Emory University, Atlanta, GA, USA; Department of Pediatrics, Emory University, Atlanta, GA, USA.
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Fu R, Chen CJ, Jinnah HA. Genotypic and phenotypic spectrum in attenuated variants of Lesch-Nyhan disease. Mol Genet Metab 2014; 112:280-5. [PMID: 24930028 PMCID: PMC4122630 DOI: 10.1016/j.ymgme.2014.05.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/20/2014] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
Abstract
Lesch-Nyhan disease and its attenuated variants are caused by deficiency of the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt). All patients exhibit excessive production of uric acid, which increases the risk for nephrolithiasis, renal failure, gouty arthritis and tophi. The mildest phenotype includes only problems related to overproduction of uric acid. The most severe clinical phenotype includes prominent neurological abnormalities and the universal feature is self-injurious behavior. In between the mildest and most severe syndromes is a broad spectrum of phenotypes with varying degrees of neurological, neurocognitive and behavioral abnormalities. The effect of HPRT1 gene mutations on residual HGprt enzyme activity is the most relevant factor contributing to disease phenotype. Attenuated clinical phenotypes are associated with residual enzyme function, whereas the most severe phenotype is usually associated with null activity. In cases of gouty arthritis with urate overproduction, a careful evaluation for motor impairments or neurocognitive abnormalities may help to identify attenuated variants of Lesch-Nyhan disease for better management.
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Affiliation(s)
- Rong Fu
- Department of Neurology, Emory University, Atlanta, GA, USA
| | - Chung-Jen Chen
- Division of Rheumatology, Allergy and Immunology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan
| | - H A Jinnah
- Department of Neurology, Emory University, Atlanta, GA, USA; Department Human Genetics, Emory University, Atlanta, GA, USA; Department Pediatrics, Emory University, Atlanta, GA, USA.
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7
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Fu R, Ceballos-Picot I, Torres RJ, Larovere LE, Yamada Y, Nguyen KV, Hegde M, Visser JE, Schretlen DJ, Nyhan WL, Puig JG, O'Neill PJ, Jinnah HA. Genotype-phenotype correlations in neurogenetics: Lesch-Nyhan disease as a model disorder. ACTA ACUST UNITED AC 2013; 137:1282-303. [PMID: 23975452 DOI: 10.1093/brain/awt202] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Establishing meaningful relationships between genetic variations and clinical disease is a fundamental goal for all human genetic disorders. However, these genotype-phenotype correlations remain incompletely characterized and sometimes conflicting for many diseases. Lesch-Nyhan disease is an X-linked recessive disorder that is caused by a wide variety of mutations in the HPRT1 gene. The gene encodes hypoxanthine-guanine phosphoribosyl transferase, an enzyme involved in purine metabolism. The fine structure of enzyme has been established by crystallography studies, and its function can be measured with very precise biochemical assays. This rich knowledge of genetic alterations in the gene and their functional effect on its protein product provides a powerful model for exploring factors that influence genotype-phenotype correlations. The present study summarizes 615 known genetic mutations, their influence on the gene product, and their relationship to the clinical phenotype. In general, the results are compatible with the concept that the overall severity of the disease depends on how mutations ultimately influence enzyme activity. However, careful evaluation of exceptions to this concept point to several additional genetic and non-genetic factors that influence genotype-phenotype correlations. These factors are not unique to Lesch-Nyhan disease, and are relevant to most other genetic diseases. The disease therefore serves as a valuable model for understanding the challenges associated with establishing genotype-phenotype correlations for other disorders.
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Affiliation(s)
- Rong Fu
- 1 Departments of Neurology, Human Genetics and Paediatrics; Emory University, Atlanta GA, USA
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8
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Muehlmann AM, Wilkinson JA, Devine DP. Individual differences in vulnerability for self-injurious behavior: studies using an animal model. Behav Brain Res 2010; 217:148-54. [PMID: 20974187 DOI: 10.1016/j.bbr.2010.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 10/05/2010] [Accepted: 10/12/2010] [Indexed: 11/24/2022]
Abstract
Self-injurious behavior (SIB) is a debilitating characteristic that is prevalent across a broad spectrum of neurodevelopmental disorders. In most of these disorders, some individuals exhibit SIB, whereas others do not. However, the neurobiological mechanisms that confer vulnerability are virtually unexplored. We examined innate characteristics that contribute to vulnerability or resistance for SIB in an animal model of the behavioral pathology. Eighteen outbred Long-Evans rats were screened for behavioral responsiveness to the mild stress of a novel environment. The rats were then categorized as high responders (HR; those rats that had the highest locomotor counts) or low responders (LR; those rats that had lower locomotor counts) by median split. All the rats were then given daily injections of the indirect monoamine agonist pemoline (150 mg/kg/day) for 10 days, and self-injury was evaluated. All 9 HR rats and 5 of the 9 LR rats exhibited self-injury. The HR rats spent more time self-injuring, injured more body sites, and caused larger areas of tissue damage than the LR rats did. Furthermore, the behavioral responsiveness to novelty stress was significantly correlated with each of these measures of self-injury. The HR rats did not exhibit substantially enhanced responses on other measures of psychostimulant action (stereotypy, grooming, locomotion, rearing). Accordingly, vulnerability to develop pemoline-induced SIB is positively correlated with, and can be predicted based upon, a behavioral measure of innate stress responsiveness. These findings suggest that characteristics that are common in developmental disorders may help predispose afflicted individuals to self-injure. The findings also extend the variety of behavioral pathologies (e.g. drug addiction) for which the HR/LR model predicts vulnerability.
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Affiliation(s)
- Amber M Muehlmann
- Department of Psychology, Behavioral Neuroscience Program, University of Florida, Gainesville, FL 32611-2250, USA
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9
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Jinnah HA, Ceballos-Picot I, Torres RJ, Visser JE, Schretlen DJ, Verdu A, Laróvere LE, Chen CJ, Cossu A, Wu CH, Sampat R, Chang SJ, de Kremer RD, Nyhan W, Harris JC, Reich SG, Puig JG. Attenuated variants of Lesch-Nyhan disease. Brain 2010; 133:671-89. [PMID: 20176575 PMCID: PMC2842514 DOI: 10.1093/brain/awq013] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
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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Affiliation(s)
- H A Jinnah
- Department of Neurology and Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA.
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10
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Cristini S, Navone S, Canzi L, Acerbi F, Ciusani E, Hladnik U, de Gemmis P, Alessandri G, Colombo A, Parati E, Invernici G. Human neural stem cells: a model system for the study of Lesch-Nyhan disease neurological aspects. Hum Mol Genet 2010; 19:1939-50. [PMID: 20159777 DOI: 10.1093/hmg/ddq072] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The study of Lesch-Nyhan-diseased (LND) human brain is crucial for understanding how mutant hypoxanthine-phosphoribosyltransferase (HPRT) might lead to neuronal dysfunction. Since LND is a rare, inherited disorder caused by a deficiency of the enzyme HPRT, human neural stem cells (hNSCs) that carry this mutation are a precious source for delineating the consequences of HPRT deficiency and for developing new treatments. In our study we have examined the effect of HPRT deficiency on the differentiation of neurons in hNSCs isolated from human LND fetal brain. We have examined the expression of a number of transcription factors essential for neuronal differentiation and marker genes involved in dopamine (DA) biosynthetic pathway. LND hNSCs demonstrate aberrant expression of several transcription factors and DA markers. HPRT-deficient dopaminergic neurons also demonstrate a striking deficit in neurite outgrowth. These results represent direct experimental evidence for aberrant neurogenesis in LND hNSCs and suggest developmental roles for other housekeeping genes in neurodevelopmental disease. Moreover, exposure of the LND hNSCs to retinoic acid medium elicited the generation of dopaminergic neurons. The lack of precise understanding of the neurological dysfunction in LND has precluded development of useful therapies. These results evidence aberrant neurogenesis in LND hNSCs and suggest a role for HPRT gene in neurodevelopment. These cells combine the peculiarity of a neurodevelopmental model and a human, neural origin to provide an important tool to investigate the pathophysiology of HPRT deficiency and more broadly demonstrate the utility of human neural stem cells for studying the disease and identifying potential therapeutics.
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Affiliation(s)
- Silvia Cristini
- Laboratory of Cellular Neurobiology, UO Cerebrovascular Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, via Celoria 11, 20133 Milan, Italy
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Camici M, Micheli V, Ipata PL, Tozzi MG. Pediatric neurological syndromes and inborn errors of purine metabolism. Neurochem Int 2009; 56:367-78. [PMID: 20005278 DOI: 10.1016/j.neuint.2009.12.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 11/25/2009] [Accepted: 12/03/2009] [Indexed: 11/17/2022]
Abstract
This review is devised to gather the presently known inborn errors of purine metabolism that manifest neurological pediatric syndromes. The aim is to draw a comprehensive picture of these rare diseases, characterized by unexpected and often devastating neurological symptoms. Although investigated for many years, most purine metabolism disorders associated to psychomotor dysfunctions still hide the molecular link between the metabolic derangement and the neurological manifestations. This basically indicates that many of the actual functions of nucleosides and nucleotides in the development and function of several organs, in particular central nervous system, are still unknown. Both superactivity and deficiency of phosphoribosylpyrophosphate synthetase cause hereditary disorders characterized, in most cases, by neurological impairments. The deficiency of adenylosuccinate lyase and 5-amino-4-imidazolecarboxamide ribotide transformylase/IMP cyclohydrolase, both belonging to the de novo purine synthesis pathway, is also associated to severe neurological manifestations. Among catabolic enzymes, hyperactivity of ectosolic 5'-nucleotidase, as well as deficiency of purine nucleoside phosphorylase and adenosine deaminase also lead to syndromes affecting the central nervous system. The most severe pathologies are associated to the deficiency of the salvage pathway enzymes hypoxanthine-guanine phosphoribosyltransferase and deoxyguanosine kinase: the former due to an unexplained adverse effect exerted on the development and/or differentiation of dopaminergic neurons, the latter due to a clear impairment of mitochondrial functions. The assessment of hypo- or hyperuricemic conditions is suggestive of purine enzyme dysfunctions, but most disorders of purine metabolism may escape the clinical investigation because they are not associated to these metabolic derangements. This review may represent a starting point stimulating both scientists and physicians involved in the study of neurological dysfunctions caused by inborn errors of purine metabolism with the aim to find novel therapeutical approaches.
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Affiliation(s)
- Marcella Camici
- Dipartimento di Biologia, Unità di Biochimica, Via S Zeno 51, 56127 Pisa, Italy.
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Hypoxanthine-guanine phosophoribosyltransferase (HPRT) deficiency: Lesch-Nyhan syndrome. Orphanet J Rare Dis 2007; 2:48. [PMID: 18067674 PMCID: PMC2234399 DOI: 10.1186/1750-1172-2-48] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 12/08/2007] [Indexed: 11/22/2022] Open
Abstract
Deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity is an inborn error of purine metabolism associated with uric acid overproduction and a continuum spectrum of neurological manifestations depending on the degree of the enzymatic deficiency. The prevalence is estimated at 1/380,000 live births in Canada, and 1/235,000 live births in Spain. Uric acid overproduction is present inall HPRT-deficient patients and is associated with lithiasis and gout. Neurological manifestations include severe action dystonia, choreoathetosis, ballismus, cognitive and attention deficit, and self-injurious behaviour. The most severe forms are known as Lesch-Nyhan syndrome (patients are normal at birth and diagnosis can be accomplished when psychomotor delay becomes apparent). Partial HPRT-deficient patients present these symptoms with a different intensity, and in the least severe forms symptoms may be unapparent. Megaloblastic anaemia is also associated with the disease. Inheritance of HPRT deficiency is X-linked recessive, thus males are generally affected and heterozygous female are carriers (usually asymptomatic). Human HPRT is encoded by a single structural gene on the long arm of the X chromosome at Xq26. To date, more than 300 disease-associated mutations in the HPRT1 gene have been identified. The diagnosis is based on clinical and biochemical findings (hyperuricemia and hyperuricosuria associated with psychomotor delay), and enzymatic (HPRT activity determination in haemolysate, intact erythrocytes or fibroblasts) and molecular tests. Molecular diagnosis allows faster and more accurate carrier and prenatal diagnosis. Prenatal diagnosis can be performed with amniotic cells obtained by amniocentesis at about 15–18 weeks' gestation, or chorionic villus cells obtained at about 10–12 weeks' gestation. Uric acid overproduction can be managed by allopurinol treatment. Doses must be carefully adjusted to avoid xanthine lithiasis. The lack of precise understanding of the neurological dysfunction has precluded development of useful therapies. Spasticity, when present, and dystonia can be managed with benzodiazepines and gamma-aminobutyric acid inhibitors such as baclofen. Physical rehabilitation, including management of dysarthria and dysphagia, special devices to enable hand control, appropriate walking aids, and a programme of posture management to prevent deformities are recommended. Self-injurious behaviour must be managed by a combination of physical restraints, behavioural and pharmaceutical treatments.
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Jinnah HA, Visser JE, Harris JC, Verdu A, Larovere L, Ceballos-Picot I, Gonzalez-Alegre P, Neychev V, Torres RJ, Dulac O, Desguerre I, Schretlen DJ, Robey KL, Barabas G, Bloem BR, Nyhan W, De Kremer R, Eddey GE, Puig JG, Reich SG. Delineation of the motor disorder of Lesch-Nyhan disease. ACTA ACUST UNITED AC 2006; 129:1201-17. [PMID: 16549399 PMCID: PMC3508431 DOI: 10.1093/brain/awl056] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lesch-Nyhan disease (LND) is caused by deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). Affected individuals exhibit over-production of uric acid, along with a characteristic neurobehavioural syndrome that includes mental retardation, recurrent self-injurious behaviour and motor disability. Prior studies involving relatively small numbers of patients have provided different conclusions on the nature of the motor disorder. The current study includes the results of a multi-centre international prospective study of the motor disorder in the largest cohort of patients studied to date. A total of 44 patients ranging from 2 to 38 years presented a characteristic motor syndrome that involved severe action dystonia superimposed on baseline hypotonia. Although some patients also displayed other extrapyramidal or pyramidal signs, these were always less prominent than dystonia. These results are compared with a comprehensive review of 122 prior reports that included a total of 254 patients. Explanations for the differing observations available in the literature are provided, along with a summary of how the motor disorder of LND relates to current understanding of its pathophysiology involving the basal ganglia.
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Affiliation(s)
- H A Jinnah
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA.
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Abstract
Eye movements were assessed in 22 patients with varying degrees of hypoxanthine-guanine phosphoribosyltransferase deficiency. Ocular motility was clinically normal in seven patients with moderate enzyme deficiency but grossly abnormal in 15 patients with severe enzyme deficiency. In patients with severe deficiency, fixation was interrupted by frequent unwanted saccades toward minor visual distractions. Voluntary saccades were associated with an initial head movement and/or eyeblink in all of these patients. When head motion was prevented, voluntary saccades were often delayed and sometimes absent. In contrast, saccade speed, reflexive saccades, and other reflexive eye movements appeared clinically normal. Four patients with severe enzyme deficiency also experienced mild blepharospasm, and two had ocular tics. These disturbances of ocular motility are consistent with dysfunction of the basal ganglia or its connections with ocular motor centers in the prefrontal cortex or midbrain.
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Affiliation(s)
- H A Jinnah
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD 21287, USA
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Abstract
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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Affiliation(s)
- L Olson
- University of South Carolina, USA
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Pellicer F, Buendía-Roldán I, Pallares-Trujillo VC. Self-mutilation in the Lesch-Nyhan syndrome: a corporal consciousness problem?--a new hypothesis. Med Hypotheses 1998; 50:43-7. [PMID: 9488181 DOI: 10.1016/s0306-9877(98)90176-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Lesch-Nyhan syndrome (LNS) has been extensively studied from the genetic and biochemical point of view. The main characteristic of the syndrome is the self-mutilation feature, which has been poorly studied and understood. We propose a new hypothesis about the self-mutilation physiopathology, which is related to the supersensitivity of the dopaminergic D1 receptors in the neuromatrix found in the cingulum cortex region. The LNS shows an increase of uric acid levels as a result of the deficiency of hypoxanthine phosphoribosyltransferase enzyme. This increase could induce damage to dopaminergic neurons. As a consequence, a decrease in dopamine synthesis during gestation and the early postnatal period could occur, producing a functional dopaminergic denervation of the D1 receptors, located on the prefrontal cortex, specifically in the cingulum bundle projections. This phenomenon could induce a codification disturbance in the 'genetic body' of the neuromatrix, that could be expressed functionally as anosognosia, giving rise to self-mutilation. We suggest that this self-mutilation is a pain consciousness problem.
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Affiliation(s)
- F Pellicer
- Laboratorio de Neurofisiología, Instituto Mexicano de Psiquiatría, Tlalpan, México DF
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Williams KS, Hankerson JG, Ernst M, Zametkin A. Use of propofol anesthesia during outpatient radiographic imaging studies in patients with Lesch-Nyhan syndrome. J Clin Anesth 1997; 9:61-5. [PMID: 9051548 DOI: 10.1016/s0952-8180(96)00177-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Lesch-Nyhan syndrome is a rare, x-linked, recessive disorder of purine metabolism resulting in hyperuricemia, spasticity, choreoathetosis, dystonia, self-injurious behavior, and aggression, without significant cognitive impairment. Anesthetic management of inpatients who demonstrate classic manifestations of Lesch-Nyhan syndrome and require surgical interventions have been described. There are no guidelines in the literature addressing the anesthetic management of the outpatient with Lesch-Nyhan syndrome. Specifically, sudden, unexplained death, abnormalities in respiration, apnea, severe bradycardia, and an increased incidence of vomiting and chronic pulmonary aspiration may preclude this patient population from receiving anesthesia for outpatient procedures. General anesthesia with spontaneous ventilation was performed for diagnostic, radiographic imaging in 11 outpatients with Lesch-Nyhan syndrome using intravenous propofol. A bolus dose of 1.5 to 2.0 mg/kg propofol was followed by maintenance doses of 60 to 160 mcg/kg/min. Results during and following sedation indicated end-tidal carbon dioxide ranges between 34 mmHg and 59 mmHg. Respiratory rates were never below 10 breaths/min and no partial/complete airway obstruction or labored breathing was clinically evident. Hemodynamics were within 30% of presedation values. No patient demonstrated nausea, vomiting, or pulmonary aspiration. Baseline neuropsychologic status was achieved following sedation, and patients were discharged from the hospital 35 to 90 minutes after sedation was completed. Potential risks and benefits of using propofol in this patient population are discussed.
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Affiliation(s)
- K S Williams
- Department of Anesthesiology, Georgetown University at National Institutes of Health, Bethesda, MD 20892-1512, USA
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18
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Petrill SA, Plomin R, McClearn GE, Smith DL, Vignetti S, Chorney MJ, Chorney K, Thompson LA, Detterman DK, Benbow C, Lubinski D, Daniels J, Owen MJ, McGuffin P. DNA markers associated with general and specific cognitive abilities. INTELLIGENCE 1996. [DOI: 10.1016/s0160-2896(96)90003-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ernst M, Zametkin AJ, Matochik JA, Pascualvaca D, Jons PH, Hardy K, Hankerson JG, Doudet DJ, Cohen RM. Presynaptic dopaminergic deficits in Lesch-Nyhan disease. N Engl J Med 1996; 334:1568-72. [PMID: 8628337 DOI: 10.1056/nejm199606133342403] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Lesch-Nyhan disease is a rare, devastating, X-linked recessive disorder of purine synthesis. Patients present with hyperuricemia, choreoathetosis, dystonia, and aggressive and self-injurious behavior. Although the genetic and biochemical abnormalities have been identified, the causes of the neuropsychiatric syndrome remain unclear. METHODS We used positron-emission tomography to measure presynaptic accumulation of fluorodopa F 18 tracer in the dopaminergic regions of the brains of 12 patients with Lesch-Nyhan disease (age, 10 to 20 years) and 15 healthy controls (age, 12 to 23). The results were expressed as ratios of specific to nonspecific radioactive counts. A low ratio indicates decreased dopa decarboxylase activity and dopamine storage. RESULTS The fluorodopa F 18 ratio was significantly lower in the putamen (31 percent of control values), caudate nucleus (39 percent), frontal cortex (44 percent), and ventral tegmental complex (substantia nigra and ventral tegmentum; 57 percent) in the patients with Lesch-Nyhan disease than in the controls. Uptake of the tracer was abnormally low even in the youngest patients tested, and there was no overlap in the values between patients and controls. CONCLUSIONS Patients with Lesch-Nyhan disease have abnormally few dopaminergic nerve terminals and cell bodies. The abnormality involves all dopaminergic pathways and is not restricted to the basal ganglia. These dopaminergic deficits are pervasive and appear to be developmental in origin, which suggests that they contribute to the characteristic neuropsychiatric manifestations of the disease.
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Affiliation(s)
- M Ernst
- Laboratory of Cerebral Metabolism, National Institute of Mental Health, Bethesda, MD 20892-4030, USA
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20
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Abstract
The present study represents the first effort to assess systematically the cognitive functioning of a population of individuals with Lesch-Nyhan syndrome using standardized psychometric instruments. Seven residents from a special hospital setting participated. They ranged in age from 10 years 1 month to 22 years 3 months (mean 13 years 7 months). Using the Stanford-Binet Intelligence Scale: IV, scores in each of the four domains assessed by this battery (Verbal Reasoning, Abstract/Visual Reasoning, Quantitative and Short-Term Memory), as well as the general composite score, ranged from moderately mentally retarded to low average. Areas of weakness included attention, the manipulation of complex visual images, the comprehension of complex or lengthy speech, mathematical ability, and multi-step reasoning.
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Affiliation(s)
- W S Matthews
- Department of Pediatrics, University of Medicine and Dentistry of New Jersey, New Brunswick, USA
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21
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Abstract
UNLABELLED Parents of 40 patients with Lesch-Nyhan disease completed a questionnaire detailing developmental history, life course, management, medication, factors influencing variability and topography of self-injury. Several conclusions were reached. Characteristics: Biting was the predominant form, perhaps only because of the difficulty of preventing it. There was considerable variability in self-injury which was strongly related to stress rather than to operant influences. Even though patients could not inhibit self-injury they could predict it and request restraints. Aggression against others was as prevalent as self-injury. MANAGEMENT Stress reduction, teeth extraction, and physical restraint were the most commonly used management techniques. Behavior modification was of limited efficacy. Benzodiazepines were the most commonly used medications for controlling self-injury. OUTCOME The severity of self-injury did not change over years. Age of onset was a predictor of outcome. The earlier the age of onset the worse the self-injury eventually became. The discussion describes research strategies, suggests dimensions along which self-injury can be classified, and highlights behavior not commonly described in patients with Lesch-Nyhan disease.
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Affiliation(s)
- L T Anderson
- Department of Psychiatry, New York University Medical Center
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