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Oliver KL, Franceschetti S, Milligan CJ, Muona M, Mandelstam SA, Canafoglia L, Boguszewska-Chachulska AM, Korczyn AD, Bisulli F, Di Bonaventura C, Ragona F, Michelucci R, Ben-Zeev B, Straussberg R, Panzica F, Massano J, Friedman D, Crespel A, Engelsen BA, Andermann F, Andermann E, Spodar K, Lasek-Bal A, Riguzzi P, Pasini E, Tinuper P, Licchetta L, Gardella E, Lindenau M, Wulf A, Møller RS, Benninger F, Afawi Z, Rubboli G, Reid CA, Maljevic S, Lerche H, Lehesjoki AE, Petrou S, Berkovic SF. Myoclonus epilepsy and ataxia due to KCNC1 mutation: Analysis of 20 cases and K + channel properties. Ann Neurol 2017; 81:677-689. [PMID: 28380698 DOI: 10.1002/ana.24929] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To comprehensively describe the new syndrome of myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK), including cellular electrophysiological characterization of observed clinical improvement with fever. METHODS We analyzed clinical, electroclinical, and neuroimaging data for 20 patients with MEAK due to recurrent KCNC1 p.R320H mutation. In vitro electrophysiological studies were conducted using whole cell patch-clamp to explore biophysical properties of wild-type and mutant KV 3.1 channels. RESULTS Symptoms began at between 3 and 15 years of age (median = 9.5), with progressively severe myoclonus and rare tonic-clonic seizures. Ataxia was present early, but quickly became overshadowed by myoclonus; 10 patients were wheelchair-bound by their late teenage years. Mild cognitive decline occurred in half. Early death was not observed. Electroencephalogram (EEG) showed generalized spike and polyspike wave discharges, with documented photosensitivity in most. Polygraphic EEG-electromyographic studies demonstrated a cortical origin for myoclonus and striking coactivation of agonist and antagonist muscles. Magnetic resonance imaging revealed symmetrical cerebellar atrophy, which appeared progressive, and a prominent corpus callosum. Unexpectedly, transient clinical improvement with fever was noted in 6 patients. To explore this, we performed high-temperature in vitro recordings. At elevated temperatures, there was a robust leftward shift in activation of wild-type KV 3.1, increasing channel availability. INTERPRETATION MEAK has a relatively homogeneous presentation, resembling Unverricht-Lundborg disease, despite the genetic and biological basis being quite different. A remarkable improvement with fever may be explained by the temperature-dependent leftward shift in activation of wild-type KV 3.1 subunit-containing channels, which would counter the loss of function observed for mutant channels, highlighting KCNC1 as a potential target for precision therapeutics. Ann Neurol 2017;81:677-689.
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Affiliation(s)
- Karen L Oliver
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Silvana Franceschetti
- Department of Neurophysiology, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Carol J Milligan
- Ion Channels and Disease Group, Epilepsy Division, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Mikko Muona
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland.,Folkhälsan Institute of Genetics, Helsinki, Finland.,Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland.,Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Simone A Mandelstam
- Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Departments of Paediatrics and Radiology, University of Melbourne, Melbourne, Victoria, Australia.,Department of Medical Imaging, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Laura Canafoglia
- Department of Neurophysiology, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | | | - Amos D Korczyn
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Francesca Bisulli
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Carlo Di Bonaventura
- Department of Neurological Sciences, University of Rome, La Sapienza, Rome, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Roberto Michelucci
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Unit of Neurology, Bellaria Hospital, Bologna, Italy
| | - Bruria Ben-Zeev
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Rachel Straussberg
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Epilepsy Unit, Schneider Children's Medical Center of Israel, Petah Tikvah, Israel
| | - Ferruccio Panzica
- Department of Neurophysiology, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - João Massano
- Department of Neurology, Hospital Pedro Hispano/ULS Matosinhos, Senhora da Hora, Portugal.,Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Daniel Friedman
- Comprehensive Epilepsy Center, New York University Langone Medical Center, New York, NY
| | - Arielle Crespel
- Epilepsy Unit, Gui de Chauliac Hospital, Montpellier, France
| | - Bernt A Engelsen
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Frederick Andermann
- Epilepsy Research Group, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada.,Departments of Neurology & Neurosurgery and Paediatrics, McGill University, Montreal, Quebec, Canada
| | - Eva Andermann
- Neurogenetics Unit and Epilepsy Research Group, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada.,Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, Quebec, Canada
| | | | - Anetta Lasek-Bal
- High School of Science, Medical University of Silesia, Department of Neurology, Upper Silesian Medical Center, Katowice, Poland
| | - Patrizia Riguzzi
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Unit of Neurology, Bellaria Hospital, Bologna, Italy
| | - Elena Pasini
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Unit of Neurology, Bellaria Hospital, Bologna, Italy
| | - Paolo Tinuper
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Licchetta
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Elena Gardella
- Danish Epilepsy Center, Dianalund, Denmark.,Institute for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Matthias Lindenau
- Department of Neurology and Epileptology, Epilepsy Center Hamburg-Alsterdorf, Hamburg, Germany
| | - Annette Wulf
- Department of Neurology and Epileptology, Epilepsy Center Hamburg-Alsterdorf, Hamburg, Germany
| | - Rikke S Møller
- Danish Epilepsy Center, Dianalund, Denmark.,Institute for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Felix Benninger
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, Petah Tikvah, Israel
| | - Zaid Afawi
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Guido Rubboli
- IRCCS-Institute of Neurological Sciences of Bologna, Bologna, Italy.,Danish Epilepsy Center, Filadelfia/University of Copenhagen, Dianalund, Denmark
| | - Christopher A Reid
- Ion Channels and Disease Group, Epilepsy Division, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Snezana Maljevic
- Ion Channels and Disease Group, Epilepsy Division, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,University of Tübingen, Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tübingen, Germany
| | - Holger Lerche
- University of Tübingen, Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tübingen, Germany
| | - Anna-Elina Lehesjoki
- Folkhälsan Institute of Genetics, Helsinki, Finland.,Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland.,Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Steven Petrou
- Ion Channels and Disease Group, Epilepsy Division, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia.,Centre for Neural Engineering, Department of Electrical Engineering, University of Melbourne, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
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