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Singh V, Auerbach DS. Neurocardiac pathologies associated with potassium channelopathies. Epilepsia 2024. [PMID: 39087855 DOI: 10.1111/epi.18066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 07/10/2024] [Accepted: 07/10/2024] [Indexed: 08/02/2024]
Abstract
Voltage-gated potassium channels are expressed throughout the human body and are essential for physiological functions. These include delayed rectifiers, A-type channels, outward rectifiers, and inward rectifiers. They impact electrical function in the heart (repolarization) and brain (repolarization and stabilization of the resting membrane potential). KCNQx and KCNHx encode Kv7.x and Kv11.x proteins, which form delayed rectifier potassium channels. KCNQx and KCNHx channelopathies are associated with both cardiac and neuronal pathologies. These include electrocardiographic abnormalities, cardiac arrhythmias, sudden cardiac death (SCD), epileptiform discharges, seizures, bipolar disorder, and sudden unexpected death in epilepsy (SUDEP). Due to the ubiquitous expression of KCNQx and KCNHx channels, abnormalities in their function can be particularly harmful, increasing the risk of sudden death. For example, KCNH2 variants have a dual role in both cardiac and neuronal pathologies, whereas KCNQ2 and KCNQ3 variants are associated with severe and refractory epilepsy. Recurrent and uncontrolled seizures lead to secondary abnormalities, which include autonomics, cardiac electrical function, respiratory drive, and neuronal electrical activity. Even with a wide array of anti-seizure therapies available on the market, one-third of the more than 70 million people worldwide with epilepsy have uncontrolled seizures (i.e., intractable/drug-resistant epilepsy), which negatively impact neurodevelopment and quality of life. To capture the current state of the field, this review examines KCNQx and KCNHx expression patterns and electrical function in the brain and heart. In addition, it discusses several KCNQx and KCNHx variants that have been clinically and electrophysiologically characterized. Because these channel variants are associated with multi-system pathologies, such as epileptogenesis, Kv7 channel modulators provide a potential anti-seizure therapy, particularly for people with intractable epilepsy. Ultimately an increased understanding of the role of Kv channels throughout the body will fuel the development of innovative, safe, and effective therapies for people at a high risk of sudden death (SCD and SUDEP).
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Affiliation(s)
- Veronica Singh
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - David S Auerbach
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, New York, USA
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Wang X, Ma J, Dong Y, Ren X, Li R, Yang G, She G, Tan Y, Chen S. Exploration on the potential efficacy and mechanism of methyl salicylate glycosides in the treatment of schizophrenia based on bioinformatics, molecular docking and dynamics simulation. SCHIZOPHRENIA (HEIDELBERG, GERMANY) 2024; 10:64. [PMID: 39019913 PMCID: PMC11255270 DOI: 10.1038/s41537-024-00484-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 07/02/2024] [Indexed: 07/19/2024]
Abstract
The etiological and therapeutic complexities of schizophrenia (SCZ) persist, prompting exploration of anti-inflammatory therapy as a potential treatment approach. Methyl salicylate glycosides (MSGs), possessing a structural parent nucleus akin to aspirin, are being investigated for their therapeutic potential in schizophrenia. Utilizing bioinformation mining, network pharmacology, molecular docking and dynamics simulation, the potential value and mechanism of MSGs (including MSTG-A, MSTG-B, and Gaultherin) in the treatment of SCZ, as well as the underlying pathogenesis of the disorder, were examined. 581 differentially expressed genes related to SCZ were identified in patients and healthy individuals, with 349 up-regulated genes and 232 down-regulated genes. 29 core targets were characterized by protein-protein interaction (PPI) network, with the top 10 core targets being BDNF, VEGFA, PVALB, KCNA1, GRIN2A, ATP2B2, KCNA2, APOE, PPARGC1A and SCN1A. The pathogenesis of SCZ primarily involves cAMP signaling, neurodegenerative diseases and other pathways, as well as regulation of ion transmembrane transport. Molecular docking analysis revealed that the three candidates exhibited binding activity with certain targets with binding affinities ranging from -4.7 to -109.2 kcal/mol. MSTG-A, MSTG-B and Gaultherin show promise for use in the treatment of SCZ, potentially through their ability to modulate the expression of multiple genes involved in synaptic structure and function, ion transport, energy metabolism. Molecular dynamics simulation revealed good binding abilities between MSTG-A, MSTG-B, Gaultherin and ATP2B2. It suggests new avenues for further investigation in this area.
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Affiliation(s)
- Xiuhuan Wang
- Peking University HuiLongGuan Clinical Medical School, Beijing HuiLongGuan Hospital, Beijing, 100096, PR China
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, PR China
| | - Jiamu Ma
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, PR China
| | - Ying Dong
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, PR China
| | - Xueyang Ren
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, PR China
| | - Ruoming Li
- Peking University HuiLongGuan Clinical Medical School, Beijing HuiLongGuan Hospital, Beijing, 100096, PR China
| | - Guigang Yang
- Peking University HuiLongGuan Clinical Medical School, Beijing HuiLongGuan Hospital, Beijing, 100096, PR China
| | - Gaimei She
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, PR China.
| | - Yunlong Tan
- Peking University HuiLongGuan Clinical Medical School, Beijing HuiLongGuan Hospital, Beijing, 100096, PR China.
| | - Song Chen
- Peking University HuiLongGuan Clinical Medical School, Beijing HuiLongGuan Hospital, Beijing, 100096, PR China.
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Qin C, Yang X, Zuo Z, Yuan P, Sun F, Luo X, Ye X, Cao Z, Chen Z, Wu Y. Differential potassium channel inhibitory activities of a novel thermostable degradation peptide BmKcug1a-P1 from scorpion medicinal material and its N-terminal truncated/restored peptides. Sci Rep 2024; 14:16092. [PMID: 38997408 PMCID: PMC11245557 DOI: 10.1038/s41598-024-66794-4] [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: 04/19/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
Thermally stable full-length scorpion toxin peptides and partially degraded peptides with complete disulfide bond pairing are valuable natural peptide resources in traditional Chinese scorpion medicinal material. However, their pharmacological activities are largely unknown. This study discovered BmKcug1a-P1, a novel N-terminal degraded peptide, in this medicinal material. BmKcug1a-P1 inhibited hKv1.2 and hKv1.3 potassium channels with IC50 values of 2.12 ± 0.27 μM and 1.54 ± 0.28 μM, respectively. To investigate the influence of N-terminal amino acid loss on the potassium channel inhibiting activities, three analogs (i.e., full-length BmKcug1a, BmKcug1a-P1-D2 and BmKcug1a-P1-D4) of BmKcug1a-P1 were prepared, and their potassium channel inhibiting activities on hKv1.3 channel were verified by whole-cell patch clamp technique. Interestingly, the potassium channel inhibiting activity of full-length BmKcug1a on the hKv1.3 channel was significantly improved compared to its N-terminal degraded form (BmKcug1a-P1), while the activities of two truncated analogs (i.e., BmKcug1a-P1-D2 and BmKcug1a-P1-D4) were similar to that of BmKcug1a-P1. Extensive alanine-scanning experiments identified the bonding interface (including two key functional residues, Asn30 and Arg34) of BmKcug1a-P1. Structural and functional dissection further elucidated whether N-terminal residues of the peptide are located at the bonding interface is important in determining whether the N-terminus significantly influences the potassium channel inhibiting activity of the peptide. Altogether, this research identified a novel N-terminal degraded active peptide, BmKcug1a-P1, from traditional Chinese scorpion medicinal material and elucidated how the N-terminus of peptides influences their potassium channel inhibiting activity, contributing to the functional identification and molecular truncation optimization of full-length and degraded peptides from traditional Chinese scorpion medicinal material Buthus martensii Karsch.
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Affiliation(s)
- Chenhu Qin
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xuhua Yang
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Zheng Zuo
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Peixin Yuan
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Fang Sun
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Xudong Luo
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
| | - Xiangdong Ye
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
- Center for BioDrug Research, Wuhan University, Wuhan, 430072, China
| | - Zongyun Chen
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China.
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.
- Center for BioDrug Research, Wuhan University, Wuhan, 430072, China.
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Shin HJ, Ko A, Kim SH, Lee JS, Kang HC. Unusual Voltage-Gated Sodium and Potassium Channelopathies Related to Epilepsy. J Clin Neurol 2024; 20:402-411. [PMID: 38951973 PMCID: PMC11220354 DOI: 10.3988/jcn.2023.0435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/03/2024] [Accepted: 01/23/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND AND PURPOSE There is extensive literature on monogenic epilepsies caused by mutations in familiar channelopathy genes such as SCN1A. However, information on other less-common channelopathy genes is scarce. This study aimed to explore the genetic and clinical characteristics of patients diagnosed with unusual voltage-gated sodium and potassium channelopathies related to epilepsy. METHODS This observational, retrospective study analyzed pediatric patients with epilepsy who carried pathogenic variants of unusual voltage-gated sodium and potassium channelopathy genes responsible for seizure-associated phenotypes. Targeted next-generation sequencing (NGS) panel tests were performed between November 2016 and June 2022 at Severance Children's Hospital, Seoul, South Korea. Clinical characteristics and the treatment responses to different types of antiseizure medications were further analyzed according to different types of gene mutation. RESULTS This study included 15 patients with the following unusual voltage-gated sodium and potassium channelopathy genes: SCN3A (n=1), SCN4A (n=1), KCNA1 (n=1), KCNA2 (n=4), KCNB1 (n=6), KCNC1 (n=1), and KCNMA1 (n=1). NGS-based genetic testing identified 13 missense mutations (87%), 1 splice-site variant (7%), and 1 copy-number variant (7%). Developmental and epileptic encephalopathy was diagnosed in nine (60%) patients. Seizure freedom was eventually achieved in eight (53%) patients, whereas seizures persisted in seven (47%) patients. CONCLUSIONS Our findings broaden the genotypic and phenotypic spectra of less-common voltage-gated sodium and potassium channelopathies associated with epilepsy.
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Affiliation(s)
- Hui Jin Shin
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Ara Ko
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
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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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6
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Xie C, Kessi M, Yin F, Peng J. Roles of KCNA2 in Neurological Diseases: from Physiology to Pathology. Mol Neurobiol 2024:10.1007/s12035-024-04120-9. [PMID: 38517617 DOI: 10.1007/s12035-024-04120-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 03/10/2024] [Indexed: 03/24/2024]
Abstract
Potassium voltage-gated channel subfamily a member 2 (Kv1.2, encoded by KCNA2) is highly expressed in the central and peripheral nervous systems. Based on the patch clamp studies, gain-of function (GOF), loss-of-function (LOF), and a mixed type (GOF/LOF) variants can cause different conditions/disorders. KCNA2-related neurological diseases include epilepsy, intellectual disability (ID), attention deficit/hyperactive disorder (ADHD), autism spectrum disorder (ASD), pain as well as autoimmune and movement disorders. Currently, the molecular mechanisms for the reported variants in causing diverse disorders are unknown. Consequently, this review brings up to date the related information regarding the structure and function of Kv1.2 channel, expression patterns, neuronal localizations, and tetramerization as well as important cell and animal models. In addition, it provides updates on human genetic variants, genotype-phenotype correlations especially highlighting the deep insight into clinical prognosis of KCNA2-related developmental and epileptic encephalopathy, mechanisms, and the potential treatment targets for all KCNA2-related neurological disorders.
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Affiliation(s)
- Changning Xie
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China.
- Hunan Intellectual and Development Disabilities Research Center, Hunan, Changsha, 410008, China.
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Nikitin ES, Postnikova TY, Proskurina EY, Borodinova AA, Ivanova V, Roshchin MV, Smirnova MP, Kelmanson I, Belousov VV, Balaban PM, Zaitsev AV. Overexpression of KCNN4 channels in principal neurons produces an anti-seizure effect without reducing their coding ability. Gene Ther 2024; 31:144-153. [PMID: 37968509 DOI: 10.1038/s41434-023-00427-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 10/13/2023] [Accepted: 10/24/2023] [Indexed: 11/17/2023]
Abstract
Gene therapy offers a potential alternative to the surgical treatment of epilepsy, which affects millions of people and is pharmacoresistant in ~30% of cases. Aimed at reducing the excitability of principal neurons, the engineered expression of K+ channels has been proposed as a treatment due to the outstanding ability of K+ channels to hyperpolarize neurons. However, the effects of K+ channel overexpression on cell physiology remain to be investigated. Here we report an adeno-associated virus (AAV) vector designed to reduce epileptiform activity specifically in excitatory pyramidal neurons by expressing the human Ca2+-gated K+ channel KCNN4 (KCa3.1). Electrophysiological and pharmacological experiments in acute brain slices showed that KCNN4-transduced cells exhibited a Ca2+-dependent slow afterhyperpolarization that significantly decreased the ability of KCNN4-positive neurons to generate high-frequency spike trains without affecting their lower-frequency coding ability and action potential shapes. Antiepileptic activity tests showed potent suppression of pharmacologically induced seizures in vitro at both single cell and local field potential levels with decreased spiking during ictal discharges. Taken together, our findings strongly suggest that the AAV-based expression of the KCNN4 channel in excitatory neurons is a promising therapeutic intervention as gene therapy for epilepsy.
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Affiliation(s)
- Evgeny S Nikitin
- Institute of Higher Nervous Activity and Neurophysiology, RAS, 117485, Moscow, Russia.
| | - Tatiana Y Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 194223, Saint Petersburg, Russia
| | - Elena Y Proskurina
- Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 194223, Saint Petersburg, Russia
| | | | - Violetta Ivanova
- Institute of Higher Nervous Activity and Neurophysiology, RAS, 117485, Moscow, Russia
| | - Matvey V Roshchin
- Institute of Higher Nervous Activity and Neurophysiology, RAS, 117485, Moscow, Russia
| | - Maria P Smirnova
- Institute of Higher Nervous Activity and Neurophysiology, RAS, 117485, Moscow, Russia
| | - Ilya Kelmanson
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 117997, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997, Moscow, Russia
| | - Vsevolod V Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 117997, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997, Moscow, Russia
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, 117997, Moscow, Russia
- Life Improvement by Future Technologies (LIFT) Center, 143025, Moscow, Russia
| | - Pavel M Balaban
- Institute of Higher Nervous Activity and Neurophysiology, RAS, 117485, Moscow, Russia
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 194223, Saint Petersburg, Russia.
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Van de Vondel L, De Winter J, Timmerman V, Baets J. Overarching pathomechanisms in inherited peripheral neuropathies, spastic paraplegias, and cerebellar ataxias. Trends Neurosci 2024; 47:227-238. [PMID: 38360512 DOI: 10.1016/j.tins.2024.01.004] [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: 08/18/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/17/2024]
Abstract
International consortia collaborating on the genetics of rare diseases have significantly boosted our understanding of inherited neurological disorders. Historical clinical classification boundaries were drawn between disorders with seemingly different etiologies, such as inherited peripheral neuropathies (IPNs), spastic paraplegias, and cerebellar ataxias. These clinically defined borders are being challenged by the identification of mutations in genes displaying wide phenotypic spectra and by shared pathomechanistic themes, which are valuable indications for therapy development. We highlight common cellular alterations that underlie this genetic landscape, including alteration of cytoskeleton, axonal transport, mitochondrial function, and DNA repair response. Finally, we discuss venues for future research using the long axonopathies of the PNS as a model to explore other neurogenetic disorders.
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Affiliation(s)
- Liedewei Van de Vondel
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Jonathan De Winter
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Vincent Timmerman
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Peripheral Neuropathy Research Group, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium.
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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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Shakeel K, Olamendi-Portugal T, Naseem MU, Becerril B, Zamudio FZ, Delgado-Prudencio G, Possani LD, Panyi G. Of Seven New K + Channel Inhibitor Peptides of Centruroides bonito, α-KTx 2.24 Has a Picomolar Affinity for Kv1.2. Toxins (Basel) 2023; 15:506. [PMID: 37624263 PMCID: PMC10467108 DOI: 10.3390/toxins15080506] [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: 07/30/2023] [Revised: 08/07/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023] Open
Abstract
Seven new peptides denominated CboK1 to CboK7 were isolated from the venom of the Mexican scorpion Centruroides bonito and their primary structures were determined. The molecular weights ranged between 3760.4 Da and 4357.9 Da, containing 32 to 39 amino acid residues with three putative disulfide bridges. The comparison of amino acid sequences with known potassium scorpion toxins (KTx) and phylogenetic analysis revealed that CboK1 (α-KTx 10.5) and CboK2 (α-KTx 10.6) belong to the α-KTx 10.x subfamily, whereas CboK3 (α-KTx 2.22), CboK4 (α-KTx 2.23), CboK6 (α-KTx 2.21), and CboK7 (α-KTx 2.24) bear > 95% amino acid similarity with members of the α-KTx 2.x subfamily, and CboK5 is identical to Ce3 toxin (α-KTx 2.10). Electrophysiological assays demonstrated that except CboK1, all six other peptides blocked the Kv1.2 channel with Kd values in the picomolar range (24-763 pM) and inhibited the Kv1.3 channel with comparatively less potency (Kd values between 20-171 nM). CboK3 and CboK4 inhibited less than 10% and CboK7 inhibited about 42% of Kv1.1 currents at 100 nM concentration. Among all, CboK7 showed out-standing affinity for Kv1.2 (Kd = 24 pM), as well as high selectivity over Kv1.3 (850-fold) and Kv1.1 (~6000-fold). These characteristics of CboK7 may provide a framework for developing tools to treat Kv1.2-related channelopathies.
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Affiliation(s)
- Kashmala Shakeel
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary; (K.S.); (M.U.N.)
| | - Timoteo Olamendi-Portugal
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (T.O.-P.); (B.B.); (F.Z.Z.); (G.D.-P.)
| | - Muhammad Umair Naseem
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary; (K.S.); (M.U.N.)
| | - Baltazar Becerril
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (T.O.-P.); (B.B.); (F.Z.Z.); (G.D.-P.)
| | - Fernando Z. Zamudio
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (T.O.-P.); (B.B.); (F.Z.Z.); (G.D.-P.)
| | - Gustavo Delgado-Prudencio
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (T.O.-P.); (B.B.); (F.Z.Z.); (G.D.-P.)
| | - Lourival Domingos Possani
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca 62210, Mexico; (T.O.-P.); (B.B.); (F.Z.Z.); (G.D.-P.)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, Research Center for Molecular Medicine, University of Debrecen, Egyetem ter. 1, 4032 Debrecen, Hungary; (K.S.); (M.U.N.)
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11
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Servettini I, Talani G, Megaro A, Setzu MD, Biggio F, Briffa M, Guglielmi L, Savalli N, Binda F, Delicata F, Bru–Mercier G, Vassallo N, Maglione V, Cauchi RJ, Di Pardo A, Collu M, Imbrici P, Catacuzzeno L, D’Adamo MC, Olcese R, Pessia M. An activator of voltage-gated K + channels Kv1.1 as a therapeutic candidate for episodic ataxia type 1. Proc Natl Acad Sci U S A 2023; 120:e2207978120. [PMID: 37487086 PMCID: PMC10401004 DOI: 10.1073/pnas.2207978120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/23/2023] [Indexed: 07/26/2023] Open
Abstract
Loss-of-function mutations in the KCNA1(Kv1.1) gene cause episodic ataxia type 1 (EA1), a neurological disease characterized by cerebellar dysfunction, ataxic attacks, persistent myokymia with painful cramps in skeletal muscles, and epilepsy. Precision medicine for EA1 treatment is currently unfeasible, as no drug that can enhance the activity of Kv1.1-containing channels and offset the functional defects caused by KCNA1 mutations has been clinically approved. Here, we uncovered that niflumic acid (NFA), a currently prescribed analgesic and anti-inflammatory drug with an excellent safety profile in the clinic, potentiates the activity of Kv1.1 channels. NFA increased Kv1.1 current amplitudes by enhancing the channel open probability, causing a hyperpolarizing shift in the voltage dependence of both channel opening and gating charge movement, slowing the OFF-gating current decay. NFA exerted similar actions on both homomeric Kv1.2 and heteromeric Kv1.1/Kv1.2 channels, which are formed in most brain structures. We show that through its potentiating action, NFA mitigated the EA1 mutation-induced functional defects in Kv1.1 and restored cerebellar synaptic transmission, Purkinje cell availability, and precision of firing. In addition, NFA ameliorated the motor performance of a knock-in mouse model of EA1 and restored the neuromuscular transmission and climbing ability in Shaker (Kv1.1) mutant Drosophila melanogaster flies (Sh5). By virtue of its multiple actions, NFA has strong potential as an efficacious single-molecule-based therapeutic agent for EA1 and serves as a valuable model for drug discovery.
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Affiliation(s)
- Ilenio Servettini
- Section of Physiology, Department of Medicine, University of Perugia, Perugia06123, Italy
| | - Giuseppe Talani
- Institute of Neuroscience, National Research Council, Monserrato09042, Italy
| | - Alfredo Megaro
- Section of Physiology, Department of Medicine, University of Perugia, Perugia06123, Italy
| | - Maria Dolores Setzu
- Department of Biomedical Sciences, University of Cagliari, Monserrato09042, Italy
| | - Francesca Biggio
- Department of Life and Environmental Sciences, University of Cagliari, Monserrato09042, Italy
| | - Michelle Briffa
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Luca Guglielmi
- Medical Research Council Laboratory of Molecular Biology, CambridgeCB2 0QH, United Kingdom
| | - Nicoletta Savalli
- Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Francesca Binda
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne 1011, Switzerland
- Centre National de la Recherche Scientifique, Institut des Neurosciences Cellulaires et Intégratives, Université de Strasbourg, StrasbourgF-67000, France
| | - Francis Delicata
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MBR3E 0T5, Canada
| | - Gilles Bru–Mercier
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain17666, United Arab Emirates
| | - Neville Vassallo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Vittorio Maglione
- Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli86077, Italy
| | - Ruben J. Cauchi
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
| | - Alba Di Pardo
- Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli86077, Italy
| | - Maria Collu
- Department of Biomedical Sciences, University of Cagliari, Monserrato09042, Italy
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari ‘‘Aldo Moro”, 70125Bari, Italy
| | - Luigi Catacuzzeno
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia06123, Italy
| | - Maria Cristina D’Adamo
- Department of Medicine and Surgery, Libera Università Mediterranea ‘‘Giuseppe DEGENNARO”, Casamassima 70010, Italy
| | - Riccardo Olcese
- Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, MsidaMSD2080, Malta
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain17666, United Arab Emirates
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12
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Manville RW, Alfredo Freites J, Sidlow R, Tobias DJ, Abbott GW. Native American ataxia medicines rescue ataxia-linked mutant potassium channel activity via binding to the voltage sensing domain. Nat Commun 2023; 14:3281. [PMID: 37280215 DOI: 10.1038/s41467-023-38834-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 05/17/2023] [Indexed: 06/08/2023] Open
Abstract
There are currently no drugs known to rescue the function of Kv1.1 voltage-gated potassium channels carrying loss-of-function sequence variants underlying the inherited movement disorder, Episodic Ataxia 1 (EA1). The Kwakwaka'wakw First Nations of the Pacific Northwest Coast used Fucus gardneri (bladderwrack kelp), Physocarpus capitatus (Pacific ninebark) and Urtica dioica (common nettle) to treat locomotor ataxia. Here, we show that extracts of these plants enhance wild-type Kv1.1 current, especially at subthreshold potentials. Screening of their constituents revealed that gallic acid and tannic acid similarly augment wild-type Kv1.1 current, with submicromolar potency. Crucially, the extracts and their constituents also enhance activity of Kv1.1 channels containing EA1-linked sequence variants. Molecular dynamics simulations reveal that gallic acid augments Kv1.1 activity via a small-molecule binding site in the extracellular S1-S2 linker. Thus, traditional Native American ataxia treatments utilize a molecular mechanistic foundation that can inform small-molecule approaches to therapeutically correcting EA1 and potentially other Kv1.1-linked channelopathies.
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Affiliation(s)
- Rían W Manville
- Bioelectricity Laboratory, Dept. of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA
| | | | | | - Douglas J Tobias
- Department of Chemistry, University of California, Irvine, CA, USA
| | - Geoffrey W Abbott
- Bioelectricity Laboratory, Dept. of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA.
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13
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Qin C, Yang X, Zhang Y, Deng G, Huang X, Zuo Z, Sun F, Cao Z, Chen Z, Wu Y. Functional Characterization of a New Degradation Peptide BmTX4-P1 from Traditional Chinese Scorpion Medicinal Material. Toxins (Basel) 2023; 15:toxins15050340. [PMID: 37235373 DOI: 10.3390/toxins15050340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
Thermally processed Buthus martensii Karsch scorpion is an important traditional Chinese medical material that has been widely used to treat various diseases in China for over one thousand years. Our recent work showed that thermally processed Buthus martensii Karsch scorpions contain many degraded peptides; however, the pharmacological activities of these peptides remain to be studied. Here, a new degraded peptide, BmTX4-P1, was identified from processed Buthus martensii Karsch scorpions. Compared with the venom-derived wild-type toxin peptide BmTX4, BmTX4-P1 missed some amino acids at the N-terminal and C-terminal regions, while containing six conserved cysteine residues, which could be used to form disulfide bond-stabilized α-helical and β-sheet motifs. Two methods (chemical synthesis and recombinant expression) were used to obtain the BmTX4-P1 peptide, named sBmTX4-P1 and rBmTX4-P1. Electrophysiological experimental results showed that sBmTX4-P1 and rBmTX4-P1 exhibited similar activities to inhibit the currents of hKv1.2 and hKv1.3 channels. In addition, the experimental electrophysiological results of recombinant mutant peptides of BmTX4-P1 indicated that the two residues of BmTX4-P1 (Lys22 and Tyr31) were the key residues for its potassium channel inhibitory activity. In addition to identifying a new degraded peptide, BmTX4-P1, from traditional Chinese scorpion medicinal material with high inhibitory activities against the hKv1.2 and hKv1.3 channels, this study also provided a useful method to obtain the detailed degraded peptides from processed Buthus martensii Karsch scorpions. Thus, the study laid a solid foundation for further research on the medicinal function of these degraded peptides.
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Affiliation(s)
- Chenhu Qin
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Xuhua Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuanyuan Zhang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Gang Deng
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xin Huang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zheng Zuo
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Fang Sun
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zongyun Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
- Center for BioDrug Research, Wuhan University, Wuhan 430072, China
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14
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Hassan A. Episodic Ataxias: Primary and Secondary Etiologies, Treatment, and Classification Approaches. Tremor Other Hyperkinet Mov (N Y) 2023; 13:9. [PMID: 37008993 PMCID: PMC10064912 DOI: 10.5334/tohm.747] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Background Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in KCNA1 and CACNA1A. EA3-8 are reported in rare families. Advances in genetic testing have broadened the KCNA1 and CACNA1A phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists. Methods A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized. Results EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (SCA-14, SCA-27, SCA-42, AOA2, CAPOS), epilepsy syndromes (KCNA2, SCN2A, PRRT2), GLUT-1, mitochondrial disorders (PDHA1, PDHX, ACO2), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause. Discussion EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.
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15
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Salpietro V, Galassi Deforie V, Efthymiou S, O'Connor E, Marcé‐Grau A, Maroofian R, Striano P, Zara F, Morrow MM, Reich A, Blevins A, Sala‐Coromina J, Accogli A, Fortuna S, Alesandrini M, Au PYB, Singhal NS, Cogne B, Isidor B, Hanna MG, Macaya A, Kullmann DM, Houlden H, Männikkö R. De novo KCNA6 variants with attenuated K V 1.6 channel deactivation in patients with epilepsy. Epilepsia 2023; 64:443-455. [PMID: 36318112 PMCID: PMC10108282 DOI: 10.1111/epi.17455] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Mutations in the genes encoding neuronal ion channels are a common cause of Mendelian neurological diseases. We sought to identify novel de novo sequence variants in cases with early infantile epileptic phenotypes and neurodevelopmental anomalies. METHODS Following clinical diagnosis, we performed whole exome sequencing of the index cases and their parents. Identified channel variants were expressed in Xenopus oocytes and their functional properties assessed using two-electrode voltage clamp. RESULTS We identified novel de novo variants in KCNA6 in four unrelated individuals variably affected with neurodevelopmental disorders and seizures with onset in the first year of life. Three of the four identified mutations affect the pore-lining S6 α-helix of KV 1.6. A prominent finding of functional characterization in Xenopus oocytes was that the channel variants showed only minor effects on channel activation but slowed channel closure and shifted the voltage dependence of deactivation in a hyperpolarizing direction. Channels with a mutation affecting the S6 helix display dominant effects on channel deactivation when co-expressed with wild-type KV 1.6 or KV 1.1 subunits. SIGNIFICANCE This is the first report of de novo nonsynonymous variants in KCNA6 associated with neurological or any clinical features. Channel variants showed a consistent effect on channel deactivation, slowing the rate of channel closure following normal activation. This specific gain-of-function feature is likely to underlie the neurological phenotype in our patients. Our data highlight KCNA6 as a novel channelopathy gene associated with early infantile epileptic phenotypes and neurodevelopmental anomalies.
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Affiliation(s)
- Vincenzo Salpietro
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Department of Biotechnological and Applied Clinical Sciences (DISCAB)University of L'AquilaL'AquilaItaly
| | | | - Stephanie Efthymiou
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Emer O'Connor
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Anna Marcé‐Grau
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Reza Maroofian
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Unit of Pediatric NeurologyIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | | | | | | | - Júlia Sala‐Coromina
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Andrea Accogli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | - Marie Alesandrini
- Neuropediatrics UnitCentre Hospitalier Universitaire NantesNantesFrance
| | - P. Y. Billie Au
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of MedicineUniversity of CalgaryAlbertaCalgaryCanada
| | - Nilika Shah Singhal
- Departments of Neurology and Pediatrics, UCSF Benioff Children's HospitalUniversity of CaliforniaCaliforniaSan FranciscoUSA
| | - Benjamin Cogne
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Bertrand Isidor
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Michael G. Hanna
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Queen Square Centre for Neuromuscular DiseasesNational Hospital for Neurology and NeurosurgeryLondonUK
| | - Alfons Macaya
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Dimitri M. Kullmann
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, University College LondonLondonUK
| | - Henry Houlden
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Roope Männikkö
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
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16
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Erro R, Magrinelli F, Bhatia KP. Paroxysmal movement disorders: Paroxysmal dyskinesia and episodic ataxia. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:347-365. [PMID: 37620078 DOI: 10.1016/b978-0-323-98817-9.00033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Paroxysmal movement disorders have traditionally been classified into paroxysmal dyskinesia (PxD), which consists in attacks of involuntary movements (mainly dystonia and/or chorea) without loss of consciousness, and episodic ataxia (EA), which features spells of cerebellar dysfunction with or without interictal neurological manifestations. In this chapter, PxD will be discussed first according to the trigger-based classification, thus reviewing clinical, genetic, and molecular features of paroxysmal kinesigenic dyskinesia, paroxysmal nonkinesigenic dyskinesia, and paroxysmal exercise-induced dyskinesia. EA will be presented thereafter according to their designated gene or genetic locus. Clinicogenetic similarities among paroxysmal movement disorders have progressively emerged, which are herein highlighted along with growing evidence that their pathomechanisms overlap those of epilepsy and migraine. Advances in our comprehension of the biological pathways underlying paroxysmal movement disorders, which involve ion channels as well as proteins associated with the vesical synaptic cycle or implicated in neuronal energy metabolism, may represent the cornerstone for defining a shared pathophysiologic framework and developing target-specific therapies.
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Affiliation(s)
- Roberto Erro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", Neuroscience Section, University of Salerno, Baronissi, Salerno, Italy
| | - Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom.
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17
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Blockade of Kv1.3 Potassium Channel Inhibits Microglia-Mediated Neuroinflammation in Epilepsy. Int J Mol Sci 2022; 23:ijms232314693. [PMID: 36499018 PMCID: PMC9740890 DOI: 10.3390/ijms232314693] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
Epilepsy is a chronic neurological disorder whose pathophysiology relates to inflammation. The potassium channel Kv1.3 in microglia has been reported as a promising therapeutic target in neurological diseases in which neuroinflammation is involved, such as multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and middle cerebral artery occlusion/reperfusion (MCAO/R). Currently, little is known about the relationship between Kv1.3 and epilepsy. In this study, we found that Kv1.3 was upregulated in microglia in the KA-induced mouse epilepsy model. Importantly, blocking Kv1.3 with its specific small-molecule blocker 5-(4-phenoxybutoxy)psoralen (PAP-1) reduced seizure severity, prolonged seizure latency, and decreased neuronal loss. Mechanistically, we further confirmed that blockade of Kv1.3 suppressed proinflammatory microglial activation and reduced proinflammatory cytokine production by inhibiting the Ca2+/NF-κB signaling pathway. These results shed light on the critical function of microglial Kv1.3 in epilepsy and provided a potential therapeutic target.
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Network-Based Data Analysis Reveals Ion Channel-Related Gene Features in COVID-19: A Bioinformatic Approach. Biochem Genet 2022; 61:471-505. [PMID: 36104591 PMCID: PMC9473477 DOI: 10.1007/s10528-022-10280-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 09/01/2022] [Indexed: 11/02/2022]
Abstract
Coronavirus disease 2019 (COVID-19) seriously threatens human health and has been disseminated worldwide. Although there are several treatments for COVID-19, its control is currently suboptimal. Therefore, the development of novel strategies to treat COVID-19 is necessary. Ion channels are located on the membranes of all excitable cells and many intracellular organelles and are key components involved in various biological processes. They are a target of interest when searching for drug targets. This study aimed to reveal the relevant molecular features of ion channel genes in COVID-19 based on bioinformatic analyses. The RNA-sequencing data of patients with COVID-19 and healthy subjects (GSE152418 and GSE171110 datasets) were obtained from the Gene Expression Omnibus (GEO) database. Ion channel genes were selected from the Hugo Gene Nomenclature Committee (HGNC) database. The RStudio software was used to process the data based on the corresponding R language package to identify ion channel-associated differentially expressed genes (DEGs). Based on the DEGs, Gene Ontology (GO) functional and pathway enrichment analyses were performed using the Enrichr web tool. The STRING database was used to generate a protein-protein interaction (PPI) network, and the Cytoscape software was used to screen for hub genes in the PPI network based on the cytoHubba plug-in. Transcription factors (TF)-DEG, DEG-microRNA (miRNA) and DEG-disease association networks were constructed using the NetworkAnalyst web tool. Finally, the screened hub genes as drug targets were subjected to enrichment analysis based on the DSigDB using the Enrichr web tool to identify potential therapeutic agents for COVID-19. A total of 29 ion channel-associated DEGs were identified. GO functional analysis showed that the DEGs were integral components of the plasma membrane and were mainly involved in inorganic cation transmembrane transport and ion channel activity functions. Pathway analysis showed that the DEGs were mainly involved in nicotine addiction, calcium regulation in the cardiac cell and neuronal system pathways. The top 10 hub genes screened based on the PPI network included KCNA2, KCNJ4, CACNA1A, CACNA1E, NALCN, KCNA5, CACNA2D1, TRPC1, TRPM3 and KCNN3. The TF-DEG and DEG-miRNA networks revealed significant TFs (FOXC1, GATA2, HINFP, USF2, JUN and NFKB1) and miRNAs (hsa-mir-146a-5p, hsa-mir-27a-3p, hsa-mir-335-5p, hsa-let-7b-5p and hsa-mir-129-2-3p). Gene-disease association network analysis revealed that the DEGs were closely associated with intellectual disability and cerebellar ataxia. Drug-target enrichment analysis showed that the relevant drugs targeting the hub genes CACNA2D1, CACNA1A, CACNA1E, KCNA2 and KCNA5 were gabapentin, gabapentin enacarbil, pregabalin, guanidine hydrochloride and 4-aminopyridine. The results of this study provide a valuable basis for exploring the mechanisms of ion channel genes in COVID-19 and clues for developing therapeutic strategies for COVID-19.
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19
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Lange LM, Gonzalez-Latapi P, Rajalingam R, Tijssen MAJ, Ebrahimi-Fakhari D, Gabbert C, Ganos C, Ghosh R, Kumar KR, Lang AE, Rossi M, van der Veen S, van de Warrenburg B, Warner T, Lohmann K, Klein C, Marras C. Nomenclature of Genetic Movement Disorders: Recommendations of the International Parkinson and Movement Disorder Society Task Force - An Update. Mov Disord 2022; 37:905-935. [PMID: 35481685 DOI: 10.1002/mds.28982] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 12/13/2022] Open
Abstract
In 2016, the Movement Disorder Society Task Force for the Nomenclature of Genetic Movement Disorders presented a new system for naming genetically determined movement disorders and provided a criterion-based list of confirmed monogenic movement disorders. Since then, a substantial number of novel disease-causing genes have been described, which warrant classification using this system. In addition, with this update, we further refined the system and propose dissolving the imaging-based categories of Primary Familial Brain Calcification and Neurodegeneration with Brain Iron Accumulation and reclassifying these genetic conditions according to their predominant phenotype. We also introduce the novel category of Mixed Movement Disorders (MxMD), which includes conditions linked to multiple equally prominent movement disorder phenotypes. In this article, we present updated lists of newly confirmed monogenic causes of movement disorders. We found a total of 89 different newly identified genes that warrant a prefix based on our criteria; 6 genes for parkinsonism, 21 for dystonia, 38 for dominant and recessive ataxia, 5 for chorea, 7 for myoclonus, 13 for spastic paraplegia, 3 for paroxysmal movement disorders, and 6 for mixed movement disorder phenotypes; 10 genes were linked to combined phenotypes and have been assigned two new prefixes. The updated lists represent a resource for clinicians and researchers alike and they have also been published on the website of the Task Force for the Nomenclature of Genetic Movement Disorders on the homepage of the International Parkinson and Movement Disorder Society (https://www.movementdisorders.org/MDS/About/Committees--Other-Groups/MDS-Task-Forces/Task-Force-on-Nomenclature-in-Movement-Disorders.htm). © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.
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Affiliation(s)
- Lara M Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Paulina Gonzalez-Latapi
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada.,Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rajasumi Rajalingam
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | - Marina A J Tijssen
- UMCG Expertise Centre Movement Disorders, Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Carolin Gabbert
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Christos Ganos
- Department of Neurology, Charité University Hospital Berlin, Berlin, Germany
| | - Rhia Ghosh
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Kishore R Kumar
- Molecular Medicine Laboratory and Department of Neurology, Concord Repatriation General Hospital, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Anthony E Lang
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | - Malco Rossi
- Movement Disorders Section, Neuroscience Department, Raul Carrea Institute for Neurological Research (FLENI), Buenos Aires, Argentina
| | - Sterre van der Veen
- UMCG Expertise Centre Movement Disorders, Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Center of Expertise for Parkinson and Movement Disorders, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Tom Warner
- Department of Clinical & Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Connie Marras
- The Edmond J. Safra Program in Parkinson's Disease and The Morton and Gloria Shulman Movement Disorder Clinic, Toronto Western Hospital, University of Toronto, Toronto, Canada
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20
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Wang H, Zhu Y, Cao D, Chen H, Ding X, Zeng Q, Zou H, Liao J. Successful medical treatment of west syndrome with a KCNA2 variant: a case report. ACTA EPILEPTOLOGICA 2022. [DOI: 10.1186/s42494-021-00069-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
West syndrome is a devastating disorder characterized by a triad of epileptic spasms, abnormal electroencephalography (EEG), and developmental arrest or psychomotor delay. In addition to early diagnosis, knowing the etiology of the condition is also important for its treatment. Among various etiologies, the genetic factors, especially mutations of ion channel genes, are very common and strongly linked to West syndrome.
Case presentation
A boy who had epileptic spasms from the age of 4 months was diagnosed with West syndrome based on the clinical manifestation and EEG results in Shenzhen Children’s Hospital in June 2019. Trios whole-exome sequencing (WES) test and protein structural model prediction were performed. We also reviewed the clinical and genetic features of this syndrome and the mechanisms of action of topiramate (TPM) by literature search in databases of Online Mendelian Inheritance in Man, Clinical Genome Resource, PubMed, Chinese National Knowledge Infrastructure and Wanfang database using keywords “KCNA2” “West syndrome” and “Topiramate” by December 2020. The relationship between the effect of TPM and the pathogenesis of the KCNA2 variant was also assessed. The WES test revealed c.244C > T/p. Arg82Cys varaint of KCNA2 (NM_004974.3) in this patient, and Sanger sequencing identified this was a de novo mutation. As far as we know, this is the first report of the c.244C > T/p. Arg82Cys variant in KCNA2, which was likely a pathogenic mutation. The seizures were successfully controlled for 10 months by TPM after failure of sodium valproate, large doses of vitamin B6, and adrenocorticotropic hormone. We speculate that the therapeutic effect of TPM in this patient is partially due to the inhibition of carbonic anhydrase.
Conclusions
Mutations in the KCNA2 gene should be considered for patients with West syndrome. The TPM treatment is probably effective for KCNA2-associated disorders.
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21
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Perilli L, Mastromoro G, Murciano M, Amedeo I, Avenoso F, Pizzuti A, Guido CA, Spalice A. Myoclonic Epilepsy: Case Report of a Mild Phenotype in a Pediatric Patient Expanding Clinical Spectrum of KCNA2 Pathogenic Variants. Front Neurol 2022; 12:806516. [PMID: 35178022 PMCID: PMC8844549 DOI: 10.3389/fneur.2021.806516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/31/2021] [Indexed: 11/24/2022] Open
Abstract
We report on the rare case of a male toddler presenting with myoclonic epilepsy characterized by daily episodes of upward movements of the eyebrows, and myoclonic jerks of both head and upper limbs. In addition, the child showed speech delay, tremors, and lack of motor coordination. Next Generation Sequencing analysis (NGS) performed in trio revealed in the proband the c.889C>T de novo missense variant in the KCNA2 gene in heterozygous state. This is the first case of myoclonic epilepsy in a toddler due to a c.889C>T KCNA2 missense variant. The patient was treated with valproic acid and ethosuximide with a good clinical response. At 6 years old, follow-up revealed that the proband was seizure-free with tremors and clumsiness in movements. According to the literature, this case supports the correlation between myoclonic epilepsy and KCNA2 alterations. This evidence suggests that performing genomic testing including the KCNA2 gene in preschool patients affected by myoclonic epilepsy, especially when associated with delayed neurodevelopment. Our goal is to expand the phenotypical spectrum of this rare condition and adding clinical features following a genotype-first approach.
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Affiliation(s)
- Lorenzo Perilli
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Gioia Mastromoro
- Faculty of Medicine and Dentistry, Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Manuel Murciano
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy.,Department of Emergency Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Ilaria Amedeo
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Federica Avenoso
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Antonio Pizzuti
- Faculty of Medicine and Dentistry, Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Cristiana Alessia Guido
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Alberto Spalice
- Department of Mother and Child and Urological Sciences, Sapienza University of Rome, Rome, Italy
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22
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Genetic paroxysmal neurological disorders featuring episodic ataxia and epilepsy. Eur J Med Genet 2022; 65:104450. [DOI: 10.1016/j.ejmg.2022.104450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 02/02/2022] [Accepted: 02/06/2022] [Indexed: 01/25/2023]
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23
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McGinn RJ, Von Stein EL, Summers Stromberg JE, Li Y. Precision medicine in epilepsy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 190:147-188. [DOI: 10.1016/bs.pmbts.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Saini L, Singanamalla B, Natarajan R, Madaan P. Role of genotype–phenotype correlation in prognostication of a child with a novel potassium channelopathy. J Pediatr Neurosci 2022. [DOI: 10.4103/jpn.jpn_294_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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25
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Marini C, Giardino M. Novel treatments in epilepsy guided by genetic diagnosis. Br J Clin Pharmacol 2021; 88:2539-2551. [PMID: 34778987 DOI: 10.1111/bcp.15139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/22/2021] [Accepted: 11/04/2021] [Indexed: 12/21/2022] Open
Abstract
In recent years, precision medicine has emerged as a new paradigm for improved and more individualized patient care. Its key objective is to provide the right treatment, to the right patient at the right time, by basing medical decisions on individual characteristics, including specific genetic biomarkers. In order to realize this objective researchers and physicians must first identify the underlying genetic cause; over the last 10 years, advances in genetics have made this possible for several monogenic epilepsies. Through next generation techniques, a precise genetic aetiology is attainable in 30-50% of genetic epilepsies beginning in the paediatric age. While committed in such search for novel genes carrying disease-causing variants, progress in the study of experimental models of epilepsy has also provided a better understanding of the mechanisms underlying the condition. Such advances are already being translated into improving care, management and treatment of some patients. Identification of a precise genetic aetiology can already direct physicians to prescribe treatments correcting specific metabolic defects, avoid antiseizure medicines that might aggravate functional consequences of the disease-causing variant or select the drugs that counteract the underlying, genetically determined, functional disturbance. Personalized, tailored treatments should not just focus on how to stop seizures but possibly prevent their onset and cure the disorder, often consisting of seizures and its comorbidities including cognitive, motor and behaviour deficiencies. This review discusses the therapeutic implications following a specific genetic diagnosis and the correlation between genetic findings, pathophysiological mechanisms and tailored seizure treatment, emphasizing the impact on current clinical practice.
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Affiliation(s)
- Carla Marini
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, United Hospitals of Ancona, Ancona, Italy
| | - Maria Giardino
- Child Neurology and Psychiatric Unit, Pediatric Hospital G. Salesi, United Hospitals of Ancona, Ancona, Italy
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26
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Hedrich UBS, Lauxmann S, Wolff M, Synofzik M, Bast T, Binelli A, Serratosa JM, Martínez-Ulloa P, Allen NM, King MD, Gorman KM, Zeev BB, Tzadok M, Wong-Kisiel L, Marjanovic D, Rubboli G, Sisodiya SM, Lutz F, Ashraf HP, Torge K, Yan P, Bosselmann C, Schwarz N, Fudali M, Lerche H. 4-Aminopyridine is a promising treatment option for patients with gain-of-function KCNA2-encephalopathy. Sci Transl Med 2021; 13:eaaz4957. [PMID: 34516822 DOI: 10.1126/scitranslmed.aaz4957] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Ulrike B S Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Markus Wolff
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, 72076 Tuebingen, Germany.,Department of Pediatric Neurology, Vivantes-Klinikum Neukölln, 12351 Berlin, Germany
| | - Matthis Synofzik
- Department of Neurology and Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Thomas Bast
- Epilepsy Center Kork, 77694 Kehl-Kork, Germany.,Medical Faculty of the University of Freiburg, 79110 Freiburg, Germany
| | - Adrian Binelli
- Department of Pediatric Neurology, Elizalde Children's Hospital, C1270 Buenos Aires, Argentina
| | - José M Serratosa
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS- Fundacio'n Jime'nez Dı'az, UAM, 28040 Madrid, Spain.,Centro de Investigacio'n Biome'dica en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | - Pedro Martínez-Ulloa
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS- Fundacio'n Jime'nez Dı'az, UAM, 28040 Madrid, Spain
| | - Nicholas M Allen
- Department of Paediatrics, Clinical Sciences Institute, National University of Ireland Galway, Galway H91 TK33, Ireland
| | - Mary D King
- Department of Neurology and Neurophysiology, Children's Health Ireland at Temple Street, Dublin DO1 YC67, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin DO4 V1W8, Ireland
| | - Kathleen M Gorman
- Department of Neurology and Neurophysiology, Children's Health Ireland at Temple Street, Dublin DO1 YC67, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin DO4 V1W8, Ireland
| | - Bruria Ben Zeev
- Sackler School of Medicine Tel Aviv University, Tel Aviv 6997801, Israel.,Pediatric Neurology Unit, Edmond and Lilly Safra Pediatric Hospital, Sheba Medical Center, 5265601 Ramat Gan, Israel
| | - Michal Tzadok
- Sackler School of Medicine Tel Aviv University, Tel Aviv 6997801, Israel.,Pediatric Neurology Unit, Edmond and Lilly Safra Pediatric Hospital, Sheba Medical Center, 5265601 Ramat Gan, Israel
| | - Lily Wong-Kisiel
- Divisions of Child Neurology & Division of Epilepsy, Department of Neurology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | | | - Guido Rubboli
- Danish Epilepsy Center, Filadelfia, 4293 Dianalund, Denmark.,University of Copenhagen, 1165 Copenhagen, Denmark
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
| | - Florian Lutz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Harshad Pannikkaveettil Ashraf
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Kirsten Torge
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Pu Yan
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Christian Bosselmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Niklas Schwarz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Monika Fudali
- Department of Neurosurgery, University of Tuebingen, 72076 Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
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27
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Lauxmann S, Sonnenberg L, Koch NA, Bosselmann C, Winter N, Schwarz N, Wuttke TV, Hedrich UBS, Liu Y, Lerche H, Benda J, Kegele J. Therapeutic Potential of Sodium Channel Blockers as a Targeted Therapy Approach in KCNA1-Associated Episodic Ataxia and a Comprehensive Review of the Literature. Front Neurol 2021; 12:703970. [PMID: 34566847 PMCID: PMC8459024 DOI: 10.3389/fneur.2021.703970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 07/23/2021] [Indexed: 11/17/2022] Open
Abstract
Introduction: Among genetic paroxysmal movement disorders, variants in ion channel coding genes constitute a major subgroup. Loss-of-function (LOF) variants in KCNA1, the gene coding for KV1.1 channels, are associated with episodic ataxia type 1 (EA1), characterized by seconds to minutes-lasting attacks including gait incoordination, limb ataxia, truncal instability, dysarthria, nystagmus, tremor, and occasionally seizures, but also persistent neuromuscular symptoms like myokymia or neuromyotonia. Standard treatment has not yet been developed, and different treatment efforts need to be systematically evaluated. Objective and Methods: Personalized therapeutic regimens tailored to disease-causing pathophysiological mechanisms may offer the specificity required to overcome limitations in therapy. Toward this aim, we (i) reviewed all available clinical reports on treatment response and functional consequences of KCNA1 variants causing EA1, (ii) examined the potential effects on neuronal excitability of all variants using a single compartment conductance-based model and set out to assess the potential of two sodium channel blockers (SCBs: carbamazepine and riluzole) to restore the identified underlying pathophysiological effects of KV1.1 channels, and (iii) provide a comprehensive review of the literature considering all types of episodic ataxia. Results: Reviewing the treatment efforts of EA1 patients revealed moderate response to acetazolamide and exhibited the strength of SCBs, especially carbamazepine, in the treatment of EA1 patients. Biophysical dysfunction of KV1.1 channels is typically based on depolarizing shifts of steady-state activation, leading to an LOF of KCNA1 variant channels. Our model predicts a lowered rheobase and an increase of the firing rate on a neuronal level. The estimated concentration dependent effects of carbamazepine and riluzole could partially restore the altered gating properties of dysfunctional variant channels. Conclusion: These data strengthen the potential of SCBs to contribute to functional compensation of dysfunctional KV1.1 channels. We propose riluzole as a new drug repurposing candidate and highlight the role of personalized approaches to develop standard care for EA1 patients. These results could have implications for clinical practice in future and highlight the need for the development of individualized and targeted therapies for episodic ataxia and genetic paroxysmal disorders in general.
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Affiliation(s)
- Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany
| | - Lukas Sonnenberg
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, Tübingen, Germany
| | - Nils A. Koch
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, Tübingen, Germany
| | - Christian Bosselmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Natalie Winter
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Niklas Schwarz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Thomas V. Wuttke
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Department of Neurosurgery, University of Tübingen, Tübingen, Germany
| | - Ulrike B. S. Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Yuanyuan Liu
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Jan Benda
- Institute of Neurobiology, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience Tübingen, Tübingen, Germany
| | - Josua Kegele
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
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28
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Lamothe SM, Kurata HT. Slc7a5 alters Kvβ-mediated regulation of Kv1.2. J Gen Physiol 2021; 152:151687. [PMID: 32311044 PMCID: PMC7335012 DOI: 10.1085/jgp.201912524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/22/2020] [Accepted: 03/13/2020] [Indexed: 01/15/2023] Open
Abstract
The voltage-gated potassium channel Kv1.2 plays a pivotal role in neuronal excitability and is regulated by a variety of known and unknown extrinsic factors. The canonical accessory subunit of Kv1.2, Kvβ, promotes N-type inactivation and cell surface expression of the channel. We recently reported that a neutral amino acid transporter, Slc7a5, alters the function and expression of Kv1.2. In the current study, we investigated the effects of Slc7a5 on Kv1.2 in the presence of Kvβ1.2 subunits. We observed that Slc7a5-induced suppression of Kv1.2 current and protein expression was attenuated with cotransfection of Kvβ1.2. However, gating effects mediated by Slc7a5, including disinhibition and a hyperpolarizing shift in channel activation, were observed together with Kvβ-mediated inactivation, indicating convergent regulation of Kv1.2 by both regulatory proteins. Slc7a5 influenced several properties of Kvβ-induced inactivation of Kv1.2, including accelerated inactivation, a hyperpolarizing shift and greater extent of steady-state inactivation, and delayed recovery from inactivation. These modified inactivation properties were also apparent in altered deactivation of the Kv1.2/Kvβ/Slc7a5 channel complex. Taken together, these findings illustrate a functional interaction arising from simultaneous regulation of Kv1.2 by Kvβ and Slc7a5, leading to powerful effects on Kv1.2 expression, gating, and overall channel function.
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Affiliation(s)
- Shawn M Lamothe
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Harley T Kurata
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
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29
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Qin C, Yang X, Zuo Z, Yang L, Yang F, Cao Z, Chen Z, Wu Y. BmK86-P1, a New Degradation Peptide with Desirable Thermostability and Kv1.2 Channel-Specific Activity from Traditional Chinese Scorpion Medicinal Material. Toxins (Basel) 2021; 13:toxins13090610. [PMID: 34564614 PMCID: PMC8472965 DOI: 10.3390/toxins13090610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 11/16/2022] Open
Abstract
Thermally processed Buthus martensii Karsch scorpions are a traditional Chinese medical material for treating various diseases. However, their pharmacological foundation remains unclear. Here, a new degraded peptide of scorpion toxin was identified in Chinese scorpion medicinal material by proteomics. It was named BmK86-P1 and has six conserved cysteine residues. Homology modeling and circular dichroism spectra experiments revealed that BmK86-P1 not only contained representative disulfide bond-stabilized α-helical and β-sheet motifs but also showed remarkable stability at test temperatures from 20-95 °C. Electrophysiology experiments indicated that BmK86-P1 was a highly potent and selective inhibitor of the hKv1.2 channel with IC50 values of 28.5 ± 6.3 nM. Structural and functional dissection revealed that two residues of BmK86-P1 (i.e., Lys19 and Ile21) were the key residues that interacted with the hKv1.2 channel. In addition, channel chimeras and mutagenesis experiments revealed that three amino acids (i.e., Gln357, Val381 and Thr383) of the hKv1.2 channel were responsible for BmK86-P1 selectivity. This research uncovered a new bioactive peptide from traditional Chinese scorpion medicinal material that has desirable thermostability and Kv1.2 channel-specific activity, which strongly suggests that thermally processed scorpions are novel peptide resources for new drug discovery for the Kv1.2 channel-related ataxia and epilepsy diseases.
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Affiliation(s)
- Chenhu Qin
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Xuhua Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zheng Zuo
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Liuting Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Fan Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zongyun Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Center for BioDrug Research, Wuhan University, Wuhan 430072, China
- Correspondence:
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30
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Abstract
The presence of unprovoked, recurrent seizures, particularly when drug resistant and associated with cognitive and behavioral deficits, warrants investigation for an underlying genetic cause. This article provides an overview of the major classes of genes associated with epilepsy phenotypes divided into functional categories along with the recommended work-up and therapeutic considerations. Gene discovery in epilepsy supports counseling and anticipatory guidance but also opens the door for precision medicine guiding therapy with a focus on those with disease-modifying effects.
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Affiliation(s)
- Luis A Martinez
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Yi-Chen Lai
- Department of Pediatrics, Section of Pediatric Critical Care Medicine, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - J Lloyd Holder
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Anne E Anderson
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA.
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31
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Gazulla J, Izquierdo-Alvarez S, Ruiz-Fernández E, Lázaro-Romero A, Berciano J. Episodic Vestibulocerebellar Ataxia Associated with a CACNA1G Missense Variant. Case Rep Neurol 2021; 13:347-354. [PMID: 34248568 PMCID: PMC8255690 DOI: 10.1159/000515974] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 03/14/2021] [Indexed: 11/29/2022] Open
Abstract
Episodic vestibulocerebellar ataxias are rare diseases, frequently linked to mutations in different ion channels. Our objective in this work was to describe a kindred with episodic vestibular dysfunction and ataxia, associated with a novel CACNA1G variant. Two individuals from successive generations developed episodes of transient dizziness, gait unsteadiness, a sensation of fall triggered by head movements, headache, and cheek numbness. These were suppressed by carbamazepine (CBZ) administration in the proband, although acetazolamide and topiramate worsened instability, and amitriptyline and flunarizine did not prevent headache spells. On examination, the horizontal head impulse test (HIT) yielded saccadic responses bilaterally and was accompanied by cerebellar signs. Two additional family members were asymptomatic, with normal neurological examinations. Reduced vestibulo-ocular reflex gain values, overt and covert saccades were shown by video-assisted HIT in affected subjects. Hearing acuity was normal. Whole-exome sequencing demonstrated the heterozygous CACNA1G missense variant c.6958G>T (p.Gly2320Cys) in symptomatic individuals. It was absent in 1 unaffected member (not tested in the other asymptomatic individual) and should be considered likely pathogenic. CACNA1G encodes for the pore-forming, α1G subunit of the T-type voltage-gated calcium channel (VGCC), in which currents are transient owing to fast inactivation, and tiny, due to small conductance. Mutations in CACNA1G cause generalized absence epilepsy and adult-onset, dominantly inherited, spinocerebellar ataxia type 42. In this kindred, the aforementioned CACNA1G variant segregated with disease, which was consistent with episodic vestibulocerebellar ataxia. CBZ proved successful in bout prevention and provided symptomatic benefit in the proband, probably as a result of interaction of this drug with VGCC. Further studies are needed to fully determine the vestibular and neurological manifestations of this form of episodic vestibulocerebellar ataxia. This novel disease variant could be designated episodic vestibulocerebellar ataxia type 10.
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Affiliation(s)
- José Gazulla
- Department of Neurology, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - Silvia Izquierdo-Alvarez
- Section of Genetics, Department of Clinical Biochemistry, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | | | - Alba Lázaro-Romero
- Department of Neurology, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - José Berciano
- Department of Neurology, Hospital Universitario Marqués de Valdecilla (IDIVAL), University of Cantabria, CIBERNED, Santander, Spain
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32
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Keihani S, Kluever V, Fornasiero EF. Brain Long Noncoding RNAs: Multitask Regulators of Neuronal Differentiation and Function. Molecules 2021; 26:molecules26133951. [PMID: 34203457 PMCID: PMC8272081 DOI: 10.3390/molecules26133951] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
The extraordinary cellular diversity and the complex connections established within different cells types render the nervous system of vertebrates one of the most sophisticated tissues found in living organisms. Such complexity is ensured by numerous regulatory mechanisms that provide tight spatiotemporal control, robustness and reliability. While the unusual abundance of long noncoding RNAs (lncRNAs) in nervous tissues was traditionally puzzling, it is becoming clear that these molecules have genuine regulatory functions in the brain and they are essential for neuronal physiology. The canonical view of RNA as predominantly a 'coding molecule' has been largely surpassed, together with the conception that lncRNAs only represent 'waste material' produced by cells as a side effect of pervasive transcription. Here we review a growing body of evidence showing that lncRNAs play key roles in several regulatory mechanisms of neurons and other brain cells. In particular, neuronal lncRNAs are crucial for orchestrating neurogenesis, for tuning neuronal differentiation and for the exact calibration of neuronal excitability. Moreover, their diversity and the association to neurodegenerative diseases render them particularly interesting as putative biomarkers for brain disease. Overall, we foresee that in the future a more systematic scrutiny of lncRNA functions will be instrumental for an exhaustive understanding of neuronal pathophysiology.
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33
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Harvey S, King MD, Gorman KM. Paroxysmal Movement Disorders. Front Neurol 2021; 12:659064. [PMID: 34177764 PMCID: PMC8232056 DOI: 10.3389/fneur.2021.659064] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/20/2021] [Indexed: 11/13/2022] Open
Abstract
Paroxysmal movement disorders (PxMDs) are a clinical and genetically heterogeneous group of movement disorders characterized by episodic involuntary movements (dystonia, dyskinesia, chorea and/or ataxia). Historically, PxMDs were classified clinically (triggers and characteristics of the movements) and this directed single-gene testing. With the advent of next-generation sequencing (NGS), how we classify and investigate PxMDs has been transformed. Next-generation sequencing has enabled new gene discovery (RHOBTB2, TBC1D24), expansion of phenotypes in known PxMDs genes and a better understanding of disease mechanisms. However, PxMDs exhibit phenotypic pleiotropy and genetic heterogeneity, making it challenging to predict genotype based on the clinical phenotype. For example, paroxysmal kinesigenic dyskinesia is most commonly associated with variants in PRRT2 but also variants identified in PNKD, SCN8A, and SCL2A1. There are no radiological or biochemical biomarkers to differentiate genetic causes. Even with NGS, diagnosis rates are variable, ranging from 11 to 51% depending on the cohort studied and technology employed. Thus, a large proportion of patients remain undiagnosed compared to other neurological disorders such as epilepsy, highlighting the need for further genomic research in PxMDs. Whole-genome sequencing, deep-sequencing, copy number variant analysis, detection of deep-intronic variants, mosaicism and repeat expansions, will improve diagnostic rates. Identifying the underlying genetic cause has a significant impact on patient care, modification of treatment, long-term prognostication and genetic counseling. This paper provides an update on the genetics of PxMDs, description of PxMDs classified according to causative gene rather than clinical phenotype, highlighting key clinical features and providing an algorithm for genetic testing of PxMDs.
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Affiliation(s)
- Susan Harvey
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Kathleen M Gorman
- Department of Paediatric Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
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34
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Ahmad MA, Pottoo FH, Akbar M. Gene Therapy Repairs for the Epileptic Brain: Potential for Treatment and Future Directions. Curr Gene Ther 2021; 19:367-375. [PMID: 32003688 DOI: 10.2174/1566523220666200131142423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 01/01/2020] [Accepted: 01/15/2020] [Indexed: 01/19/2023]
Abstract
Epilepsy is a syndrome specified by frequent seizures and is one of the most prevalent neurological conditions, and that one-third of people of epilepsy are resistant to available drugs. Surgery is supposed to be the main treatment for the remedy of multiple drug-resistant epilepsy, but it is a drastic procedure. Advancement in genomic technologies indicates that gene therapy can make such surgery unnecessary. The considerable number of new studies show the significance of mutation in mammalian target of rapamycin pathway, NMDA receptors, GABA receptors, potassium channels and G-protein coupled receptors. Illustration of the meticulous drug in epilepsy targeting new expression of mutations in SCN8A, GRIN2A, GRIN2D and KCNT1 are conferred. Various methods are utilized to express a gene in a precise area of the brain; Transplantation of cells in an ex vivo approach (fetal cells, fibroblasts, immortalized cells), nonviral vector delivery and viral vector delivery like retrovirus, herpes simplex virus adenovirus and adeno-related virus. Gene therapy has thus been explored to generate anti-epileptogenic, anti-seizure and disease-modifying effects. Specific targeting of the epileptogenic region is facilitated by gene therapy, hence sparing the adjacent healthy tissue and decreasing the adverse effects that frequently go hand in hand with antiepileptic medication.
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Affiliation(s)
- Md A Ahmad
- Department of Pharmacology, Faculty of Pharmacy, Integral University, Lucknow, India
| | - Faheem H Pottoo
- Department of Pharmacology, College of Clinical Pharmacy, Imam Abdul Rahman Bin Faisal University, P.O. Box 1982, Dammam, 31441, Saudi Arabia
| | - Md Akbar
- Department of Pharmacology, School of Pharmaceutical, Education and Research, Jamia Hamdard, New Delhi- 110062, India
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35
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Field MJ, Kumar R, Hackett A, Kayumi S, Shoubridge CA, Ewans LJ, Ivancevic AM, Dudding-Byth T, Carroll R, Kroes T, Gardner AE, Sullivan P, Ha TT, Schwartz CE, Cowley MJ, Dinger ME, Palmer EE, Christie L, Shaw M, Roscioli T, Gecz J, Corbett MA. Different types of disease-causing noncoding variants revealed by genomic and gene expression analyses in families with X-linked intellectual disability. Hum Mutat 2021; 42:835-847. [PMID: 33847015 DOI: 10.1002/humu.24207] [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: 07/05/2020] [Revised: 03/19/2021] [Accepted: 04/08/2021] [Indexed: 11/06/2022]
Abstract
The pioneering discovery research of X-linked intellectual disability (XLID) genes has benefitted thousands of individuals worldwide; however, approximately 30% of XLID families still remain unresolved. We postulated that noncoding variants that affect gene regulation or splicing may account for the lack of a genetic diagnosis in some cases. Detecting pathogenic, gene-regulatory variants with the same sensitivity and specificity as structural and coding variants is a major challenge for Mendelian disorders. Here, we describe three pedigrees with suggestive XLID where distinctive phenotypes associated with known genes guided the identification of three different noncoding variants. We used comprehensive structural, single-nucleotide, and repeat expansion analyses of genome sequencing. RNA-Seq from patient-derived cell lines, reverse-transcription polymerase chain reactions, Western blots, and reporter gene assays were used to confirm the functional effect of three fundamentally different classes of pathogenic noncoding variants: a retrotransposon insertion, a novel intronic splice donor, and a canonical splice variant of an untranslated exon. In one family, we excluded a rare coding variant in ARX, a known XLID gene, in favor of a regulatory noncoding variant in OFD1 that correlated with the clinical phenotype. Our results underscore the value of genomic research on unresolved XLID families to aid novel, pathogenic noncoding variant discovery.
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Affiliation(s)
- Michael J Field
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia
| | - Raman Kumar
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Anna Hackett
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - Sayaka Kayumi
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Cheryl A Shoubridge
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Lisa J Ewans
- St Vincent's Clinical School, University of New South Wales, Darlinghurst, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Atma M Ivancevic
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| | - Tracy Dudding-Byth
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - Renée Carroll
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Thessa Kroes
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Alison E Gardner
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Patricia Sullivan
- Children's Cancer Institute, University of New South Wales, Kensington, New South Wales, Australia
| | - Thuong T Ha
- Molecular Pathology Department, Centre for Cancer Biology, SA Pathology, Adelaide, South Australia, Australia
| | | | - Mark J Cowley
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.,Children's Cancer Institute, University of New South Wales, Kensington, New South Wales, Australia
| | - Marcel E Dinger
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales, Australia
| | - Elizabeth E Palmer
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia.,School of Women's and Children's Health, University of New South Wales, Kensington, Sydney, New South Wales, Australia
| | - Louise Christie
- NSW Genetics of Learning Disability Service, Newcastle, New South Wales, Australia
| | - Marie Shaw
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
| | - Tony Roscioli
- NeuRA, University of New South Wales, Sydney, New South Wales, Australia.,Centre for Clinical Genetics, Sydney Children's Hospital, Randwick, Sydney, New South Wales, Australia
| | - Jozef Gecz
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Mark A Corbett
- Adelaide Medical School and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
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36
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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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37
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de Gusmão CM, Garcia L, Mikati MA, Su S, Silveira-Moriyama L. Paroxysmal Genetic Movement Disorders and Epilepsy. Front Neurol 2021; 12:648031. [PMID: 33833732 PMCID: PMC8021799 DOI: 10.3389/fneur.2021.648031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 02/22/2021] [Indexed: 01/08/2023] Open
Abstract
Paroxysmal movement disorders include paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia, and episodic ataxias. In recent years, there has been renewed interest and recognition of these disorders and their intersection with epilepsy, at the molecular and pathophysiological levels. In this review, we discuss how these distinct phenotypes were constructed from a historical perspective and discuss how they are currently coalescing into established genetic etiologies with extensive pleiotropy, emphasizing clinical phenotyping important for diagnosis and for interpreting results from genetic testing. We discuss insights on the pathophysiology of select disorders and describe shared mechanisms that overlap treatment principles in some of these disorders. In the near future, it is likely that a growing number of genes will be described associating movement disorders and epilepsy, in parallel with improved understanding of disease mechanisms leading to more effective treatments.
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Affiliation(s)
- Claudio M. de Gusmão
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
| | - Lucas Garcia
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
| | - Mohamad A. Mikati
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Samantha Su
- Division of Pediatric Neurology and Developmental Medicine, Duke University Medical Center, Durham, NC, United States
| | - Laura Silveira-Moriyama
- Department of Neurology, Universidade Estadual de Campinas (UNICAMP), São Paulo, Brazil
- Department of Medicine, Universidade 9 de Julho, São Paulo, Brazil
- Education Unit, University College London Institute of Neurology, University College London, London, United Kingdom
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38
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Heron SE, Regan BM, Harris RV, Gardner AE, Coleman MJ, Bennett MF, Grinton BE, Helbig KL, Sperling MR, Haut S, Geller EB, Widdess-Walsh P, Pelekanos JT, Bahlo M, Petrovski S, Heinzen EL, Hildebrand MS, Corbett MA, Scheffer IE, Gécz J, Berkovic SF. Association of SLC32A1 Missense Variants With Genetic Epilepsy With Febrile Seizures Plus. Neurology 2021; 96:e2251-e2260. [PMID: 34038384 DOI: 10.1212/wnl.0000000000011855] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/05/2021] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the causative gene in a large unsolved family with genetic epilepsy with febrile seizures plus (GEFS+), we sequenced the genomes of family members, and then determined the contribution of the identified gene to the pathogenicity of epilepsies by examining sequencing data from 2,772 additional patients. METHODS We performed whole genome sequencing of 3 members of a GEFS+ family. Subsequently, whole exome sequencing data from 1,165 patients with epilepsy from the Epi4K dataset and 1,329 Australian patients with epilepsy from the Epi25 dataset were interrogated. Targeted resequencing was performed on 278 patients with febrile seizures or GEFS+ phenotypes. Variants were validated and familial segregation examined by Sanger sequencing. RESULTS Eight previously unreported missense variants were identified in SLC32A1, coding for the vesicular inhibitory amino acid cotransporter VGAT. Two variants cosegregated with the phenotype in 2 large GEFS+ families containing 8 and 10 affected individuals, respectively. Six further variants were identified in smaller families with GEFS+ or idiopathic generalized epilepsy (IGE). CONCLUSION Missense variants in SLC32A1 cause GEFS+ and IGE. These variants are predicted to alter γ-aminobutyric acid (GABA) transport into synaptic vesicles, leading to altered neuronal inhibition. Examination of further epilepsy cohorts will determine the full genotype-phenotype spectrum associated with SLC32A1 variants.
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Affiliation(s)
- Sarah E Heron
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Brigid M Regan
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Rebekah V Harris
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Alison E Gardner
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Matthew J Coleman
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Mark F Bennett
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Bronwyn E Grinton
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Katherine L Helbig
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Michael R Sperling
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Sheryl Haut
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Eric B Geller
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Peter Widdess-Walsh
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - James T Pelekanos
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Melanie Bahlo
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Slavé Petrovski
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Erin L Heinzen
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Michael S Hildebrand
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Mark A Corbett
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Ingrid E Scheffer
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Jozef Gécz
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia.
| | - Samuel F Berkovic
- From the Adelaide Medical School, Faculty of Health and Medical Sciences (S.E.H., A.E.G., M.A.C., J.G.), and Robinson Research Institute (J.G.), The University of Adelaide; Epilepsy Research Centre, Department of Medicine (B.M.R., R.V.H., M.C., B.E.G., M.F.B., S.P., M.S.H., I.E.S., S.F.B.), Austin Health, University of Melbourne, Heidelberg; Population Health and Immunity Division (M.F.B., M.B.), The Walter and Eliza Hall Institute of Medical Research; Department of Medical Biology (M.F.B., M.B.), University of Melbourne, Parkville, Australia; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia; Department of Neurology (M.R.S.), Thomas Jefferson University, Philadelphia, PA; Department of Neurology (S.H.), Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY; Institute of Neurology and Neurosurgery at Saint Barnabas (E.B.G.), Livingston, NJ; Department of Neurology (P.W.-W.), Beaumont Hospital, Dublin, Ireland; Royal Brisbane and Women's Hospital (J.T.P.), Brisbane, Australia; Centre for Genomics Research (S.P.), Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK; Institute for Genomic Medicine (E.L.H.), Columbia University Medical Center, New York, NY; Murdoch Children's Research Institute (M.S.H., I.E.S.), Parkville; Department of Paediatrics (I.E.S.), Royal Children's Hospital, University of Melbourne; Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne; and Healthy Mothers, Babies and Children (J.G.), South Australian Health and Medical Research Institute, Adelaide, Australia
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Refining Genotypes and Phenotypes in KCNA2-Related Neurological Disorders. Int J Mol Sci 2021; 22:ijms22062824. [PMID: 33802230 PMCID: PMC7999221 DOI: 10.3390/ijms22062824] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 02/06/2023] Open
Abstract
Pathogenic variants in KCNA2, encoding for the voltage-gated potassium channel Kv1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of KCNA2-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel KCNA2 variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)–valine(406)–proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of KCNA2-related disorders. Our study provides further insights into the clinical spectrum, genotype–phenotype correlation, variability, and predicted functional impact of KCNA2 variants.
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Morrison-Levy N, Borlot F, Jain P, Whitney R. Early-Onset Developmental and Epileptic Encephalopathies of Infancy: An Overview of the Genetic Basis and Clinical Features. Pediatr Neurol 2021; 116:85-94. [PMID: 33515866 DOI: 10.1016/j.pediatrneurol.2020.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 12/19/2022]
Abstract
Our current knowledge of genetically determined forms of epilepsy has shortened the diagnostic pathway usually experienced by the families of infants diagnosed with early-onset developmental and epileptic encephalopathies. Genetic causes can be found in up to 80% of infants presenting with early-onset developmental and epileptic encephalopathies, often in the context of an uneventful perinatal history and with no clear underlying brain abnormalities. Although current disease-specific therapies remain limited and patient outcomes are often guarded, a genetic diagnosis may lead to early therapeutic intervention using new and/or repurposed therapies. In this review, an overview of epilepsy genetics, the indications for genetic testing in infants, the advantages and limitations of each test, and the challenges and ethical implications of genetic testing are discussed. In addition, the following causative genes associated with early-onset developmental and epileptic encephalopathies are discussed in detail: KCNT1, KCNQ2, KCNA2, SCN2A, SCN8A, STXBP1, CDKL5, PIGA, SPTAN1, and GNAO1. The epilepsy phenotypes, comorbidities, electroencephalgraphic findings, neuroimaging findings, and potential targeted therapies for each gene are reviewed.
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Affiliation(s)
| | - Felippe Borlot
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Puneet Jain
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Robyn Whitney
- Division of Neurology, Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada.
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Zhang S, Zhang X, Purmann C, Ma S, Shrestha A, Davis KN, Ho M, Huang Y, Pattni R, Hung Wong W, Bernstein JA, Hallmayer J, Urban AE. Network Effects of the 15q13.3 Microdeletion on the Transcriptome and Epigenome in Human-Induced Neurons. Biol Psychiatry 2021; 89:497-509. [PMID: 32919612 PMCID: PMC9359316 DOI: 10.1016/j.biopsych.2020.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND The 15q13.3 microdeletion is associated with several neuropsychiatric disorders, including autism and schizophrenia. Previous association and functional studies have investigated the potential role of several genes within the deletion in neuronal dysfunction, but the molecular effects of the deletion as a whole remain largely unknown. METHODS Induced pluripotent stem cells, from 3 patients with the 15q13.3 microdeletion and 3 control subjects, were generated and converted into induced neurons. We analyzed the effects of the 15q13.3 microdeletion on genome-wide gene expression, DNA methylation, chromatin accessibility, and sensitivity to cisplatin-induced DNA damage. Furthermore, we measured gene expression changes in induced neurons with CRISPR (clustered regularly interspaced short palindromic repeats) knockouts of individual 15q13.3 microdeletion genes. RESULTS In both induced pluripotent stem cells and induced neurons, gene copy number change within the 15q13.3 microdeletion was accompanied by significantly decreased gene expression and no compensatory changes in DNA methylation or chromatin accessibility, supporting the model that haploinsufficiency of genes within the deleted region drives the disorder. Furthermore, we observed global effects of the microdeletion on the transcriptome and epigenome, with disruptions in several neuropsychiatric disorder-associated pathways and gene families, including Wnt signaling, ribosome function, DNA binding, and clustered protocadherins. Individual gene knockouts mirrored many of the observed changes in an overlapping fashion between knockouts. CONCLUSIONS Our multiomics analysis of the 15q13.3 microdeletion revealed downstream effects in pathways previously associated with neuropsychiatric disorders and indications of interactions between genes within the deletion. This molecular systems analysis can be applied to other chromosomal aberrations to further our etiological understanding of neuropsychiatric disorders.
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Affiliation(s)
- Siming Zhang
- Department of Genetics, School of Humanities and Science, Stanford University, Stanford, California
| | - Xianglong Zhang
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Carolin Purmann
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Shining Ma
- Department of Pediatrics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Anima Shrestha
- School of Medicine, Stanford University, and Department of Statistics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Kasey N Davis
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Marcus Ho
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Yiling Huang
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Reenal Pattni
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Wing Hung Wong
- Department of Pediatrics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Jonathan A Bernstein
- Department of Human Biology, School of Humanities and Science, Stanford University, Stanford, California
| | - Joachim Hallmayer
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Alexander E Urban
- Department of Genetics, School of Humanities and Science, Stanford University, Stanford, California; Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California.
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Qin C, Wan X, Li S, Yang F, Yang L, Zuo Z, Cao Z, Chen Z, Wu Y. Different pharmacological properties between scorpion toxin BmKcug2 and its degraded analogs highlight the diversity of K + channel blockers from thermally processed scorpions. Int J Biol Macromol 2021; 178:143-153. [PMID: 33636268 DOI: 10.1016/j.ijbiomac.2021.02.155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/16/2021] [Accepted: 02/20/2021] [Indexed: 11/16/2022]
Abstract
Novel degraded potassium channel-modulatory peptides were recently found in thermally processed scorpions, but their pharmacological properties remain unclear. Here, we identified a full-length scorpion toxin (i.e., BmKcug2) and its four truncated analogs (i.e., BmKcug2-P1, BmKcug2-P2, BmKcug2-P3 and BmKcug2-P4) with three conserved disulfide bonds in processed scorpion medicinal material by mass spectrometry. The pharmacological experiments revealed that the recombinant BmKcug2 and BmKcug2-P1 could selectively inhibit the human Kv1.2 and human Kv1.3 potassium channels, while the other three analogs showed a much weaker inhibitory effect on potassium channels. BmKcug2 inhibited hKv1.2 and hKv1.3 channels, with IC50 values of 45.6 ± 5.8 nM and 215.2 ± 39.7 nM, respectively, and BmKcug2-P1 inhibited hKv1.2 and hKv1.3, with IC50 values of 89.9 ± 9.6 nM and 1142.4 ± 64.5 nM, respectively. The chromatographic analysis and pharmacological properties of BmKcug2 and BmKcug2-P1 boiled in water for different times further strongly supported their good thermal stability. Structural and functional dissection indicated that one amino acid, i.e., Tyr36, determined the differential affinities of BmKcug2 and four BmKcug2 analogs. Altogether, this research investigated the different pharmacological properties of BmKcug2 and its truncated analogs, and the findings highlighted the diversity of K+ channel blockers from various scorpion species through thermal processing.
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Affiliation(s)
- Chenhu Qin
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiuping Wan
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Songryong Li
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Department of Biotechnology, Institute for Life Science, Kim Hyong Jik University of Education, Pyongyang, Democratic People's Republic of Korea
| | - Fan Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Liuting Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zheng Zuo
- Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zongyun Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China.
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Timäus C, von Gottberg P, Hirschel S, Lange C, Wiltfang J, Hansen N. KCNA2 Autoimmunity in Progressive Cognitive Impairment: Case Series and Literature Review. Brain Sci 2021; 11:89. [PMID: 33445475 PMCID: PMC7826663 DOI: 10.3390/brainsci11010089] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 12/31/2022] Open
Abstract
Autoimmune dementia is a novel and expanding field which subsumes neuropsychiatric disorders with predominant cognitive impairments due to an underlying autoimmune etiology. Progressive dementias with atypical clinical presentation should trigger a thorough diagnostic approach including testing for neural surface and intracellular antibodies to avoid a delay in accurate diagnosis and initiating appropriate therapy. Here, we present two emerging cases of progressive dementia with co-existing serum autoantibodies against the KCNA2 (potassium voltage-gated channel subfamily A member 2) subunit. We found various cognitive deficits with dominant impairments in the memory domain, particularly in delayed recall. One patient presented a subacute onset of then-persisting cognitive deficits, while the other patient's cognitive impairments progressed more chronically and fluctuated. Cognitive impairments coincided with additional neuropsychiatric symptoms. Both had a potential paraneoplastic background according to their medical history and diagnostic results. We discuss the potential role of KCNA2 autoantibodies in these patients and in general by reviewing the literature. The pathogenetic role of KCNA2 antibodies in cognitive impairment is not well delineated; clinical presentations are heterogeneous, and thus a causal link between antibodies remains questionable. Current evidence indicates an intracellular rather than extracellular epitope. We strongly suggest additional prospective studies to explore KCNA2 antibodies in specifically-defined cohorts of cognitively impaired patients via a systematic assessment of clinical, neuropsychological, neuroimaging, as well as laboratory and CSF (cerebrospinal fluid) parameters, and antibody studies to (1) determine the epitope's location (intracellular vs. extracellular), (2) the mode of action, and (3) seek co-existing, novel pathogenetic autoantibodies in sera and CSF.
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Affiliation(s)
- Charles Timäus
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Philipp von Gottberg
- Department of Neuroradiology, University Medical Center Goettingen, Robert-Koch-Str. 40, 37075 Goettingen, Germany;
| | - Sina Hirschel
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Claudia Lange
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Jens Wiltfang
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Goettingen, Germany
- Neurosciences and Signaling Group, Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Niels Hansen
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
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Pantazis A, Kaneko M, Angelini M, Steccanella F, Westerlund AM, Lindström SH, Nilsson M, Delemotte L, Saitta SC, Olcese R. Tracking the motion of the K V1.2 voltage sensor reveals the molecular perturbations caused by a de novo mutation in a case of epilepsy. J Physiol 2020; 598:5245-5269. [PMID: 32833227 PMCID: PMC8923147 DOI: 10.1113/jp280438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/14/2020] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS KV1.2 channels, encoded by the KCNA2 gene, regulate neuronal excitability by conducting K+ upon depolarization. A new KCNA2 missense variant was discovered in a patient with epilepsy, causing amino acid substitution F302L at helix S4, in the KV1.2 voltage-sensing domain. Immunocytochemistry and flow cytometry showed that F302L does not impair KCNA2 subunit surface trafficking. Molecular dynamics simulations indicated that F302L alters the exposure of S4 residues to membrane lipids. Voltage clamp fluorometry revealed that the voltage-sensing domain of KV1.2-F302L channels is more sensitive to depolarization. Accordingly, KV1.2-F302L channels opened faster and at more negative potentials; however, they also exhibited enhanced inactivation: that is, F302L causes both gain- and loss-of-function effects. Coexpression of KCNA2-WT and -F302L did not fully rescue these effects. The proband's symptoms are more characteristic of patients with loss of KCNA2 function. Enhanced KV1.2 inactivation could lead to increased synaptic release in excitatory neurons, steering neuronal circuits towards epilepsy. ABSTRACT An exome-based diagnostic panel in an infant with epilepsy revealed a previously unreported de novo missense variant in KCNA2, which encodes voltage-gated K+ channel KV1.2. This variant causes substitution F302L, in helix S4 of the KV1.2 voltage-sensing domain (VSD). F302L does not affect KCNA2 subunit membrane trafficking. However, it does alter channel functional properties, accelerating channel opening at more hyperpolarized membrane potentials, indicating gain of function. F302L also caused loss of KV1.2 function via accelerated inactivation onset, decelerated recovery and shifted inactivation voltage dependence to more negative potentials. These effects, which are not fully rescued by coexpression of wild-type and mutant KCNA2 subunits, probably result from the enhancement of VSD function, as demonstrated by optically tracking VSD depolarization-evoked conformational rearrangements. In turn, molecular dynamics simulations suggest altered VSD exposure to membrane lipids. Compared to other encephalopathy patients with KCNA2 mutations, the proband exhibits mild neurological impairment, more characteristic of patients with KCNA2 loss of function. Based on this information, we propose a mechanism of epileptogenesis based on enhanced KV1.2 inactivation leading to increased synaptic release preferentially in excitatory neurons, and hence the perturbation of the excitatory/inhibitory balance of neuronal circuits.
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Affiliation(s)
- Antonios Pantazis
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
- Wallenberg Center for Molecular Medicine, Linköping University, Linköping, Sweden
| | - Maki Kaneko
- Center for Personalized Medicine, Children's Hospital, Los Angeles, Los Angeles, CA, USA
- Division of Genomic Medicine, Department of Pathology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Marina Angelini
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Federica Steccanella
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Annie M Westerlund
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Sarah H Lindström
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Michelle Nilsson
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Lucie Delemotte
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Sulagna C Saitta
- Department of Obstetrics and Gynecology and Division of Medical Genetics, Department of Pediatrics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Riccardo Olcese
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Department of Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
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Hirose S, Tanaka Y, Shibata M, Kimura Y, Ishikawa M, Higurashi N, Yamamoto T, Ichise E, Chiyonobu T, Ishii A. Application of induced pluripotent stem cells in epilepsy. Mol Cell Neurosci 2020; 108:103535. [DOI: 10.1016/j.mcn.2020.103535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
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Chivukula AS, Suslova M, Kortzak D, Kovermann P, Fahlke C. Functional consequences of SLC1A3 mutations associated with episodic ataxia 6. Hum Mutat 2020; 41:1892-1905. [PMID: 32741053 DOI: 10.1002/humu.24089] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/09/2020] [Accepted: 07/27/2020] [Indexed: 11/09/2022]
Abstract
The episodic ataxias (EA) are a group of inherited neurological diseases characterized by paroxysmal cerebellar incoordination. There exist nine forms of episodic ataxia with distinct neurological symptoms and genetic origins. Episodic ataxia type 6 (EA6) differs from other EA forms in long attack duration, epilepsy and absent myokymia, nystagmus, and tinnitus. It has been described in seven families, and mutations in SLC1A3, the gene encoding the glial glutamate transporter EAAT1, were reported in each family. How these mutations affect EAAT1 expression, subcellular localization, and function, and how such alterations result in the complex neurological phenotype of EA6 is insufficiently understood. We here compare the functional consequences of all currently known mutations by heterologous expression in mammalian cells, biochemistry, confocal imaging, and whole-cell patch clamp recordings of EAAT1 transport and anion currents. We observed impairments of multiple EAAT1 properties ranging from changes in transport function, impaired trafficking to increased protein expression. Many mutations caused only slight changes illustrating how sensitively the cerebellum reacts on impaired EAAT1 functions.
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Affiliation(s)
- Aparna S Chivukula
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Jülich, Germany
| | - Mariia Suslova
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Jülich, Germany
| | - Daniel Kortzak
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Jülich, Germany
| | - Peter Kovermann
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Jülich, Germany
| | - Christoph Fahlke
- Institute of Biological Information Processing, Molekular- und Zellphysiologie (IBI-1) Forschungszentrum Jülich, Jülich, Germany
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Giunti P, Mantuano E, Frontali M. Episodic Ataxias: Faux or Real? Int J Mol Sci 2020; 21:ijms21186472. [PMID: 32899446 PMCID: PMC7555854 DOI: 10.3390/ijms21186472] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 11/22/2022] Open
Abstract
The term Episodic Ataxias (EA) was originally used for a few autosomal dominant diseases, characterized by attacks of cerebellar dysfunction of variable duration and frequency, often accompanied by other ictal and interictal signs. The original group subsequently grew to include other very rare EAs, frequently reported in single families, for some of which no responsible gene was found. The clinical spectrum of these diseases has been enormously amplified over time. In addition, episodes of ataxia have been described as phenotypic variants in the context of several different disorders. The whole group is somewhat confused, since a strong evidence linking the mutation to a given phenotype has not always been established. In this review we will collect and examine all instances of ataxia episodes reported so far, emphasizing those for which the pathophysiology and the clinical spectrum is best defined.
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Affiliation(s)
- Paola Giunti
- Laboratory of Neurogenetics, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC2N 5DU, UK
- Correspondence: (P.G.); (M.F.)
| | - Elide Mantuano
- Laboratory of Neurogenetics, Institute of Translational Pharmacology, National Research Council of Italy, 00133 Rome, Italy;
| | - Marina Frontali
- Laboratory of Neurogenetics, Institute of Translational Pharmacology, National Research Council of Italy, 00133 Rome, Italy;
- Correspondence: (P.G.); (M.F.)
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Lewis-Smith D, Ellis CA, Helbig I, Thomas RH. Early-onset genetic epilepsies reaching adult clinics. Brain 2020; 143:e19. [PMID: 32203577 DOI: 10.1093/brain/awaa029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- David Lewis-Smith
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UK.,Royal Victoria Infirmary, Newcastle-upon-Tyne, UK
| | - Colin A Ellis
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | - Ingo Helbig
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Biomedical and Health Informatics (DBHi), Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rhys H Thomas
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne, UK.,Royal Victoria Infirmary, Newcastle-upon-Tyne, UK
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Chow CY, Absalom N, Biggs K, King GF, Ma L. Venom-derived modulators of epilepsy-related ion channels. Biochem Pharmacol 2020; 181:114043. [PMID: 32445870 DOI: 10.1016/j.bcp.2020.114043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/18/2020] [Indexed: 12/18/2022]
Abstract
Epilepsy is characterised by spontaneous recurrent seizures that are caused by an imbalance between neuronal excitability and inhibition. Since ion channels play fundamental roles in the generation and propagation of action potentials as well as neurotransmitter release at a subset of excitatory and inhibitory synapses, their dysfunction has been linked to a wide variety of epilepsies. Indeed, these unique proteins are the major biological targets for antiepileptic drugs. Selective targeting of a specific ion channel subtype remains challenging for small molecules, due to the high level of homology among members of the same channel family. As a consequence, there is a growing trend to target ion channels with biologics. Venoms are the best known natural source of ion channel modulators, and venom peptides are increasingly recognised as potential therapeutics due to their high selectivity and potency gained through millions of years of evolutionary selection pressure. Here we describe the major ion channel families involved in the pathogenesis of various types of epilepsy, including voltage-gated Na+, K+, Ca2+ channels, Cys-loop receptors, ionotropic glutamate receptors and P2X receptors, and currently available venom-derived peptides that target these channel proteins. Although only a small number of venom peptides have successfully progressed to the clinic, there is reason to be optimistic about their development as antiepileptic drugs, notwithstanding the challenges associated with development of any class of peptide drug.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nathan Absalom
- Brain and Mind Centre, School of Pharmacy, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW 2050, Australia
| | - Kimberley Biggs
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Linlin Ma
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia.
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50
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Clinical and Genetic Overview of Paroxysmal Movement Disorders and Episodic Ataxias. Int J Mol Sci 2020; 21:ijms21103603. [PMID: 32443735 PMCID: PMC7279391 DOI: 10.3390/ijms21103603] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/15/2022] Open
Abstract
Paroxysmal movement disorders (PMDs) are rare neurological diseases typically manifesting with intermittent attacks of abnormal involuntary movements. Two main categories of PMDs are recognized based on the phenomenology: Paroxysmal dyskinesias (PxDs) are characterized by transient episodes hyperkinetic movement disorders, while attacks of cerebellar dysfunction are the hallmark of episodic ataxias (EAs). From an etiological point of view, both primary (genetic) and secondary (acquired) causes of PMDs are known. Recognition and diagnosis of PMDs is based on personal and familial medical history, physical examination, detailed reconstruction of ictal phenomenology, neuroimaging, and genetic analysis. Neurophysiological or laboratory tests are reserved for selected cases. Genetic knowledge of PMDs has been largely incremented by the advent of next generation sequencing (NGS) methodologies. The wide number of genes involved in the pathogenesis of PMDs reflects a high complexity of molecular bases of neurotransmission in cerebellar and basal ganglia circuits. In consideration of the broad genetic and phenotypic heterogeneity, a NGS approach by targeted panel for movement disorders, clinical or whole exome sequencing should be preferred, whenever possible, to a single gene approach, in order to increase diagnostic rate. This review is focused on clinical and genetic features of PMDs with the aim to (1) help clinicians to recognize, diagnose and treat patients with PMDs as well as to (2) provide an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.
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