101
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Zorzi G, Carecchio M, Zibordi F, Garavaglia B, Nardocci N. Diagnosis and treatment of pediatric onset isolated dystonia. Eur J Paediatr Neurol 2018; 22:238-244. [PMID: 29396174 DOI: 10.1016/j.ejpn.2018.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/14/2017] [Accepted: 01/08/2018] [Indexed: 12/14/2022]
Abstract
Isolated dystonia refers to a genetic heterogeneous group of progressive conditions with onset of symptoms during childhood or adolescence, progressive course with frequent generalization and marked functional impairment. There are well-known monogenic forms of isolated dystonia with pediatric onset such as DYT1 and DYT6 transmitted with autosomal dominant inheritance and low penetrance. Genetic findings of the past years have widened the etiological spectrum and the phenotype. The recently discovered genes (GNAL, ANO-3, KTM2B) or variant of already known diseases, such as Ataxia-Teleangectasia, are emerging as another causes of pediatric onset dystonia, sometimes with a more complex phenotype, but their incidence is unknown and still a considerable number of cases remains genetically undetermined. Due to the severe disability of pediatric onset dystonia treatment remains unsatisfactory and still mainly based upon oral pharmacological agents. However, deep brain stimulation is now extensively applied with good to excellent results especially when patients are treated early during the course of the disease.
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Affiliation(s)
- Giovanna Zorzi
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy.
| | - Miryam Carecchio
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy; Molecular Neurogenetics Unit, IRCCS Fondazione C. Besta, Milan, Italy
| | - Federica Zibordi
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy
| | | | - Nardo Nardocci
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy
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102
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Baizabal-Carvallo JF, Alonso-Juarez M. Generalized dystonia associated with mutation in the histone methyltransferase gene KMT2B (DYT28) and white matter abnormalities. Parkinsonism Relat Disord 2018; 49:116-117. [PMID: 29396090 DOI: 10.1016/j.parkreldis.2018.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 12/14/2022]
Affiliation(s)
- José Fidel Baizabal-Carvallo
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA; University of Guanajuato, Mexico.
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103
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Hiraide T, Nakashima M, Yamoto K, Fukuda T, Kato M, Ikeda H, Sugie Y, Aoto K, Kaname T, Nakabayashi K, Ogata T, Matsumoto N, Saitsu H. De novo variants in SETD1B are associated with intellectual disability, epilepsy and autism. Hum Genet 2018; 137:95-104. [DOI: 10.1007/s00439-017-1863-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/26/2017] [Indexed: 01/10/2023]
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104
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Histone Lysine Methylases and Demethylases in the Landscape of Human Developmental Disorders. Am J Hum Genet 2018; 102:175-187. [PMID: 29276005 DOI: 10.1016/j.ajhg.2017.11.013] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/17/2017] [Indexed: 11/23/2022] Open
Abstract
Histone lysine methyltransferases (KMTs) and demethylases (KDMs) underpin gene regulation. Here we demonstrate that variants causing haploinsufficiency of KMTs and KDMs are frequently encountered in individuals with developmental disorders. Using a combination of human variation databases and existing animal models, we determine 22 KMTs and KDMs as additional candidates for dominantly inherited developmental disorders. We show that KMTs and KDMs that are associated with, or are candidates for, dominant developmental disorders tend to have a higher level of transcription, longer canonical transcripts, more interactors, and a higher number and more types of post-translational modifications than other KMT and KDMs. We provide evidence to firmly associate KMT2C, ASH1L, and KMT5B haploinsufficiency with dominant developmental disorders. Whereas KMT2C or ASH1L haploinsufficiency results in a predominantly neurodevelopmental phenotype with occasional physical anomalies, KMT5B mutations cause an overgrowth syndrome with intellectual disability. We further expand the phenotypic spectrum of KMT2B-related disorders and show that some individuals can have severe developmental delay without dystonia at least until mid-childhood. Additionally, we describe a recessive histone lysine-methylation defect caused by homozygous or compound heterozygous KDM5B variants and resulting in a recognizable syndrome with developmental delay, facial dysmorphism, and camptodactyly. Collectively, these results emphasize the significance of histone lysine methylation in normal human development and the importance of this process in human developmental disorders. Our results demonstrate that systematic clinically oriented pathway-based analysis of genomic data can accelerate the discovery of rare genetic disorders.
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105
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Abstract
PURPOSE OF REVIEW Deep brain stimulation (DBS) has recently emerged as an important management option in children with medically refractory dystonia. DBS is most commonly used, best studied, and thought to be most efficacious for a select group of childhood or adolescent onset monogenic dystonias (designated with a standard 'DYT' prefix). We review how to clinically recognize these types of dystonia and the relative efficacy of DBS for key monogenic dystonias. RECENT FINDINGS Though used for dystonia in adults for several years, DBS has only lately been used in children. Recent evidence shows that patients with shorter duration of dystonia often experience greater benefit following DBS. This suggests that early recognition of the appropriate dystonic phenotypes and consideration of DBS in these patients may improve the management of dystonia. SUMMARY DBS should be considered early in patients who have medically refractory dystonia, especially for the monogenic dystonias that have a high response rate to DBS. It is important to differentiate between these monogenic dystonias and dystonias of other causes to properly prognosticate for these patients and to determine whether DBS is an appropriate management option.
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106
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Abstract
Purpose of Review Hyperkinetic movement disorders can manifest alone or as part of complex phenotypes. In the era of next-generation sequencing (NGS), the list of monogenic complex movement disorders is rapidly growing. This review will explore the main features of these newly identified conditions. Recent Findings Mutations in ADCY5 and PDE10A have been identified as important causes of childhood-onset dyskinesias and KMT2B mutations as one of the most frequent causes of complex dystonia in children. The delineation of the phenotypic spectrum associated with mutations in ATP1A3, FOXG1, GNAO1, GRIN1, FRRS1L, and TBC1D24 is revealing an expanding genetic overlap between epileptic encephalopathies, developmental delay/intellectual disability, and hyperkinetic movement disorders,. Summary Thanks to NGS, the etiology of several complex hyperkinetic movement disorders has been elucidated. Importantly, NGS is changing the way clinicians diagnose these complex conditions. Shared molecular pathways, involved in early stages of brain development and normal synaptic transmission, underlie basal ganglia dysfunction, epilepsy, and other neurodevelopmental disorders.
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Affiliation(s)
- Miryam Carecchio
- Molecular Neurogenetics Unit, IRCCS Foundation Carlo Besta Neurological Institute, Via L. Temolo 4, 20126, Milan, Italy.,Department of Pediatric Neurology, IRCCS Foundation Carlo Besta Neurological Institute, Via Celoria 11, 20131, Milan, Italy.,Department of Medicine and Surgery, PhD Programme in Molecular and Translational Medicine, Milan Bicocca University, Via Cadore 48, 20900, Monza, Italy
| | - Niccolò E Mencacci
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL, 60611, USA. .,Department of Molecular Neuroscience, UCL Institute of Neurology, London, WC1N 3BG, UK.
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107
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Lange LM, Tunc S, Tennstedt S, Münchau A, Klein C, Assmann B, Lohmann K. A novel, in-frame KMT2B deletion in a patient with apparently isolated, generalized dystonia. Mov Disord 2017; 32:1495-1497. [PMID: 28921672 DOI: 10.1002/mds.27137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/10/2017] [Accepted: 07/14/2017] [Indexed: 02/03/2023] Open
Affiliation(s)
- Lara M Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Sinem Tunc
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Department of Neurology, University Hospital Schleswig-Holstein, Campus Lübeck, Germany
| | | | - Alexander Münchau
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Department of Neurology, University Hospital Schleswig-Holstein, Campus Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.,Department of Neurology, University Hospital Schleswig-Holstein, Campus Lübeck, Germany
| | - Birgit Assmann
- Department of Neuropediatrics, University Children's Hospital, Heidelberg, Germany
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
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108
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Molecular diversity of combined and complex dystonia: insights from diagnostic exome sequencing. Neurogenetics 2017; 18:195-205. [PMID: 28849312 DOI: 10.1007/s10048-017-0521-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/10/2017] [Indexed: 12/22/2022]
Abstract
Combined and complex dystonias are heterogeneous movement disorders combining dystonia with other motor and/or systemic signs. Although we are beginning to understand the diverse molecular causes of these disease entities, clinical pattern recognition and conventional genetic workup achieve an etiological diagnosis only in a minority of cases. Our goal was to provide a window into the variable genetic origins and distinct clinical patterns of combined/complex dystonia more broadly. Between August 2016 and January 2017, we applied whole-exome sequencing to a cohort of nine patients with varied combined and/or complex dystonic presentations, being on a diagnostic odyssey. Bioinformatics analyses, co-segregation studies, and sequence-interpretation algorithms were employed to detect causative mutations. Comprehensive clinical review was undertaken to define the phenotypic spectra and optimal management strategies. On average, we observed a delay in diagnosis of 23 years before whole-exome analysis enabled determination of each patient's genetic defect. Whereas mutations in ACTB, ATP1A3, ADCY5, and SGCE were associated with particular phenotypic clues, trait manifestations arising from mutations in PINK1, MRE11A, KMT2B, ATM, and SLC6A1 were different from those previously reported in association with these genes. Apart from improving counseling for our entire cohort, genetic findings had actionable consequences on preventative measures and therapeutic interventions for five patients. Our investigation confirms unique genetic diagnoses, highlights key clinical features and phenotypic expansions, and suggests whole-exome sequencing as a first-tier diagnostic for combined/complex dystonia. These results might stimulate independent teams to extend the scope of agnostic genetic screening to this particular phenotypic group that remains poorly characterized through existing studies.
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109
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Abstract
Mainly due to the advent of next-generation sequencing (NGS), the field of genetics of dystonia has rapidly grown in recent years, which led to the discovery of a number of novel dystonia genes and the development of a new classification and nomenclature for inherited dystonias. In addition, new findings from both in vivo and in vitro studies have been published on the role of previously known dystonia genes, extending our understanding of the pathophysiology of dystonia. We here review the current knowledge and recent findings in the known genes for isolated dystonia TOR1A, THAP1, and GNAL as well as for the combined dystonias due to mutations in GCH1, ATP1A3, and SGCE. We present confirmatory evidence for a role of dystonia genes that had not yet been unequivocally established including PRKRA, TUBB4A, ANO3, and TAF1. We finally discuss selected novel genes for dystonia such as KMT2B and VAC14 along with the challenges for gene identification in the NGS era and the translational importance of dystonia genetics in clinical practice.
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110
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Zech M, Jech R, Havránková P, Fečíková A, Berutti R, Urgošík D, Kemlink D, Strom TM, Roth J, Růžička E, Winkelmann J. KMT2B rare missense variants in generalized dystonia. Mov Disord 2017; 32:1087-1091. [PMID: 28520167 DOI: 10.1002/mds.27026] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/22/2017] [Accepted: 04/03/2017] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Recently a novel syndrome of childhood-onset generalized dystonia originating from mutations in lysine-specific methyltransferase 2B (KMT2B) has been reported. METHODS We sequenced the exomes of 4 generalized dystonia-affected probands recruited from a Prague movement disorders center (Czech Republic). Bioinformatics analyses were conducted to select candidate causal variants in described dystonia-mutated genes. After cosegregation testing, checklists from the American College of Medical Genetics and Genomics were adopted to judge variant pathogenicity. RESULTS Three novel, predicted protein-damaging missense variants in KMT2B were identified (p.Glu1234Lys, p.Ala1541Val, p.Arg1779Gln). Meeting pathogenicity criteria, p.Glu1234Lys was absent from population-based controls, situated in a key protein domain, and had occurred de novo. The associated phenotype comprised adolescence-onset generalized isolated dystonia with prominent speech impairment. Although linked to a similar clinical expression, p.Ala1541Val and p.Arg1779Gln remained of uncertain significance. CONCLUSIONS Rare missense variation in KMT2B represents an additional cause of generalized dystonia. Application of sequence interpretation standards is required before assigning pathogenicity to a KMT2B missense variant. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Michael Zech
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany.,Klinik und Poliklinik für Neurologie, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Robert Jech
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Petra Havránková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Anna Fečíková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Riccardo Berutti
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, Germany
| | - Dušan Urgošík
- Department of Stereotactic Neurosurgery and Radiosurgery, Na Homolce Hospital, Prague, Czech Republic
| | - David Kemlink
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Tim M Strom
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, Germany.,Institut für Humangenetik, Technische Universität München, Munich, Germany
| | - Jan Roth
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Evžen Růžička
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Juliane Winkelmann
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany.,Klinik und Poliklinik für Neurologie, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Institut für Humangenetik, Technische Universität München, Munich, Germany.,Munich Cluster for Systems Neurology, SyNergy, Munich, Germany
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111
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Affiliation(s)
- Daniel E Lumsden
- Complex Motor Disorder Service, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK.
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112
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Balint B, Valente EM. KMT2B: A new twist in dystonia genetics. Mov Disord 2017; 32:529. [PMID: 28218417 DOI: 10.1002/mds.26957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 01/23/2017] [Indexed: 11/07/2022] Open
Affiliation(s)
- Bettina Balint
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology Queen Square, London, UK
- Department of Neurology, University Hospital Heidelberg, Germany
| | - Enza Maria Valente
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy
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113
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Siow S, Kumar KR. New gene implicated in early‐onset generalized dystonia:
Lysine‐specific methyltransferase 2B (KMT2B). Mov Disord 2017; 32:395. [DOI: 10.1002/mds.26928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 01/02/2023] Open
Affiliation(s)
- Sue‐Faye Siow
- Department of NeurogeneticsKolling Institute of Medical Research and Royal North Shore HospitalSt Leonards New South Wales Australia
| | - Kishore R. Kumar
- Department of NeurogeneticsKolling Institute of Medical Research and Royal North Shore HospitalSt Leonards New South Wales Australia
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
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