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Zhao T, Wang L, Chen F. Potassium channel-related epilepsy: Pathogenesis and clinical features. Epilepsia Open 2024; 9:891-905. [PMID: 38560778 PMCID: PMC11145612 DOI: 10.1002/epi4.12934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 03/11/2024] [Accepted: 03/17/2024] [Indexed: 04/04/2024] Open
Abstract
Variants in potassium channel-related genes are one of the most important mechanisms underlying abnormal neuronal excitation and disturbances in the cellular resting membrane potential. These variants can cause different forms of epilepsy, which can seriously affect the physical and mental health of patients, especially those with refractory epilepsy or status epilepticus, which are common among pediatric patients and are potentially life-threatening. Variants in potassium ion channel-related genes have been reported in few studies; however, to our knowledge, no systematic review has been published. This study aimed to summarize the epilepsy phenotypes, functional studies, and pharmacological advances associated with different potassium channel gene variants to assist clinical practitioners and drug development teams to develop evidence-based medicine and guide research strategies. PubMed and Google Scholar were searched for relevant literature on potassium channel-related epilepsy reported in the past 5-10 years. Various common potassium ion channel gene variants can lead to heterogeneous epilepsy phenotypes, and functional effects can result from gene deletions and compound effects. Administration of select anti-seizure medications is the primary treatment for this type of epilepsy. Most patients are refractory to anti-seizure medications, and some novel anti-seizure medications have been found to improve seizures. Use of targeted drugs to correct aberrant channel function based on the type of potassium channel gene variant can be used as an evidence-based pathway to achieve precise and individualized treatment for children with epilepsy. PLAIN LANGUAGE SUMMARY: In this article, the pathogenesis and clinical characteristics of epilepsy caused by different types of potassium channel gene variants are reviewed in the light of the latest research literature at home and abroad, with the expectation of providing a certain theoretical basis for the diagnosis and treatment of children with this type of disease.
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Affiliation(s)
- Tong Zhao
- Hebei Children's HospitalShijiazhuangHebeiChina
| | - Le Wang
- Hebei Children's HospitalShijiazhuangHebeiChina
| | - Fang Chen
- Hebei Children's HospitalShijiazhuangHebeiChina
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2
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G S B Lima PL, Nobrega PR, Freua F, Braga-Neto P, Paiva ARB, Guimarães TG, Kok F. Myoclonus improvement after seizures in progressive myoclonic epilepsy type 7: a case report. BMC Neurol 2024; 24:169. [PMID: 38783211 PMCID: PMC11112770 DOI: 10.1186/s12883-024-03625-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 04/05/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Progressive Myoclonic Epilepsy (PME) is a group of rare diseases that are difficult to differentiate from one another based on phenotypical characteristics. CASE REPORT We report a case of PME type 7 due to a pathogenic variant in KCNC1 with myoclonus improvement after epileptic seizures. DISCUSSION Myoclonus improvement after seizures may be a clue to the diagnosis of Progressive Myoclonic Epilepsy type 7.
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Affiliation(s)
| | - Paulo R Nobrega
- Division of Neurology, Federal University of Ceara, Fortaleza, Ceara, Brazil
- Centro Universitário Christus, Fortaleza, Ceara, Brazil
| | - Fernando Freua
- Neurogenetics Center, Department of Neurology, University of Sao Paulo, Sao Paulo, Brazil
| | - Pedro Braga-Neto
- Division of Neurology, Federal University of Ceara, Fortaleza, Ceara, Brazil
| | - Anderson R B Paiva
- Neurogenetics Center, Department of Neurology, University of Sao Paulo, Sao Paulo, Brazil
| | - Thiago Gonçalves Guimarães
- Movement Disorders Center, Department of Neurology, University of Sao Paulo, Av. Dr. Eneas de Carvalho Aguiar, 255, 5th Floor, Room 5084, Cerqueira Cesar, Sao Paulo, Sao Paulo, 05403-900, Brazil.
| | - Fernando Kok
- Neurogenetics Center, Department of Neurology, University of Sao Paulo, Sao Paulo, Brazil
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3
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Gazulla J, Berciano J. Potential Benefit of Channel Activators in Loss-of-Function Primary Potassium Channelopathies Causing Heredoataxia. CEREBELLUM (LONDON, ENGLAND) 2024; 23:833-837. [PMID: 37460907 DOI: 10.1007/s12311-023-01584-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/29/2023] [Indexed: 03/20/2024]
Abstract
Potassium channels (KCN) are transmembrane complexes that regulate the resting membrane potential and the duration of action potentials in cells. The opening of KCN brings about an efflux of K+ ions that induces cell repolarization after depolarization, returns the transmembrane potential to its resting state, and enables for continuous spiking ability. The aim of this work was to assess the role of KCN dysfunction in the pathogenesis of hereditary ataxias and the mechanisms of action of KCN opening agents (KCO). In consequence, a review of the ad hoc medical literature was performed. Among hereditary KCN diseases causing ataxia, mutated Kv3.3, Kv4.3, and Kv1.1 channels provoke spinocerebellar ataxia (SCA) type 13, SCA19/22, and episodic ataxia type 1 (EA1), respectively. The K+ efflux was found to be reduced in experimental models of these diseases, resulting in abnormally prolonged depolarization and incomplete repolarization, thereby interfering with repetitive discharges in the cells. Hence, substances able to promote normal spiking activity in the cerebellum could provide symptomatic benefit. Although drugs used in clinical practice do not activate Kv3.3 or Kv4.3 directly, available KCO probably could ameliorate ataxic symptoms in SCA13 and SCA19/22, as verified with acetazolamide in EA1, and retigabine in a mouse model of hypokalemic periodic paralysis. To summarize, ataxia could possibly be improved by non-specific KCO in SCA13 and SCA19/22. The identification of new specific KCO agents will undoubtedly constitute a promising therapeutic strategy for these diseases.
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Affiliation(s)
- José Gazulla
- Department of Neurology, Hospital Universitario Miguel Servet, Isabel la Católica, 1-3, 50009, Saragossa, Spain.
| | - José Berciano
- Department of Neurology, Hospital Universitario Marqués de Valdecilla (IDIVAL), University of Cantabria, CIBERNED, Avenida de Valdecilla S/N, 39008, Santander, Spain
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4
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Feng H, Clatot J, Kaneko K, Flores-Mendez M, Wengert ER, Koutcher C, Hoddeson E, Lopez E, Lee D, Arias L, Liang Q, Zhang X, Somarowthu A, Covarrubias M, Gunthorpe MJ, Large CH, Akizu N, Goldberg EM. Targeted therapy improves cellular dysfunction, ataxia, and seizure susceptibility in a model of a progressive myoclonus epilepsy. Cell Rep Med 2024; 5:101389. [PMID: 38266642 PMCID: PMC10897515 DOI: 10.1016/j.xcrm.2023.101389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 11/09/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024]
Abstract
The recurrent variant KCNC1-p.Arg320His causes progressive myoclonus epilepsy (EPM) type 7, defined by progressive myoclonus, epilepsy, and ataxia, and is without effective treatment. KCNC1 encodes the voltage-gated potassium channel subunit Kv3.1, specifically expressed in high-frequency-firing neurons. Variant subunits act via loss of function; hence, EPM7 pathogenesis may involve impaired excitability of Kv3.1-expressing neurons, while enhancing Kv3 activity could represent a viable therapeutic strategy. We generate a mouse model, Kcnc1-p.Arg320His/+, which recapitulates the core features of EPM7, including progressive ataxia and seizure susceptibility. Kv3.1-expressing cerebellar granule cells and neocortical parvalbumin-positive GABAergic interneurons exhibit abnormalities consistent with Kv3 channel dysfunction. A Kv3-specific positive modulator (AUT00206) selectively enhances the firing frequency of Kv3.1-expressing neurons and improves motor function and seizure susceptibility in Kcnc1-Arg320His/+ mice. This work identifies a cellular and circuit basis of dysfunction in EPM7 and demonstrates that Kv3 positive modulators such as AUT00206 have therapeutic potential for the treatment of EPM7.
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Affiliation(s)
- Huijie Feng
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jerome Clatot
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; The Epilepsy Neurogenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Keisuke Kaneko
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Anesthesiology, Nihon University, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Marco Flores-Mendez
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Eric R Wengert
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Carly Koutcher
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Emily Hoddeson
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Emily Lopez
- The University of Pennsylvania School of Arts and Sciences, Philadelphia, PA, USA
| | - Demetrius Lee
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Leroy Arias
- The University of Pennsylvania School of Arts and Sciences, Philadelphia, PA, USA
| | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Xiaohong Zhang
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ala Somarowthu
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Martin J Gunthorpe
- Autifony Therapeutics, Ltd., Stevenage Bioscience Catalyst, Stevenage SG1 2FX, UK
| | - Charles H Large
- Autifony Therapeutics, Ltd., Stevenage Bioscience Catalyst, Stevenage SG1 2FX, UK
| | - Naiara Akizu
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Departments of Pathology & Laboratory Medicine, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ethan M Goldberg
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; The Epilepsy Neurogenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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5
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Gandini MA, Zamponi GW. Opening the K V3.1 gates: A therapeutic strategy for progressive myoclonus epilepsy type 7? Cell Rep Med 2024; 5:101425. [PMID: 38382469 PMCID: PMC10897601 DOI: 10.1016/j.xcrm.2024.101425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 01/21/2024] [Accepted: 01/21/2024] [Indexed: 02/23/2024]
Abstract
Progressive myoclonus epilepsy type 7, a debilitating neurological disorder, is caused by a loss-of-function mutation in the KV3.1 channel. Exciting work by Feng et al.1 utilizes a new knockin mouse model to identify a potential therapeutic intervention.
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Affiliation(s)
- Maria A Gandini
- Department of Clinical Neurosciences, University of Calgary, Calgary, Canada
| | - Gerald W Zamponi
- Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.
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6
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Clatot J, Currin CB, Liang Q, Pipatpolkai T, Massey SL, Helbig I, Delemotte L, Vogels TP, Covarrubias M, Goldberg EM. A structurally precise mechanism links an epilepsy-associated KCNC2 potassium channel mutation to interneuron dysfunction. Proc Natl Acad Sci U S A 2024; 121:e2307776121. [PMID: 38194456 PMCID: PMC10801864 DOI: 10.1073/pnas.2307776121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/17/2023] [Indexed: 01/11/2024] Open
Abstract
De novo heterozygous variants in KCNC2 encoding the voltage-gated potassium (K+) channel subunit Kv3.2 are a recently described cause of developmental and epileptic encephalopathy (DEE). A de novo variant in KCNC2 c.374G > A (p.Cys125Tyr) was identified via exome sequencing in a patient with DEE. Relative to wild-type Kv3.2, Kv3.2-p.Cys125Tyr induces K+ currents exhibiting a large hyperpolarizing shift in the voltage dependence of activation, accelerated activation, and delayed deactivation consistent with a relative stabilization of the open conformation, along with increased current density. Leveraging the cryogenic electron microscopy (cryo-EM) structure of Kv3.1, molecular dynamic simulations suggest that a strong π-π stacking interaction between the variant Tyr125 and Tyr156 in the α-6 helix of the T1 domain promotes a relative stabilization of the open conformation of the channel, which underlies the observed gain of function. A multicompartment computational model of a Kv3-expressing parvalbumin-positive cerebral cortex fast-spiking γ-aminobutyric acidergic (GABAergic) interneuron (PV-IN) demonstrates how the Kv3.2-Cys125Tyr variant impairs neuronal excitability and dysregulates inhibition in cerebral cortex circuits to explain the resulting epilepsy.
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Affiliation(s)
- Jerome Clatot
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA19104
- The Epilepsy Neurogenetics Initiative, The Children’s Hospital of Philadelphia, Philadelphia,PA19104
| | | | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA19107
| | - Tanadet Pipatpolkai
- Department of Applied Physics, Science for Life Laboratory, Royal Institute of Technology, SolnaSE-171 21, Sweden
| | - Shavonne L. Massey
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA19104
- The Epilepsy Neurogenetics Initiative, The Children’s Hospital of Philadelphia, Philadelphia,PA19104
- The Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA19104
| | - Ingo Helbig
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA19104
- The Epilepsy Neurogenetics Initiative, The Children’s Hospital of Philadelphia, Philadelphia,PA19104
- The Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA19104
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA19104
| | - Lucie Delemotte
- Department of Applied Physics, Science for Life Laboratory, Royal Institute of Technology, SolnaSE-171 21, Sweden
| | - Tim P. Vogels
- The Institute of Science and Technology Austria, Klosterneuburg3400, Austria
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA19107
| | - Ethan M. Goldberg
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, PA19104
- The Epilepsy Neurogenetics Initiative, The Children’s Hospital of Philadelphia, Philadelphia,PA19104
- The Department of Neurology, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA19104
- The Department of Neuroscience, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA19104
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7
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Khan R, Chaturvedi P, Sahu P, Ludhiadch A, Singh P, Singh G, Munshi A. Role of Potassium Ion Channels in Epilepsy: Focus on Current Therapeutic Strategies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:67-87. [PMID: 36578258 DOI: 10.2174/1871527322666221227112621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Epilepsy is one of the prevalent neurological disorders characterized by disrupted synchronization between inhibitory and excitatory neurons. Disturbed membrane potential due to abnormal regulation of neurotransmitters and ion transport across the neural cell membrane significantly contributes to the pathophysiology of epilepsy. Potassium ion channels (KCN) regulate the resting membrane potential and are involved in neuronal excitability. Genetic alterations in the potassium ion channels (KCN) have been reported to result in the enhancement of the release of neurotransmitters, the excitability of neurons, and abnormal rapid firing rate, which lead to epileptic phenotypes, making these ion channels a potential therapeutic target for epilepsy. The aim of this study is to explore the variations reported in different classes of potassium ion channels (KCN) in epilepsy patients, their functional evaluation, and therapeutic strategies to treat epilepsy targeting KCN. METHODOLOGY A review of all the relevant literature was carried out to compile this article. RESULTS A large number of variations have been reported in different genes encoding various classes of KCN. These genetic alterations in KCN have been shown to be responsible for disrupted firing properties of neurons. Antiepileptic drugs (AEDs) are the main therapeutic strategy to treat epilepsy. Some patients do not respond favorably to the AEDs treatment, resulting in pharmacoresistant epilepsy. CONCLUSION Further to address the challenges faced in treating epilepsy, recent approaches like optogenetics, chemogenetics, and genome editing, such as clustered regularly interspaced short palindromic repeats (CRISPR), are emerging as target-specific therapeutic strategies.
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Affiliation(s)
- Rahul Khan
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Pragya Chaturvedi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Prachi Sahu
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Abhilash Ludhiadch
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, 151001 India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
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8
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Chen YT, Hong MR, Zhang XJ, Kostas J, Li Y, Kraus RL, Santarelli VP, Wang D, Gomez-Llorente Y, Brooun A, Strickland C, Soisson SM, Klein DJ, Ginnetti AT, Marino MJ, Stachel SJ, Ishchenko A. Identification, structural, and biophysical characterization of a positive modulator of human Kv3.1 channels. Proc Natl Acad Sci U S A 2023; 120:e2220029120. [PMID: 37812700 PMCID: PMC10589703 DOI: 10.1073/pnas.2220029120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 08/16/2023] [Indexed: 10/11/2023] Open
Abstract
Voltage-gated potassium channels (Kv) are tetrameric membrane proteins that provide a highly selective pathway for potassium ions (K+) to diffuse across a hydrophobic cell membrane. These unique voltage-gated cation channels detect changes in membrane potential and, upon activation, help to return the depolarized cell to a resting state during the repolarization stage of each action potential. The Kv3 family of potassium channels is characterized by a high activation potential and rapid kinetics, which play a crucial role for the fast-spiking neuronal phenotype. Mutations in the Kv3.1 channel have been shown to have implications in various neurological diseases like epilepsy and Alzheimer's disease. Moreover, disruptions in neuronal circuitry involving Kv3.1 have been correlated with negative symptoms of schizophrenia. Here, we report the discovery of a novel positive modulator of Kv3.1, investigate its biophysical properties, and determine the cryo-EM structure of the compound in complex with Kv3.1. Structural analysis reveals the molecular determinants of positive modulation in Kv3.1 channels by this class of compounds and provides additional opportunities for rational drug design for the treatment of associated neurological disorders.
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Affiliation(s)
- Yun-Ting Chen
- Computational and Structural Chemistry, Merck & Co., Inc., Kenilworth, NJ07033
| | - Mee Ra Hong
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | - Xin-Jun Zhang
- Department of Neuroscience, Merck & Co., Inc., West Point, PA19486
| | - James Kostas
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | - Yuxing Li
- Department of Neuroscience, Merck & Co., Inc., West Point, PA19486
| | - Richard L. Kraus
- Department of Neuroscience, Merck & Co., Inc., West Point, PA19486
| | | | - Deping Wang
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | | | - Alexei Brooun
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | - Corey Strickland
- Computational and Structural Chemistry, Merck & Co., Inc., Kenilworth, NJ07033
| | - Stephen M. Soisson
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | - Daniel J. Klein
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
| | | | | | | | - Andrii Ishchenko
- Computational and Structural Chemistry, Merck & Co., Inc., West Point, PA19486
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9
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Cameron JM, Ellis CA, Berkovic SF. ILAE Genetics Literacy series: Progressive myoclonus epilepsies. Epileptic Disord 2023; 25:670-680. [PMID: 37616028 PMCID: PMC10947580 DOI: 10.1002/epd2.20152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/21/2023] [Accepted: 08/19/2023] [Indexed: 08/25/2023]
Abstract
Progressive Myoclonus Epilepsy (PME) is a rare epilepsy syndrome characterized by the development of progressively worsening myoclonus, ataxia, and seizures. A molecular diagnosis can now be established in approximately 80% of individuals with PME. Almost fifty genetic causes of PME have now been established, although some remain extremely rare. Herein, we provide a review of clinical phenotypes and genotypes of the more commonly encountered PMEs. Using an illustrative case example, we describe appropriate clinical investigation and therapeutic strategies to guide the management of this often relentlessly progressive and devastating epilepsy syndrome. This manuscript in the Genetic Literacy series maps to Learning Objective 1.2 of the ILAE Curriculum for Epileptology (Epileptic Disord. 2019;21:129).
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Affiliation(s)
- Jillian M. Cameron
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
| | - Colin A. Ellis
- Department of NeurologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvaniaUSA
| | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
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10
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Ma D, Sun C, Manne R, Guo T, Bosc C, Barry J, Magliery T, Andrieux A, Li H, Gu C. A cytoskeleton-membrane interaction conserved in fast-spiking neurons controls movement, emotion, and memory. Mol Psychiatry 2023; 28:3994-4010. [PMID: 37833406 PMCID: PMC10905646 DOI: 10.1038/s41380-023-02286-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 09/20/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023]
Abstract
The pathogenesis of schizophrenia is believed to involve combined dysfunctions of many proteins including microtubule-associated protein 6 (MAP6) and Kv3.1 voltage-gated K+ (Kv) channel, but their relationship and functions in behavioral regulation are often not known. Here we report that MAP6 stabilizes Kv3.1 channels in parvalbumin-positive (PV+ ) fast-spiking GABAergic interneurons, regulating behavior. MAP6-/- and Kv3.1-/- mice display similar hyperactivity and avoidance reduction. Their proteins colocalize in PV+ interneurons and MAP6 deletion markedly reduces Kv3.1 protein level. We further show that two microtubule-binding modules of MAP6 bind the Kv3.1 tetramerization domain with high affinity, maintaining the channel level in both neuronal soma and axons. MAP6 knockdown by AAV-shRNA in the amygdala or the hippocampus reduces avoidance or causes hyperactivity and recognition memory deficit, respectively, through elevating projection neuron activity. Finally, knocking down Kv3.1 or disrupting the MAP6-Kv3.1 binding in these brain regions causes avoidance reduction and hyperactivity, consistent with the effects of MAP6 knockdown. Thus, disrupting this conserved cytoskeleton-membrane interaction in fast-spiking neurons causes different degrees of functional vulnerability in various neural circuits.
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Affiliation(s)
- Di Ma
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
| | - Chao Sun
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- MCDB graduate program, The Ohio State University, Columbus, OH, USA
| | - Rahul Manne
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
| | - Tianqi Guo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Christophe Bosc
- Univ. Grenoble Alpes, Inserm, U1216, CEA, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Joshua Barry
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Thomas Magliery
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Annie Andrieux
- Univ. Grenoble Alpes, Inserm, U1216, CEA, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Houzhi Li
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
| | - Chen Gu
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA.
- MCDB graduate program, The Ohio State University, Columbus, OH, USA.
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11
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Alam KA, Svalastoga P, Martinez A, Glennon JC, Haavik J. Potassium channels in behavioral brain disorders. Molecular mechanisms and therapeutic potential: A narrative review. Neurosci Biobehav Rev 2023; 152:105301. [PMID: 37414376 DOI: 10.1016/j.neubiorev.2023.105301] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/26/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023]
Abstract
Potassium channels (K+-channels) selectively control the passive flow of potassium ions across biological membranes and thereby also regulate membrane excitability. Genetic variants affecting many of the human K+-channels are well known causes of Mendelian disorders within cardiology, neurology, and endocrinology. K+-channels are also primary targets of many natural toxins from poisonous organisms and drugs used within cardiology and metabolism. As genetic tools are improving and larger clinical samples are being investigated, the spectrum of clinical phenotypes implicated in K+-channels dysfunction is rapidly expanding, notably within immunology, neurosciences, and metabolism. K+-channels that previously were considered to be expressed in only a few organs and to have discrete physiological functions, have recently been found in multiple tissues and with new, unexpected functions. The pleiotropic functions and patterns of expression of K+-channels may provide additional therapeutic opportunities, along with new emerging challenges from off-target effects. Here we review the functions and therapeutic potential of K+-channels, with an emphasis on the nervous system, roles in neuropsychiatric disorders and their involvement in other organ systems and diseases.
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Affiliation(s)
| | - Pernille Svalastoga
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway; Children and Youth Clinic, Haukeland University Hospital, Bergen, Norway
| | | | - Jeffrey Colm Glennon
- Conway Institute for Biomolecular and Biomedical Research, School of Medicine, University College Dublin, Dublin, Ireland.
| | - Jan Haavik
- Department of Biomedicine, University of Bergen, Norway; Division of Psychiatry, Haukeland University Hospital, Norway.
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12
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Baykan B, Franceschetti S, Canafoglia L, Cavalleri GL, Michelucci R, Scheffer IE. Differential diagnosis of familial adult myoclonic epilepsy. Epilepsia 2023. [PMID: 36751956 DOI: 10.1111/epi.17536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/27/2023] [Accepted: 02/06/2023] [Indexed: 02/09/2023]
Abstract
OBJECTIVE Familial adult myoclonic epilepsy (FAME) is an under-recognized disorder characterized by cortical myoclonus, generalized tonic-clonic seizures, and additional clinical symptoms, which vary depending on the FAME subtype. FAME is caused by pentanucleotide repeat expansions of intronic TTTCA/TTTTA in different genes. FAME should be distinguished from a range of differential diagnoses. METHODS The differential diagnoses and frequent presentations leading to misdiagnosis of FAME were investigated from the available literature and reported based on an expert opinion survey. RESULTS The phenotypic features of FAME, including generalized tonic-clonic and myoclonic seizures, are also seen in other epilepsy syndromes, such as juvenile myoclonic epilepsy, with a resultant risk of misdiagnosis and lack of identification of the underlying cause. Cortical myoclonus may mimic essential tremor or drug-induced tremor. In younger individuals, the differential diagnosis includes progressive myoclonus epilepsies (PMEs), such as Unverricht-Lundborg disease, whereas, in adulthood, late-onset variants of PMEs, such as sialidoses, myoclonus epilepsy, and ataxia due to potassium channel pathogenic variants should be considered. PMEs may also be suggested by cognitive impairment, cerebellar signs, or psychiatric disorders. Electroencephalography (EEG) may show similarities to other idiopathic generalized epilepsies or PMEs, with generalized spike-wave activity. Signs of cortical hyperexcitability may be seen, such as an increased amplitude of somatosensory evoked potentials or enhanced cortical reflex to sensory stimuli, together with the neurophysiological pattern of the movement disorder. SIGNIFICANCE Recognition of FAME will inform prognostic and genetic counseling and diagnosis of the insidious progression, which may occur in older individuals who show mild cognitive deterioration. Distinguishing FAME from other disorders in individuals or families with this constellation of symptoms is essential to allow the identification of underlying etiology.
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Affiliation(s)
- Betul Baykan
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.,EMAR Medical Center, Istanbul, Turkey
| | - Silvana Franceschetti
- Department of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Canafoglia
- Department of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Gianpiero L Cavalleri
- The School of Pharmacy and Biomolecular Sciences, The Royal College of Surgeons in Ireland, Dublin, Ireland.,The Science Foundation Ireland, FutureNeuro Centre of Excellence, Dublin, Ireland
| | - Roberto Michelucci
- Unit of Neurology and Epileptology, Bellaria Hospital, IRCCS - Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Ingrid E Scheffer
- Austin and Royal Children's Hospital, Florey and Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia
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13
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Clatot J, Ginn N, Costain G, Goldberg EM. A KCNC1-related neurological disorder due to gain of Kv3.1 function. Ann Clin Transl Neurol 2022; 10:111-117. [PMID: 36419348 PMCID: PMC9852383 DOI: 10.1002/acn3.51707] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To further clarify genotype:phenotype correlations associated with variants in KCNC1 encoding the voltage-gated potassium (K+) channel subunit Kv3.1 and which are an emerging cause of a spectrum of neurological disease including intellectual disability, isolated myoclonus, progressive myoclonus epilepsy, and developmental and epileptic encephalopathy. METHODS We describe the clinical and genetic characteristics of a series of three patients with de novo heterozygous missense variants in KCNC1 associated with nonspecific developmental delay/intellectual disability and central hypotonia without epilepsy or ataxia. All three variants lead to amino acids alterations with mild predicted differences in physicochemical properties yet are localized to the S6 pore region of the Kv3.1 protein between the selectivity filter and PXP motif important for K+ channel gating. We performed whole-cell voltage clamp electrophysiological recording of wild-type versus variants in a heterologous mammalian expression system. RESULTS We demonstrate a prominent leftward (hyperpolarized) shift in the voltage dependence of activation and slowed deactivation of all variants in the clinically defined series. INTERPRETATION Electrophysiological recordings are consistent with a gain of K+ channel function that is predicted to exert a loss of function on the excitability of Kv3-expressing high frequency- firing neurons based on the unique electrophysiological properties of Kv3 channels. These results define a clinical-genetic syndrome within the spectrum of KCNC1-related neurological disorders.
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Affiliation(s)
- Jerome Clatot
- Division of Neurology, Department of PediatricsThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA,The Epilepsy Neurogenetics InitiativeThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Natalie Ginn
- Division of Neurology, Department of PediatricsThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA,The Epilepsy Neurogenetics InitiativeThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Gregory Costain
- Division of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenTorontoOntarioCanada,Genetics and Genome BiologySickKids Research InstituteTorontoOntarioCanada
| | - Ethan M. Goldberg
- Division of Neurology, Department of PediatricsThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA,The Epilepsy Neurogenetics InitiativeThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA,Department of NeurologyThe University of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvaniaUSA,Department of NeuroscienceThe University of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvaniaUSA
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14
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Gao K, Lin Z, Wen S, Jiang Y. Potassium channels and epilepsy. Acta Neurol Scand 2022; 146:699-707. [PMID: 36225112 DOI: 10.1111/ane.13695] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 08/16/2022] [Indexed: 01/10/2023]
Abstract
With the development and application of next-generation sequencing technology, the aetiological diagnosis of genetic epilepsy is rapidly becoming easier and less expensive. Additionally, there is a growing body of research into precision therapy based on genetic diagnosis. The numerous genes in the potassium ion channel family constitute the largest family of ion channels: this family is divided into different subtypes. Potassium ion channels play a crucial role in the electrical activity of neurons and are directly involved in the mechanism of epileptic seizures. In China, scientific research on genetic diagnosis and studies of precision therapy for genetic epilepsy are progressing rapidly. Many cases of epilepsy caused by mutation of potassium channel genes have been identified, and several potassium channel gene targets and drug candidates have been discovered. The purpose of this review is to briefly summarize the progress of research on the precise diagnosis and treatment of potassium ion channel-related genetic epilepsy, especially the research conducted in China. Here in, we review several large cohort studies on the genetic diagnosis of epilepsy in China in recent years, summarized the proportion of potassium channel genes. We focus on the progress of precison therapy on some hot epilepsy related potassium channel genes: KCNA1, KCNA2, KCNB1, KCNC1, KCND2, KCNQ2, KCNQ3, KCNMA1, and KCNT1.
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Affiliation(s)
- Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Zehong Lin
- Department of Neurology, Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Sijia Wen
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic Diseases, Beijing, China.,Children Epilepsy Center, Peking University First Hospital, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
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15
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Chi G, Liang Q, Sridhar A, Cowgill JB, Sader K, Radjainia M, Qian P, Castro-Hartmann P, Venkaya S, Singh NK, McKinley G, Fernandez-Cid A, Mukhopadhyay SMM, Burgess-Brown NA, Delemotte L, Covarrubias M, Dürr KL. Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain. Nat Commun 2022; 13:4087. [PMID: 35840580 PMCID: PMC9287412 DOI: 10.1038/s41467-022-29594-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 03/24/2022] [Indexed: 11/26/2022] Open
Abstract
Kv3 channels have distinctive gating kinetics tailored for rapid repolarization in fast-spiking neurons. Malfunction of this process due to genetic variants in the KCNC1 gene causes severe epileptic disorders, yet the structural determinants for the unusual gating properties remain elusive. Here, we present cryo-electron microscopy structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic tetramerization domain T1 which facilitates interactions with C-terminal axonal targeting motif and key components of the gating machinery. Additional interactions between S1/S2 linker and turret domain strengthen the interface between voltage sensor and pore domain. Supported by molecular dynamics simulations, electrophysiological and mutational analyses, we identify several residues in the S4/S5 linker which influence the gating kinetics and an electrostatic interaction between acidic residues in α6 of T1 and R449 in the pore-flanking S6T helices. These findings provide insights into gating control and disease mechanisms and may guide strategies for the design of pharmaceutical drugs targeting Kv3 channels.
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Affiliation(s)
- Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Akshay Sridhar
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - John B Cowgill
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Mazdak Radjainia
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Shayla Venkaya
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nanki Kaur Singh
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Gavin McKinley
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Alejandra Fernandez-Cid
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Shubhashish M M Mukhopadhyay
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Lucie Delemotte
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Katharina L Dürr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- OMass Therapeutics, Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK.
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16
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Gunthorpe MJ. Timing is everything: structural insights into the disease-linked Kv3 channels controlling fast action-potential firing in the brain. Nat Commun 2022; 13:4086. [PMID: 35840565 PMCID: PMC9287389 DOI: 10.1038/s41467-022-31537-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/21/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Martin J Gunthorpe
- Autifony Therapeutics Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK.
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17
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McTague A, Brunklaus A, Barcia G, Varadkar S, Zuberi SM, Chatron N, Parrini E, Mei D, Nabbout R, Lesca G. Defining causal variants in rare epilepsies: an essential team effort between biomedical scientists, geneticists and epileptologists. Eur J Med Genet 2022; 65:104531. [PMID: 35618197 DOI: 10.1016/j.ejmg.2022.104531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 05/01/2022] [Accepted: 05/19/2022] [Indexed: 11/23/2022]
Abstract
In the last few years, with the advent of next generation sequencing (NGS), our knowledge of genes associated with monogenic epilepsies has significantly improved. NGS is also a powerful diagnostic tool for patients with epilepsy, through gene panels, exomes and genomes. This has improved diagnostic yield, reducing the time between the first seizure and a definitive molecular diagnosis. However, these developments have also increased the complexity of data interpretation, due to the large number of variants identified in a given patient and due to the phenotypic variability associated with many of the epilepsy-related genes. In this paper, we present examples of variant classification in "real life" clinic situations. We emphasize the importance of accurate phenotyping of the epilepsies including recognising variable/milder phenotypes and expansion of previously described phenotypes. There are some important issues specific to rare epilepsies - mosaicism and reduced penetrance - which affect genetic counselling. These challenges may be overcome through multidisciplinary meetings including epileptologists, pediatric neurologists, and clinical and molecular geneticists, in which every specialist learns from the others in a process which leads to for rapid and accurate diagnosis. This is an important milestone to achieve as targeted therapiesbased on the functional effects of pathogenic variants become available.
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Affiliation(s)
- Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK; Department of Neurology, Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK.
| | - Andreas Brunklaus
- The Pediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK; Institute of Health and Wellbeing, University of Glasgow, Member of the ERN EpiCARE, Glasgow, UK
| | - Giulia Barcia
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Member of the ERN EpiCARE, Paris, France
| | - Sophia Varadkar
- Department of Neurology, Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK
| | - Sameer M Zuberi
- The Pediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK; Institute of Health and Wellbeing, University of Glasgow, Member of the ERN EpiCARE, Glasgow, UK
| | - Nicolas Chatron
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Member of the ERN EpiCARE, Lyon, France
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital - University of Florence, Member of the ERN EpiCARE, Florence, Italy
| | - Davide Mei
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital - University of Florence, Member of the ERN EpiCARE, Florence, Italy
| | - Rima Nabbout
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Member of the ERN EpiCARE, Paris, France
| | - Gaetan Lesca
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Member of the ERN EpiCARE, Lyon, France
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18
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Botte M, Huber S, Bucher D, Klint JK, Rodríguez D, Tagmose L, Chami M, Cheng R, Hennig M, Abdul Rahman W. Apo and ligand-bound high resolution Cryo-EM structures of the human Kv3.1 channel reveal a novel binding site for positive modulators. PNAS NEXUS 2022; 1:pgac083. [PMID: 36741467 PMCID: PMC9896932 DOI: 10.1093/pnasnexus/pgac083] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 06/08/2022] [Indexed: 02/07/2023]
Abstract
Kv3 ion-channels constitute a class of functionally distinct voltage-gated ion channels characterized by their ability to fire at a high frequency. Several disease relevant mutants, together with biological data, suggest the importance of this class of ion channels as drug targets for CNS disorders, and several drug discovery efforts have been reported. Despite the increasing interest for this class of ion channels, no structure of a Kv3 channel has been reported yet. We have determined the cryo-EM structure of Kv3.1 at 2.6 Å resolution using full-length wild type protein. When compared to known structures for potassium channels from other classes, a novel domain organization is observed with the cytoplasmic T1 domain, containing a well-resolved Zinc site and displaying a rotation by 35°. This suggests a distinct cytoplasmic regulation mechanism for the Kv3.1 channel. A high resolution structure was obtained for Kv3.1 in complex with a novel positive modulator Lu AG00563. The structure reveals a novel ligand binding site for the Kv class of ion channels located between the voltage sensory domain and the channel pore, a region which constitutes a hotspot for disease causing mutations. The discovery of a novel binding site for a positive modulator of a voltage-gated potassium channel could shed light on the mechanism of action for these small molecule potentiators. This finding could enable structure-based drug design on these targets with high therapeutic potential for the treatment of multiple CNS disorders.
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Affiliation(s)
- Mathieu Botte
- leadXpro AG, PARK InnovAARE, 5234 Villigen, Switzerland
| | - Sophie Huber
- leadXpro AG, PARK InnovAARE, 5234 Villigen, Switzerland
| | - Denis Bucher
- leadXpro AG, PARK InnovAARE, 5234 Villigen, Switzerland
| | | | | | - Lena Tagmose
- H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Mohamed Chami
- BioEM laboratory, Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Robert Cheng
- leadXpro AG, PARK InnovAARE, 5234 Villigen, Switzerland
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19
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Mahale RR, Tiwari R, Arunachal G, Padmanabha H, Mailankody P. Myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK): a cause of progressive myoclonic epilepsy. Acta Neurol Belg 2022; 122:801-803. [PMID: 33725338 DOI: 10.1007/s13760-021-01645-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 03/06/2021] [Indexed: 11/25/2022]
Affiliation(s)
- Rohan R Mahale
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, Karnataka, 560029, India.
| | - Ravindu Tiwari
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, Karnataka, 560029, India
| | | | - Hansashree Padmanabha
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, Karnataka, 560029, India
| | - Pooja Mailankody
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, Karnataka, 560029, India
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20
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Qiuju H, Jianlong Z, Qi W, Zhifa L, Ding W, Xiaofang S, Yingjun X. Epilepsy Combined With Multiple Gene Heterozygous Mutation. Front Pediatr 2022; 10:763642. [PMID: 35299674 PMCID: PMC8921529 DOI: 10.3389/fped.2022.763642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 01/26/2022] [Indexed: 11/16/2022] Open
Abstract
The fast pace of gene discovery has resulted in groundbreaking advances in the field of epilepsy genetics. Clinical testing using comprehensive gene panels, exomes, or genomes is now increasingly available and has significantly increased the diagnostic yield for early-onset epilepsies and enabled precision medicine approaches. In this paper, we report a case of epilepsy in a pedigree. The proband had heterozygous mutations in KCNC1 (NM_001112741.1:c.959G>A, p. Arg320His), CAPN3 (NM_000070.2:c.526G>A, p. Val176Met), and NEFH (NM_021076.3:c. 2595 delC, p. Lys866Argfs*51). Sanger sequencing verification was consistent with the results of whole-exome sequencing. The KCNC1 mutation was a de novo mutation, and the CAPN3 and NEFH mutations were inherited from their father and mother, respectively. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, a heterozygous mutation was found for APOB (NM_000384.2: c.10579C > T, p. Arg3527Trp). The heterozygous mutation at this site was inherent in the pedigree. Coexpression analysis indicated that heterozygous mutations of KCNC1, CAPN3, NEFH, and APOB were closely related to the clinical phenotypes of the patient, and the clinical phenotypic heterogeneity of the disease may be the result of the interaction of multiple genes.
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Affiliation(s)
- He Qiuju
- Department of Obstetrics and Gynaecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Clinical Medicine, The Third Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Zhuang Jianlong
- Prenatal Diagnosis Center, Quanzhou Women's and Children's Hospital, Quanzhou, China
| | - Wen Qi
- Department of Obstetrics and Gynaecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Clinical Medicine, The Third Clinical School of Guangzhou Medical University, Guangzhou, China
| | - Li Zhifa
- Gastrointestinal Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Wang Ding
- Department of Obstetrics and Gynaecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Sun Xiaofang
- Department of Obstetrics and Gynaecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xie Yingjun
- Department of Obstetrics and Gynaecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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Canafoglia L, Franceschetti S, Gambardella A, Striano P, Giallonardo AT, Tinuper P, Di Bonaventura C, Michelucci R, Ferlazzo E, Granata T, Magaudda A, Licchetta L, Filla A, La Neve A, Riguzzi P, Cantisani TA, Fanella M, CASTELLOTTI BARBARA, Gellera C, Bahlo M, Zara F, Courage C, Lehesjoki AE, Oliver KL, Berkovic SF. Progressive Myoclonus Epilepsies. Neurol Genet 2021; 7:e641. [PMID: 34786481 PMCID: PMC8589262 DOI: 10.1212/nxg.0000000000000641] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/08/2021] [Indexed: 11/28/2022]
Abstract
Background and Objectives To assess the current diagnostic yield of genetic testing for the progressive myoclonus epilepsies (PMEs) of an Italian series described in 2014 where Unverricht-Lundborg and Lafora diseases accounted for ∼50% of the cohort. Methods Of 47/165 unrelated patients with PME of indeterminate genetic origin, 38 underwent new molecular evaluations. Various next-generation sequencing (NGS) techniques were applied including gene panel analysis (n = 7) and/or whole-exome sequencing (WES) (WES singleton n = 29, WES trio n = 7, and WES sibling n = 4). In 1 family, homozygosity mapping was followed by targeted NGS. Clinically, the patients were grouped in 4 phenotypic categories: “Unverricht-Lundborg disease-like PME,” “late-onset PME,” “PME plus developmental delay,” and “PME plus dementia.” Results Sixteen of 38 (42%) unrelated patients reached a positive diagnosis, increasing the overall proportion of solved families in the total series from 72% to 82%. Likely pathogenic variants were identified in NEU1 (2 families), CERS1 (1 family), and in 13 nonfamilial patients in KCNC1 (3), DHDDS (3), SACS, CACNA2D2, STUB1, AFG3L2, CLN6, NAXE, and CHD2. Across the different phenotypic categories, the diagnostic rate was similar, and the same gene could be found in different phenotypic categories. Discussion The application of NGS technology to unsolved patients with PME has revealed a collection of very rare genetic causes. Pathogenic variants were detected in both established PME genes and in genes not previously associated with PME, but with progressive ataxia or with developmental encephalopathies. With a diagnostic yield >80%, PME is one of the best genetically defined epilepsy syndromes.
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Benarroch E. What Is the Role of Potassium Channels in Ataxia? Neurology 2021; 97:938-941. [PMID: 34782409 DOI: 10.1212/wnl.0000000000012870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 11/15/2022] Open
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Li X, Zheng Y, Li S, Nair U, Sun C, Zhao C, Lu J, Zhang VW, Maljevic S, Petrou S, Lin J. Kv3.1 channelopathy: a novel loss-of-function variant and the mechanistic basis of its clinical phenotypes. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1397. [PMID: 34733949 PMCID: PMC8506712 DOI: 10.21037/atm-21-1885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/11/2021] [Indexed: 11/26/2022]
Abstract
Background KCNC1 encodes Kv3.1, a subunit of the Kv3 voltage-gated potassium channels. It is predominantly expressed in inhibitory GABAergic interneurons and cerebellar neurons. Kv3.1 channelopathy has been linked to a variety of human diseases including epilepsy, developmental delay, and ataxia. Characterization of structural and functional disturbances of this channel, and its relationship to a heterogenous group of clinical phenotypes, is a current topic of research. We herein characterize the clinical phenotype as well as the functional and structural consequences of the novel KCNC1 p.R317S variant. We further set out to explore the mechanistic basis for the spectrum of KCNC1 related channelopathies. Methods Variant was identified via whole-exome sequencing and its functional impact was determined using two-electrode voltage clamp recordings in Xenopus laevis oocytes. Homolog modeling and in silico structural analysis were performed on the p.R317S variant and other KCNC1 related variants. Results We identified a novel loss-of-function KCNC1 variant c.949C>A (p.R317S) presenting with symptoms similar to myoclonic epilepsy and ataxia due to potassium channel (MEAK), but with distinct radiological features. Functional analysis in the Xenopus laevis oocyte’s expression system revealed that the current amplitudes were significantly decreased in the p.R317S variant compared to the wild type, indicating a dominant-negative effect. Atomic structural analysis of the KCNC1 related variants provided a possible mechanistic explanation for the heterogeneity in the clinical spectrum. Conclusions We have identified the p.R317S loss-of-function variant in the KCNC1 gene, expanded the spectrum of potassium channelopathy and provided mechanistic insights into KCNC1 related disorders.
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Affiliation(s)
- Xiaoyang Li
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.,Department of Neurology, University of North Carolina, Chapel Hill, USA
| | - Yongsheng Zheng
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | | | - Umesh Nair
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Chong Sun
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiahong Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | | | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Jie Lin
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
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Carpenter JC, Lignani G. Gene Editing and Modulation: the Holy Grail for the Genetic Epilepsies? Neurotherapeutics 2021; 18:1515-1523. [PMID: 34235638 PMCID: PMC8608979 DOI: 10.1007/s13311-021-01081-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2021] [Indexed: 02/04/2023] Open
Abstract
Epilepsy is a complex neurological disorder for which there are a large number of monogenic subtypes. Monogenic epilepsies are often severe and disabling, featuring drug-resistant seizures and significant developmental comorbidities. These disorders are potentially amenable to a precision medicine approach, of which genome editing using CRISPR/Cas represents the holy grail. Here we consider mutations in some of the most 'common' rare epilepsy genes and discuss the different CRISPR/Cas approaches that could be taken to cure these disorders. We consider scenarios where CRISPR-mediated gene modulation could serve as an effective therapeutic strategy and discuss whether a single gene corrective approach could hold therapeutic potential in the context of homeostatic compensation in the developing, highly dynamic brain. Despite an incomplete understanding of the mechanisms of the genetic epilepsies and current limitations of gene editing tools, CRISPR-mediated approaches have game-changing potential in the treatment of genetic epilepsy over the next decade.
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Affiliation(s)
- Jenna C Carpenter
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK.
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Carpenter JC, Männikkö R, Heffner C, Heneine J, Sampedro‐Castañeda M, Lignani G, Schorge S. Progressive myoclonus epilepsy KCNC1 variant causes a developmental dendritopathy. Epilepsia 2021; 62:1256-1267. [PMID: 33735526 PMCID: PMC8436768 DOI: 10.1111/epi.16867] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Mutations in KCNC1 can cause severe neurological dysfunction, including intellectual disability, epilepsy, and ataxia. The Arg320His variant, which occurs in the voltage-sensing domain of the channel, causes a highly penetrant and specific form of progressive myoclonus epilepsy with severe ataxia, designated myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK). KCNC1 encodes the voltage-gated potassium channel KV 3.1, a channel that is important for enabling high-frequency firing in interneurons, raising the possibility that MEAK is associated with reduced interneuronal function. METHODS To determine how this variant triggers MEAK, we expressed KV 3.1bR320H in cortical interneurons in vitro and investigated the effects on neuronal function and morphology. We also performed electrophysiological recordings of oocytes expressing KV 3.1b to determine whether the mutation introduces gating pore currents. RESULTS Expression of the KV 3.1bR320H variant profoundly reduced excitability of mature cortical interneurons, and cells expressing these channels were unable to support high-frequency firing. The mutant channel also had an unexpected effect on morphology, severely impairing neurite development and interneuron viability, an effect that could not be rescued by blocking KV 3 channels. Oocyte recordings confirmed that in the adult KV 3.1b isoform, R320H confers a dominant negative loss-of-function effect by slowing channel activation, but does not introduce potentially toxic gating pore currents. SIGNIFICANCE Overall, our data suggest that, in addition to the regulation of high-frequency firing, KV 3.1 channels play a hitherto unrecognized role in neuronal development. MEAK may be described as a developmental dendritopathy.
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Affiliation(s)
- Jenna C. Carpenter
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Roope Männikkö
- Department of Neuromuscular DiseasesUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Catherine Heffner
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Jana Heneine
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Marisol Sampedro‐Castañeda
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Gabriele Lignani
- Department of Clinical and Experimental EpilepsyUniversity College London Queen Square Institute of NeurologyLondonUK
| | - Stephanie Schorge
- Department of PharmacologyUniversity College London School of PharmacyLondonUK
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26
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Nikitin ES, Vinogradova LV. Potassium channels as prominent targets and tools for the treatment of epilepsy. Expert Opin Ther Targets 2021; 25:223-235. [PMID: 33754930 DOI: 10.1080/14728222.2021.1908263] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION K+ channels are of great interest to epilepsy research as mutations in their genes are found in humans with inherited epilepsy. At the level of cellular physiology, K+ channels control neuronal intrinsic excitability and are the main contributors to membrane repolarization of active neurons. Recently, a genetically modified voltage-dependent K+ channel has been patented as a remedy for epileptic seizures. AREAS COVERED We review the role of potassium channels in excitability, clinical and experimental evidence for the association of potassium channelopathies with epilepsy, the targeting of K+ channels by drugs, and perspectives of gene therapy in epilepsy with the expression of extra K+ channels in the brain. EXPERT OPINION Control over K+ conductance is of great potential benefit for the treatment of epilepsy. Nowadays, gene therapy affecting K+ channels is one of the most promising approaches to treat pharmacoresistant focal epilepsy.
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Affiliation(s)
- E S Nikitin
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - L V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
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27
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Courage C, Oliver KL, Park EJ, Cameron JM, Grabińska KA, Muona M, Canafoglia L, Gambardella A, Said E, Afawi Z, Baykan B, Brandt C, di Bonaventura C, Chew HB, Criscuolo C, Dibbens LM, Castellotti B, Riguzzi P, Labate A, Filla A, Giallonardo AT, Berecki G, Jackson CB, Joensuu T, Damiano JA, Kivity S, Korczyn A, Palotie A, Striano P, Uccellini D, Giuliano L, Andermann E, Scheffer IE, Michelucci R, Bahlo M, Franceschetti S, Sessa WC, Berkovic SF, Lehesjoki AE. Progressive myoclonus epilepsies-Residual unsolved cases have marked genetic heterogeneity including dolichol-dependent protein glycosylation pathway genes. Am J Hum Genet 2021; 108:722-738. [PMID: 33798445 DOI: 10.1016/j.ajhg.2021.03.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 03/05/2021] [Indexed: 02/04/2023] Open
Abstract
Progressive myoclonus epilepsies (PMEs) comprise a group of clinically and genetically heterogeneous rare diseases. Over 70% of PME cases can now be molecularly solved. Known PME genes encode a variety of proteins, many involved in lysosomal and endosomal function. We performed whole-exome sequencing (WES) in 84 (78 unrelated) unsolved PME-affected individuals, with or without additional family members, to discover novel causes. We identified likely disease-causing variants in 24 out of 78 (31%) unrelated individuals, despite previous genetic analyses. The diagnostic yield was significantly higher for individuals studied as trios or families (14/28) versus singletons (10/50) (OR = 3.9, p value = 0.01, Fisher's exact test). The 24 likely solved cases of PME involved 18 genes. First, we found and functionally validated five heterozygous variants in NUS1 and DHDDS and a homozygous variant in ALG10, with no previous disease associations. All three genes are involved in dolichol-dependent protein glycosylation, a pathway not previously implicated in PME. Second, we independently validate SEMA6B as a dominant PME gene in two unrelated individuals. Third, in five families, we identified variants in established PME genes; three with intronic or copy-number changes (CLN6, GBA, NEU1) and two very rare causes (ASAH1, CERS1). Fourth, we found a group of genes usually associated with developmental and epileptic encephalopathies, but here, remarkably, presenting as PME, with or without prior developmental delay. Our systematic analysis of these cases suggests that the small residuum of unsolved cases will most likely be a collection of very rare, genetically heterogeneous etiologies.
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Affiliation(s)
- Carolina Courage
- Folkhälsan Research Center, Helsinki 00290, Finland; Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki 00290, Finland
| | - Karen L Oliver
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg 3084, Victoria, Australia; Population Health and Immunity Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3010, Australia
| | - Eon Joo Park
- Department of Pharmacology and Vascular Biology and Therapeutics Program, Yale University School of Medicine, 10 Amistad Street, New Haven, CT 06520, USA
| | - Jillian M Cameron
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg 3084, Victoria, Australia
| | - Kariona A Grabińska
- Department of Pharmacology and Vascular Biology and Therapeutics Program, Yale University School of Medicine, 10 Amistad Street, New Haven, CT 06520, USA
| | - Mikko Muona
- Folkhälsan Research Center, Helsinki 00290, Finland; Blueprint Genetics, Espoo 02150, Finland
| | - Laura Canafoglia
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | | | - Edith Said
- Section of Medical Genetics, Mater dei Hospital, Msida MSD2090, Malta; Department of Anatomy and Cell Biology, University of Malta, Msida MSD2090, Malta
| | - Zaid Afawi
- Center for Neuroscience, Ben-Gurion University of the Negev, Be'er Sheva 8410402, Israel
| | - Betul Baykan
- Departments of Neurology and Clinical Neurophysiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul 34452, Turkey
| | | | - Carlo di Bonaventura
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy
| | - Hui Bein Chew
- Genetics Department, Kuala Lumpur Hospital, Ministry of Health Malaysia, Jalan Pahang, 50586 Kuala Lumpur, Malaysia
| | - Chiara Criscuolo
- Department of Neuroscience, Reproductive, and Odontostomatological Sciences, University of Naples Federico II, Naples 80138, Italy
| | - Leanne M Dibbens
- Epilepsy Research Group, Australian Centre for Precision Health, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Istituto Neurologico Carlo Besta Milan 20133, Italy
| | - Patrizia Riguzzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Unit of Neurology, Bellaria Hospital, Bologna 40139, Italy
| | - Angelo Labate
- Institute of Neurology, University Magna Græcia, Catanzaro 88100, Italy
| | - Alessandro Filla
- Department of Neuroscience, Reproductive, and Odontostomatological Sciences, University of Naples Federico II, Naples 80138, Italy
| | - Anna T Giallonardo
- Neurology Unit, Human Neurosciences Department, Sapienza University, Rome 00185, Italy
| | - Geza Berecki
- Ion Channels and Disease Group, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3052, Australia
| | - Christopher B Jackson
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | | | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg 3084, Victoria, Australia
| | - Sara Kivity
- Epilepsy Unit, Schneider Children's Medical Center of Israel, Petah Tiqvah 4922297, Israel
| | - Amos Korczyn
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 60198, Israel
| | - Aarno Palotie
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki 00290, Finland; Analytic and Translational Genetics Unit, Department of Medicine, Department of Neurology and Department of Psychiatry Massachusetts General Hospital, Boston, MA 02114, USA; The Stanley Center for Psychiatric Research and Program in Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, Boston, MA 02142, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "G. Gaslini," Genova 16147, Italy
| | - Davide Uccellini
- Neurology - Neurophysiology Unit, ASST dei Sette Laghi, Galmarini Tradate Hospital, Tradate 21049, Italy
| | - Loretta Giuliano
- Dipartimento "G.F. Ingrassia," Università degli Studi di Catania, Catania 95131, Italy
| | - Eva Andermann
- Neurogenetics Unit and Epilepsy Research Group, Montreal Neurological Hospital and Institute, Montreal, QC H3A 2B4, Canada; Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, QC H3A 0G4, Canada
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg 3084, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia; Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia; The Florey Institute, Parkville, VIC 3052, Australia
| | - Roberto Michelucci
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Unit of Neurology, Bellaria Hospital, Bologna 40139, Italy
| | - Melanie Bahlo
- Population Health and Immunity Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia; Department of Medical Biology, the University of Melbourne, Melbourne, VIC 3010, Australia
| | - Silvana Franceschetti
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | - William C Sessa
- Department of Pharmacology and Vascular Biology and Therapeutics Program, Yale University School of Medicine, 10 Amistad Street, New Haven, CT 06520, USA
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg 3084, Victoria, Australia.
| | - Anna-Elina Lehesjoki
- Folkhälsan Research Center, Helsinki 00290, Finland; Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki 00290, Finland.
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Franceschetti S, Visani E, Rossi Sebastiano D, Duran D, Granata T, Solazzi R, Varotto G, Canafoglia L, Panzica F. Cortico-muscular and cortico-cortical coherence changes resulting from Perampanel treatment in patients with cortical myoclonus. Clin Neurophysiol 2021; 132:1057-1063. [PMID: 33756404 DOI: 10.1016/j.clinph.2021.01.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 01/14/2021] [Accepted: 01/30/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies. METHODS The subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.7 of the maximum (set to 1) were grouped as central (C) regions of interest (ROI), while adjacent sensors showing CMC values >0.3 were grouped as Surrounding (Sr) ROIs. RESULTS Under PER treatment, CMC decreased on Co C and Sr ROIs, but also on homologous ipsilateral (Ip) ROIs; out-degrees and betweenness centrality increased in Co ROIs and decreased in Ip ROIs. The flow from Ip to Co ROIs and from activated muscles to Ip C ROI decreased. CONCLUSION The improvement of myoclonus corresponded to decreased CMC and recovered leadership of the cortical regions directly involved in the motor task, with a reduced interference of ipsilateral areas. SIGNIFICANCE Our study highlights on mechanisms suitable to treating myoclonus and suggests the role of a reduced local synchronization together a better control of distant synaptic effects.
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Affiliation(s)
- S Franceschetti
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - E Visani
- Department of Epileptology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - D Rossi Sebastiano
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - D Duran
- Department of Epileptology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - T Granata
- Department of Epileptology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - R Solazzi
- Department of Epileptology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - G Varotto
- Unit of Clinical and Biomedical Engineering, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - L Canafoglia
- Department of Epileptology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
| | - F Panzica
- Unit of Clinical and Biomedical Engineering, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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29
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Baumgartner T, Carreño M, Rocamora R, Bisulli F, Boni A, Brázdil M, Horak O, Craiu D, Pereira C, Guerrini R, San Antonio‐Arce V, Schulze‐Bonhage A, Zuberi SM, Hallböök T, Kalviainen R, Lagae L, Nguyen S, Quintas S, Franco A, Cross JH, Walker M, Arzimanoglou A, Rheims S, Granata T, Canafoglia L, Johannessen Landmark C, Sen A, Rattihalli R, Nabbout R, Tartara E, Santos M, Rangel R, Krsek P, Marusic P, Specchio N, Braun KPJ, Smeyers P, Villanueva V, Kotulska K, Surges R. A survey of the European Reference Network EpiCARE on clinical practice for selected rare epilepsies. Epilepsia Open 2021; 6:160-170. [PMID: 33681659 PMCID: PMC7918306 DOI: 10.1002/epi4.12459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/26/2020] [Accepted: 12/09/2020] [Indexed: 11/11/2022] Open
Abstract
Objective Clinical care of rare and complex epilepsies is challenging, because evidence-based treatment guidelines are scarce, the experience of many physicians is limited, and interdisciplinary treatment of comorbidities is required. The pathomechanisms of rare epilepsies are, however, increasingly understood, which potentially fosters novel targeted therapies. The objectives of our survey were to obtain an overview of the clinical practice in European tertiary epilepsy centers treating patients with 5 arbitrarily selected rare epilepsies and to get an estimate of potentially available patients for future studies. Methods Members of the European Reference Network for rare and complex epilepsies (EpiCARE) were invited to participate in a web-based survey on clinical practice of patients with Dravet syndrome, tuberous sclerosis complex (TSC), autoimmune encephalitis, and progressive myoclonic epilepsies including Unverricht Lundborg and Unverricht-like diseases. A consensus-based questionnaire was generated for each disease. Results Twenty-six of 30 invited epilepsy centers participated. Cohorts were present in most responding centers for TSC (87%), Dravet syndrome (85%), and autoimmune encephalitis (71%). Patients with TSC and Dravet syndrome represented the largest cohorts in these centers. The antiseizure drug treatments were rather consistent across the centers especially with regard to Dravet syndrome, infantile spasms in TSC, and Unverricht Lundborg / Unverricht-like disease. Available, widely used targeted therapies included everolimus in TSC and immunosuppressive therapies in autoimmune encephalitis. Screening for comorbidities was routinely done, but specific treatment protocols were lacking in most centers. Significance The survey summarizes the current clinical practice for selected rare epilepsies in tertiary European epilepsy centers and demonstrates consistency as well as heterogeneity in the treatment, underscoring the need for controlled trials and recommendations. The survey also provides estimates for potential participants of clinical trials recruited via EpiCARE, emphasizing the great potential of Reference Networks for future studies to evaluate new targeted therapies and to identify novel biomarkers.
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Affiliation(s)
| | - Mar Carreño
- Epilepsy UnitChild Neurology DepartmentHospital San Juan de DiosBarcelonaSpain
- Hospital Clinic de BarcelonaBarcelonaSpain
| | - Rodrigo Rocamora
- Epilepsy CentreFaculty of Health and Life SciencesHospital del Mar‐IMIMUniversitat Pompeu FabraBarcelonaSpain
| | | | - Antonella Boni
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
| | - Milan Brázdil
- Brno Epilepsy CenterDepartment of NeurologySt. Anne´s University HospitalMedical Faculty of Masaryk UniversityBrnoCzech Republic
| | - Ondrej Horak
- Brno Epilepsy CenterDepartment of Child NeurologyBrno University HospitalMedical Faculty of Masaryk UniversityBrnoCzech Republic
| | - Dana Craiu
- Alexandru Obregia Clinical HospitalBucharestRomania
| | | | - Renzo Guerrini
- Children's Hospital A. Meyer‐University of FlorenceFlorenceItaly
| | - Victoria San Antonio‐Arce
- Epilepsy UnitChild Neurology DepartmentHospital San Juan de DiosBarcelonaSpain
- Epilepsy CenterFaculty of MedicineUniversity Medical CenterFreiburgGermany
| | | | | | - Tove Hallböök
- Department of PediatricsInstitute of Clinical SciencesSahlgrenska AcademyUniversity of Gothenburg and Queen Silvia Children’s HospitalSahlgrenska University HospitalGothenburgSweden
| | - Reetta Kalviainen
- Pohjois‐Savon SairaanhoitopiiriKuopio University Hospital, (KUH)KuopioFinland
| | - Lieven Lagae
- University Hospital Gasthuisberg KULeuvenBelgium
| | | | - Sofia Quintas
- Centro Hospitalar Universitário Lisboa Norte ‐ Hospital de Santa MariaLisboaPortugal
| | - Ana Franco
- Centro Hospitalar Universitário Lisboa Norte ‐ Hospital de Santa MariaLisboaPortugal
| | - J. Helen Cross
- Great Ormond Street Hospital for ChildrenNHS TrustLondonUK
| | - Matthew Walker
- University College London Hospitals NHS Foundation TrustLondonUK
| | - Alexis Arzimanoglou
- Epilepsy UnitChild Neurology DepartmentHospital San Juan de DiosBarcelonaSpain
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional NeurologyUniversity Hospitals of Lyon (HCL)LyonFrance
| | - Sylvain Rheims
- Department of Functional Neurology and EpileptologyHospices Civils de LyonUniversity of LyonLyonFrance
| | - Tiziana Granata
- Department of PediatricNeuroscience FondazioneIRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Laura Canafoglia
- Epilepsy UnitFondazione IRCCS Istituto Neurologico Carlo BestaMilanItaly
| | - Cecilie Johannessen Landmark
- Department of PharmacologyOslo University HospitalThe National Center for EpilepsyOslo Metropolitan UniversityOsloNorway
| | - Arjune Sen
- Oxford Epilepsy Research GroupNIHR Oxford Biomedical Research CentreNuffield Department of Clinical NeurosciencesJohn Radcliffe HospitalOxfordUK
| | - Rohini Rattihalli
- Department of Paediatric NeurologyChildren's HospitalJohn Radcliffe HospitalOxfordUK
| | - Rima Nabbout
- Department of Pediatric NeurologyAPHP, Imagine InstituteReference Centre for Rare EpilepsiesParis Descartes UniversityParisFrance
| | | | | | - Rui Rangel
- Centro Hospitalar Universitário do PortoPortoPortugal
| | - Pavel Krsek
- Departement of NeurologyCharles UniversitySecond Faculty of Medicine and Motol University HospitalPragueCzech Republic
| | - Petr Marusic
- Departement of NeurologyCharles UniversitySecond Faculty of Medicine and Motol University HospitalPragueCzech Republic
| | - Nicola Specchio
- Rare and Complex Epilepsy UnitDepartment of NeuroscienceBambino Gesu’ Children’s Hospital, IRCCSRomeItaly
| | - Kees P. J. Braun
- Department of Child NeurologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Patricia Smeyers
- Refractory Epilepsy Unit of Hospital Universitario y Politécnico La FeValenciaSpain
| | - Vicente Villanueva
- Refractory Epilepsy Unit of Hospital Universitario y Politécnico La FeValenciaSpain
| | | | - Rainer Surges
- Department of EpileptologyUniversity Hospital BonnBonnGermany
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Montnach J, Lorenzini M, Lesage A, Simon I, Nicolas S, Moreau E, Marionneau C, Baró I, De Waard M, Loussouarn G. Computer modeling of whole-cell voltage-clamp analyses to delineate guidelines for good practice of manual and automated patch-clamp. Sci Rep 2021; 11:3282. [PMID: 33558601 PMCID: PMC7870888 DOI: 10.1038/s41598-021-82077-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 12/21/2020] [Indexed: 01/17/2023] Open
Abstract
The patch-clamp technique and more recently the high throughput patch-clamp technique have contributed to major advances in the characterization of ion channels. However, the whole-cell voltage-clamp technique presents certain limits that need to be considered for robust data generation. One major caveat is that increasing current amplitude profoundly impacts the accuracy of the biophysical analyses of macroscopic ion currents under study. Using mathematical kinetic models of a cardiac voltage-gated sodium channel and a cardiac voltage-gated potassium channel, we demonstrated how large current amplitude and series resistance artefacts induce an undetected alteration in the actual membrane potential and affect the characterization of voltage-dependent activation and inactivation processes. We also computed how dose-response curves are hindered by high current amplitudes. This is of high interest since stable cell lines frequently demonstrating high current amplitudes are used for safety pharmacology using the high throughput patch-clamp technique. It is therefore critical to set experimental limits for current amplitude recordings to prevent inaccuracy in the characterization of channel properties or drug activity, such limits being different from one channel type to another. Based on the predictions generated by the kinetic models, we draw simple guidelines for good practice of whole-cell voltage-clamp recordings.
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Affiliation(s)
- Jérôme Montnach
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Maxime Lorenzini
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Adrien Lesage
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Isabelle Simon
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Sébastien Nicolas
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Eléonore Moreau
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
- Laboratoire Signalisation Fonctionnelle des Canaux Ioniques et des Récepteurs (SiFCIR), UPRES EA 2647, USC INRA 1330, SFR QUASAV 4207, UFR Sciences, Université d'Angers, Angers, France
| | - Céline Marionneau
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Isabelle Baró
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
| | - Michel De Waard
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France
- LabEx "Ion Channels, Science & Therapeutics", 06560, Valbonne, France
| | - Gildas Loussouarn
- Université de Nantes, CNRS, INSERM, l'institut du thorax, F-44000, Nantes, France.
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31
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Abstract
Genetic mutations have long been implicated in epilepsy, particularly in genes that encode ion channels and neurotransmitter receptors. Among some of those identified are voltage-gated sodium, potassium and calcium channels, and ligand-gated gamma-aminobutyric acid (GABA), neuronal nicotinic acetylcholine (CHRN), and glutamate receptors, making them key therapeutic targets. In this chapter we discuss the use of automated electrophysiological technologies to examine the impact of gene defects in two potassium channels associated with different epilepsy syndromes. The hKCNC1 gene encodes the voltage-gated potassium channel hKV3.1, and mutations in this gene cause progressive myoclonus epilepsy (PME) and ataxia due to a potassium channel mutation (MEAK). The hKCNT1 gene encodes the weakly voltage-dependent sodium-activated potassium channel hKCNT1, and mutations in this gene cause a wide spectrum of seizure disorders, including severe autosomal dominant sleep-related hypermotor epilepsy (ADSHE) and epilepsy of infancy with migrating focal seizures (EIMFS), both conditions associated with drug-resistance. Importantly, both of these potassium channels play vital roles in regulating neuronal excitability. Since its discovery in the late nineteen seventies, the patch-clamp technique has been regarded as the bench-mark technology for exploring ion channel characteristics. In more recent times, innovations in automated patch-clamp technologies, of which there are many, are enabling the study of ion channels with much greater productivity that manual systems are capable of. Here we describe aspects of Nanion NPC-16 Patchliner, examining the effects of temperature on stably and transiently transfected mammalian cells, the latter of which for most automated systems on the market is quite challenging. Remarkable breakthroughs in the development of other automated electrophysiological technologies, such as multielectrode arrays that support extracellular signal recordings, provide additional features to examine network activity in the area of ion channel research, particularly epilepsy. Both of these automated technologies enable the acquisition of consistent, robust, and reproducible data. Numerous systems have been developed with very similar capabilities, however, not all the systems on the market are adapted to work with primary cells, particularly neurons that can be problematic. This chapter also showcases methods that demonstrate the versatility of Nanion NPC-16 Patchliner and the Multi Channel Systems (MCS) multielectrode array (MEA) assay for acutely dissociated murine primary cortical neurons, enabling the study of potassium channel mutations implicated in severe refractory epilepsies.
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32
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Rossi M, van der Veen S, Merello M, Tijssen MAJ, van de Warrenburg B. Myoclonus-Ataxia Syndromes: A Diagnostic Approach. Mov Disord Clin Pract 2020; 8:9-24. [PMID: 33426154 DOI: 10.1002/mdc3.13106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/30/2020] [Accepted: 10/14/2020] [Indexed: 12/30/2022] Open
Abstract
Background A myriad of disorders combine myoclonus and ataxia. Most causes are genetic and an increasing number of genes are being associated with myoclonus-ataxia syndromes (MAS), due to recent advances in genetic techniques. A proper etiologic diagnosis of MAS is clinically relevant, given the consequences for genetic counseling, treatment, and prognosis. Objectives To review the causes of MAS and to propose a diagnostic algorithm. Methods A comprehensive and structured literature search following PRISMA criteria was conducted to identify those disorders that may combine myoclonus with ataxia. Results A total of 135 causes of combined myoclonus and ataxia were identified, of which 30 were charted as the main causes of MAS. These include four acquired entities: opsoclonus-myoclonus-ataxia syndrome, celiac disease, multiple system atrophy, and sporadic prion diseases. The distinction between progressive myoclonus epilepsy and progressive myoclonus ataxia poses one of the main diagnostic dilemmas. Conclusions Diagnostic algorithms for pediatric and adult patients, based on clinical manifestations including epilepsy, are proposed to guide the differential diagnosis and corresponding work-up of the most important and frequent causes of MAS. A list of genes associated with MAS to guide genetic testing strategies is provided. Priority should be given to diagnose or exclude acquired or treatable disorders.
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Affiliation(s)
- Malco Rossi
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina
| | - Sterre van der Veen
- Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina.,Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands
| | - Marcelo Merello
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina.,Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina
| | - Marina A J Tijssen
- Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands.,Expertise Center Movement Disorders Groningen University Medical Center Groningen (UMCG) Groningen The Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition & Behaviour Radboud University Medical Center Nijmegen The Netherlands
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Zhang J, Yang Y, Niu X, Chen J, Sun W, Ding C, Dai L, Zhang L, Zeng Q, Chen Y, Tian X, Yang X, Ji T, Yang Z, Yang Y, Jiang Y, Zhang Y. Clinical phenotype features and genetic etiologies of 38 children with progressive myoclonic epilepsy. ACTA EPILEPTOLOGICA 2020. [DOI: 10.1186/s42494-020-00023-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Abstract
Background
Progressive myoclonic epilepsy (PME) is a group of neurodegenerative diseases with genetic heterogeneity and phenotypic similarities, and many cases remain unknown of the genetic causes. This study is aim to summarize the clinical features and study the genetic causes of PME patients.
Methods
Sanger sequencing of the target gene, Next Generation Sequencing (NGS) panels of epilepsy, trio-based Whole Exome Sequencing (WES) and detection of cytosine-adenine-guanine (CAG) repeat number were used to investigate the genetic causes of PME patients.
Results
Thirty-eight children with PME whose seizure onset age ranged from 3 months to 12 years were collected from February 2012 to November 2019 in three hospitals in Beijing, China. The seizure types included myoclonic seizures (n = 38), focal seizures (n = 19), generalized tonic-clonie seizure (GTCS) (n = 13), absence seizures (n = 4), atonic seizures (n = 3), epileptic spasms (n = 2) and tonic seizures (n = 1). Twenty-seven cases were sporadic and 11 had family members affected. Established PME-related genes were identified in 30 out of 38 (78.9%) patients who had either recessively inherited or de novo heterozygous mutations. Among these 30 cases, there were 12 cases (31.6%) of neuronal ceroid lipofuscinoses (the causing gene contains TPP1, PPT1, CLN5, CLN6 and MFSD8), two cases of sialidosis (the causing gene is NEU1), two cases of neuronopathic Gaucher disease (the causing gene is GBA), one case of spinal muscular atrophy-progressive myoclonic epilepsy (the causing gene is ASAH1), four cases of KCNC1 mutation-related PME, four cases of KCTD7 mutation-related PME, two cases of TBC1D24 mutation-related PME, one case of GOSR2 related PME, and two of dentatorubral-pallidoluysian atrophy (the causing gene is ATN1). In total, 13 PME genes were identified in our cohort. The etiology was not clear in eight patients.
Conclusion
PME is a group of clinically and genetically heterogeneous diseases. Genetic diagnosis was clear in 78.9% of PME patients. Various of genetic testing methods could increase the rate of genetic diagnosis. Neuronal ceroid lipofuscinoses (NCL) is the most common etiology of PME in children. Nearly one third PME children were diagnosed with NCL. GOSR2 related PME was in our cohort in Asia for the first time.
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Deep Transcriptomic Analysis Reveals the Dynamic Developmental Progression during Early Development of Channel Catfish ( Ictalurus punctatus). Int J Mol Sci 2020; 21:ijms21155535. [PMID: 32748829 PMCID: PMC7432863 DOI: 10.3390/ijms21155535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/21/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
The transition from fertilized egg to larva in fish is accompanied with various biological processes. We selected seven early developmental stages in channel catfish, Ictalurus punctatus, for transcriptome analysis, and covered 22,635 genes with 590 million high-quality RNA-sequencing (seq) reads. Differential expression analysis between neighboring developmental timepoints revealed significantly enriched biological categories associated with growth, development and morphogenesis, which was most evident at 2 vs. 5 days post fertilization (dpf) and 5 vs. 6 dpf. A gene co-expression network was constructed using the Weighted Gene Co-expression Network Analysis (WGCNA) approach and four critical modules were identified. Among candidate hub genes, GDF10, FOXA2, HCEA and SYCE3 were involved in head formation, egg development and the transverse central element of synaptonemal complexes. CK1, OAZ2, DARS1 and UBE2V2 were mainly associated with regulation of cell cycle, growth, brain development, differentiation and proliferation of enterocytes. IFI44L and ZIP10 were critical for the regulation of immune activity and ion transport. Additionally, TCK1 and TGFB1 were related to phosphate transport and regulating cell proliferation. All these genes play vital roles in embryogenesis and regulation of early development. These results serve as a rich dataset for functional genomic studies. Our work reveals new insights of the underlying mechanisms in channel catfish early development.
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35
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Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA. The expanding spectrum of movement disorders in genetic epilepsies. Dev Med Child Neurol 2020; 62:178-191. [PMID: 31784983 DOI: 10.1111/dmcn.14407] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 12/27/2022]
Abstract
An ever-increasing number of neurogenetic conditions presenting with both epilepsy and atypical movements are now recognized. These disorders within the 'genetic epilepsy-dyskinesia' spectrum are clinically and genetically heterogeneous. Increased clinical awareness is therefore necessary for a rational diagnostic approach. Furthermore, careful interpretation of genetic results is key to establishing the correct diagnosis and initiating disease-specific management strategies in a timely fashion. In this review we describe the spectrum of movement disorders associated with genetically determined epilepsies. We also propose diagnostic strategies and putative pathogenic mechanisms causing these complex syndromes associated with both seizures and atypical motor control. WHAT THIS PAPER ADDS: Implicated genes encode proteins with very diverse functions. Pathophysiological mechanisms by which epilepsy and movement disorder phenotypes manifest are often not clear. Early diagnosis of treatable disorders is essential and next generation sequencing may be required.
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Affiliation(s)
- Apostolos Papandreou
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Federica Rachele Danti
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Robert Spaull
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
- Bristol Medical School, University of Bristol, Bristol, UK
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
| | - Amy Mctague
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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36
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Allen NM, Weckhuysen S, Gorman K, King MD, Lerche H. Genetic potassium channel-associated epilepsies: Clinical review of the K v family. Eur J Paediatr Neurol 2020; 24:105-116. [PMID: 31932120 DOI: 10.1016/j.ejpn.2019.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/22/2022]
Abstract
Next-generation sequencing has enhanced discovery of many disease-associated genes in previously unexplained epilepsies, mainly in developmental and epileptic encephalopathies and familial epilepsies. We now classify these disorders according to the underlying molecular pathways, which encompass a diverse array of cellular and sub-cellular compartments/signalling processes including voltage-gated ion-channel defects. With the aim to develop and increase the use of precision medicine therapies, understanding the pathogenic mechanisms and consequences of disease-causing variants has gained major relevance in clinical care. The super-family of voltage-gated potassium channels is the largest and most diverse family among the ion channels, encompassing approximately 80 genes. Key potassium channelopathies include those affecting the KV, KCa and Kir families, a significant proportion of which have been implicated in neurological disease. As for other ion channel disorders, different pathogenic variants within any individual voltage-gated potassium channel gene tend to affect channel protein function differently, causing heterogeneous clinical phenotypes. The focus of this review is to summarise recent clinical developments regarding the key voltage-gated potassium (KV) family-related epilepsies, which now encompasses approximately 12 established disease-associated genes, from the KCNA-, KCNB-, KCNC-, KCND-, KCNV-, KCNQ- and KCNH-subfamilies.
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Affiliation(s)
- Nicholas M Allen
- Department of Paediatrics, National University of Ireland, Galway, Ireland; Department of Paediatrics (Neurology), Galway University Hospital, Ireland; Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
| | - Sarah Weckhuysen
- Neurogenetics Group, Center for Molecular Neurology, VIB-University of Antwerp, Antwerp, Belgium; Department of Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Kathleen Gorman
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tubingen, Germany
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37
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Lambrechts RA, Polet SS, Hernandez-Pichardo A, van Ninhuys L, Gorter JA, Grzeschik NA, de Koning-Tijssen MAJ, de Koning TJ, Sibon OCM. North Sea Progressive Myoclonus Epilepsy is Exacerbated by Heat, A Phenotype Primarily Associated with Affected Glia. Neuroscience 2019; 423:1-11. [PMID: 31682953 DOI: 10.1016/j.neuroscience.2019.10.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 01/05/2023]
Abstract
Progressive myoclonic epilepsies (PMEs) comprise a group of rare disorders of different genetic aetiologies, leading to childhood-onset myoclonus, myoclonic seizures and subsequent neurological decline. One of the genetic causes for PME, a mutation in the gene coding for Golgi SNAP receptor 2 (GOSR2), gives rise to a PME-subtype prevalent in Northern Europe and hence referred to as North Sea Progressive Myoclonic Epilepsy (NS-PME). Treatment for NS-PME, as for all PME subtypes, is symptomatic; the pathophysiology of NS-PME is currently unknown, precluding targeted therapy. Here, we investigated the pathophysiology of NS-PME. By means of chart review in combination with interviews with patients (n = 14), we found heat to be an exacerbating factor for a majority of NS-PME patients (86%). To substantiate these findings, we designed a NS-PME Drosophila melanogaster model. Downregulation of the Drosophila GOSR2-orthologue Membrin leads to heat-induced seizure-like behaviour. Specific downregulation of GOSR2/Membrin in glia but not in neuronal cells resulted in a similar phenotype, which was progressive as the flies aged and was partially responsive to treatment with sodium barbital. Our data suggest a role for GOSR2 in glia in the pathophysiology of NS-PME.
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Affiliation(s)
- Roald A Lambrechts
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Sjoukje S Polet
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Alejandra Hernandez-Pichardo
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Lisa van Ninhuys
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Jenke A Gorter
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Nicola A Grzeschik
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Marina A J de Koning-Tijssen
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Tom J de Koning
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Department of Medical Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Ody C M Sibon
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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38
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Jędrychowska J, Korzh V. Kv2.1 voltage-gated potassium channels in developmental perspective. Dev Dyn 2019; 248:1180-1194. [PMID: 31512327 DOI: 10.1002/dvdy.114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/01/2019] [Accepted: 09/03/2019] [Indexed: 11/11/2022] Open
Abstract
Kv2.1 voltage-gated potassium channels consist of two types of α-subunits: (a) electrically-active Kcnb1 α-subunits and (b) silent or modulatory α-subunits plus β-subunits that, similar to silent α-subunits, also regulate electrically-active subunits. Voltage-gated potassium channels were traditionally viewed, mainly by electrophysiologists, as regulators of the electrical activity of the plasma membrane in excitable cells, a role that is performed by transmembrane protein domains of α-subunits that form the electric pore. Genetic studies revealed a role for this region of α-subunits of voltage-gated potassium channels in human neurodevelopmental disorders, such as epileptic encephalopathy. The N- and C-terminal domains of α-subunits interact to form the cytoplasmic subunit of heterotetrameric potassium channels that regulate electric pores. Subsequent animal studies revealed the developmental functions of Kcnb1-containing voltage-gated potassium channels and illustrated their role during brain development and reproduction. These functions of potassium channels are discussed in this review in the context of regulatory interactions between electrically-active and regulatory subunits.
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Affiliation(s)
- Justyna Jędrychowska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw, Poland
| | - Vladimir Korzh
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
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39
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Ranjan R, Logette E, Marani M, Herzog M, Tâche V, Scantamburlo E, Buchillier V, Markram H. A Kinetic Map of the Homomeric Voltage-Gated Potassium Channel (Kv) Family. Front Cell Neurosci 2019; 13:358. [PMID: 31481875 PMCID: PMC6710402 DOI: 10.3389/fncel.2019.00358] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 07/19/2019] [Indexed: 11/13/2022] Open
Abstract
The voltage-gated potassium (Kv) channels, encoded by 40 genes, repolarize all electrically excitable cells, including plant, cardiac, and neuronal cells. Although these genes were fully sequenced decades ago, a comprehensive kinetic characterization of all Kv channels is still missing, especially near physiological temperature. Here, we present a standardized kinetic map of the 40 homomeric Kv channels systematically characterized at 15, 25, and 35°C. Importantly, the Kv kinetics at 35°C differ significantly from commonly reported kinetics, usually performed at room temperature. We observed voltage-dependent Q10 for all active Kv channels and inherent heterogeneity in kinetics for some of them. Kinetic properties are consistent across different host cell lines and conserved across mouse, rat, and human. All electrophysiology data from all Kv channels are made available through a public website (Channelpedia). This dataset provides a solid foundation for exploring kinetics of heteromeric channels, roles of auxiliary subunits, kinetic modulation, and for building accurate Kv models.
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Affiliation(s)
- Rajnish Ranjan
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Emmanuelle Logette
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Michela Marani
- Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mirjia Herzog
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Valérie Tâche
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Enrico Scantamburlo
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Valérie Buchillier
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Henry Markram
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Laboratory of Neural Microcircuitry, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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40
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Canafoglia L, Barbella G, Ferlazzo E, Striano P, Magaudda A, d'Orsi G, Martino T, Avolio C, Aguglia U, Sueri C, Giuliano L, Sofia V, Zibordi F, Ragona F, Freri E, Costa C, Nardi Cesarini E, Fanella M, Rossi Sebastiano D, Riguzzi P, Gambardella A, Di Bonaventura C, Michelucci R, Granata T, Bisulli F, Licchetta L, Tinuper P, Beccaria F, Visani E, Franceschetti S. An Italian multicentre study of perampanel in progressive myoclonus epilepsies. Epilepsy Res 2019; 156:106191. [PMID: 31446282 DOI: 10.1016/j.eplepsyres.2019.106191] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 07/23/2019] [Accepted: 08/15/2019] [Indexed: 01/24/2023]
Abstract
Perampanel (PER) is a novel anti-seizure medication useful in different types of epilepsy. We intended to assess the effectiveness of PER on cortical myoclonus and seizure frequency in patients with progressive myoclonus epilepsy (PME), using quantitative validated scales. Forty-nine patients aged 36.6 ± 15.6 years with PME of various aetiology (18 EPM1, 12 EPM2, five with sialidosis, one with Kufs disease, one with EPM7, and 12 undetermined) were enrolled between January 2017 and June 2018. PER at the dose of 2-12 mg (5.3 ± 2.5) was added to existing therapy. Myoclonus severity was assessed using a minimal myoclonus scale (MMS) in all the patients before and after 4-6 months of steady PER dose, and by means of the Unified Myoclonus Rating Scale (UMRS) in 20 patients. Logistic regression analysis was used to identify the factors potentially predicting treatment efficacy. Four patients dropped out in the first two months due to psychiatric side effects. In the remaining patients, PER reduced myoclonus severity as assessed using MMS (Wilcoxon test: p < 0.001) and UMRS (p < 0.001), with the 'Action myoclonus' section of the UMRS showing the greatest improvement. The patients with EPM1 or EPM1-like phenotype were more likely to improve with PER (p = 0.011). Convulsive seizures which have recurred at least monthly in 17 patients were reduced by >50%. Side effects occurred in 22/49 (44.8%) patients, the most common being irritability followed by drowsiness. PER is effective in treating myoclonus and seizures in PME patients. The frequency of psychiatric side effects suggests the need for careful patient monitoring.
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Affiliation(s)
- Laura Canafoglia
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Giuseppina Barbella
- Neurology Unit, San Gerardo Hospital, Monza, Italy; School of Medicine and Surgery and Milan-Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy
| | - Edoardo Ferlazzo
- Magna Greacia University of Catanzaro, Catanzaro, Italy; Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli" of Reggio Calabria, Reggio Calabria, Italy
| | - Pasquale Striano
- Neurologia Pediatrica e Malattie Muscolari, IRCCS Istituto G. Gaslini, Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), Università di Genova, Genova, Italy
| | - Adriana Magaudda
- Dipartimento di Neuroscienze e Centro Epilessia, G. Martino Policlinico AOU, Università di Messina, Messina, Italy
| | - Giuseppe d'Orsi
- Epilepsy Centre - Clinic of Nervous System Diseases, Riuniti Hospital, Foggia, Italy
| | - Tommaso Martino
- Epilepsy Centre - Clinic of Nervous System Diseases, Riuniti Hospital, Foggia, Italy
| | - Carlo Avolio
- Epilepsy Centre - Clinic of Nervous System Diseases, Riuniti Hospital, Foggia, Italy
| | - Umberto Aguglia
- Magna Greacia University of Catanzaro, Catanzaro, Italy; Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli" of Reggio Calabria, Reggio Calabria, Italy
| | - Chiara Sueri
- Magna Greacia University of Catanzaro, Catanzaro, Italy; Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli" of Reggio Calabria, Reggio Calabria, Italy
| | - Loretta Giuliano
- Dipartimento "G.F. Ingrassia", Università degli Studi di Catania, Catania, Italy
| | - Vito Sofia
- Dipartimento "G.F. Ingrassia", Università degli Studi di Catania, Catania, Italy
| | - Federica Zibordi
- Pediatric Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Pediatric Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Freri
- Pediatric Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Cinzia Costa
- Università degli Studi di Perugia, Clinica Neurologica, Ospedale S.M. della Misericordia, Italy
| | - Elena Nardi Cesarini
- Università degli Studi di Perugia, Clinica Neurologica, Ospedale S.M. della Misericordia, Italy
| | - Martina Fanella
- Epilepsy Unit, Department of Neurosciences/Mental Health, "Sapienza" University, Rome, Italy
| | | | - Patrizia Riguzzi
- Unità di Neurologia, Bologna IRCCS Istituto di Scienze Neurologiche, Ospedale Bellaria, Bologna, Italy
| | - Antonio Gambardella
- Dipartimento di Scienze Mediche e Chirurgiche, Università della Magna Graecia, Catanzaro, Istituto di Scienze Neurologiche CNR Mangone, Cosenza, Italy
| | - Carlo Di Bonaventura
- Epilepsy Unit, Department of Neurosciences/Mental Health, "Sapienza" University, Rome, Italy
| | - Roberto Michelucci
- Unità di Neurologia, Bologna IRCCS Istituto di Scienze Neurologiche, Ospedale Bellaria, Bologna, Italy
| | - Tiziana Granata
- Pediatric Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Bisulli
- Unità di Neurologia, Bologna IRCCS Istituto di Scienze Neurologiche, Ospedale Bellaria, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Italy
| | - Laura Licchetta
- Unità di Neurologia, Bologna IRCCS Istituto di Scienze Neurologiche, Ospedale Bellaria, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Italy
| | - Paolo Tinuper
- Unità di Neurologia, Bologna IRCCS Istituto di Scienze Neurologiche, Ospedale Bellaria, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Italy
| | - Francesca Beccaria
- Epilepsy Center, Department of Child Neuropsychiatry, ASST Mantova, Mantua, Italy
| | - Elisa Visani
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvana Franceschetti
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
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41
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Cameron JM, Maljevic S, Nair U, Aung YH, Cogné B, Bézieau S, Blair E, Isidor B, Zweier C, Reis A, Koenig MK, Maarup T, Sarco D, Afenjar A, Huq AHMM, Kukolich M, Billette de Villemeur T, Nava C, Héron B, Petrou S, Berkovic SF. Encephalopathies with KCNC1 variants: genotype-phenotype-functional correlations. Ann Clin Transl Neurol 2019; 6:1263-1272. [PMID: 31353855 PMCID: PMC6649578 DOI: 10.1002/acn3.50822] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 06/04/2019] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE To analyze clinical phenotypes associated with KCNC1 variants other than the Progressive Myoclonus Epilepsy-causing variant p.Arg320His, determine the electrophysiological functional impact of identified variants and explore genotype-phenotype-physiological correlations. METHODS Ten cases with putative pathogenic variants in KCNC1 were studied. Variants had been identified via whole-exome sequencing or gene panel testing. Clinical phenotypic data were analyzed. To determine functional impact of variants detected in the Kv 3.1 channel encoded by KCNC1, Xenopus laevis oocyte expression system and automated two-electrode voltage clamping were used. RESULTS Six unrelated patients had a Developmental and Epileptic Encephalopathy and a recurrent de novo variant p.Ala421Val (c.1262C > T). Functional analysis of p.Ala421Val revealed loss of function through a significant reduction in whole-cell current, but no dominant-negative effect. Three patients had a contrasting phenotype of Developmental Encephalopathy without seizures and different KCNC1 variants, all of which caused loss of function with reduced whole-cell currents. Evaluation of the variant p.Ala513Val (c.1538C > T) in the tenth case, suggested it was a variant of uncertain significance. INTERPRETATION These are the first reported cases of Developmental and Epileptic Encephalopathy due to KCNC1 mutation. The spectrum of phenotypes associated with KCNC1 is now broadened to include not only a Progressive Myoclonus Epilepsy, but an infantile onset Developmental and Epileptic Encephalopathy, as well as Developmental Encephalopathy without seizures. Loss of function is a key feature, but definitive electrophysiological separation of these phenotypes has not yet emerged.
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Affiliation(s)
- Jillian M. Cameron
- Epilepsy Research Centre, Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergMelbourneAustralia
| | - Snezana Maljevic
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneAustralia
| | - Umesh Nair
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneAustralia
| | - Ye Htet Aung
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneAustralia
| | - Benjamin Cogné
- L'institut du thoraxINSERM, CNRS, UNIV NantesNantesFrance
- Service de génétique medicaleCentre Hospitalier, Université de NantesNantesFrance
| | - Stéphane Bézieau
- L'institut du thoraxINSERM, CNRS, UNIV NantesNantesFrance
- Service de génétique medicaleCentre Hospitalier, Université de NantesNantesFrance
| | - Edward Blair
- Oxford Centre for Genomic Medicine, ACE BuildingNuffield Orthopaedic CentreWindmill RoadOxfordUnited Kingdom
| | - Bertrand Isidor
- L'institut du thoraxINSERM, CNRS, UNIV NantesNantesFrance
- Service de génétique medicaleCentre Hospitalier, Université de NantesNantesFrance
| | - Christiane Zweier
- Institute of Human GeneticsFriedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU)ErlangenGermany
| | - André Reis
- Institute of Human GeneticsFriedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU)ErlangenGermany
| | - Mary Kay Koenig
- Department of Paediatrics, Division of Child & Adolescent NeurologyThe University of Texas McGovern Medical SchoolHoustonTexas
| | - Timothy Maarup
- Southern California Permanente Medical GroupPasadenaCalifornia
| | - Dean Sarco
- Southern California Permanente Medical GroupPasadenaCalifornia
| | - Alexandra Afenjar
- Centre de référence des malformations et maladies congénitales du cervelet, Département de génétique médicaleSorbonne Université, GRC ConCer‐LD, AP‐HP, Hôpital Armand TrousseauF‐75012ParisFrance
| | | | - Mary Kukolich
- Genetics DepartmentCook Children’s Health Care SystemFort WorthTexas
| | | | - Caroline Nava
- Département de GénétiqueSorbonne Universités, Institut du Cerveau et de la Moelle épinière, ICM, Inserm U1127, CNRS UMR 7225, AP‐HP, Hôpital de la Pitié SalpêtrièreF‐75013ParisFrance
| | - Bénédicte Héron
- Sorbonne Université, GRC N°19, Service de Neuropediatrie, Hôpital Trousseau La Roche Guyon (APHP)La Roche GuyonFrance
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneAustralia
| | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of MedicineUniversity of Melbourne, Austin HealthHeidelbergMelbourneAustralia
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42
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Park J, Koko M, Hedrich UBS, Hermann A, Cremer K, Haberlandt E, Grimmel M, Alhaddad B, Beck‐Woedl S, Harrer M, Karall D, Kingelhoefer L, Tzschach A, Matthies LC, Strom TM, Ringelstein EB, Sturm M, Engels H, Wolff M, Lerche H, Haack TB. KCNC1-related disorders: new de novo variants expand the phenotypic spectrum. Ann Clin Transl Neurol 2019; 6:1319-1326. [PMID: 31353862 PMCID: PMC6649617 DOI: 10.1002/acn3.50799] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 05/11/2019] [Indexed: 12/30/2022] Open
Abstract
A recurrent de novo missense variant in KCNC1, encoding a voltage-gated potassium channel expressed in inhibitory neurons, causes progressive myoclonus epilepsy and ataxia, and a nonsense variant is associated with intellectual disability. We identified three new de novo missense variants in KCNC1 in five unrelated individuals causing different phenotypes featuring either isolated nonprogressive myoclonus (p.Cys208Tyr), intellectual disability (p.Thr399Met), or epilepsy with myoclonic, absence and generalized tonic-clonic seizures, ataxia, and developmental delay (p.Ala421Val, three patients). Functional analyses demonstrated no measurable currents for all identified variants and dominant-negative effects for p.Thr399Met and p.Ala421Val predicting neuronal disinhibition as the underlying disease mechanism.
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Affiliation(s)
- Joohyun Park
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Mahmoud Koko
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Ulrike B. S. Hedrich
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht‐Kossel”, Department of Neurology and Center for Transdisciplinary Neurosciences Rostock (CTNR)University Medical Center Rostock, University of Rostock18147RostockGermany
- German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald18147RostockGermany
| | - Kirsten Cremer
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Edda Haberlandt
- Clinic for PediatricsKrankenhaus Stadt DornbirnDornbirnAustria
| | - Mona Grimmel
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Bader Alhaddad
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Stefanie Beck‐Woedl
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Merle Harrer
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Daniela Karall
- Clinic for Pediatrics, Division of Inherited Metabolic DisordersMedical University of InnsbruckInnsbruckAustria
| | - Lisa Kingelhoefer
- Department of NeurologyTechnische Universität Dresden and German Center for Neurodegenerative Diseases, Research Side DresdenDresdenGermany
| | - Andreas Tzschach
- Institute of Clinical GeneticsTechnische Universität DresdenDresdenGermany
| | - Lars C. Matthies
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Tim M. Strom
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Institute of Human GeneticsHelmholtz Zentrum MünchenNeuherbergGermany
| | - Erich Bernd Ringelstein
- Department of NeurologyUniversity Hospital of MuensterMuensterGermany
- German Neuroscience CenterDubaiUnited Arab Emirates
| | - Marc Sturm
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
| | - Hartmut Engels
- Institute of Human GeneticsUniversity of Bonn, School of Medicine and University Hospital BonnBonnGermany
| | - Markus Wolff
- Department of NeuropediatricsUniversity of TübingenTübingenGermany
| | - Holger Lerche
- Department of Neurology and EpileptologyHertie Institute for Clinical Brain Research, University of TübingenTübingenGermany
| | - Tobias B. Haack
- Institute of Medical Genetics and Applied GenomicsUniversity of TübingenTübingenGermany
- Institute of Human GeneticsTechnische Universität MünchenMunichGermany
- Centre for Rare DiseasesUniversity of TübingenTübingenGermany
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43
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Berkovic SF, Oliver KL, Canafoglia L, Krieger P, Damiano JA, Hildebrand MS, Morbin M, Vears DF, Sofia V, Giuliano L, Garavaglia B, Simonati A, Santorelli FM, Gambardella A, Labate A, Belcastro V, Castellotti B, Ozkara C, Zeman A, Rankin J, Mole SE, Aguglia U, Farrell M, Rajagopalan S, McDougall A, Brammah S, Andermann F, Andermann E, Dahl HHM, Franceschetti S, Carpenter S. Kufs disease due to mutation ofCLN6: clinical, pathological and molecular genetic features. Brain 2018; 142:59-69. [DOI: 10.1093/brain/awy297] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 01/22/2023] Open
Affiliation(s)
- Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Karen L Oliver
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Laura Canafoglia
- Department of Neurophysiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Penina Krieger
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Michela Morbin
- Neuropathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Danya F Vears
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Vito Sofia
- Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, Section of Neurosciences, University of Catania, Catania, Italy
| | - Loretta Giuliano
- Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, Section of Neurosciences, University of Catania, Catania, Italy
| | - Barbara Garavaglia
- Medical Genetics and Neurogenetics Unit, Bicocca Laboratories, Fondazione IRCCS Istituto Neurologico “Carlo Besta”, Milan, Italy
| | - Alessandro Simonati
- Department of Neuroscience, Biomedicine, Movement-Neurology and Neuropathology, Policlinico GB Rossi, P.le LA Scuro, Verona, Italy
| | | | - Antonio Gambardella
- Institute of Neurology, University Magna Græcia Catanzaro, Italy; Institute of Molecular Bioimaging and Physiology of the National Research Council (IBFM-CNR) Germaneto, CZ, Italy
| | - Angelo Labate
- Institute of Neurology, University Magna Græcia Catanzaro, Italy; Institute of Molecular Bioimaging and Physiology of the National Research Council (IBFM-CNR) Germaneto, CZ, Italy
| | | | - Barbara Castellotti
- Unit Genetics of Neurodegenerative and Metabolic Diseases, IRCCS Foundation C. Besta Neurological Institute, Milan, Italy
| | - Cigdem Ozkara
- Istanbul University-Cerrahpaşa, Medical Faculty, Department of Neurology, Istanbul, Turkey
| | - Adam Zeman
- University of Exeter Medical School, St Luke’s Campus, Magdalen Road, Exeter EX1 2LU, UK
| | - Julia Rankin
- Clinical Genetics, Royal Devon and Exeter Hospital, Gladstone Road, Exeter, UK
| | - Sara E Mole
- MRC Laboratory for Molecular Cell Biology and UCL GOS Institute of Child Health, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Umberto Aguglia
- Department of Medical and Surgical Sciences, University Magna Græcia Catanzaro, Italy
- Institute of Molecular Bioimaging and Physiology of the National Research Council (IBFM-CNR) Germaneto, CZ, Italy
| | - Michael Farrell
- Department of Neuropathology, Beaumont Hospital, Dublin 9, Ireland
| | - Sulekha Rajagopalan
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, New South Wales Australia
| | - Alan McDougall
- Department of Neurology, Liverpool Hospital, Liverpool, New South Wales Australia
| | - Susan Brammah
- Central Sydney Electron Microscope Unit, Concord Repatriation General Hospital, Concord, New South Wales, Australia
| | - Frederick Andermann
- Epilepsy Research Group, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada
- Departments of Neurology and Neurosurgery and Paediatrics, McGill University, Montreal, Quebec, Canada
| | - Eva Andermann
- Epilepsy Research Group, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada
- Departments of Neurology and Neurosurgery and Paediatrics, McGill University, Montreal, Quebec, Canada
| | - Hans-Henrik M Dahl
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Silvana Franceschetti
- Department of Neurophysiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Stirling Carpenter
- Consultant in Neuropathology, Centro Hospitalar São João, Porto, Portugal
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44
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Metz KA, Teng X, Coppens I, Lamb HM, Wagner BE, Rosenfeld JA, Chen X, Zhang Y, Kim HJ, Meadow ME, Wang TS, Haberlandt ED, Anderson GW, Leshinsky-Silver E, Bi W, Markello TC, Pratt M, Makhseed N, Garnica A, Danylchuk NR, Burrow TA, Jayakar P, McKnight D, Agadi S, Gbedawo H, Stanley C, Alber M, Prehl I, Peariso K, Ong MT, Mordekar SR, Parker MJ, Crooks D, Agrawal PB, Berry GT, Loddenkemper T, Yang Y, Maegawa GHB, Aouacheria A, Markle JG, Wohlschlegel JA, Hartman AL, Hardwick JM. KCTD7 deficiency defines a distinct neurodegenerative disorder with a conserved autophagy-lysosome defect. Ann Neurol 2018; 84:766-780. [PMID: 30295347 DOI: 10.1002/ana.25351] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 08/27/2018] [Accepted: 09/23/2018] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Several small case series identified KCTD7 mutations in patients with a rare autosomal recessive disorder designated progressive myoclonic epilepsy (EPM3) and neuronal ceroid lipofuscinosis (CLN14). Despite the name KCTD (potassium channel tetramerization domain), KCTD protein family members lack predicted channel domains. We sought to translate insight gained from yeast studies to uncover disease mechanisms associated with deficiencies in KCTD7 of unknown function. METHODS Novel KCTD7 variants in new and published patients were assessed for disease causality using genetic analyses, cell-based functional assays of patient fibroblasts and knockout yeast, and electron microscopy of patient samples. RESULTS Patients with KCTD7 mutations can exhibit movement disorders or developmental regression before seizure onset, and are distinguished from similar disorders by an earlier age of onset. Although most published KCTD7 patient variants were excluded from a genome sequence database of normal human variations, most newly identified patient variants are present in this database, potentially challenging disease causality. However, genetic analysis and impaired biochemical interactions with cullin 3 support a causal role for patient KCTD7 variants, suggesting deleterious alleles of KCTD7 and other rare disease variants may be underestimated. Both patient-derived fibroblasts and yeast lacking Whi2 with sequence similarity to KCTD7 have impaired autophagy consistent with brain pathology. INTERPRETATION Biallelic KCTD7 mutations define a neurodegenerative disorder with lipofuscin and lipid droplet accumulation but without defining features of neuronal ceroid lipofuscinosis or lysosomal storage disorders. KCTD7 deficiency appears to cause an underlying autophagy-lysosome defect conserved in yeast, thereby assigning a biological role for KCTD7. Ann Neurol 2018;84:774-788.
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Affiliation(s)
- Kyle A Metz
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Xinchen Teng
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Heather M Lamb
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Bart E Wagner
- Histopathology Department, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Xianghui Chen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Yu Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Hee Jong Kim
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Michael E Meadow
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Tim Sen Wang
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Edda D Haberlandt
- Clinical Department of Pediatrics I, Innsbruck Medical University, Innsbruck, Austria.,Department of Child and Youth Health, Hospital of Dornbirn, Dornbirn, Austria
| | - Glenn W Anderson
- Histopathology Department, Great Ormond Street Hospital for Children, London, United Kingdom
| | | | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Thomas C Markello
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Marsha Pratt
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK
| | - Nawal Makhseed
- Department of Pediatrics, Jahra Hospital, Ministry of Health, Al Jahra, Kuwait
| | - Adolfo Garnica
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Noelle R Danylchuk
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Thomas A Burrow
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Parul Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital, Miami, FL
| | | | - Satish Agadi
- Department of Neurology, Texas Children's Hospital, Houston, TX
| | | | | | - Michael Alber
- Pediatric Neurology and Developmental Medicine, University of Tübingen, Tübingen, Germany
| | | | - Katrina Peariso
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Min Tsui Ong
- Department of Paediatric Neurology, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Santosh R Mordekar
- Department of Paediatric Neurology, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Michael J Parker
- Sheffield Clinical Genetics Service, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Daniel Crooks
- Department of Neuropathology, Walton Centre National Health Service Foundation Trust, Liverpool, United Kingdom
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Gerard T Berry
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Gustavo H B Maegawa
- Department of Pediatrics/Genetics and Metabolism, University of Florida, Gainesville, FL
| | - Abdel Aouacheria
- Montpellier Institute of Evolution Sciences, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Janet G Markle
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Adam L Hartman
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
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Bhat S, Ganesh S. New discoveries in progressive myoclonus epilepsies: a clinical outlook. Expert Rev Neurother 2018; 18:649-667. [DOI: 10.1080/14737175.2018.1503949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Shweta Bhat
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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Munch AS, Saljic A, Boddum K, Grunnet M, Hougaard C, Jespersen T. Pharmacological rescue of mutated Kv3.1 ion-channel linked to progressive myoclonus epilepsies. Eur J Pharmacol 2018; 833:255-262. [DOI: 10.1016/j.ejphar.2018.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/20/2022]
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Kim H, Lee S, Choi M, Kim H, Hwang H, Choi J, Chae JH, Kim KJ, Lim BC. Familial cases of progressive myoclonic epilepsy caused by maternal somatic mosaicism of a recurrent KCNC1 p.Arg320His mutation. Brain Dev 2018; 40:429-432. [PMID: 29428275 DOI: 10.1016/j.braindev.2018.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 01/16/2018] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
Abstract
PURPOSE A recurrent de novo mutation in KCNC1 (c.959G > A, p.Arg320His) has been identified recently as one of the important genetic causes of progress myoclonic epilepsy (PME). The clinical phenotype resulting from this mutation has been named as myoclonus epilepsy and ataxia due to potassium channel mutation (MEAK). This finding carries important clinical implications in that autosomal dominant inheritance and de novo occurrence need to be considered when conducting genetic tests in patients with PME. We present two familial cases of MEAK in siblings with a recurrent p.Arg320His mutation in KCNC1. METHOD Whole exome sequencing and subsequent Sanger sequencing were performed for the cases and their parents. RESULTS A recurrent p.Arg320His mutation in KCNC1 was identified in the two brothers who showed characteristic features of MEAK: near normal early development, onset of myoclonus around 10 years of age, infrequent generalized tonic-clonic seizures, relatively mild cognitive impairment, and generalized epileptiform discharges. Interestingly, the asymptomatic mother was suspected as being mosaic for this mutation. This finding could lead to misleading inheritance patterns and make genetic diagnosis of PME more complicated. CONCLUSIONS Our familial MEAK cases show that consideration of parental mosaicism in addition to meticulous phenotyping is needed when conducting KCNC1 genetic testing.
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Affiliation(s)
- Hyuna Kim
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
| | - Sangmoon Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Murim Choi
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Hunmin Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, South Korea
| | - Hee Hwang
- Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, South Korea
| | - JiEun Choi
- Department of Pediatrics, Seoul National University Boramae Medical Center, Seoul, South Korea
| | - Jong Hee Chae
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
| | - Ki Joong Kim
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
| | - Byung Chan Lim
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea.
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Carpenter JC, Schorge S. The voltage-gated channelopathies as a paradigm for studying epilepsy-causing genes. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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50
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Lesca G. Aspetti genetici delle epilessie. Neurologia 2018. [DOI: 10.1016/s1634-7072(18)41286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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