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Stern WM, Desikan M, Hoad D, Jaffer F, Strigaro G, Sander JW, Rothwell JC, Sisodiya SM. Spontaneously Fluctuating Motor Cortex Excitability in Alternating Hemiplegia of Childhood: A Transcranial Magnetic Stimulation Study. PLoS One 2016; 11:e0151667. [PMID: 26999520 PMCID: PMC4801356 DOI: 10.1371/journal.pone.0151667] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/02/2016] [Indexed: 01/01/2023] Open
Abstract
Background Alternating hemiplegia of childhood is a very rare and serious neurodevelopmental syndrome; its genetic basis has recently been established. Its characteristic features include typically-unprovoked episodes of hemiplegia and other transient or more persistent neurological abnormalities. Methods We used transcranial magnetic stimulation to assess the effect of the condition on motor cortex neurophysiology both during and between attacks of hemiplegia. Nine people with alternating hemiplegia of childhood were recruited; eight were successfully tested using transcranial magnetic stimulation to study motor cortex excitability, using single and paired pulse paradigms. For comparison, data from ten people with epilepsy but not alternating hemiplegia, and ten healthy controls, were used. Results One person with alternating hemiplegia tested during the onset of a hemiplegic attack showed progressively diminishing motor cortex excitability until no response could be evoked; a second person tested during a prolonged bilateral hemiplegic attack showed unusually low excitability. Three people tested between attacks showed asymptomatic variation in cortical excitability, not seen in controls. Paired pulse paradigms, which probe intracortical inhibitory and excitatory circuits, gave results similar to controls. Conclusions We report symptomatic and asymptomatic fluctuations in motor cortex excitability in people with alternating hemiplegia of childhood, not seen in controls. We propose that such fluctuations underlie hemiplegic attacks, and speculate that the asymptomatic fluctuation we detected may be useful as a biomarker for disease activity.
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Affiliation(s)
- William M. Stern
- NIHR University College London Hospitals Biomedical Research Centre, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom
- Epilepsy Society, Chalfont St Peter, SL9 0RJ, United Kingdom
| | - Mahalekshmi Desikan
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom
| | - Damon Hoad
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom
| | - Fatima Jaffer
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Gionata Strigaro
- Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale “A. Avogadro”, Novara, Italy
| | - Josemir W. Sander
- NIHR University College London Hospitals Biomedical Research Centre, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom
- Epilepsy Society, Chalfont St Peter, SL9 0RJ, United Kingdom
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - John C. Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom
| | - Sanjay M. Sisodiya
- NIHR University College London Hospitals Biomedical Research Centre, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom
- Epilepsy Society, Chalfont St Peter, SL9 0RJ, United Kingdom
- * E-mail:
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152
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Sweadner KJ, Toro C, Whitlow CT, Snively BM, Cook JF, Ozelius LJ, Markello TC, Brashear A. ATP1A3 Mutation in Adult Rapid-Onset Ataxia. PLoS One 2016; 11:e0151429. [PMID: 26990090 PMCID: PMC4798776 DOI: 10.1371/journal.pone.0151429] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/28/2016] [Indexed: 11/18/2022] Open
Abstract
A 21-year old male presented with ataxia and dysarthria that had appeared over a period of months. Exome sequencing identified a de novo missense variant in ATP1A3, the gene encoding the α3 subunit of Na,K-ATPase. Several lines of evidence suggest that the variant is causative. ATP1A3 mutations can cause rapid-onset dystonia-parkinsonism (RDP) with a similar age and speed of onset, as well as severe diseases of infancy. The patient's ATP1A3 p.Gly316Ser mutation was validated in the laboratory by the impaired ability of the expressed protein to support the growth of cultured cells. In a crystal structure of Na,K-ATPase, the mutated amino acid was directly apposed to a different amino acid mutated in RDP. Clinical evaluation showed that the patient had many characteristics of RDP, however he had minimal fixed dystonia, a defining symptom of RDP. Successive magnetic resonance imaging (MRI) revealed progressive cerebellar atrophy, explaining the ataxia. The absence of dystonia in the presence of other RDP symptoms corroborates other evidence that the cerebellum contributes importantly to dystonia pathophysiology. We discuss the possibility that a second de novo variant, in ubiquilin 4 (UBQLN4), a ubiquitin pathway component, contributed to the cerebellar neurodegenerative phenotype and differentiated the disease from other manifestations of ATP1A3 mutations. We also show that a homozygous variant in GPRIN1 (G protein-regulated inducer of neurite outgrowth 1) deletes a motif with multiple copies and is unlikely to be causative.
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Affiliation(s)
- Kathleen J. Sweadner
- Departments of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, and Office of the Clinical Director, NHGRI, Bethesda, Maryland, United States of America
| | - Christopher T. Whitlow
- Departments of Radiology and Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Beverly M. Snively
- Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Jared F. Cook
- Department of Neurology, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Laurie J. Ozelius
- Department of Neurology, Massachusetts General Hospital, Boston Massachusetts, United States of America
| | - Thomas C. Markello
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH, and Human Biochemical Genetics Section, Medical Genetics Branch, NHGRI, Bethesda, Maryland, United States of America
| | - Allison Brashear
- Department of Neurology, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
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153
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de Gusmao CM, Dy M, Sharma N. Beyond Dystonia-Parkinsonism: Chorea and Ataxia with ATP1A3 Mutations. Mov Disord Clin Pract 2016; 3:402-404. [PMID: 30363590 DOI: 10.1002/mdc3.12317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/24/2015] [Accepted: 11/29/2015] [Indexed: 11/07/2022] Open
Abstract
Mutations in the ATP1A3 gene (the α-3 subunit of the Na+/K+ ATPase) are associated with rapid-onset dystonia-parkinsonism; alternating hemiplegia of childhood; and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS syndrome). The authors report 3 cases with pleiotropic movement disorders, including a novel mutation in a patient who presented with ataxia and dysphagia. Case 1 had a history of attention deficit hyperactivity disorder and developed dysphagia, chorea, and limb dystonia after a febrile illness at age 12 years. Case 2 presented with limb dystonia at age 26 years and dysarthia and dysphagia after a febrile illness. Case 3 had a history of learning disability and developed progressive ataxia with cerebellar atrophy at age 20 years. In all cases, deleterious mutations were identified in ATP1A3. They illustrate wide phenotypic variability, including chorea and ataxia. New cases are likely to be diagnosed as knowledge about the phenotypic spectrum expands.
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Affiliation(s)
- Claudio M de Gusmao
- Department of Neurology Massachusetts General Hospital Boston Massachusetts USA
| | - Marisela Dy
- Department of Neurology Boston Children's Hospital Boston Massachusetts USA
| | - Nutan Sharma
- Department of Neurology Massachusetts General Hospital Boston Massachusetts USA
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154
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Gupta SN, Gupta VS, Borad N. Spectrum of migraine variants and beyond: The individual syndromes in children. Brain Dev 2016; 38:10-26. [PMID: 26081103 DOI: 10.1016/j.braindev.2015.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/07/2015] [Accepted: 05/10/2015] [Indexed: 01/03/2023]
Abstract
"Migraine-related conditions" are probably the second most common condition after seizure encountered in pediatric neurology requiring frequent Emergency Department visits. Among migraines, migraine-related condition presents with an acute onset sign or symptom other than headache or visual aura of unknown etiology. A delay in diagnosis is a common occurrence. Previously, the authors proposed a common clinical profile and suggested that the future review should seek the applicability of the common profile in aid to clinical diagnosis of migraine-related individual syndromes. Authors describe the clinical characteristics and differential diagnosis of the spectrum of migraine variants and beyond in children.
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Affiliation(s)
- Surya N Gupta
- Section of Child Neurology, Women's and Children's Hospital, Charleston Area Medical Center, Charleston, WV, USA.
| | - Vikash S Gupta
- MS-IV, Texila American University, Woolford Ave, Georgetown, Guyana.
| | - Nirali Borad
- Department of Physiology, P.D.U. Government Medical College, Rajkot, Gujarat, India.
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155
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Dard R, Mignot C, Durr A, Lesca G, Sanlaville D, Roze E, Mochel F. Relapsing encephalopathy with cerebellar ataxia related to an ATP1A3 mutation. Dev Med Child Neurol 2015; 57:1183-6. [PMID: 26400718 DOI: 10.1111/dmcn.12927] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/16/2015] [Indexed: 11/30/2022]
Abstract
ATP1A3, the gene encoding the α3-subunit of the Na(+) /K(+) -ATPase pump, has been involved in four clinical neurological entities: (1) alternating hemiplegia of childhood (AHC); (2) rapid-onset dystonia parkinsonism (RDP); (3) CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, sensorineural hearing loss) syndrome; and (4) early infantile epileptic encephalopathy. Here, we report on a 34-year-old female presenting with a new ATP1A3-related entity involving a relapsing encephalopathy characterized by recurrent episodes of cerebellar ataxia and altered consciousness during febrile illnesses. The term RECA is suggested - relapsing encephalopathy with cerebellar ataxia. The phenotype of this patient, resembling mitochondrial oxidative phosphorylation defects, emphasizes the possible role of brain energy deficiency in patients with ATP1A3 mutations. Rather than multiple overlapping syndromes, ATP1A3-related disorders might be seen as a phenotypic continuum.
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Affiliation(s)
- Rodolphe Dard
- Department of Genetics, AP-HP, La Pitié-Salpêtrière University Hospital, Paris, France
| | - Cyril Mignot
- Department of Genetics, AP-HP, La Pitié-Salpêtrière University Hospital, Paris, France
| | - Alexandra Durr
- Department of Genetics, AP-HP, La Pitié-Salpêtrière University Hospital, Paris, France.,Inserm, Institut du Cerveau et de la Moelle épinière, Sorbonne Universités, UPMC University Paris, Paris, France
| | - Gaetan Lesca
- Department of Medical Genetics, Lyon University Hospital, Lyon, France
| | - Damien Sanlaville
- Department of Medical Genetics, Lyon University Hospital, Lyon, France
| | - Emmanuel Roze
- Inserm, Institut du Cerveau et de la Moelle épinière, Sorbonne Universités, UPMC University Paris, Paris, France.,Department of Neurology, AP-HP, La Pitié-Salpêtrière University Hospital, Paris, France
| | - Fanny Mochel
- Department of Genetics, AP-HP, La Pitié-Salpêtrière University Hospital, Paris, France.,Inserm, Institut du Cerveau et de la Moelle épinière, Sorbonne Universités, UPMC University Paris, Paris, France.,Bioclinic and Genetic Unit of Neurometabolic Diseases, Pitié-Salpêtrière Hospital, Paris, France
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156
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Kirshenbaum GS, Dachtler J, Roder JC, Clapcote SJ. Characterization of cognitive deficits in mice with an alternating hemiplegia-linked mutation. Behav Neurosci 2015; 129:822-31. [PMID: 26501181 PMCID: PMC4655871 DOI: 10.1037/bne0000097] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 07/09/2015] [Accepted: 08/03/2015] [Indexed: 11/21/2022]
Abstract
Cognitive impairment is a prominent feature in a range of different movement disorders. Children with Alternating Hemiplegia of Childhood are prone to developmental delay, with deficits in cognitive functioning becoming progressively more evident as they grow older. Heterozygous mutations of the ATP1A3 gene, encoding the Na+,K+-ATPase α3 subunit, have been identified as the primary cause of Alternating Hemiplegia. Heterozygous Myshkin mice have an amino acid change (I810N) in Na+,K+-ATPase α3 that is also found in Alternating Hemiplegia. To investigate whether Myshkin mice exhibit learning and memory deficits resembling the cognitive impairments of patients with Alternating Hemiplegia, we subjected them to a range of behavioral tests that interrogate various cognitive domains. Myshkin mice showed impairments in spatial memory, spatial habituation, locomotor habituation, object recognition, social recognition, and trace fear conditioning, as well as in the visible platform version of the Morris water maze. Increasing the duration of training ameliorated the deficit in social recognition but not in spatial habituation. The deficits of Myshkin mice in all of the learning and memory tests used are consistent with the cognitive impairment of the vast majority of AHC patients. These mice could thus help advance our understanding of the underlying neural mechanisms influencing cognitive impairment in patients with ATP1A3-related disorders.
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Affiliation(s)
| | | | - John C Roder
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital
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157
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Laird JG, Pan Y, Modestou M, Yamaguchi DM, Song H, Sokolov M, Baker SA. Identification of a VxP Targeting Signal in the Flagellar Na+ /K+ -ATPase. Traffic 2015; 16:1239-53. [PMID: 26373354 DOI: 10.1111/tra.12332] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 09/11/2015] [Accepted: 09/11/2015] [Indexed: 12/15/2022]
Abstract
Na(+) /K(+) -ATPase (NKA) participates in setting electrochemical gradients, cardiotonic steroid signaling and cellular adhesion. Distinct isoforms of NKA are found in different tissues and subcellular localization patterns. For example, NKA α1 is widely expressed, NKA α3 is enriched in neurons and NKA α4 is a testes-specific isoform found in sperm flagella. In some tissues, ankyrin, a key component of the membrane cytoskeleton, can regulate the trafficking of NKA. In the retina, NKA and ankyrin-B are expressed in multiple cell types and immunostaining for each is striking in the synaptic layers. Labeling for NKA is also prominent along the inner segment plasma membrane (ISPM) of photoreceptors. NKA co-immunoprecipitates with ankyrin-B, but on a subcellular level colocalization of these two proteins varies dependent on the cell type. We used transgenic Xenopus laevis tadpoles to evaluate the subcellular trafficking of NKA in photoreceptors. GFP-NKA α3 and α1 are localized to the ISPM, but α4 is localized to outer segments (OSs). We identified a VxP motif responsible for the OS targeting by using a series of chimeric and mutant NKA constructs. This motif is similar to previously identified ciliary targeting motifs. Given the structural similarities between OSs and flagella, our findings shed light on the subcellular targeting of this testes-specific NKA isoform.
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Affiliation(s)
- Joseph G Laird
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Yuan Pan
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Current address: Department of Neurology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Modestos Modestou
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - David M Yamaguchi
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Hongman Song
- Department of Ophthalmology, West Virginia University School of Medicine and West Virginia University Eye Institute, Morgantown, WV, 26506, USA.,Current address: Section for Translational Research in Retina & Macular Degeneration, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, 20892, USA
| | - Maxim Sokolov
- Department of Ophthalmology, West Virginia University School of Medicine and West Virginia University Eye Institute, Morgantown, WV, 26506, USA
| | - Sheila A Baker
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
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158
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Kirshenbaum GS, Dachtler J, Roder JC, Clapcote SJ. Transgenic rescue of phenotypic deficits in a mouse model of alternating hemiplegia of childhood. Neurogenetics 2015; 17:57-63. [PMID: 26463346 PMCID: PMC4701769 DOI: 10.1007/s10048-015-0461-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 09/16/2015] [Indexed: 11/13/2022]
Abstract
Missense mutations in ATP1A3 encoding Na+,K+-ATPase α3 are the primary cause of alternating hemiplegia of childhood (AHC). Most ATP1A3 mutations in AHC lie within a cluster in or near transmembrane α-helix TM6, including I810N that is also found in the Myshkin mouse model of AHC. These mutations all substantially reduce Na+,K+-ATPase α3 activity. Herein, we show that Myshkin mice carrying a wild-type Atp1a3 transgene that confers a 16 % increase in brain-specific total Na+,K+-ATPase activity show significant phenotypic improvements compared with non-transgenic Myshkin mice. Interventions to increase the activity of wild-type Na+,K+-ATPase α3 in AHC patients should be investigated further.
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Affiliation(s)
- Greer S Kirshenbaum
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University Avenue, Toronto, ON, M5G 1X5, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - James Dachtler
- School of Biomedical Sciences, Garstang Building, University of Leeds, Leeds, LS2 9JT, UK
| | - John C Roder
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University Avenue, Toronto, ON, M5G 1X5, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Steven J Clapcote
- School of Biomedical Sciences, Garstang Building, University of Leeds, Leeds, LS2 9JT, UK.
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159
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Panagiotakaki E, De Grandis E, Stagnaro M, Heinzen EL, Fons C, Sisodiya S, de Vries B, Goubau C, Weckhuysen S, Kemlink D, Scheffer I, Lesca G, Rabilloud M, Klich A, Ramirez-Camacho A, Ulate-Campos A, Campistol J, Giannotta M, Moutard ML, Doummar D, Hubsch-Bonneaud C, Jaffer F, Cross H, Gurrieri F, Tiziano D, Nevsimalova S, Nicole S, Neville B, van den Maagdenberg AMJM, Mikati M, Goldstein DB, Vavassori R, Arzimanoglou A. Clinical profile of patients with ATP1A3 mutations in Alternating Hemiplegia of Childhood-a study of 155 patients. Orphanet J Rare Dis 2015; 10:123. [PMID: 26410222 PMCID: PMC4583741 DOI: 10.1186/s13023-015-0335-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/01/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutations in the gene ATP1A3 have recently been identified to be prevalent in patients with alternating hemiplegia of childhood (AHC2). Based on a large series of patients with AHC, we set out to identify the spectrum of different mutations within the ATP1A3 gene and further establish any correlation with phenotype. METHODS Clinical data from an international cohort of 155 AHC patients (84 females, 71 males; between 3 months and 52 years) were gathered using a specifically formulated questionnaire and analysed relative to the mutational ATP1A3 gene data for each patient. RESULTS In total, 34 different ATP1A3 mutations were detected in 85 % (132/155) patients, seven of which were novel. In general, mutations were found to cluster into five different regions. The most frequent mutations included: p.Asp801Asn (43 %; 57/132), p.Glu815Lys (16 %; 22/132), and p.Gly947Arg (11 %; 15/132). Of these, p.Glu815Lys was associated with a severe phenotype, with more severe intellectual and motor disability. p.Asp801Asn appeared to confer a milder phenotypic expression, and p.Gly947Arg appeared to correlate with the most favourable prognosis, compared to the other two frequent mutations. Overall, the comparison of the clinical profiles suggested a gradient of severity between the three major mutations with differences in intellectual (p = 0.029) and motor (p = 0.039) disabilities being statistically significant. For patients with epilepsy, age at onset of seizures was earlier for patients with either p.Glu815Lys or p.Gly947Arg mutation, compared to those with p.Asp801Asn mutation (p < 0.001). With regards to the five mutation clusters, some clusters appeared to correlate with certain clinical phenotypes. No statistically significant clinical correlations were found between patients with and without ATP1A3 mutations. CONCLUSIONS Our results, demonstrate a highly variable clinical phenotype in patients with AHC2 that correlates with certain mutations and possibly clusters within the ATP1A3 gene. Our description of the clinical profile of patients with the most frequent mutations and the clinical picture of those with less common mutations confirms the results from previous studies, and further expands the spectrum of genotype-phenotype correlations. Our results may be useful to confirm diagnosis and may influence decisions to ensure appropriate early medical intervention in patients with AHC. They provide a stronger basis for the constitution of more homogeneous groups to be included in clinical trials.
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Affiliation(s)
- Eleni Panagiotakaki
- Epilepsy, Sleep and Pediatric Neurophysiology Department (ESEFNP), University Hospitals of Lyon (HCL), Lyon, France.
| | - Elisa De Grandis
- Department of Child Neuropsychiatry, G. Gaslini Hospital, University of Genoa, Genoa, Italy
| | - Michela Stagnaro
- Department of Child Neuropsychiatry, G. Gaslini Hospital, University of Genoa, Genoa, Italy
| | - Erin L Heinzen
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Carmen Fons
- Department of Child Neurology, Sant Joan de Déu Hospital, Barcelona, Spain
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Boukje de Vries
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Christophe Goubau
- Department of Child Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Sarah Weckhuysen
- Department of Molecular Genetics, Neurogenetics Group, VIB, Antwerp, Belgium
| | - David Kemlink
- Department of Neurology, Charles University, First Faculty of Medicine and Teaching Hospital, Prague, Czech Republic
| | - Ingrid Scheffer
- Department of Medicine, University of Melbourne, Austin Health, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia
| | - Gaëtan Lesca
- Department of Genetics, University Hospitals of Lyon (HCL) and Claude Bernard Lyon I University, Lyon, France.,Lyon Neuroscience Research Center (CRNL), CNRS UMR 5292, INSERM U1028, Lyon, France
| | - Muriel Rabilloud
- Biostatistics Department, University Hospitals of Lyon and UMR 5558, Lyon, France
| | - Amna Klich
- Biostatistics Department, University Hospitals of Lyon and UMR 5558, Lyon, France
| | - Alia Ramirez-Camacho
- Epilepsy, Sleep and Pediatric Neurophysiology Department (ESEFNP), University Hospitals of Lyon (HCL), Lyon, France.,Department of Child Neurology, Sant Joan de Déu Hospital, Barcelona, Spain
| | | | - Jaume Campistol
- Department of Child Neurology, Sant Joan de Déu Hospital, Barcelona, Spain
| | | | - Marie-Laure Moutard
- Department of Child Neurology, Armand Trousseau Hospital, APHP, Paris, France
| | - Diane Doummar
- Department of Child Neurology, Armand Trousseau Hospital, APHP, Paris, France
| | | | - Fatima Jaffer
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Helen Cross
- Institute of Child Health, University College London, London, UK
| | - Fiorella Gurrieri
- Institute of Medical Genetics, University Cattolica del Sacro Cuore, Policlinics A. Gemelli, Rome, Italy
| | - Danilo Tiziano
- Institute of Medical Genetics, University Cattolica del Sacro Cuore, Policlinics A. Gemelli, Rome, Italy
| | - Sona Nevsimalova
- Department of Neurology, Charles University, First Faculty of Medicine and Teaching Hospital, Prague, Czech Republic
| | - Sophie Nicole
- Institut National de la Santé et de la Recherche Médicale, U975, Centre de Recherche de l'Institut du Cerveau et de la Moelle, Paris, France.,Centre National de la Recherche Scientifique, UMR7225, Paris, France
| | - Brian Neville
- Institute of Child Health, University College London, London, UK
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands.,Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Mohamad Mikati
- Division of Pediatric Neurology and Department of Neurobiology, Duke University, School of Medicine, Durham, NC, USA
| | - David B Goldstein
- Center for Human Genome Variation, Duke University School of Medicine, Durham, NC, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Rosaria Vavassori
- Associazione Italiana per la Sindrome di Emiplegia Alternante (A.I.S.EA Onlus), Lecco, Italy
| | - Alexis Arzimanoglou
- Epilepsy, Sleep and Pediatric Neurophysiology Department (ESEFNP), University Hospitals of Lyon (HCL), Lyon, France.,DYCOG team, Lyon Neuroscience Research Centre (CRNL), INSERM U1028; CNRS UMR 5292, Lyon, France
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160
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Termsarasab P, Yang AC, Frucht SJ. Intermediate Phenotypes of ATP1A3 Mutations: Phenotype-Genotype Correlations. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2015; 5:336. [PMID: 26417536 PMCID: PMC4578012 DOI: 10.7916/d8mg7ns8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 08/25/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND ATP1A3-related disorders include rapid-onset dystonia-parkinsonism (RDP or DYT12), alternating hemiplegia of childhood (AHC), and CAPOS syndrome (Cerebellar ataxia, Areflexia, Pes cavus, Optic atrophy, and Sensorineural hearing loss). CASE REPORT We report two cases with intermediate forms between RDP and AHC. Patient 1 initially presented with the AHC phenotype, but the RDP phenotype emerged at age 14 years. The second patient presented with levodopa-responsive paroxysmal oculogyria, a finding never before reported in ATP1A3-related disorders. Genetic testing confirmed heterozygous changes in the ATP1A3 gene in both patients, one of them novel. DISCUSSION Intermediate phenotypes of RDP and AHC support the concept that these two disorders are part of a spectrum. We add our cases to the phenotype-genotype correlations of ATP1A3-related disorders.
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Affiliation(s)
- Pichet Termsarasab
- Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amy C Yang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steven J Frucht
- Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Brown A, Clark JD. A Parent's Journey: Incorporating Principles of Palliative Care into Practice for Children with Chronic Neurologic Diseases. Semin Pediatr Neurol 2015; 22:159-65. [PMID: 26358425 DOI: 10.1016/j.spen.2015.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Rather than in conflict or in competition with the curative model of care, pediatric palliative care is a complementary and transdisciplinary approach used to optimize medical care for children with complex medical conditions. It provides care to the whole child, including physical, mental, and spiritual dimensions, in addition to support for the family. Through the voice of a parent, the following case-based discussion demonstrates how the fundamentals of palliative care medicine, when instituted early in the course of disease, can assist parents and families with shared medical decision making, ultimately improving the quality of life for children with life-limiting illnesses. Pediatric neurologists, as subspecialists who provide medical care for children with chronic and complex conditions, should consider invoking the principles of palliative care early in the course of a disease process, either through applying general facets or, if available, through consultation with a specialty palliative care service.
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Affiliation(s)
- Allyson Brown
- Department of Pediatrics, Division of Critical Care Medicine, University of Washington School of Medicine, Seattle, WA; Department of Pediatrics, Seattle Children's Hospital, Seattle, WA
| | - Jonna D Clark
- Department of Pediatrics, Seattle Children's Hospital, Seattle, WA; Treuman Katz Center for Pediatric Bioethics, University of Washington School of Medicine, Seattle, WA.
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Jaffer F, Avbersek A, Vavassori R, Fons C, Campistol J, Stagnaro M, De Grandis E, Veneselli E, Rosewich H, Gianotta M, Zucca C, Ragona F, Granata T, Nardocci N, Mikati M, Helseth AR, Boelman C, Minassian BA, Johns S, Garry SI, Scheffer IE, Gourfinkel-An I, Carrilho I, Aylett SE, Parton M, Hanna MG, Houlden H, Neville B, Kurian MA, Novy J, Sander JW, Lambiase PD, Behr ER, Schyns T, Arzimanoglou A, Cross JH, Kaski JP, Sisodiya SM. Faulty cardiac repolarization reserve in alternating hemiplegia of childhood broadens the phenotype. Brain 2015; 138:2859-74. [PMID: 26297560 PMCID: PMC4671482 DOI: 10.1093/brain/awv243] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 06/30/2015] [Indexed: 12/29/2022] Open
Abstract
Alternating hemiplegia of childhood is a rare disorder caused by de novo mutations in the ATP1A3 gene, expressed in neurons and cardiomyocytes. As affected individuals may survive into adulthood, we use the term 'alternating hemiplegia'. The disorder is characterized by early-onset, recurrent, often alternating, hemiplegic episodes; seizures and non-paroxysmal neurological features also occur. Dysautonomia may occur during hemiplegia or in isolation. Premature mortality can occur in this patient group and is not fully explained. Preventable cardiorespiratory arrest from underlying cardiac dysrhythmia may be a cause. We analysed ECG recordings of 52 patients with alternating hemiplegia from nine countries: all had whole-exome, whole-genome, or direct Sanger sequencing of ATP1A3. Data on autonomic dysfunction, cardiac symptoms, medication, and family history of cardiac disease or sudden death were collected. All had 12-lead electrocardiogram recordings available for cardiac axis, cardiac interval, repolarization pattern, and J-point analysis. Where available, historical and prolonged single-lead electrocardiogram recordings during electrocardiogram-videotelemetry were analysed. Half the cohort (26/52) had resting 12-lead electrocardiogram abnormalities: 25/26 had repolarization (T wave) abnormalities. These abnormalities were significantly more common in people with alternating hemiplegia than in an age-matched disease control group of 52 people with epilepsy. The average corrected QT interval was significantly shorter in people with alternating hemiplegia than in the disease control group. J wave or J-point changes were seen in six people with alternating hemiplegia. Over half the affected cohort (28/52) had intraventricular conduction delay, or incomplete right bundle branch block, a much higher proportion than in the normal population or disease control cohort (P = 0.0164). Abnormalities in alternating hemiplegia were more common in those ≥16 years old, compared with those <16 (P = 0.0095), even with a specific mutation (p.D801N; P = 0.045). Dynamic, beat-to-beat or electrocardiogram-to-electrocardiogram, changes were noted, suggesting the prevalence of abnormalities was underestimated. Electrocardiogram changes occurred independently of seizures or plegic episodes. Electrocardiogram abnormalities are common in alternating hemiplegia, have characteristics reflecting those of inherited cardiac channelopathies and most likely amount to impaired repolarization reserve. The dynamic electrocardiogram and neurological features point to periodic systemic decompensation in ATP1A3-expressing organs. Cardiac dysfunction may account for some of the unexplained premature mortality of alternating hemiplegia. Systematic cardiac investigation is warranted in alternating hemiplegia of childhood, as cardiac arrhythmic morbidity and mortality are potentially preventable.
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Affiliation(s)
- Fatima Jaffer
- 1 MRC Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK 2 Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Andreja Avbersek
- 3 NIHR UCLH Biomedical Research Centre Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK 4 Epilepsy Society, Chalfont-St-Peter, Bucks, SL9 0RJ, UK
| | - Rosaria Vavassori
- 5 A.I.S.EA Onlus, Via Sernovella, 37 - Verderio Superiore, 23878 Lecco, Italy
| | - Carmen Fons
- 6 Paediatric Neurology Department, Hospital Sant Joan de Déu, P° de Sant Joan de Déu, 2 08950 Esplugues de Llobregat, Barcelona University, Barcelona, Spain
| | - Jaume Campistol
- 6 Paediatric Neurology Department, Hospital Sant Joan de Déu, P° de Sant Joan de Déu, 2 08950 Esplugues de Llobregat, Barcelona University, Barcelona, Spain
| | - Michela Stagnaro
- 7 Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Children's Sciences, Istituto Giannina Gaslini, Largo Gaslini 5, 26148, University of Genoa, Genoa, Italy
| | - Elisa De Grandis
- 7 Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Children's Sciences, Istituto Giannina Gaslini, Largo Gaslini 5, 26148, University of Genoa, Genoa, Italy
| | - Edvige Veneselli
- 7 Child Neuropsychiatry Unit, Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Children's Sciences, Istituto Giannina Gaslini, Largo Gaslini 5, 26148, University of Genoa, Genoa, Italy
| | - Hendrik Rosewich
- 8 University Medical Center Göttingen, Georg August University, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, Georg August University, Robert Koch Strasse 40, 37099 Göttingen, Germany
| | - Melania Gianotta
- 9 Child Neurology Unit IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Via Altura 3, 40139 Bologna, Italy
| | - Claudio Zucca
- 10 Clinical Neurophysiology Unit, IRCCS "E. Medea", Via Don L. Monza 20, 23842 Bosisio Parini (LC), Italy
| | - Francesca Ragona
- 11 Department of Pediatric Neuroscience, IRCCS Foundation Neurological Institute C. Besta, Via Celoria 11, 20133 Milano, Italy
| | - Tiziana Granata
- 11 Department of Pediatric Neuroscience, IRCCS Foundation Neurological Institute C. Besta, Via Celoria 11, 20133 Milano, Italy
| | - Nardo Nardocci
- 11 Department of Pediatric Neuroscience, IRCCS Foundation Neurological Institute C. Besta, Via Celoria 11, 20133 Milano, Italy
| | - Mohamed Mikati
- 12 Division of Paediatric Neurology, Duke University, T0913J Children Health Centre, Duke University Medical Centre, Durham, USA
| | - Ashley R Helseth
- 12 Division of Paediatric Neurology, Duke University, T0913J Children Health Centre, Duke University Medical Centre, Durham, USA
| | - Cyrus Boelman
- 13 Division of Neurology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, 555 University Avenue, Toronto, Ontario, Canada, M5G 1X8
| | - Berge A Minassian
- 13 Division of Neurology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, 555 University Avenue, Toronto, Ontario, Canada, M5G 1X8
| | - Sophia Johns
- 14 Inherited Cardiovascular Diseases Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, and Institute of Cardiovascular Science, University College London, London, WC1N 3JH, UK
| | - Sarah I Garry
- 15 Florey Institute of Neurosciences and Mental Health, and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia
| | - Ingrid E Scheffer
- 15 Florey Institute of Neurosciences and Mental Health, and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia
| | - Isabelle Gourfinkel-An
- 16 Centre de reference epilepsies rares et Sclérose tubéreuse de Bourneville (site Parisien adolescents-adultes), Hôpital Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital 75651 Paris cedex 13, France
| | - Ines Carrilho
- 17 Neuropediatric Department Centro Hospitalar do Porto, Rua da Boavista, 8274050-111, Porto, Portugal
| | - Sarah E Aylett
- 18 Clinical Neurosciences, Developmental Neuroscience Programme, UCL Institute of Child Health, & Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Matthew Parton
- 1 MRC Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Michael G Hanna
- 1 MRC Centre for Neuromuscular Diseases, The National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Henry Houlden
- 2 Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Brian Neville
- 18 Clinical Neurosciences, Developmental Neuroscience Programme, UCL Institute of Child Health, & Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Manju A Kurian
- 19 Molecular Neurosciences, Developmental Neurosciences Programme, UCL Institute of Child Health and Department of Neurology, Great Ormond Street Hospital, London, London, WC1N 3JH, UK
| | - Jan Novy
- 3 NIHR UCLH Biomedical Research Centre Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK 4 Epilepsy Society, Chalfont-St-Peter, Bucks, SL9 0RJ, UK
| | - Josemir W Sander
- 3 NIHR UCLH Biomedical Research Centre Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK 4 Epilepsy Society, Chalfont-St-Peter, Bucks, SL9 0RJ, UK
| | - Pier D Lambiase
- 20 Department of Cardiac Electrophysiology, The Heart Hospital, Institute of Cardiovascular Science, University College London, 16-18 Westmoreland St, London W1G 8PH, UK
| | - Elijah R Behr
- 21 Cardiac and Cell Sciences Institute, St George's University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Tsveta Schyns
- 22 European Network for Research on Alternating Hemiplegia, ENRAH, Brussels, Belgium
| | - Alexis Arzimanoglou
- 23 Epilepsy, Sleep and Paediatric Neurophysiology Department (ESEFNP), University Hospitals of Lyon (HCL), and DYCOG team, Lyon Neuroscience Research Centre (CRNL), INSERM U1028; CNRS UMR 5292, Lyon, France
| | - J Helen Cross
- 18 Clinical Neurosciences, Developmental Neuroscience Programme, UCL Institute of Child Health, & Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK 24 Young Epilepsy, St. Piers Lane, Lingfield, Surrey RH7 6PW, UK
| | - Juan P Kaski
- 14 Inherited Cardiovascular Diseases Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, and Institute of Cardiovascular Science, University College London, London, WC1N 3JH, UK
| | - Sanjay M Sisodiya
- 3 NIHR UCLH Biomedical Research Centre Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK 4 Epilepsy Society, Chalfont-St-Peter, Bucks, SL9 0RJ, UK
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Abstract
Neurodegeneration correlates with Alzheimer's disease (AD) symptoms, but the molecular identities of pathogenic amyloid β-protein (Aβ) oligomers and their targets, leading to neurodegeneration, remain unclear. Amylospheroids (ASPD) are AD patient-derived 10- to 15-nm spherical Aβ oligomers that cause selective degeneration of mature neurons. Here, we show that the ASPD target is neuron-specific Na(+)/K(+)-ATPase α3 subunit (NAKα3). ASPD-binding to NAKα3 impaired NAKα3-specific activity, activated N-type voltage-gated calcium channels, and caused mitochondrial calcium dyshomeostasis, tau abnormalities, and neurodegeneration. NMR and molecular modeling studies suggested that spherical ASPD contain N-terminal-Aβ-derived "thorns" responsible for target binding, which are distinct from low molecular-weight oligomers and dodecamers. The fourth extracellular loop (Ex4) region of NAKα3 encompassing Asn(879) and Trp(880) is essential for ASPD-NAKα3 interaction, because tetrapeptides mimicking this Ex4 region bound to the ASPD surface and blocked ASPD neurotoxicity. Our findings open up new possibilities for knowledge-based design of peptidomimetics that inhibit neurodegeneration in AD by blocking aberrant ASPD-NAKα3 interaction.
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Peall KJ, Kuiper A, de Koning TJ, Tijssen MAJ. Non-motor symptoms in genetically defined dystonia: Homogenous groups require systematic assessment. Parkinsonism Relat Disord 2015. [PMID: 26210889 DOI: 10.1016/j.parkreldis.2015.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Dystonia is a movement disorder involving sustained or intermittent muscle contractions resulting in abnormal movements and postures. Identification of disease causing genes has allowed examination of genetically homogenous groups. Unlike the motor symptoms, non-motor characteristics are less clearly defined, despite their impact on a patient's quality of life. This review aims to examine the evidence for non-motor symptoms, addressing cohort size and methods of assessment in each study. METHODS A systematic and standardised search strategy was used to identify the published literature relating to psychiatric symptoms, cognition, sleep disorders, sensory abnormalities and pain in each of the genetically determined dystonias. Studies were divided according to cohort size, method of assessment and whether comparison was made to an appropriate control group. RESULTS Ninety-five articles were identified including reported clinical histories (n = 42), case reports and smaller case series (n = 12), larger case series (n = 23) and case-control cohorts (n = 18). Psychiatric symptoms were the most frequently investigated with anxiety, depression and Obsessive-Compulsive disorder being most common. Cognitive impairment involved either global deficits or isolated difficulties in specific domains. Disturbances to sleep were most common in the dopa-responsive dystonias. Sensory testing in DYT1 cases identified an intermediate subclinical phenotype. CONCLUSION Non-motor symptoms form an integral component of the dystonia phenotype. However, future studies should involve a complete assessment of all symptom subtypes in order to understand the frequency and gene-specificity of these symptoms. This will enable early symptom identification, appropriate clinical management, and provide additional outcome measures in future clinical trials.
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Affiliation(s)
- K J Peall
- Department of Neurology, University of Groningen, Groningen, The Netherlands; Institute of Psychological Medicine and Clinical Neurosciences, MRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, UK.
| | - A Kuiper
- Department of Neurology, University of Groningen, Groningen, The Netherlands.
| | - T J de Koning
- Department of Neurology, University of Groningen, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands.
| | - M A J Tijssen
- Department of Neurology, University of Groningen, Groningen, The Netherlands.
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Funck V, Ribeiro L, Pereira L, de Oliveira C, Grigoletto J, Della-Pace I, Fighera M, Royes L, Furian A, Larrick J, Oliveira M. Contrasting effects of Na+, K+-ATPase activation on seizure activity in acute versus chronic models. Neuroscience 2015; 298:171-9. [DOI: 10.1016/j.neuroscience.2015.04.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 03/02/2015] [Accepted: 04/14/2015] [Indexed: 10/23/2022]
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Fremont R, Tewari A, Khodakhah K. Aberrant Purkinje cell activity is the cause of dystonia in a shRNA-based mouse model of Rapid Onset Dystonia-Parkinsonism. Neurobiol Dis 2015; 82:200-212. [PMID: 26093171 DOI: 10.1016/j.nbd.2015.06.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 11/19/2022] Open
Abstract
Loss-of-function mutations in the α3 isoform of the sodium pump are responsible for Rapid Onset Dystonia-Parkinsonism (RDP). A pharmacologic model of RDP replicates the most salient features of RDP, and implicates both the cerebellum and basal ganglia in the disorder; dystonia is associated with aberrant cerebellar output, and the parkinsonism-like features are attributable to the basal ganglia. The pharmacologic agent used to generate the model, ouabain, is selective for sodium pumps. However, close to the infusion sites in vivo it likely affects all sodium pump isoforms. Therefore, it remains to be established whether selective loss of α3-containing sodium pumps replicates the pharmacologic model. Moreover, while the pharmacologic model suggested that aberrant firing of Purkinje cells was the main cause of abnormal cerebellar output, it did not allow the scrutiny of this hypothesis. To address these questions RNA interference using small hairpin RNAs (shRNAs) delivered via adeno-associated viruses (AAV) was used to specifically knockdown α3-containing sodium pumps in different regions of the adult mouse brain. Knockdown of the α3-containing sodium pumps mimicked both the behavioral and electrophysiological changes seen in the pharmacologic model of RDP, recapitulating key aspects of the human disorder. Further, we found that knockdown of the α3 isoform altered the intrinsic pacemaking of Purkinje cells, but not the neurons of the deep cerebellar nuclei. Therefore, acute knockdown of proteins associated with inherited dystonias may be a good strategy for developing phenotypic genetic mouse models where traditional transgenic models have failed to produce symptomatic mice.
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Affiliation(s)
- Rachel Fremont
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ambika Tewari
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kamran Khodakhah
- Dominick P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Recessive mutations in the α3 (VI) collagen gene COL6A3 cause early-onset isolated dystonia. Am J Hum Genet 2015; 96:883-93. [PMID: 26004199 DOI: 10.1016/j.ajhg.2015.04.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022] Open
Abstract
Isolated dystonia is a disorder characterized by involuntary twisting postures arising from sustained muscle contractions. Although autosomal-dominant mutations in TOR1A, THAP1, and GNAL have been found in some cases, the molecular mechanisms underlying isolated dystonia are largely unknown. In addition, although emphasis has been placed on dominant isolated dystonia, the disorder is also transmitted as a recessive trait, for which no mutations have been defined. Using whole-exome sequencing in a recessive isolated dystonia-affected kindred, we identified disease-segregating compound heterozygous mutations in COL6A3, a collagen VI gene associated previously with muscular dystrophy. Genetic screening of a further 367 isolated dystonia subjects revealed two additional recessive pedigrees harboring compound heterozygous mutations in COL6A3. Strikingly, all affected individuals had at least one pathogenic allele in exon 41, including an exon-skipping mutation that induced an in-frame deletion. We tested the hypothesis that disruption of this exon is pathognomonic for isolated dystonia by inducing a series of in-frame deletions in zebrafish embryos. Consistent with our human genetics data, suppression of the exon 41 ortholog caused deficits in axonal outgrowth, whereas suppression of other exons phenocopied collagen deposition mutants. All recessive mutation carriers demonstrated early-onset segmental isolated dystonia without muscular disease. Finally, we show that Col6a3 is expressed in neurons, with relevant mRNA levels detectable throughout the adult mouse brain. Taken together, our data indicate that loss-of-function mutations affecting a specific region of COL6A3 cause recessive isolated dystonia with underlying neurodevelopmental deficits and highlight the brain extracellular matrix as a contributor to dystonia pathogenesis.
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169
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Viollet L, Glusman G, Murphy KJ, Newcomb TM, Reyna SP, Sweney M, Nelson B, Andermann F, Andermann E, Acsadi G, Barbano RL, Brown C, Brunkow ME, Chugani HT, Cheyette SR, Collins A, DeBrosse SD, Galas D, Friedman J, Hood L, Huff C, Jorde LB, King MD, LaSalle B, Leventer RJ, Lewelt AJ, Massart MB, Mérida MR, Ptáček LJ, Roach JC, Rust RS, Renault F, Sanger TD, Sotero de Menezes MA, Tennyson R, Uldall P, Zhang Y, Zupanc M, Xin W, Silver K, Swoboda KJ. Alternating Hemiplegia of Childhood: Retrospective Genetic Study and Genotype-Phenotype Correlations in 187 Subjects from the US AHCF Registry. PLoS One 2015; 10:e0127045. [PMID: 25996915 PMCID: PMC4440742 DOI: 10.1371/journal.pone.0127045] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 04/11/2015] [Indexed: 11/21/2022] Open
Abstract
Mutations in ATP1A3 cause Alternating Hemiplegia of Childhood (AHC) by disrupting function of the neuronal Na+/K+ ATPase. Published studies to date indicate 2 recurrent mutations, D801N and E815K, and a more severe phenotype in the E815K cohort. We performed mutation analysis and retrospective genotype-phenotype correlations in all eligible patients with AHC enrolled in the US AHC Foundation registry from 1997-2012. Clinical data were abstracted from standardized caregivers’ questionnaires and medical records and confirmed by expert clinicians. We identified ATP1A3 mutations by Sanger and whole genome sequencing, and compared phenotypes within and between 4 groups of subjects, those with D801N, E815K, other ATP1A3 or no ATP1A3 mutations. We identified heterozygous ATP1A3 mutations in 154 of 187 (82%) AHC patients. Of 34 unique mutations, 31 (91%) are missense, and 16 (47%) had not been previously reported. Concordant with prior studies, more than 2/3 of all mutations are clustered in exons 17 and 18. Of 143 simplex occurrences, 58 had D801N (40%), 38 had E815K (26%) and 11 had G937R (8%) mutations. Patients with an E815K mutation demonstrate an earlier age of onset, more severe motor impairment and a higher prevalence of status epilepticus. This study further expands the number and spectrum of ATP1A3 mutations associated with AHC and confirms a more deleterious effect of the E815K mutation on selected neurologic outcomes. However, the complexity of the disorder and the extensive phenotypic variability among subgroups merits caution and emphasizes the need for further studies.
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Affiliation(s)
- Louis Viollet
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Gustavo Glusman
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Kelley J. Murphy
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Tara M. Newcomb
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Sandra P. Reyna
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Matthew Sweney
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Benjamin Nelson
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Frederick Andermann
- Neurogenetics Unit, Montreal Neurologic Institute and Hospital, McGill University, Montreal Quebec, Canada
| | - Eva Andermann
- Neurogenetics Unit, Montreal Neurologic Institute and Hospital, McGill University, Montreal Quebec, Canada
| | - Gyula Acsadi
- Departments of Pediatrics and Neurology, Connecticut Children's Medical Center and University of Connecticut School of Medicine, Hartford, CT, United States of America
| | - Richard L. Barbano
- Department of Neurology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Candida Brown
- Diablo Valley Child Neurology, an affiliate of Stanford Health Alliance, Pleasant Hill, California, United States of America
| | - Mary E. Brunkow
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Harry T. Chugani
- Division of Pediatric Neurology, Children's Hospital of Michigan, Wayne State University, Detroit, Michigan, United States of America
| | - Sarah R. Cheyette
- Department of Child Neurology, Palo Alto Medical Foundation Redwood City Clinic, Redwood City, California, United States of America
| | - Abigail Collins
- Department of Pediatric Neurology, Children’s Hospital Colorado, University of Colorado Hospital, Aurora, Colorado, United States of America
| | - Suzanne D. DeBrosse
- Departments of Genetics and Genome Sciences, Pediatrics, and Neurology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - David Galas
- Pacific Northwest Diabetes Research Institute, Seattle, Washington, United States of America
| | - Jennifer Friedman
- Departments of Neuroscience and Pediatrics, University of California San Diego, San Diego, California, United States of America
| | - Lee Hood
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Chad Huff
- Department of Epidemiology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Lynn B. Jorde
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Mary D. King
- Departments of Pediatrics and Neurology, University College Dublin School of Medicine and Medical Science, Dublin, Ireland
| | - Bernie LaSalle
- Department of Biomedical Informatics, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Richard J. Leventer
- Children’s Neuroscience Centre, Murdoch Childrens Research Institute, University of Melbourne Department of Paediatrics, The Royal Children’s Hospital Melbourne, Parkville Victoria, Australia
| | - Aga J. Lewelt
- Department of Pediatrics, College of Medicine Jacksonville, University of Florida, Jacksonville, Florida, United States of America
| | - Mylynda B. Massart
- Department of Family Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mario R. Mérida
- Stevens Henager College, Salt Lake City, Utah, United States of America
| | - Louis J. Ptáček
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Jared C. Roach
- Institute for Systems Biology, Seattle, Washington, United States of America
| | - Robert S. Rust
- Center for Medical Ethics and Humanities in Medicine, University Of Virginia UVA health system, Charlottesville, Virginia, United States of America
| | - Francis Renault
- Departement de Neurophysiologie. Hopital Armand Trousseau APHP, Paris, France
| | - Terry D. Sanger
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
| | | | - Rachel Tennyson
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
| | - Peter Uldall
- Department of Paediatrics and Adolescent Medicine, Juliane Marie Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Yue Zhang
- Study Design and Biostatistics Center, University of Utah, Salt Lake City, Utah, United States of America
| | - Mary Zupanc
- Department of Neurology, Children’s Hospital Orange County, and Department of Pediatrics, University of California, Orange, California, United States of America
| | - Winnie Xin
- Center for Human Genetic Research, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Kenneth Silver
- Departments of Pediatrics and Neurology, University of Chicago and Comer Children's Hospital, Chicago, Illinois, United States of America
| | - Kathryn J. Swoboda
- Pediatric Motor Disorders Research Program, Departments of Neurology and Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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Camargo CHF, Camargos ST, Cardoso FEC, Teive HAG. The genetics of the dystonias--a review based on the new classification of the dystonias. ARQUIVOS DE NEURO-PSIQUIATRIA 2015; 73:350-8. [PMID: 25992527 DOI: 10.1590/0004-282x20150030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 01/07/2015] [Indexed: 11/22/2022]
Abstract
The definition and classification of the dystonias was recently revisited. In the new 2013 classification, the dystonias are subdivided in terms of their etiology according to whether they are the result of pathological changes or structural damage, have acquired causes or are inherited. As hereditary dystonias are clinically and genetically heterogeneous, we sought to classify them according to the new recently defined criteria. We observed that although the new classification is still the subject of much debate and controversy, it is easy to use in a logical and objective manner with the inherited dystonias. With the discovery of new genes, however, it remains to be seen whether the new classification will continue to be effective.
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Affiliation(s)
- Carlos Henrique F Camargo
- Unidade de Distúrbios do Movimento, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Sarah Teixeira Camargos
- Unidade de Distúrbios do Movimento, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Francisco Eduardo C Cardoso
- Unidade de Distúrbios do Movimento, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Hélio Afonso G Teive
- Unidade de Distúrbios do Movimento, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil
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171
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Abstract
Decades of experimental work have established an imbalance of excitation and inhibition as the leading mechanism of the transition from normal brain function to seizure. In epilepsy, these transitions are rare and abrupt. Transition processes incorporating positive feedback, such as activity-dependent disinhibition, could provide these uncommon timing features. A rapidly expanding array of genetic etiologies will help delineate the molecular mechanism(s). This delineation will entail quite a bit of cell biology. The genes discovered so far are more remarkable for their diversity than their similarities.
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172
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Holm R, Einholm AP, Andersen JP, Vilsen B. Rescue of Na+ affinity in aspartate 928 mutants of Na+,K+-ATPase by secondary mutation of glutamate 314. J Biol Chem 2015; 290:9801-11. [PMID: 25713066 DOI: 10.1074/jbc.m114.625509] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Indexed: 11/06/2022] Open
Abstract
The Na(+),K(+)-ATPase binds Na(+) at three transport sites denoted I, II, and III, of which site III is Na(+)-specific and suggested to be the first occupied in the cooperative binding process activating phosphorylation from ATP. Here we demonstrate that the asparagine substitution of the aspartate associated with site III found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood causes a dramatic reduction of Na(+) affinity in the α1-, α2-, and α3-isoforms of Na(+),K(+)-ATPase, whereas other substitutions of this aspartate are much less disruptive. This is likely due to interference by the amide function of the asparagine side chain with Na(+)-coordinating residues in site III. Remarkably, the Na(+) affinity of site III aspartate to asparagine and alanine mutants is rescued by second-site mutation of a glutamate in the extracellular part of the fourth transmembrane helix, distant to site III. This gain-of-function mutation works without recovery of the lost cooperativity and selectivity of Na(+) binding and does not affect the E1-E2 conformational equilibrium or the maximum phosphorylation rate. Hence, the rescue of Na(+) affinity is likely intrinsic to the Na(+) binding pocket, and the underlying mechanism could be a tightening of Na(+) binding at Na(+) site II, possibly via movement of transmembrane helix four. The second-site mutation also improves Na(+),K(+) pump function in intact cells. Rescue of Na(+) affinity and Na(+) and K(+) transport by second-site mutation is unique in the history of Na(+),K(+)-ATPase and points to new possibilities for treatment of neurological patients carrying Na(+),K(+)-ATPase mutations.
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Affiliation(s)
- Rikke Holm
- From the Department of Biomedicine, Aarhus University, Ole Worms Allé 4, Building 1160, DK-8000 Aarhus C, Denmark
| | - Anja P Einholm
- From the Department of Biomedicine, Aarhus University, Ole Worms Allé 4, Building 1160, DK-8000 Aarhus C, Denmark
| | - Jens P Andersen
- From the Department of Biomedicine, Aarhus University, Ole Worms Allé 4, Building 1160, DK-8000 Aarhus C, Denmark
| | - Bente Vilsen
- From the Department of Biomedicine, Aarhus University, Ole Worms Allé 4, Building 1160, DK-8000 Aarhus C, Denmark
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173
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Noebels J. Pathway-driven discovery of epilepsy genes. Nat Neurosci 2015; 18:344-50. [PMID: 25710836 DOI: 10.1038/nn.3933] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/22/2014] [Indexed: 12/12/2022]
Abstract
Epilepsy genes deliver critical insights into the molecular control of brain synchronization and are revolutionizing our understanding and treatment of the disease. The epilepsy-associated genome is rapidly expanding, and two powerful complementary approaches, isolation of de novo exome variants in patients and targeted mutagenesis in model systems, account for the steep increase. In sheer number, the tally of genes linked to seizures will likely match that of cancer and exceed it in biological diversity. The proteins act within most intracellular compartments and span the molecular determinants of firing and wiring in the developing brain. Every facet of neurotransmission, from dendritic spine to exocytotic machinery, is in play, and defects of synaptic inhibition are over-represented. The contributions of somatic mutations and noncoding microRNAs are also being explored. The functional spectrum of established epilepsy genes and the arrival of rapid, precise technologies for genome editing now provide a robust scaffold to prioritize hypothesis-driven discovery and further populate this genetic proto-map. Although each gene identified offers translational potential to stratify patient care, the complexity of individual variation and covert actions of genetic modifiers may confound single-gene solutions for the clinical disorder. In vivo genetic deconstruction of epileptic networks, ex vivo validation of variant profiles in patient-derived induced pluripotent stem cells, in silico variant modeling and modifier gene discovery, now in their earliest stages, will help clarify individual patterns. Because seizures stand at the crossroads of all neuronal synchronization disorders in the developing and aging brain, the neurobiological analysis of epilepsy-associated genes provides an extraordinary gateway to new insights into higher cortical function.
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Affiliation(s)
- Jeffrey Noebels
- Developmental Neurogenetics Laboratory, Departments of Neurology, Neuroscience, and Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
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174
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P2C-Type ATPases and Their Regulation. Mol Neurobiol 2015; 53:1343-1354. [DOI: 10.1007/s12035-014-9076-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 12/29/2014] [Indexed: 12/12/2022]
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175
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de Koning TJ, Tijssen MAJ. Genetic advances spark a revolution in dystonia phenotyping. Nat Rev Neurol 2015; 11:78-9. [DOI: 10.1038/nrneurol.2014.254] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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176
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Tan AH, Ozelius LJ, Brashear A, Lang AE, Ahmad-Annuar A, Tan CT, Lim SY. Rapid-Onset Dystonia-Parkinsonism in a Chinese Girl with a De Novo ATP1A3 c.2267G>A (p.R756H) Genetic Mutation. Mov Disord Clin Pract 2014; 2:74-75. [PMID: 30713883 DOI: 10.1002/mdc3.12122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/20/2014] [Accepted: 11/05/2014] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ai Huey Tan
- Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders; and the Department of Biomedical Science Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
| | - Laurie J Ozelius
- Departments of Genetics and Genomic Sciences and Neurology Mount Sinai School of Medicine New York New York USA
| | - Allison Brashear
- Department of Neurology Wake Forest University School of Medicine Winston-Salem North Carolina USA
| | - Anthony E Lang
- Morton and Gloria Shulman Movement Disorders Center Toronto Western Hospital and the Edmond J. Safra Program in Parkinson's Disease Research University of Toronto Toronto Ontario Canada
| | - Azlina Ahmad-Annuar
- Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders; and the Department of Biomedical Science Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
| | - Chong Tin Tan
- Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders; and the Department of Biomedical Science Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
| | - Shen-Yang Lim
- Division of Neurology and the Mah Pooi Soo & Tan Chin Nam Centre for Parkinson's & Related Disorders; and the Department of Biomedical Science Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
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177
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Hunanyan AS, Fainberg NA, Linabarger M, Arehart E, Leonard AS, Adil SM, Helseth AR, Swearingen AK, Forbes SL, Rodriguiz RM, Rhodes T, Yao X, Kibbi N, Hochman DW, Wetsel WC, Hochgeschwender U, Mikati MA. Knock-in mouse model of alternating hemiplegia of childhood: behavioral and electrophysiologic characterization. Epilepsia 2014; 56:82-93. [PMID: 25523819 DOI: 10.1111/epi.12878] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Mutations in the ATP1α3 subunit of the neuronal Na+/K+-ATPase are thought to be responsible for seizures, hemiplegias, and other symptoms of alternating hemiplegia of childhood (AHC). However, the mechanisms through which ATP1A3 mutations mediate their pathophysiologic consequences are not yet understood. The following hypotheses were investigated: (1) Our novel knock-in mouse carrying the most common heterozygous mutation causing AHC (D801N) will exhibit the manifestations of the human condition and display predisposition to seizures; and (2) the underlying pathophysiology in this mouse model involves increased excitability in response to electrical stimulation of Schaffer collaterals and abnormal predisposition to spreading depression (SD). METHODS We generated the D801N mutant mouse (Mashlool, Mashl+/-) and compared mutant and wild-type (WT) littermates. Behavioral tests, amygdala kindling, flurothyl-induced seizure threshold, spontaneous recurrent seizures (SRS), and other paroxysmal activities were compared between groups. In vitro electrophysiologic slice experiments on hippocampus were performed to assess predisposition to hyperexcitability and SD. RESULTS Mutant mice manifested a distinctive phenotype similar to that of humans with AHC. They had abnormal impulsivity, memory, gait, motor coordination, tremor, motor control, endogenous nociceptive response, paroxysmal hemiplegias, diplegias, dystonias, and SRS, as well as predisposition to kindling, to flurothyl-induced seizures, and to sudden unexpected death. Hippocampal slices of mutants, in contrast to WT animals, showed hyperexcitable responses to 1 Hz pulse-trains of electrical stimuli delivered to the Schaffer collaterals and had significantly longer duration of K+-induced SD responses. SIGNIFICANCE Our model reproduces the major characteristics of human AHC, and indicates that ATP1α3 dysfunction results in abnormal short-term plasticity with increased excitability (potential mechanism for seizures) and a predisposition to more severe SD responses (potential mechanism for hemiplegias). This model of the human condition should help in understanding the molecular pathways underlying these phenotypes and may lead to identification of novel therapeutic strategies of ATP1α3 related disorders and seizures.
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Affiliation(s)
- Arsen S Hunanyan
- Division of Pediatric Neurology, Department of Pediatrics, School of Medicine, Duke University, Durham, North Carolina, U.S.A
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178
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Blesa J, Przedborski S. Parkinson's disease: animal models and dopaminergic cell vulnerability. Front Neuroanat 2014; 8:155. [PMID: 25565980 PMCID: PMC4266040 DOI: 10.3389/fnana.2014.00155] [Citation(s) in RCA: 330] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 11/27/2014] [Indexed: 12/18/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder that affects about 1.5% of the global population over 65 years of age. A hallmark feature of PD is the degeneration of the dopamine (DA) neurons in the substantia nigra pars compacta (SNc) and the consequent striatal DA deficiency. Yet, the pathogenesis of PD remains unclear. Despite tremendous growth in recent years in our knowledge of the molecular basis of PD and the molecular pathways of cell death, important questions remain, such as: (1) why are SNc cells especially vulnerable; (2) which mechanisms underlie progressive SNc cell loss; and (3) what do Lewy bodies or α-synuclein reveal about disease progression. Understanding the variable vulnerability of the dopaminergic neurons from the midbrain and the mechanisms whereby pathology becomes widespread are some of the primary objectives of research in PD. Animal models are the best tools to study the pathogenesis of PD. The identification of PD-related genes has led to the development of genetic PD models as an alternative to the classical toxin-based ones, but does the dopaminergic neuronal loss in actual animal models adequately recapitulate that of the human disease? The selection of a particular animal model is very important for the specific goals of the different experiments. In this review, we provide a summary of our current knowledge about the different in vivo models of PD that are used in relation to the vulnerability of the dopaminergic neurons in the midbrain in the pathogenesis of PD.
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Affiliation(s)
- Javier Blesa
- Department of Pathology and Cell Biology, Center for Motor Neuron Biology and Disease, College of Physicians and Surgeons, Columbia UniversityNew York, NY, USA
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179
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Wilcox R, Brænne I, Brüggemann N, Winkler S, Wiegers K, Bertram L, Anderson T, Lohmann K. Genome sequencing identifies a novel mutation in ATP1A3 in a family with dystonia in females only. J Neurol 2014; 262:187-93. [PMID: 25359261 DOI: 10.1007/s00415-014-7547-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 01/28/2023]
Abstract
Dystonia is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal movements or postures. Several genetic causes of dystonia have been elucidated but genetic causes of dystonia specifically affecting females have not yet been described. In the present study, we investigated a large dystonia family from New Zealand in which only females were affected. They presented with a generalized form of the disorder including laryngeal, cervical, and arm dystonia. We found a novel, likely disease-causing, three base-pair deletion (c.443_445delGAG, p.Ser148del) in ATP1A3 in this family by combining genome and exome sequencing. Mutations in ATP1A3 have previously been linked to rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and CAPOS syndrome. Therefore, we re-examined our patients with a specific focus on typical symptoms of these conditions. It turned out that all patients reported a rapid onset of dystonic symptoms following a trigger suggesting a diagnosis of RDP. Notably, none of the patients showed clear symptoms of parkinsonism or symptoms specific for AHC or CAPOS. The ATP1A3 gene is located on chromosome 19q13.2, thus, providing no obvious explanation for the preponderance to affect females. Interestingly, we also identified one unaffected male offspring carrying the p.Ser148del mutation suggesting reduced penetrance of this mutation, a phenomenon that has also been observed for other RDP-causing mutations in ATP1A3. Although phenotypic information in this family was initially incomplete, the identification of the p.Ser148del ATP1A3 mutation elicited clinical re-examination of patients subsequently allowing establishing the correct diagnosis, a phenomenon known as "reverse phenotyping".
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Affiliation(s)
- Robert Wilcox
- Department of Neurology, Flinders Medical Centre, Adelaide, Australia
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