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Abstract
PURPOSE OF REVIEW Tremor is an important phenotypic feature of dystonia with wide variability in the reported prevalence ranging from 14 to 86.67%. This variability may be due to the types of dystonia patients reported in different studies. This article reviews research articles reporting tremor in primary monogenic dystonia. RECENT FINDINGS We searched the MDS gene data and selected all research articles reporting tremor in primary monogenic dystonia. Tremor was reported in nine dystonia genes, namely DYT-HPCA, DYT-ANO3, DYT-KCTD17, DYT-THAP1, DYT-PRKRA, DYT-GNAL, DYT-TOR1A, DYT-KMT2B, and DYT-SGCE in the descending order of its frequency. HPCA gene mutation is rare, but all reported patients had tremor. Similarly, tremor was reported in eight genes associated with dystonia parkinsonism, namely DYT-SLC6A3, DYT-TH, DYT-SPR, DYT-PTS, DYT-GCH1, DYT-TAF1, DYT-QDPR, and DYT-SCL30A10 in the descending order of its prevalence. DYT-HPCA and DYT-ANO3 gene showed the highest prevalence of tremor in isolated dystonia, and DYT-SLC6A3 has the highest prevalence of tremor in combined dystonia.
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Affiliation(s)
- Sanjay Pandey
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, Academic Block, Room No 501, New Delhi, 110002, India.
| | - Sonali Bhattad
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, Academic Block, Room No 501, New Delhi, 110002, India
| | - Shreya Dinesh
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, Academic Block, Room No 501, New Delhi, 110002, India
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2
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Opladen T, López-Laso E, Cortès-Saladelafont E, Pearson TS, Sivri HS, Yildiz Y, Assmann B, Kurian MA, Leuzzi V, Heales S, Pope S, Porta F, García-Cazorla A, Honzík T, Pons R, Regal L, Goez H, Artuch R, Hoffmann GF, Horvath G, Thöny B, Scholl-Bürgi S, Burlina A, Verbeek MM, Mastrangelo M, Friedman J, Wassenberg T, Jeltsch K, Kulhánek J, Kuseyri Hübschmann O. Consensus guideline for the diagnosis and treatment of tetrahydrobiopterin (BH 4) deficiencies. Orphanet J Rare Dis 2020; 15:126. [PMID: 32456656 PMCID: PMC7251883 DOI: 10.1186/s13023-020-01379-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/07/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Tetrahydrobiopterin (BH4) deficiencies comprise a group of six rare neurometabolic disorders characterized by insufficient synthesis of the monoamine neurotransmitters dopamine and serotonin due to a disturbance of BH4 biosynthesis or recycling. Hyperphenylalaninemia (HPA) is the first diagnostic hallmark for most BH4 deficiencies, apart from autosomal dominant guanosine triphosphate cyclohydrolase I deficiency and sepiapterin reductase deficiency. Early supplementation of neurotransmitter precursors and where appropriate, treatment of HPA results in significant improvement of motor and cognitive function. Management approaches differ across the world and therefore these guidelines have been developed aiming to harmonize and optimize patient care. Representatives of the International Working Group on Neurotransmitter related Disorders (iNTD) developed the guidelines according to the SIGN (Scottish Intercollegiate Guidelines Network) methodology by evaluating all available evidence for the diagnosis and treatment of BH4 deficiencies. CONCLUSION Although the total body of evidence in the literature was mainly rated as low or very low, these consensus guidelines will help to harmonize clinical practice and to standardize and improve care for BH4 deficient patients.
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Affiliation(s)
- Thomas Opladen
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany.
| | - Eduardo López-Laso
- Pediatric Neurology Unit, Department of Pediatrics, University Hospital Reina Sofía, IMIBIC and CIBERER, Córdoba, Spain
| | - Elisenda Cortès-Saladelafont
- Inborn errors of metabolism Unit, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
- Unit of Pediatric Neurology and Metabolic Disorders, Department of Pediatrics, Hospital Germans Trias i Pujol, and Faculty of Medicine, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Toni S Pearson
- Department of Neurology, Washington University School of Medicine, St. Louis, USA
| | - H Serap Sivri
- Department of Pediatrics, Section of Metabolism, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
| | - Yilmaz Yildiz
- Department of Pediatrics, Section of Metabolism, Hacettepe University, Faculty of Medicine, 06100, Ankara, Turkey
| | - Birgit Assmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Manju A Kurian
- Developmental Neurosciences, UCL Great Ormond Street-Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Vincenzo Leuzzi
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Simon Heales
- Neurometabolic Unit, National Hospital, Queen Square, London, UK
| | - Simon Pope
- Neurometabolic Unit, National Hospital, Queen Square, London, UK
| | - Francesco Porta
- Department of Pediatrics, AOU Città della Salute e della Scienza, Torino, Italy
| | - Angeles García-Cazorla
- Inborn errors of metabolism Unit, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Barcelona, Spain
| | - Tomáš Honzík
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Roser Pons
- First Department of Pediatrics of the University of Athens, Aghia Sofia Hospital, Athens, Greece
| | - Luc Regal
- Department of Pediatric, Pediatric Neurology and Metabolism Unit, UZ Brussel, Brussels, Belgium
| | - Helly Goez
- Department of Pediatrics, University of Alberta Glenrose Rehabilitation Hospital, Edmonton, Canada
| | - Rafael Artuch
- Clinical biochemistry department, Institut de Recerca Sant Joan de Déu, CIBERER and MetabERN Hospital Sant Joan de Déu, Barcelona, Spain
| | - Georg F Hoffmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Gabriella Horvath
- Department of Pediatrics, Division of Biochemical Genetics, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital Zurich, Zürich, Switzerland
| | - Sabine Scholl-Bürgi
- Clinic for Pediatrics I, Medical University of Innsbruck, Anichstr 35, Innsbruck, Austria
| | - Alberto Burlina
- U.O.C. Malattie Metaboliche Ereditarie, Dipartimento della Salute della Donna e del Bambino, Azienda Ospedaliera Universitaria di Padova - Campus Biomedico Pietro d'Abano, Padova, Italy
| | - Marcel M Verbeek
- Departments of Neurology and Laboratory Medicine, Alzheimer Centre, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Mario Mastrangelo
- Unit of Child Neurology and Psychiatry, Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Jennifer Friedman
- UCSD Departments of Neuroscience and Pediatrics, Rady Children's Hospital Division of Neurology; Rady Children's Institute for Genomic Medicine, San Diego, USA
| | - Tessa Wassenberg
- Department of Pediatric, Pediatric Neurology and Metabolism Unit, UZ Brussel, Brussels, Belgium
| | - Kathrin Jeltsch
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
| | - Jan Kulhánek
- Department of Paediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
| | - Oya Kuseyri Hübschmann
- Division of Child Neurology and Metabolic Disorders, University Children's Hospital, Heidelberg, Germany
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Abstract
Most attempts at rational development of new analgesics have failed, in part because chronic pain involves multiple processes that remain poorly understood. To improve translational success, one strategy is to select novel targets for which there is proof of clinical relevance, either genetically through heritable traits, or pharmacologically. Such an approach by definition yields targets with high clinical validity. The biology of these targets can be elucidated in animal models before returning to the patients with a refined therapeutic. For optimal treatment, having biomarkers of drug action available is also a plus. Here we describe a case study in rational drug design: the use of controlled inhibition of peripheral tetrahydrobiopterin (BH4) synthesis to reduce abnormal chronic pain states without altering nociceptive-protective pain. Initially identified in a population of patients with low back pain, the association between BH4 production and chronic pain has been confirmed in more than 12 independent cohorts, through a common haplotype (present in 25% of Caucasians) of the rate-limiting enzyme for BH4 synthesis, GTP cyclohydrolase 1 (GCH1). Genetic tools in mice have demonstrated that both injured sensory neurons and activated macrophages engage increased BH4 synthesis to cause chronic pain. GCH1 is an obligate enzyme for de novo BH4 production. Therefore, inhibiting GCH1 activity eliminates all BH4 production, affecting the synthesis of multiple neurotransmitters and signaling molecules and interfering with physiological function. In contrast, targeting the last enzyme of the BH4 synthesis pathway, sepiapterin reductase (SPR), allows reduction of pathological BH4 production without completely blocking physiological BH4 synthesis. Systemic SPR inhibition in mice has not revealed any safety concerns to date, and available genetic and pharmacologic data suggest similar responses in humans. Finally, because it is present in vivo only when SPR is inhibited, sepiapterin serves as a reliable biomarker of target engagement, allowing potential quantification of drug efficacy. The emerging development of therapeutics that target BH4 synthesis to treat chronic pain illustrates the power of combining human and mouse genetics: human genetic studies for clinical selection of relevant targets, coupled with causality studies in mice, allowing the rational engineering of new analgesics.
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Affiliation(s)
- Alban Latremoliere
- Kirby Neurobiology Center, Boston Children's Hospital and Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Michael Costigan
- Kirby Neurobiology Center, Boston Children's Hospital and Department of Neurobiology, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, 02115, USA.
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Kim J, Kim Y, Nakajima R, Shin A, Jeong M, Park AH, Jeong Y, Jo S, Yang S, Park H, Cho SH, Cho KH, Shim I, Chung JH, Paik SB, Augustine GJ, Kim D. Inhibitory Basal Ganglia Inputs Induce Excitatory Motor Signals in the Thalamus. Neuron 2017; 95:1181-1196.e8. [PMID: 28858620 DOI: 10.1016/j.neuron.2017.08.028] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/07/2017] [Accepted: 08/15/2017] [Indexed: 10/19/2022]
Abstract
Basal ganglia (BG) circuits orchestrate complex motor behaviors predominantly via inhibitory synaptic outputs. Although these inhibitory BG outputs are known to reduce the excitability of postsynaptic target neurons, precisely how this change impairs motor performance remains poorly understood. Here, we show that optogenetic photostimulation of inhibitory BG inputs from the globus pallidus induces a surge of action potentials in the ventrolateral thalamic (VL) neurons and muscle contractions during the post-inhibitory period. Reduction of the neuronal population with this post-inhibitory rebound firing by knockout of T-type Ca2+ channels or photoinhibition abolishes multiple motor responses induced by the inhibitory BG input. In a low dopamine state, the number of VL neurons showing post-inhibitory firing increases, while reducing the number of active VL neurons via photoinhibition of BG input, effectively prevents Parkinson disease (PD)-like motor symptoms. Thus, BG inhibitory input generates excitatory motor signals in the thalamus and, in excess, promotes PD-like motor abnormalities. VIDEO ABSTRACT.
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Affiliation(s)
- Jeongjin Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea; Center for Neuroscience, KIST, Seoul 02792, Republic of Korea
| | - Youngsoo Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea; Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Ryuichi Nakajima
- Center for Functional Connectomics, KIST, Seoul 02792, Republic of Korea
| | - Anna Shin
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Minju Jeong
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Ah Hyung Park
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Yongcheol Jeong
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Seonmi Jo
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Seungkyoung Yang
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Hosung Park
- School of Computing, KAIST, Daejeon 34141, Republic of Korea
| | - Sung-Hwan Cho
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Kwang-Hyun Cho
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - Insop Shim
- Department of Science in Korean Medicine, Graduate School, College of Korean Medicine, Kyung Hee University, Seoul 02453, Republic of Korea
| | - Jae Hoon Chung
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea
| | - Se-Bum Paik
- Department of Bio and Brain Engineering, KAIST, Daejeon 34141, Republic of Korea
| | - George J Augustine
- Center for Functional Connectomics, KIST, Seoul 02792, Republic of Korea; Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore, 308232, Singapore; Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Daesoo Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Republic of Korea.
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Martins-de-Souza D, Cassoli JS, Nascimento JM, Hensley K, Guest PC, Pinzon-Velasco AM, Turck CW. The protein interactome of collapsin response mediator protein-2 (CRMP2/DPYSL2) reveals novel partner proteins in brain tissue. Proteomics Clin Appl 2015; 9:817-31. [PMID: 25921334 DOI: 10.1002/prca.201500004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/23/2015] [Accepted: 04/27/2015] [Indexed: 01/18/2023]
Abstract
PURPOSE Collapsin response mediator protein-2 (CRMP2) is a CNS protein involved in neuronal development, axonal and neuronal growth, cell migration, and protein trafficking. Recent studies have linked perturbations in CRMP2 function to neurodegenerative disorders such as Alzheimer's disease, neuropathic pain, and Batten disease, and to psychiatric disorders such as schizophrenia. Like most proteins, CRMP2 functions though interactions with a molecular network of proteins and other molecules. EXPERIMENTAL DESIGN Here, we have attempted to identify additional proteins of the CRMP2 interactome to provide further leads about its roles in neurological functions. We used a combined co-immunoprecipitation and shotgun proteomic approach in order to identify CRMP2 protein partners. RESULTS We identified 78 CRMP2 protein partners not previously reported in public protein interaction databases. These were involved in seven biological processes, which included cell signaling, growth, metabolism, trafficking, and immune function, according to Gene Ontology classifications. Furthermore, 32 different molecular functions were found to be associated with these proteins, such as RNA binding, ribosomal functions, transporter activity, receptor activity, serine/threonine phosphatase activity, cell adhesion, cytoskeletal protein binding and catalytic activity. In silico pathway interactome construction revealed a highly connected network with the most overrepresented functions corresponding to semaphorin interactions, along with axon guidance and WNT5A signaling. CONCLUSIONS AND CLINICAL RELEVANCE Taken together, these findings suggest that the CRMP2 pathway is critical for regulating neuronal and synaptic architecture. Further studies along these lines might uncover novel biomarkers and drug targets for use in drug discovery.
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Affiliation(s)
- Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.,UNICAMP's Neurobiology Center, Campinas, Brazil
| | - Juliana S Cassoli
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Juliana M Nascimento
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil.,D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
| | - Kenneth Hensley
- Department of Pathology, University of Toledo, Toledo, OH, USA.,Department of Neurosciences, University of Toledo, Toledo, OH, USA
| | - Paul C Guest
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Andres M Pinzon-Velasco
- Bioinformatics and Computational Systems Biology Group, Institute for Genetics, National University of Colombia, Bogotá, Colombia
| | - Christoph W Turck
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
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7
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Abstract
The monoamine neurotransmitter disorders are increasingly recognized as an expanding group of inherited neurometabolic syndromes caused by disturbances in the synthesis, transport and metabolism of the biogenic amines, including the catecholamines (dopamine, norepinephrine, and epinephrine) and serotonin. Disturbances in monoamine metabolism lead to neurological syndromes that frequently mimic other conditions, such as hypoxic ischemic encephalopathy, cerebral palsy, parkinsonism-dystonia syndromes, primary genetic dystonia and paroxysmal disorders. As a consequence, neurotransmitter disorders are frequently misdiagnosed. Early and accurate diagnosis of these neurotransmitter disorders is important, as many are highly amenable to, and some even cured by, therapeutic intervention. In this review, we highlight recent advances in the field, particularly the recent extensive characterization of known neurotransmitter disorders and identification of novel neurotransmitter disorders. We also provide an overview of current and future research in the field focused on developing novel treatment strategies.
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Affiliation(s)
- Clara Marecos
- Department of Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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Koht J, Rengmark A, Opladen T, Bjørnarå KA, Selberg T, Tallaksen CME, Blau N, Toft M. Clinical and genetic studies in a family with a novel mutation in the sepiapterin reductase gene. Acta Neurol Scand 2014:7-12. [PMID: 24588500 DOI: 10.1111/ane.12230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Sepiapterin reductase deficiency is a rare, but treatable inherited disorder of tetrahydrobiopterin and neurotransmitter metabolism. This disorder is most probably underdiagnosed. To date, only 44 cases have been described in the literature. We present the clinical and genetic investigations in a family with a complex movement disorder. MATERIALS AND METHODS We examined two affected sisters and three healthy family members. The cerebrospinal fluid was analyzed for neurotransmitter and pterins, and the sepiapterin reductase gene (SPR) was sequenced. RESULTS The sisters had a complex movement disorders with dystonia and diurnal fluctuations. Both had oculogyric crises, and the older sister also hypersomnia. Both sisters had raised prolactin levels twice above the reference level. One sister had a dramatic response to levodopa, the other responded, but developed dyskinesia despite low doses. Both patients improved dramatically over time with levodopa (2.3 and 1.5 mg/kg/day). Very low levels of homovanillic acid and 5-hydroxyindoleacetic acid and increased levels of sepiapterin and dihydrobiopterin were measured in the cerebrospinal fluid before treatment. DNA analyses revealed a novel homozygous mutation in exon 2 in the SPR gene, c.364A>G/p.(Tyr123Cys), located in a highly conserved region in the gene. Both parents and the healthy sister were carriers for the same mutation. CONCLUSIONS A new homozygous mutation in the SPR gene was found in two sisters with dopa-responsive dystonia. This important and treatable neurotransmitter disorder must be considered in patients with a complex movement disorder with diurnal fluctuations with or without intellectual impairment. Patients with these symptoms should undergo levodopa trial, cerebrospinal fluid investigations, and genetic analyses.
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Affiliation(s)
- J. Koht
- Department of Neurology; Drammen Hospital; Vestre Viken Health Trust; Drammen Norway
| | - A. Rengmark
- Department of Neurology; Oslo University Hospital; Rikshospitalet; Oslo Norway
| | - T. Opladen
- Department of General Pediatrics; University of Heidelberg; Heidelberg Germany
| | - K. A. Bjørnarå
- Department of Neurology; Drammen Hospital; Vestre Viken Health Trust; Drammen Norway
| | - T. Selberg
- Department of Habilitation; Drammen Hospital; Vestre Viken Health Trust; Drammen Norway
| | - C. M. E. Tallaksen
- Faculty of Medicine; University of Oslo; Oslo Norway
- Department of Neurology; Oslo University Hospital; Ullevål Norway
| | - N. Blau
- Department of General Pediatrics; University of Heidelberg; Heidelberg Germany
| | - M. Toft
- Department of Neurology; Oslo University Hospital; Rikshospitalet; Oslo Norway
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Kara B, Ayhan Ö, Gökçay G, Başboğaoğlu N, Tolun A. Adult phenotype and further phenotypic variability in SRD5A3-CDG. BMC Med Genet 2014; 15:10. [PMID: 24433453 PMCID: PMC3898029 DOI: 10.1186/1471-2350-15-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 01/08/2014] [Indexed: 12/22/2022]
Abstract
Background SRD5A3 is responsible for SRD5A3-CDG, a type of congenital disorder of glycosylation, and mutations have been reported in 15 children. All the mutations are recessive and truncating. Case presentation We present 2 brothers at the age of 38 and 40 years with an initial diagnosis of cerebellar ataxia. We found the candidate disease loci via linkage analysis using data from single nucleotide polymorphism genome scans and homozygous truncating mutation SRD5A3 p.W19X, which was previously reported in 3 unrelated children, by exome sequencing. Clinical investigations included physical and ocular examinations and blood tests. Severe ocular involvement with retinal bone spicule pigmentation and optic atrophy are the most prominent disabling clinical features of the disease. The serum transferrin isoelectric focusing (TIEF) pattern is abnormal in the patient investigated. Conclusion Our patients are older, with later onset and milder clinical phenotypes than all patients with SRD5A3-CDG reported so far. They also have atypical ocular findings and variable phenotypes. Our findings widen the spectrum of phenotypes resulting from SRD5A3 mutations and the clinical variability of SRD5A3-CDG, and suggest screening for SRD5A3 mutations in new patients with at least a few of the clinical symptoms of SRD5A3-CDG.
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Affiliation(s)
| | | | | | | | - Aslıhan Tolun
- Department of Molecular Biology and Genetics, Boğaziçi University, Istanbul, Turkey.
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10
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Lange I, Geerts D, Feith DJ, Mocz G, Koster J, Bachmann AS. Novel interaction of ornithine decarboxylase with sepiapterin reductase regulates neuroblastoma cell proliferation. J Mol Biol 2013; 426:332-46. [PMID: 24096079 DOI: 10.1016/j.jmb.2013.09.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/21/2013] [Accepted: 09/25/2013] [Indexed: 01/24/2023]
Abstract
Ornithine decarboxylase (ODC) is the sentinel enzyme in polyamine biosynthesis. Both ODC and polyamines regulate cell division, proliferation, and apoptosis. Sepiapterin reductase (SPR) catalyzes the last step in the biosynthesis of tetrahydrobiopterin (BH4), an essential cofactor of nitric oxide synthase, and has been implicated in neurological diseases but not yet in cancer. In this study, we present compelling evidence that native ODC and SPR physically interact, and we defined the individual amino acid residues involved in both enzymes using in silico protein-protein docking simulations. The resulting heterocomplex is a surprisingly compact structure, featuring two energetically and structurally equivalent binding modes both in monomer and in dimer conformations. The novel interaction between ODC and SPR proteins was confirmed under physiological conditions by co-immunoprecipitation and co-localization in neuroblastoma (NB) cells. Importantly, we showed that siRNA (small interfering RNA)-mediated knockdown of SPR expression significantly reduced endogenous ODC enzyme activity in NB cells, thus demonstrating the biological relevance of the ODC-SPR interaction. Finally, in a cohort of 88 human NB tumors, we found that high SPR mRNA expression correlated significantly with poor survival prognosis using a Kaplan-Meier analysis (log-rank test, P=5 × 10(-4)), suggesting an oncogenic role for SPR in NB tumorigenesis. In conclusion, we showed that ODC binds SPR and thus propose a new concept in which two well-characterized biochemical pathways converge via the interaction of two enzymes. We identified SPR as a novel regulator of ODC enzyme activity and, based on clinical evidence, present a model in which SPR drives ODC-mediated malignant progression in NB.
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Affiliation(s)
- Ingo Lange
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI 96720, USA
| | - Dirk Geerts
- Department of Pediatric Oncology/Hematology, Sophia Children's Hospital, Erasmus University Medical Center, 3015 GE Rotterdam, The Netherlands
| | - David J Feith
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Gabor Mocz
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Jan Koster
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - André S Bachmann
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI 96720, USA; Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA.
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Abstract
SUMMARY It has been generally recognized that, in most cases of Parkinson’s disease (PD), the causes are a result of the complex interaction of genetic and environmental factors. Only approximately 10–15% of PD cases appear to be rare forms with a Mendelian genetic cause. There has been an increasing need and demand in daily clinical work to look for a molecular diagnosis, although a number of neurologists feel uneasy when dealing with the growing number of possible genes and risk factors related to PD that are accessible for diagnosis. Research has highlighted the consequences not only for hereditary but also sporadic forms of PD. This review will provide an overview of the principal aspects of the genetics of PD. It will focus on their differences and similarities, and discuss several useful tools for clinicians, and the role and importance of a neurogeneticist.
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Affiliation(s)
- Ebba Lohmann
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, & Deutsches Zentrum für Neurodegenerative Erkrankungen, German Center for Neurodegenerative Diseases, Tübingen, Germany; and Istanbul University, Department of Neurology, Medical School, Istanbul, Turkey
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12
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Abstract
BACKGROUND Infantile neuroaxonal dystrophy (INAD) is a recessive disease that results in total neurological degeneration and death in childhood. PLA2G6 mutation is the underlying genetic defect, but rare genetic heterogeneity has been demonstrated. One of the five families we studied did not link to PLA2G6 locus, and in the family one of the two affected siblings additionally had atypical features including facial dysmorphism, pectus carinatum, scoliosis, pes varus, zygodactyly and bilateral cryptorchidism as well as cerebellar atrophy, as previously reported. METHODS Sural biopsy was investigated by electron microscopy. PLA2G6 was screened for mutations by Sanger sequencing. In the mutation-free family, candidate disease loci were found via linkage analysis using data from single nucleotide polymorphism genome scans. Exome sequencing was applied to find the variants at the loci. RESULTS PLA2G6 mutations were identified in four families including the one with an unusually severe phenotype that led to death within the first 2 years of life. In the remaining family, seven candidate loci totalling 15.2 Mb were found and a homozygous truncating mutation p.Q642X was identified in NALCN at 13q32.3. The patients are around 20-years-old. CONCLUSIONS NALCN is the gene responsible for INAD with facial dysmorphism. The patients have lived to adulthood despite severe growth and neuromotor retardation. NALCN forms a voltage-independent ion channel with a role in the regulation of neuronal excitability. Our findings broaden the spectrum of genes associated with neuroaxonal dystrophy. Testing infants with idiopathic severe growth retardation and neurodegeneration for NALCN mutations could benefit families.
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Affiliation(s)
- Çiğdem Köroğlu
- Department of Molecular Biology and Genetics, Boğaziçi University, Istanbul, Turkey
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13
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Abstract
Dystonia has been defined as a syndrome of involuntary, sustained muscle contractions affecting one or more sites of the body, frequently causing twisting and repetitive movements or abnormal postures. Dystonia is also a clinical sign that can be the presenting or prominent manifestation of many neurodegenerative and neurometabolic disorders. Etiological categories include primary dystonia, secondary dystonia, heredodegenerative diseases with dystonia, and dystonia plus. Primary dystonia includes syndromes in which dystonia is the sole phenotypic manifestation with the exception that tremor can be present as well. Most primary dystonia begins in adults, and approximately 10% of probands report one or more affected family members. Many cases of childhood- and adolescent-onset dystonia are due to mutations in TOR1A and THAP1. Mutations in THAP1 and CIZ1 have been associated with sporadic and familial adult-onset dystonia. Although significant recent progress had been made in defining the genetic basis for most of the dystonia-plus and heredodegenerative diseases with dystonia, a major gap remains in understanding the genetic etiologies for most cases of adult-onset primary dystonia. Common themes in the cellular biology of dystonia include G1/S cell cycle control, monoaminergic neurotransmission, mitochondrial dysfunction, and the neuronal stress response.
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Affiliation(s)
- Mark S LeDoux
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
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