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Montanucci L, Brünger T, Bhattarai N, Boßelmann CM, Kim S, Allen JP, Zhang J, Klöckner C, Fariselli P, May P, Lemke JR, Myers SJ, Yuan H, Traynelis SF, Lal D. Distances from ligands as main predictive features for pathogenicity and functional effect of variants in NMDA receptors. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.06.24306939. [PMID: 38766179 PMCID: PMC11100844 DOI: 10.1101/2024.05.06.24306939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Genetic variants in genes GRIN1 , GRIN2A , GRIN2B , and GRIN2D , which encode subunits of the N-methyl-D-aspartate receptor (NMDAR), have been associated with severe and heterogeneous neurologic diseases. Missense variants in these genes can result in gain or loss of the NMDAR function, requiring opposite therapeutic treatments. Computational methods that predict pathogenicity and molecular functional effects are therefore crucial for accurate diagnosis and therapeutic applications. We assembled missense variants: 201 from patients, 631 from general population, and 159 characterized by electrophysiological readouts showing whether they can enhance or reduce the receptor function. This includes new functional data from 47 variants reported here, for the first time. We found that pathogenic/benign variants and variants that increase/decrease the channel function were distributed unevenly on the protein structure, with spatial proximity to ligands bound to the agonist and antagonist binding sites being key predictive features. Leveraging distances from ligands, we developed two independent machine learning-based predictors for NMDAR missense variants: a pathogenicity predictor which outperforms currently available predictors (AUC=0.945, MCC=0.726), and the first binary predictor of molecular function (increase or decrease) (AUC=0.809, MCC=0.523). Using these, we reclassified variants of uncertain significance in the ClinVar database and refined a previous genome-informed epidemiological model to estimate the birth incidence of molecular mechanism-defined GRIN disorders. Our findings demonstrate that distance from ligands is an important feature in NMDARs that can enhance variant pathogenicity prediction and enable functional prediction. Further studies with larger numbers of phenotypically and functionally characterized variants will enhance the potential clinical utility of this method.
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Szymanowicz O, Drużdż A, Słowikowski B, Pawlak S, Potocka E, Goutor U, Konieczny M, Ciastoń M, Lewandowska A, Jagodziński PP, Kozubski W, Dorszewska J. A Review of the CACNA Gene Family: Its Role in Neurological Disorders. Diseases 2024; 12:90. [PMID: 38785745 PMCID: PMC11119137 DOI: 10.3390/diseases12050090] [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: 03/30/2024] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
Calcium channels are specialized ion channels exhibiting selective permeability to calcium ions. Calcium channels, comprising voltage-dependent and ligand-gated types, are pivotal in neuronal function, with their dysregulation is implicated in various neurological disorders. This review delves into the significance of the CACNA genes, including CACNA1A, CACNA1B, CACNA1C, CACNA1D, CACNA1E, CACNA1G, and CACNA1H, in the pathogenesis of conditions such as migraine, epilepsy, cerebellar ataxia, dystonia, and cerebellar atrophy. Specifically, variants in CACNA1A have been linked to familial hemiplegic migraine and epileptic seizures, underscoring its importance in neurological disease etiology. Furthermore, different genetic variants of CACNA1B have been associated with migraine susceptibility, further highlighting the role of CACNA genes in migraine pathology. The complex relationship between CACNA gene variants and neurological phenotypes, including focal seizures and ataxia, presents a variety of clinical manifestations of impaired calcium channel function. The aim of this article was to explore the role of CACNA genes in various neurological disorders, elucidating their significance in conditions such as migraine, epilepsy, and cerebellar ataxias. Further exploration of CACNA gene variants and their interactions with molecular factors, such as microRNAs, holds promise for advancing our understanding of genetic neurological disorders.
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Affiliation(s)
- Oliwia Szymanowicz
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Artur Drużdż
- Department of Neurology, Municipal Hospital in Poznan, 61-285 Poznan, Poland;
| | - Bartosz Słowikowski
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (B.S.); (P.P.J.)
| | - Sandra Pawlak
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Ewelina Potocka
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Ulyana Goutor
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Mateusz Konieczny
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Małgorzata Ciastoń
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Aleksandra Lewandowska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
| | - Paweł P. Jagodziński
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (B.S.); (P.P.J.)
| | - Wojciech Kozubski
- Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland;
| | - Jolanta Dorszewska
- Laboratory of Neurobiology, Department of Neurology, Poznan University of Medical Sciences, 61-701 Poznan, Poland; (O.S.); (S.P.); (E.P.); (U.G.); (M.K.); (M.C.); (A.L.)
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Sun WB, Fu JX, Chen YL, Li HF, Wu ZY, Chen DF. Both gain- and loss-of-function variants of KCNA1 are associated with paroxysmal kinesigenic dyskinesia. J Genet Genomics 2024:S1673-8527(24)00066-3. [PMID: 38570113 DOI: 10.1016/j.jgg.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/05/2024]
Abstract
KCNA1 is the coding gene for Kv1.1 voltage-gated potassium-channel α subunit. Three variants of KCNA1 have been reported to manifest as paroxysmal kinesigenic dyskinesia (PKD), but the correlation between them remains unclear due to the phenotypic complexity of KCNA1 variants as well as the rarity of PKD cases. Using the whole exome sequencing followed by Sanger sequencing, we screen for potential pathogenic KCNA1 variants in patients clinically diagnosed with paroxysmal movement disorders and identify three previously unreported missense variants of KCNA1 in three unrelated Chinese families. The proband of one family (c.496G>A, p.A166T) manifests as episodic ataxia type 1, and the other two (c.877G>A, p.V293I and c.1112C>A, p.T371A) manifest as PKD. The pathogenicity of these variants is confirmed by functional studies, suggesting that p.A166T and p.T371A cause a loss-of-function of the channel, while p.V293I leads to a gain-of-function with the property of voltage-dependent gating and activation kinetic affected. By reviewing the locations of PKD-manifested KCNA1 variants in Kv1.1 protein, we find that these variants tend to cluster around the pore domain, which is similar to epilepsy. Thus, our study strengthens the correlation between KCNA1 variants and PKD and provides more information on genotype-phenotype correlations of KCNA1 channelopathy.
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Affiliation(s)
- Wan-Bing Sun
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China
| | - Jing-Xin Fu
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Yu-Lan Chen
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Hong-Fu Li
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China
| | - Zhi-Ying Wu
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; Nanhu Brain-computer Interface Institute, Hangzhou, Zhejiang 314050, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310012, China.
| | - Dian-Fu Chen
- Department of Medical Genetics and Center for Rare Diseases, and Department of Neurology, and Zhejiang Key Laboratory of Rare Diseases for Precision Medicine and Clinical Translation in Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China; MOE Frontier Science Center for Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310012, China.
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Bashir S, Aiman A, Shahid M, Chaudhary AA, Sami N, Basir SF, Hassan I, Islam A. Amyloid-induced neurodegeneration: A comprehensive review through aggregomics perception of proteins in health and pathology. Ageing Res Rev 2024; 96:102276. [PMID: 38499161 DOI: 10.1016/j.arr.2024.102276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 03/12/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
Amyloidosis of protein caused by fibrillation and aggregation are some of the most exciting new edges not only in protein sciences but also in molecular medicines. The present review discusses recent advancements in the field of neurodegenerative diseases and therapeutic applications with ongoing clinical trials, featuring new areas of protein misfolding resulting in aggregation. The endogenous accretion of protein fibrils having fibrillar morphology symbolizes the beginning of neuro-disorders. Prognostic amyloidosis is prominent in numerous degenerative infections such as Alzheimer's and Parkinson's disease, Amyotrophic lateral sclerosis (ALS), etc. However, the molecular basis determining the intracellular or extracellular evidence of aggregates, playing a significant role as a causative factor in neurodegeneration is still unclear. Structural conversions and protein self-assembly resulting in the formation of amyloid oligomers and fibrils are important events in the pathophysiology of the disease. This comprehensive review sheds light on the evolving landscape of potential treatment modalities, highlighting the ongoing clinical trials and the potential socio-economic impact of novel therapeutic interventions in the realm of neurodegenerative diseases. Furthermore, many drugs are undergoing different levels of clinical trials that would certainly help in treating these disorders and will surely improve the socio-impact of human life.
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Affiliation(s)
- Sania Bashir
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Ayesha Aiman
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India; Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Mohammad Shahid
- Department of Basic Medical Sciences, College of Medicine, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
| | - Anis Ahmad Chaudhary
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia.
| | - Neha Sami
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Seemi Farhat Basir
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
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Mascherpa M, Fichera A, Orabona R, Recupero D, Borroni B, Odicino FE, Prefumo F. Inherited episodic ataxia type 2 in pregnancy: A case report. Int J Gynaecol Obstet 2024; 165:387-389. [PMID: 38059694 DOI: 10.1002/ijgo.15292] [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: 09/11/2023] [Revised: 11/15/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023]
Abstract
SynopsisAn optimal materno‐neonatal outcome was obtained in a pregnancy with inherited episodic ataxia through a multidisciplinary team handling timing and mode of delivery.
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Affiliation(s)
- Margaret Mascherpa
- Department of Obstetrics and Gynecology, ASST-Spedali Civili, Brescia, Italy
| | - Anna Fichera
- Department of Obstetrics and Gynecology, ASST-Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Rossana Orabona
- Department of Obstetrics and Gynecology, ASST-Spedali Civili, Brescia, Italy
| | - Daniela Recupero
- Department of Anesthesiology 1, Spedali Civili of Brescia, University of Brescia, Brescia, Italy
| | - Barbara Borroni
- Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Franco Edoardo Odicino
- Department of Obstetrics and Gynecology, ASST-Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Federico Prefumo
- Obstetrics and Gynecology Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy
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Pilotto F, Del Bondio A, Puccio H. Hereditary Ataxias: From Bench to Clinic, Where Do We Stand? Cells 2024; 13:319. [PMID: 38391932 PMCID: PMC10886822 DOI: 10.3390/cells13040319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/24/2024] Open
Abstract
Cerebellar ataxias are a wide heterogeneous group of movement disorders. Within this broad umbrella of diseases, there are both genetics and sporadic forms. The clinical presentation of these conditions can exhibit a diverse range of symptoms across different age groups, spanning from pure cerebellar manifestations to sensory ataxia and multisystemic diseases. Over the last few decades, advancements in our understanding of genetics and molecular pathophysiology related to both dominant and recessive ataxias have propelled the field forward, paving the way for innovative therapeutic strategies aimed at preventing and arresting the progression of these diseases. Nevertheless, the rarity of certain forms of ataxia continues to pose challenges, leading to limited insights into the etiology of the disease and the identification of target pathways. Additionally, the lack of suitable models hampers efforts to comprehensively understand the molecular foundations of disease's pathophysiology and test novel therapeutic interventions. In the following review, we describe the epidemiology, symptomatology, and pathological progression of hereditary ataxia, including both the prevalent and less common forms of these diseases. Furthermore, we illustrate the diverse molecular pathways and therapeutic approaches currently undergoing investigation in both pre-clinical studies and clinical trials. Finally, we address the existing and anticipated challenges within this field, encompassing both basic research and clinical endeavors.
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Affiliation(s)
- Federica Pilotto
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Andrea Del Bondio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Hélène Puccio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
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de Sousa FA, Alves CS, Pinto AN, Meireles L, Rego ÂR. Pharmacological Treatment of Acute Unilateral Vestibulopathy: A Review. J Audiol Otol 2024; 28:18-28. [PMID: 37953517 PMCID: PMC10808386 DOI: 10.7874/jao.2023.00066] [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: 02/20/2023] [Revised: 05/18/2023] [Accepted: 06/22/2023] [Indexed: 11/14/2023] Open
Abstract
There have been few investigations on the epidemiology, etiology, and medical management of acute unilateral vestibulopathy (AUV). Short-term pharmaceutical resolutions include vestibular symptomatic suppressants, anti-emetics, and some cause-based therapies. Anticholinergics, phenothiazines, antihistamines, antidopaminergics, benzodiazepines, and calcium channel antagonists are examples of vestibular suppressants. Some of these medications may show their effects through multiple mechanisms. In contrast, N-acetyl-L-leucine, Ginkgo biloba, and betahistine improve central vestibular compensation. Currently, AUV pathophysiology is poorly understood. Diverse hypotheses have previously been identified which have brought about some causal treatments presently used. According to some publications, acute administration of anti-inflammatory medications may have a deleterious impact on both post-lesional functional recovery and endogenous adaptive plasticity processes. Thus, some authors do not recommend the use of corticosteroids in AUV. Antivirals are even more contentious in the context of AUV treatment. Although vascular theories have been presented, no verified investigations employing anti-clotting or vasodilator medications have been conducted. There are no standardized treatment protocols for AUV to date, and the pharmacological treatment of AUV is still questionable. This review addresses the most current developments and controversies in AUV medical treatment.
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Affiliation(s)
- Francisco Alves de Sousa
- Otorhinolaryngology and Head & Neck Surgery Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Clara Serdoura Alves
- Otorhinolaryngology and Head & Neck Surgery Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana Nóbrega Pinto
- Otorhinolaryngology and Head & Neck Surgery Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Luís Meireles
- Otorhinolaryngology and Head & Neck Surgery Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ângela Reis Rego
- Otorhinolaryngology and Head & Neck Surgery Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
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Lyu H, Boßelmann CM, Johannesen KM, Koko M, Ortigoza-Escobar JD, Aguilera-Albesa S, Garcia-Navas Núñez D, Linnankivi T, Gaily E, van Ruiten HJA, Richardson R, Betzler C, Horvath G, Brilstra E, Geerdink N, Orsucci D, Tessa A, Gardella E, Fleszar Z, Schöls L, Lerche H, Møller RS, Liu Y. Clinical and electrophysiological features of SCN8A variants causing episodic or chronic ataxia. EBioMedicine 2023; 98:104855. [PMID: 38251463 PMCID: PMC10628346 DOI: 10.1016/j.ebiom.2023.104855] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 11/29/2023] Open
Abstract
BACKGROUND Variants in SCN8A are associated with a spectrum of epilepsies and neurodevelopmental disorders. Ataxia as a predominant symptom of SCN8A variation has not been well studied. We set out to investigate disease mechanisms and genotype-phenotype correlations of SCN8A-related ataxia. METHODS We collected genetic and electro-clinical data of ten individuals from nine unrelated families carrying novel SCN8A variants associated with chronic progressive or episodic ataxia. Electrophysiological characterizations of these variants were performed in ND7/23 cells and cultured neurons. FINDINGS Variants associated with chronic progressive ataxia either decreased Na+ current densities and shifted activation curves towards more depolarized potentials (p.Asn995Asp, p.Lys1498Glu and p.Trp1266Cys) or resulted in a premature stop codon (p.Trp937Ter). Three variants (p.Arg847Gln and biallelic p.Arg191Trp/p.Asp1525Tyr) were associated with episodic ataxia causing loss-of-function by decreasing Na+ current densities or a hyperpolarizing shift of the inactivation curve. Two additional episodic ataxia-associated variants caused mixed gain- and loss-of function effects in ND7/23 cells and were further examined in primary murine hippocampal neuronal cultures. Neuronal firing in excitatory neurons was increased by p.Arg1629His, but decreased by p.Glu1201Lys. Neuronal firing in inhibitory neurons was decreased for both variants. No functional effect was observed for p.Arg1913Trp. In four individuals, treatment with sodium channel blockers exacerbated symptoms. INTERPRETATION We identified episodic or chronic ataxia as predominant phenotypes caused by variants in SCN8A. Genotype-phenotype correlations revealed a more pronounced loss-of-function effect for variants causing chronic ataxia. Sodium channel blockers should be avoided under these conditions. FUNDING BMBF, DFG, the Italian Ministry of Health, University of Tuebingen.
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Affiliation(s)
- Hang Lyu
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Christian M Boßelmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Katrine M Johannesen
- Department of Clinical Genetics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark; Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre (Member of the ERN EpiCARE), Dianalund, Denmark
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Juan Dario Ortigoza-Escobar
- Movement Disorders Unit, Institut de Recerca Sant Joan de Déu, CIBERER-ISCIII and European Reference Network for Rare Neurological Diseases (ERN-RND), Barcelona, Spain
| | - Sergio Aguilera-Albesa
- Pediatric Neurology Unit, Department of Pediatrics, Hospital Universitario de Navarra, Pamplona, Spain; Navarrabiomed-Fundación Miguel Servet, Pamplona, Spain
| | | | - Tarja Linnankivi
- Department of Pediatric Neurology, New Children's Hospital and Pediatric Research Center, Epilepsia Helsinki, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Eija Gaily
- Department of Pediatric Neurology, New Children's Hospital and Pediatric Research Center, Epilepsia Helsinki, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Henriette J A van Ruiten
- Newcastle Upon Tyne Hospitals NHS Foundation Trust, Great North Children's Hospital, Newcastle upon Tyne, UK
| | - Ruth Richardson
- Northern Genetics Service, The Newcastle Upon Tyne Hospitals NHS Foundation Trust, UK
| | - Cornelia Betzler
- Institute for Rehabilitation, Transition and Palliation, Paracelsus Medical University, Salzburg, Austria; Specialist Center for Paediatric Neurology, Neuro-Rehabilitation and Epileptology, Schön Klinik Vogtareuth, Germany
| | - Gabriella Horvath
- Adult Metabolic Diseases Clinic, BC Children's Hospital, Vancouver, Canada
| | - Eva Brilstra
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Niels Geerdink
- Department of Pediatrics, Rijnstate Hospital, Arnhem, the Netherlands
| | | | | | - Elena Gardella
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre (Member of the ERN EpiCARE), Dianalund, Denmark; Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Denmark
| | - Zofia Fleszar
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre (Member of the ERN EpiCARE), Dianalund, Denmark; Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Denmark
| | - Yuanyuan Liu
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Tuebingen, Germany.
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Waung MW, Ma F, Wheeler AG, Zai CC, So J. The Diagnostic Landscape of Adult Neurogenetic Disorders. BIOLOGY 2023; 12:1459. [PMID: 38132285 PMCID: PMC10740572 DOI: 10.3390/biology12121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023]
Abstract
Neurogenetic diseases affect individuals across the lifespan, but accurate diagnosis remains elusive for many patients. Adults with neurogenetic disorders often undergo a long diagnostic odyssey, with multiple specialist evaluations and countless investigations without a satisfactory diagnostic outcome. Reasons for these diagnostic challenges include: (1) clinical features of neurogenetic syndromes are diverse and under-recognized, particularly those of adult-onset, (2) neurogenetic syndromes may manifest with symptoms that span multiple neurological and medical subspecialties, and (3) a positive family history may not be present or readily apparent. Furthermore, there is a large gap in the understanding of how to apply genetic diagnostic tools in adult patients, as most of the published literature focuses on the pediatric population. Despite these challenges, accurate genetic diagnosis is imperative to provide affected individuals and their families guidance on prognosis, recurrence risk, and, for an increasing number of disorders, offer targeted treatment. Here, we provide a framework for recognizing adult neurogenetic syndromes, describe the current diagnostic approach, and highlight studies using next-generation sequencing in different neurological disease cohorts. We also discuss diagnostic pitfalls, barriers to achieving a definitive diagnosis, and emerging technology that may increase the diagnostic yield of testing.
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Affiliation(s)
- Maggie W. Waung
- Division of General Neurology, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Fion Ma
- Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
| | - Allison G. Wheeler
- Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Clement C. Zai
- Tanenbaum Centre for Pharmacogenetics, Molecular Brain Science, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, Institute of Medical Science, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Joyce So
- Division of Medical Genetics, Department of Pediatrics, University of California, San Francisco, CA 94158, USA
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Gaudio A, Gotta F, Ponti C, Sanguineri F, Trevisan L, Geroldi A, Patrone S, Gemelli C, Cabona C, Astrea G, Fiorillo C, Gustincich S, Grandis M, Mandich P. Case report: Episodic ataxia without ataxia? Front Neurol 2023; 14:1224241. [PMID: 37965175 PMCID: PMC10640972 DOI: 10.3389/fneur.2023.1224241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/03/2023] [Indexed: 11/16/2023] Open
Abstract
Hereditary myopathies represent a clinically and genetically heterogeneous group of neuromuscular disorders, characterized by highly variable clinical presentations and frequently overlapping phenotypes with other neuromuscular disorders, likely influenced by genetic and environmental modifiers. Genetic testing is often challenging due to ambiguous clinical diagnosis. Here, we present the case of a family with clinical and Electromyography (EMG) features resembling a myotonia-like disorder in which Whole Exome Sequencing (WES) analysis revealed the co-segregation of two rare missense variants in UBR4 and HSPG2, genes previously associated with episodic ataxia 8 (EA8). A review of the literature highlighted a striking overlap between the clinical and the molecular features of our family and the previously described episodic ataxias (EAs), which raises concerns about the genotype-phenotype correlation, clinical variability, and the confounding overlap in these groups of disorders. This emphasizes the importance of thoroughly framing the patient's phenotype. The more clear-cut the diagnosis, the easier the identification of a genetic determinant, and the better the prognosis and the treatment of patients.
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Affiliation(s)
- Andrea Gaudio
- IRCCS Ospedale Policlinico San Martino—UOC Genetica Medica, Genova, Italy
| | - Fabio Gotta
- IRCCS Ospedale Policlinico San Martino—UOC Genetica Medica, Genova, Italy
| | - Clarissa Ponti
- IRCCS Ospedale Policlinico San Martino—UOC Genetica Medica, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
| | - Francesca Sanguineri
- IRCCS Ospedale Policlinico San Martino—UOC Genetica Medica, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
| | - Lucia Trevisan
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
- IRCCS Ospedale Policlinico San Martino—SS Centro Tumori Ereditari, Genova, Italy
| | - Alessandro Geroldi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
| | - Serena Patrone
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
| | - Chiara Gemelli
- IRCCS-Ospedale Policlinico San Martino—UOC Clinica Neurologica, Genova, Italy
| | - Corrado Cabona
- IRCCS-Ospedale Policlinico San Martino—UOC Neurofisiopatologia, Genova, Italy
| | | | - Chiara Fiorillo
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
- IRCCS Istituto Giannina Gaslini—UOC Neuropsichiatria Infantile, Genova, Italy
| | - Stefano Gustincich
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy
| | - Marina Grandis
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
- IRCCS-Ospedale Policlinico San Martino—UOC Clinica Neurologica, Genova, Italy
| | - Paola Mandich
- IRCCS Ospedale Policlinico San Martino—UOC Genetica Medica, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genova, Genova, Italy
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11
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Tedesco Silva LM, Sharma S, Schrauwen I, Margolesky J, Detyniecki K. A De Novo HECW2 Variant in a Patient with Acetazolamide-Responsive Episodic Ataxia. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1029-1033. [PMID: 35987951 DOI: 10.1007/s12311-022-01458-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
To the best of our knowledge, this is the first case to address episodic ataxia (EA) as a possible phenotypic feature of HECW2-related disorder. This single case study describes a 26-year-old female born at term with mild intellectual disability, neonatal hypotonia, and a history of febrile seizures who presented with paroxysmal events since the age of 2. These episodes include frequent falls due to imbalance, dilated pupils, vertigo, diaphoresis, nausea, vomiting, and nystagmus. Brain imaging was normal. A prolonged electroencephalogram (EEG) revealed interictal epileptiform discharges but failed to capture her clinical events. For several years, she was treated for presumed focal seizures with preserved awareness and trialed on adequate dosing of several antiepileptic medications without improvement. After 25 years, given the more prolonged nature of her episodes and the mild interictal cerebellar signs, empiric treatment with acetazolamide was initiated for a presumed diagnosis of EA. Acetazolamide treatment led to a dramatic reduction in event frequency and severity. The initial EA genetic panel was negative. Clinical exome sequence analysis revealed a novel pathogenic de novo missense variant in the HECW2 gene [c.3829 T > C;(p.Tyr1277His)], located in the HECT domain. HECW2 variants are associated with neurodevelopmental delay, hypotonia, and epilepsy. This study expands the genetic and clinical spectrum of HECW2-related disorder and adds EA to the phenotypic spectrum in affected individuals.
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Affiliation(s)
- Leticia Maria Tedesco Silva
- Epilepsy Division, Neurology Department, University of Miami, 1120 NW 14th St, 13th Floor, Miami, FL, 33136, USA.
| | - Sonali Sharma
- Epilepsy Division, Neurology Department, University of Miami, 1120 NW 14th St, 13th Floor, Miami, FL, 33136, USA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, and the Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Jason Margolesky
- Movements Disorders Division, Neurology Department, University of Miami, Miami, FL, USA
| | - Kamil Detyniecki
- Epilepsy Division, Neurology Department, University of Miami, 1120 NW 14th St, 13th Floor, Miami, FL, 33136, USA
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12
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Rey Hipolito AG, van der Heijden ME, Sillitoe RV. Physiology of Dystonia: Animal Studies. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 169:163-215. [PMID: 37482392 DOI: 10.1016/bs.irn.2023.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Dystonia is currently ranked as the third most prevalent motor disorder. It is typically characterized by involuntary muscle over- or co-contractions that can cause painful abnormal postures and jerky movements. Dystonia is a heterogenous disorder-across patients, dystonic symptoms vary in their severity, body distribution, temporal pattern, onset, and progression. There are also a growing number of genes that are associated with hereditary dystonia. In addition, multiple brain regions are associated with dystonic symptoms in both genetic and sporadic forms of the disease. The heterogeneity of dystonia has made it difficult to fully understand its underlying pathophysiology. However, the use of animal models has been used to uncover the complex circuit mechanisms that lead to dystonic behaviors. Here, we summarize findings from animal models harboring mutations in dystonia-associated genes and phenotypic animal models with overt dystonic motor signs resulting from spontaneous mutations, neural circuit perturbations, or pharmacological manipulations. Taken together, an emerging picture depicts dystonia as a result of brain-wide network dysfunction driven by basal ganglia and cerebellar dysfunction. In the basal ganglia, changes in dopaminergic, serotonergic, noradrenergic, and cholinergic signaling are found across different animal models. In the cerebellum, abnormal burst firing activity is observed in multiple dystonia models. We are now beginning to unveil the extent to which these structures mechanistically interact with each other. Such mechanisms inspire the use of pre-clinical animal models that will be used to design new therapies including drug treatments and brain stimulation.
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Affiliation(s)
- Alejandro G Rey Hipolito
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Meike E van der Heijden
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States
| | - Roy V Sillitoe
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States; Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, United States; Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States; Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States.
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13
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Riant F, Burglen L, Corpechot M, Robert J, Durr A, Solé G, Petit F, Freihuber C, De Marco O, Sarret C, Castelnovo G, Devillard F, Afenjar A, Héron B, Lasserve ET. Characterization of novel CACNA1A splice variants by RNA-sequencing in patients with episodic or congenital ataxia. Clin Genet 2023. [PMID: 37177896 DOI: 10.1111/cge.14358] [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: 03/03/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
Loss of function variants in CACNA1A cause a broad spectrum of neurological disorders, including episodic ataxia, congenital or progressive ataxias, epileptic manifestations or developmental delay. Variants located on the AG/GT consensus splice sites are usually considered as responsible of splicing defects, but exonic or intronic variants located outside of the consensus splice site can also lead to abnormal splicing. We investigated the putative consequences on splicing of 11 CACNA1A variants of unknown significance (VUS) identified in patients with episodic ataxia or congenital ataxia. In silico splice predictions were performed and RNA obtained from fibroblasts was analyzed by Sanger sequencing. The presence of abnormal transcripts was confirmed in 10/11 patients, nine of them were considered as deleterious and one remained of unknown significance. Targeted next-generation RNA sequencing was done in a second step to compare the two methods. This method was successful to obtain the full cDNA sequence of CACNA1A. Despite the presence of several isoforms in the fibroblastic cells, it detected most of the abnormally spliced transcripts. In conclusion, RNA sequencing was efficient to confirm the pathogenicity of nine novel CACNA1A variants. Sanger or Next generation methods can be used depending on the facilities and organization of the laboratories.
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Affiliation(s)
- Florence Riant
- AP-HP, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
| | - Lydie Burglen
- Département de Génétique et Embryologie Médicale, APHP, Sorbonne Université, Centre de Référence Malformations et Maladies Congénitales du Cervelet, Hôpital Trousseau, Paris, France
| | - Michaelle Corpechot
- AP-HP, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
| | - Julien Robert
- AP-HP, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
| | - Alexandra Durr
- Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), INSERM, CNRS, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Guilhem Solé
- Service de Neurologie, Unité Neuromusculaire, CHU de Bordeaux - Hôpital Pellegrin, Bordeaux, France
| | - Florence Petit
- CHU Lille, Clinique de Génétique Guy Fontaine, Lille, France
| | - Cécile Freihuber
- Service de Neuropédiatrie, APHP, Hôpital Trousseau, Paris, France
| | - Olivier De Marco
- Service de Neurologie, Hôpital de La Roche sur Yon, La Roche sur Yon, France
| | - Catherine Sarret
- Service de Pédiatrie, Hôpital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | | | - Françoise Devillard
- Département de Génétique et Procréation, Hôpital Couple-Enfant, CHU de Grenoble, Grenoble, France
| | - Alexandra Afenjar
- Département de Génétique et Embryologie Médicale, APHP, Sorbonne Université, Centre de Référence Malformations et Maladies Congénitales du Cervelet, Hôpital Trousseau, Paris, France
| | - Bénédicte Héron
- Service de Neuropédiatrie, APHP, Hôpital Trousseau, Paris, France
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14
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Benussi A, Batsikadze G, França C, Cury RG, Maas RPPWM. The Therapeutic Potential of Non-Invasive and Invasive Cerebellar Stimulation Techniques in Hereditary Ataxias. Cells 2023; 12:cells12081193. [PMID: 37190102 DOI: 10.3390/cells12081193] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/17/2023] Open
Abstract
The degenerative ataxias comprise a heterogeneous group of inherited and acquired disorders that are characterized by a progressive cerebellar syndrome, frequently in combination with one or more extracerebellar signs. Specific disease-modifying interventions are currently not available for many of these rare conditions, which underscores the necessity of finding effective symptomatic therapies. During the past five to ten years, an increasing number of randomized controlled trials have been conducted examining the potential of different non-invasive brain stimulation techniques to induce symptomatic improvement. In addition, a few smaller studies have explored deep brain stimulation (DBS) of the dentate nucleus as an invasive means to directly modulate cerebellar output, thereby aiming to alleviate ataxia severity. In this paper, we comprehensively review the clinical and neurophysiological effects of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and dentate nucleus DBS in patients with hereditary ataxias, as well as the presumed underlying mechanisms at the cellular and network level and perspectives for future research.
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Affiliation(s)
- Alberto Benussi
- Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, 25121 Brescia, Italy
| | - Giorgi Batsikadze
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, University of Duisburg-Essen, 45147 Essen, Germany
| | - Carina França
- Movement Disorders Center, Department of Neurology, University of São Paulo, São Paulo 05508-010, Brazil
| | - Rubens G Cury
- Movement Disorders Center, Department of Neurology, University of São Paulo, São Paulo 05508-010, Brazil
| | - Roderick P P W M Maas
- Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
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15
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Colucci E, Anshari ZR, Patiño-Ruiz MF, Nemchinova M, Whittaker J, Slotboom DJ, Guskov A. Mutation in glutamate transporter homologue GltTk provides insights into pathologic mechanism of episodic ataxia 6. Nat Commun 2023; 14:1799. [PMID: 37002226 PMCID: PMC10066184 DOI: 10.1038/s41467-023-37503-y] [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: 07/22/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Episodic ataxias (EAs) are rare neurological conditions affecting the nervous system and typically leading to motor impairment. EA6 is linked to the mutation of a highly conserved proline into an arginine in the glutamate transporter EAAT1. In vitro studies showed that this mutation leads to a reduction in the substrates transport and an increase in the anion conductance. It was hypothesised that the structural basis of these opposed functional effects might be the straightening of transmembrane helix 5, which is kinked in the wild-type protein. In this study, we present the functional and structural implications of the mutation P208R in the archaeal homologue of glutamate transporters GltTk. We show that also in GltTk the P208R mutation leads to reduced aspartate transport activity and increased anion conductance, however a cryo-EM structure reveals that the kink is preserved. The arginine side chain of the mutant points towards the lipidic environment, where it may engage in interactions with the phospholipids, thereby potentially interfering with the transport cycle and contributing to stabilisation of an anion conducting state.
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Affiliation(s)
- Emanuela Colucci
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands
| | - Zaid R Anshari
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands
| | - Miyer F Patiño-Ruiz
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands
| | - Mariia Nemchinova
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands
| | - Jacob Whittaker
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands
| | - Dirk J Slotboom
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands.
| | - Albert Guskov
- Groningen Institute for Biomolecular Sciences and Biotechnology, University of Groningen, 9747AG, Groningen, the Netherlands.
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16
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Lin CYR, Kuo SH. Ataxias: Hereditary, Acquired, and Reversible Etiologies. Semin Neurol 2023; 43:48-64. [PMID: 36828010 DOI: 10.1055/s-0043-1763511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
A variety of etiologies can cause cerebellar dysfunction, leading to ataxia symptoms. Therefore, the accurate diagnosis of the cause for cerebellar ataxia can be challenging. A step-wise investigation will reveal underlying causes, including nutritional, toxin, immune-mediated, genetic, and degenerative disorders. Recent advances in genetics have identified new genes for both autosomal dominant and autosomal recessive ataxias, and new therapies are on the horizon for targeting specific biological pathways. New diagnostic criteria for degenerative ataxias have been proposed, specifically for multiple system atrophy, which will have a broad impact on the future clinical research in ataxia. In this article, we aim to provide a review focus on symptoms, laboratory testing, neuroimaging, and genetic testing for the diagnosis of cerebellar ataxia causes, with a special emphasis on recent advances. Strategies for the management of cerebellar ataxia is also discussed.
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Affiliation(s)
- Chi-Ying R Lin
- Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas.,Department of Neurology, Alzheimer's Disease and Memory Disorders Center, Baylor College of Medicine, Houston, Texas
| | - Sheng-Han Kuo
- Department of Neurology, College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York.,Initiative for Columbia Ataxia and Tremor, Columbia University Irving Medical Center, New York, New York
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17
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Gray MM, Naik A, Ebner TJ, Carter RE. Altered brain state during episodic dystonia in tottering mice decouples primary motor cortex from limb kinematics. DYSTONIA 2023; 2:10974. [PMID: 37800168 PMCID: PMC10554815 DOI: 10.3389/dyst.2023.10974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Episodic Ataxia Type 2 (EA2) is a rare neurological disorder caused by a mutation in the CACNA1A gene, encoding the P/Q-type voltage-gated Ca2+ channel important for neurotransmitter release. Patients with this channelopathy exhibit both cerebellar and cerebral pathologies, suggesting the condition affects both regions. The tottering (tg/tg) mouse is the most commonly used EA2 model due to an orthologous mutation in the cacna1a gene. The tg/tg mouse has three prominent behavioral phenotypes: a dramatic episodic dystonia; absence seizures with generalized spike and wave discharges (GSWDs); and mild ataxia. We previously observed a novel brain state, transient low-frequency oscillations (LFOs) in the cerebellum and cerebral cortex under anesthesia. In this study, we examine the relationships among the dystonic attack, GSWDs, and LFOs in the cerebral cortex. Previous studies characterized LFOs in the motor cortex of anesthetized tg/tg mice using flavoprotein autofluorescence imaging testing the hypothesis that LFOs provide a mechanism for the paroxysmal dystonia. We sought to obtain a more direct understanding of motor cortex (M1) activity during the dystonic episodes. Using two-photon Ca2+ imaging to investigate neuronal activity in M1 before, during, and after the dystonic attack, we show that there is not a significant change in the activity of M1 neurons from baseline through the attack. We also conducted simultaneous, multi-electrode recordings to further understand how M1 cellular activity and local field potentials change throughout the progression of the dystonic attack. Neither putative pyramidal nor inhibitory interneuron firing rate changed during the dystonic attack. However, we did observe a near complete loss of GSWDs during the dystonic attack in M1. Finally, using spike triggered averaging to align simultaneously recorded limb kinematics to the peak Ca2+ response, and vice versa, revealed a reduction in the spike triggered average during the dystonic episodes. Both the loss of GSWDs and the reduction in the coupling suggest that, during the dystonic attack, M1 is effectively decoupled from other structures. Overall, these results indicate that the attack is not initiated or controlled in M1, but elsewhere in the motor circuitry. The findings also highlight that LFOs, GSWDs, and dystonic attacks represent three brain states in tg/tg mice.
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Affiliation(s)
- Madelyn M Gray
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Anant Naik
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Russell E Carter
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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18
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Indelicato E, Boesch S. CACNA1A-Related Channelopathies: Clinical Manifestations and Treatment Options. Handb Exp Pharmacol 2023; 279:227-248. [PMID: 36592223 DOI: 10.1007/164_2022_625] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In the last decade, variants in the Ca2+ channel gene CACNA1A emerged as a frequent aetiology of rare neurological phenotypes sharing a common denominator of variable paroxysmal manifestations and chronic cerebellar dysfunction. The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders. Additional chronic neurological symptoms range from severe developmental phenotypes in early-onset cases to neurobehavioural disorders and chronic cerebellar ataxia in older children and adults.In the present review we systematically approach the clinical manifestations of CACNA1A variants, delineate genotype-phenotype correlations and elaborate on the emerging concept of an age-dependent phenotypic spectrum in CACNA1A disease. We furthermore reflect on different therapy options available for paroxysmal symptoms in CACNA1A and address open issues to prioritize in the future clinical research.
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Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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19
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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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20
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Ataxia in Neurometabolic Disorders. Metabolites 2022; 13:metabo13010047. [PMID: 36676973 PMCID: PMC9866741 DOI: 10.3390/metabo13010047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 12/29/2022] Open
Abstract
Ataxia is a movement disorder that manifests during the execution of purposeful movements. It results from damage to the structures of the cerebellum and its connections or the posterior cords of the spinal cord. It should be noted that, in addition to occurring as part of many diseases, pediatric ataxia is a common symptom in neurometabolic diseases. To date, there are more than 150 inherited metabolic disorders that can manifest as ataxia in children. Neuroimaging studies (magnetic resonance imaging of the head and spinal cord) are essential in the diagnosis of ataxia, and genetic studies are performed when metabolic diseases are suspected. It is important to remember that most of these disorders are progressive if left untreated. Therefore, it is crucial to include neurometabolic disorders in the differential diagnosis of ataxia, so that an early diagnosis can be made. Initiating prompt treatment influences positive neurodevelopmental outcomes.
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21
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Benign Paroxysmal Vertigo of Childhood. Video Recordings of Episodes. Otol Neurotol 2022; 43:e1045-e1048. [PMID: 36026590 DOI: 10.1097/mao.0000000000003646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES The main objective was to describe the nystagmus observed during benign paroxysmal vertigo (BPV) of childhood, which is one of the criteria included in the three versions of the International Classification of Headache Disorders that has never been specified. The secondary objectives were to emphasize the usefulness of a mobile phone to record nystagmus and discuss the physiopathology of this nystagmus. PATIENT A 6-year-old boy complained of approximately 30 to 50 vertigo attacks, most of them lasting around 1 minute, during a 6-month period. INTERVENTION Otoneurologic history and examination, audiovestibular exploration, and brain imaging were performed between the attacks. Video recording by the parents' mobile phone and video electroencephalography recording during a 1-day hospitalization were performed during the episodes. MAIN OUTCOME MEASURE Analysis of seven video recordings performed by the parents and four during a 1-day hospitalization, as well as follow-up. RESULTS The assessment between the attacks confirmed the diagnosis of BPV according to International Classification of Headache Disorders criteria. Video recordings constantly demonstrated a strong left horizontal nystagmus present at fixation in all direction of gaze, enhanced in left gaze. This nystagmus was associated with a rightward body deviation. CONCLUSION The clinical presentation was more consistent with a peripheral vestibular deficit than with a central disorder. We encourage video recording of their child by the parents because it will help both to define the ictal nystagmus and to understand the underlying pathophysiology. The latter is discussed and is probably more complex than initially thought in BPV.
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Radmard S, Zesiewicz TA, Kuo SH. Evaluation of Cerebellar Ataxic Patients. Neurol Clin 2022; 41:21-44. [DOI: 10.1016/j.ncl.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chen I, Wu Q, Font J, Ryan RM. The twisting elevator mechanism of glutamate transporters reveals the structural basis for the dual transport-channel functions. Curr Opin Struct Biol 2022; 75:102405. [PMID: 35709614 DOI: 10.1016/j.sbi.2022.102405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 11/16/2022]
Abstract
Glutamate transporters facilitate the removal of this excitatory neurotransmitter from the synapse. Increasing evidence indicates that this process is linked to intrinsic chloride channel activity that is thermodynamically uncoupled from substrate transport. A recent cryo-EM structure of GltPh - an archaeal homolog of the glutamate transporters - in an open channel state has shed light on the structural basis for channel opening formed at the interface of two domains within the transporter which is gated by two clusters of hydrophobic residues. These transporters cycle through several conformational states during the transport process, including the chloride conducting state, which appears to be stabilised by protein-membrane interactions and membrane deformation. Several point mutations that perturb the chloride conductance can have detrimental effects and are linked to the pathogenesis of the neurological disorder, episodic ataxia type 6.
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Affiliation(s)
- Ichia Chen
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW, Australia
| | - Qianyi Wu
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW, Australia
| | - Josep Font
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW, Australia
| | - Renae M Ryan
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, NSW, Australia.
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Speech Impairment in Cerebellar Ataxia Affects Naturalness More Than Intelligibility. THE CEREBELLUM 2022:10.1007/s12311-022-01427-y. [PMID: 35670895 DOI: 10.1007/s12311-022-01427-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/31/2022] [Indexed: 10/18/2022]
Abstract
The purpose of this analysis was to document intelligibility and naturalness in ataxia, a neurological condition that results from cerebellar damage. The cerebellum is important for normal speech production to scale and coordinate articulatory and laryngeal movements. The disruption of these cerebellar mechanisms has unique implications for how intelligibility and naturalness are affected in ataxia. The results of research on speech in ataxia have important clinical implications for assessment and treatment of individuals with ataxic dysarthria. Speech samples from 27 participants with ataxia and 28 age- and sex-matched control participants were assessed by nine speech-language pathology graduate students for intelligibility and naturalness. Intelligibility was measured as the percentage of words transcribed correctly, and naturalness was assessed as a subjective rating on a seven-point interval scale. Both intra- and inter-rater reliability were moderate to high for both intelligibility and naturalness. Speech intelligibility and naturalness were robustly decreased in the ataxia group compared to the control group; however, the difference was greater for measures of speech naturalness. There were robust relationships among dysarthria severity, length of diagnosis, and speech naturalness in speakers with ataxia, but there were no other robust effects for age, sex, or impact on quality of life for intelligibility or naturalness. Speech naturalness was more impaired than intelligibility in speakers with ataxia. Impaired naturalness can have debilitating consequences for communicative participation, effectiveness, and quality of life. Assessment and treatment for ataxic dysarthria should include aspects of prosodic control for speech naturalness.
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Graves TD, Griggs RC, Bundy BN, Jen JC, Baloh RW, Hanna MG. Episodic Ataxia Type 1: Natural History and Effect on Quality of Life. CEREBELLUM (LONDON, ENGLAND) 2022:10.1007/s12311-021-01360-6. [PMID: 35655106 DOI: 10.1007/s12311-021-01360-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 06/15/2023]
Abstract
Episodic ataxia type 1 (EA1) is a rare autosomal potassium channelopathy, due to mutations in KCNA1. Patients have childhood onset of intermittent attacks of ataxia, dizziness or imbalance. In order to quantify the natural history of EA1, its effect on quality of life and in preparation for future clinical trials, we set up an international multi-centre study of EA1. We recruited thirty-three participants with EA1: twenty-three completed 1-year follow-up and eighteen completed 2-year follow-up. There was very little accumulation of disability or impairment over the course of the 2 years of the study. The outcome measures of ataxia (SARA and functional rating of ataxia) and the activities of daily living scale were largely stable over time. Self-reported health-related quality of life (SF-36) scores were lower across all domains than controls, in keeping with a chronic condition. Physical subdomain scores appeared to deteriorate over time, which seems to be driven by the female participants in the study. This is an interesting finding and warrants further study. Attacks of EA1 reported by participants in real time via an interactive voice response system showed that symptoms were not stereotyped; however, attack duration and frequency was stable between individuals. This large prospective study is the first ever completed in subjects with EA1. We document the natural history of the disorder over 2 years. These data will enable the development of outcome measures for clinical trials of treatment.
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Affiliation(s)
- Tracey D Graves
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Hinchingbrooke Hospital, Northwest Anglia NHS Foundation Trust, Hinchingbrooke Park, Huntingdon, PE29 6NT, UK
| | - Robert C Griggs
- Department of Neurology, University of Rochester School of Medicine & Dentistry, Rochester, NY, 14642, USA
| | - Brian N Bundy
- Pediatrics Epidemiology Center, University of South Florida College of Medicine, Tampa, FL, 33612, USA
| | - Joanna C Jen
- Department of Neurology, UCLA Medical School, Los Angeles, CA, 90095-1769, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, 5 East 98th Avenue, New York, NY, 10029, USA
| | - Robert W Baloh
- Department of Neurology, UCLA Medical School, Los Angeles, CA, 90095-1769, USA
| | - Michael G Hanna
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK.
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26
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Subramony SH, Burns M, Kugelmann EL, Zingariello CD. Inherited Ataxias in Children. Pediatr Neurol 2022; 131:54-62. [PMID: 35490578 DOI: 10.1016/j.pediatrneurol.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/28/2022] [Accepted: 04/01/2022] [Indexed: 10/18/2022]
Abstract
The purpose of this review is to describe the current diagnostic approach to inherited ataxias during childhood. With the expanding use and availability of gene testing technologies including large sequencing panels, the ability to arrive at a precise genetic diagnosis in this group of disorders has been improving. We have reviewed all the gene sequencing studies of ataxias available by a comprehensive literature search and summarize their results. We provide a logical algorithm for a diagnostic approach in the context of this evolving information. We stress the fact that both autosomal recessive and autosomal dominant mutations can occur in children with ataxias and the need for keeping in mind nucleotide repeat expansions, which cannot be detected by sequencing technologies, as a possible cause of progressive ataxias in children. We discuss the traditional phenotype-based diagnostic approach in the context of gene testing technologies. Finally, we summarize those disorders in which a specific therapy may be indicated.
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Affiliation(s)
- Sub H Subramony
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida; Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.
| | - Matthew Burns
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
| | - E Lee Kugelmann
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
| | - Carla D Zingariello
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
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Snell HD, Vitenzon A, Tara E, Chen C, Tindi J, Jordan BA, Khodakhah K. Mechanism of stress-induced attacks in an episodic neurologic disorder. SCIENCE ADVANCES 2022; 8:eabh2675. [PMID: 35442745 PMCID: PMC9020779 DOI: 10.1126/sciadv.abh2675] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 03/02/2022] [Indexed: 05/21/2023]
Abstract
Stress is the most common trigger among episodic neurologic disorders. In episodic ataxia type 2 (EA2), physical or emotional stress causes episodes of severe motor dysfunction that manifest as ataxia and dystonia. We used the tottering (tg/tg) mouse, a faithful animal model of EA2, to dissect the mechanisms underlying stress-induced motor attacks. We find that in response to acute stress, activation of α1-adrenergic receptors (α1-Rs) on Purkinje cells by norepinephrine leads to their erratic firing and consequently motor attacks. We show that norepinephrine induces erratic firing of Purkinje cells by disrupting their spontaneous intrinsic pacemaking via a casein kinase 2 (CK2)-dependent signaling pathway, which likely reduces the activity of calcium-dependent potassium channels. Moreover, we report that disruption of this signaling cascade at a number of nodes prevents stress-induced attacks in the tottering mouse. Together, our results suggest that norepinephrine and CK2 are required for the initiation of stress-induced attacks in EA2 and provide previously unidentified targets for therapeutic intervention.
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Affiliation(s)
- Heather D. Snell
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariel Vitenzon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Esra Tara
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Chris Chen
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jaafar Tindi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Bryen A. Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Psychiatry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kamran Khodakhah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Psychiatry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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UBR4/POE facilitates secretory trafficking to maintain circadian clock synchrony. Nat Commun 2022; 13:1594. [PMID: 35332162 PMCID: PMC8948264 DOI: 10.1038/s41467-022-29244-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 03/02/2022] [Indexed: 11/08/2022] Open
Abstract
Ubiquitin ligases control the degradation of core clock proteins to govern the speed and resetting properties of the circadian pacemaker. However, few studies have addressed their potential to regulate other cellular events within clock neurons beyond clock protein turnover. Here, we report that the ubiquitin ligase, UBR4/POE, strengthens the central pacemaker by facilitating neuropeptide trafficking in clock neurons and promoting network synchrony. Ubr4-deficient mice are resistant to jetlag, whereas poe knockdown flies are prone to arrhythmicity, behaviors reflective of the reduced axonal trafficking of circadian neuropeptides. At the cellular level, Ubr4 ablation impairs the export of secreted proteins from the Golgi apparatus by reducing the expression of Coronin 7, which is required for budding of Golgi-derived transport vesicles. In summary, UBR4/POE fulfills a conserved and unexpected role in the vesicular trafficking of neuropeptides, a function that has important implications for circadian clock synchrony and circuit-level signal processing. Although ubiquitin ligases are known to control clock protein degradation, their other roles in clock neurons are unclear. Here the authors report that UBR4 promotes export of neuropeptides from the Golgi for axonal trafficking, which is important for circadian clock synchrony in mice and flies.
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Malamud E, Otallah SI. Use of Dalfampridine in a Young Child with Episodic Ataxia Type 2. Child Neurol Open 2022; 9:2329048X221075447. [PMID: 35127965 PMCID: PMC8811424 DOI: 10.1177/2329048x221075447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/03/2021] [Accepted: 01/06/2022] [Indexed: 11/16/2022] Open
Abstract
Episodic ataxia type 2 (EA2) is a rare autosomal dominant disorder associated with mutations of the CACNA1A gene. 1 Because there is no curative therapy available, EA2 is typically managed symptomatically. First line treatment has typically been with acetazolamide. 2 Dalfampridine has also been noted to decrease the frequency and duration of ataxic attacks in patients ranging in age from adolescence through adulthood. 3 , 4 The efficacy and dosing of dalfampridine has not yet been studied in younger pediatric populations. The lack of published experience in younger children can and has led to these patients going without potentially safe and effective treatment. Thus, we describe an 8-year-old girl with EA2 and a confirmed CACNA1A gene mutation whose symptoms had been previously unrelieved by acetazolamide. She was subsequently trialed on dalfampridine and experienced symptomatic relief at a dose of 0.3 mg/kg.
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Affiliation(s)
| | - Scott I. Otallah
- Division of Pediatric Neurology, Department of Neurology, Atrium Health Wake Forest Baptist, Medical Center Boulevard, JT9, Winston-Salem, NC
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Li XL, Li ZJ, Liang XY, Liu DT, Jiang M, Gao LD, Li H, Tang XQ, Shi YW, Li BM, He N, Li B, Bian WJ, Yi YH, Cheng CF, Wang J. CACNA1A Mutations Associated With Epilepsies and Their Molecular Sub-Regional Implications. Front Mol Neurosci 2022; 15:860662. [PMID: 35600082 PMCID: PMC9116572 DOI: 10.3389/fnmol.2022.860662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 04/05/2022] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Previously, mutations in the voltage-gated calcium channel subunit alpha1 A (CACNA1A) gene have been reported to be associated with paroxysmal disorders, typically as episodic ataxia type 2. To determine the relationship between CACNA1A and epilepsies and the role of molecular sub-regional on the phenotypic heterogeneity. METHODS Trio-based whole-exome sequencing was performed in 318 cases with partial epilepsy and 150 cases with generalized epilepsy. We then reviewed all previously reported CACNA1A mutations and analyzed the genotype-phenotype correlations with molecular sub-regional implications. RESULTS We identified 12 CACNA1A mutations in ten unrelated cases of epilepsy, including four de novo null mutations (c.2963_2964insG/p.Gly989Argfs*78, c.3089 + 1G > A, c.4755 + 1G > T, and c.6340-1G > A), four de novo missense mutations (c.203G > T/p.Arg68Leu, c.3965G > A/p.Gly1322Glu, c.5032C > T/p.Arg1678Cys, and c.5393C > T/p.Ser1798Leu), and two pairs of compound heterozygous missense mutations (c.4891A > G/p.Ile1631Val& c.5978C > T/p.Pro1993Leu and c.3233C > T/p.Ser1078Leu&c.6061G > A/p.Glu2021Lys). The eight de novo mutations were evaluated as pathogenic or likely pathogenic mutations according to the criteria of American College of Medical Genetics and Genomics (ACMG). The frequencies of the compound heterozygous CACNA1A mutations identified in this cohort were significantly higher than that in the controls of East Asian and all populations (P = 7.30 × 10-4, P = 2.53 × 10-4). All of the ten cases were ultimately seizure-free after antiepileptic treatment, although frequent epileptic seizures were observed in four cases. Further analysis revealed that episodic ataxia type 2 (EA2) had a tendency of higher frequency of null mutations than epilepsies. The missense mutations in severe epileptic phenotypes were more frequently located in the pore region than those in milder epileptic phenotypes (P = 1.67 × 10-4); de novo mutations in the epilepsy with intellectual disability (ID) had a higher percentage than those in the epilepsy without ID (P = 1.92 × 10-3). CONCLUSION This study suggested that CACNA1A mutations were potentially associated with pure epilepsy and the spectrum of epileptic phenotypes potentially ranged from the mild form of epilepsies such as absence epilepsy or partial epilepsy, to the severe form of developmental epileptic encephalopathy. The clinical phenotypes variability is potentially associated with the molecular sub-regional of the mutations.
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Affiliation(s)
- Xue-Lian Li
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Neurology, The Affiliated Yuebei People’s Hospital of Shantou University Medical College, Shaoguan, China
| | - Zong-Jun Li
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiao-Yu Liang
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - De-Tian Liu
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Mi Jiang
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Liang-Di Gao
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Huan Li
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xue-Qing Tang
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yi-Wu Shi
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bing-Mei Li
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Na He
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bin Li
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Wen-Jun Bian
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yong-Hong Yi
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chuan-Fang Cheng
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Cardiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
- *Correspondence: Chuan-Fang Cheng,
| | - Jie Wang
- Key Laboratory of Neurogenetics and Channelopathies of the Ministry of Education of China, Department of Neurology, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Jie Wang,
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Choi JH, Oh EH, Choi SY, Kim HJ, Lee SK, Choi JY, Kim JS, Choi KD. Vestibular impairments in episodic ataxia type 2. J Neurol 2021; 269:2687-2695. [PMID: 34709445 DOI: 10.1007/s00415-021-10856-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 10/20/2022]
Abstract
Episodic ataxia type 2 (EA2) can present diverse ocular motor abnormalities, but few studies have systematically evaluated vestibular function during the interictal periods. This study aimed to determine vestibular impairments in patients with EA2 during the interictal periods. We recruited 17 patients with genetically confirmed EA2 (10 men, age range = 16-85 years, median = 32 years). We systematically evaluated the vestibular function by measuring the semicircular canals (SCCs) function with bithermal caloric tests, rotatory chair test, and video head impulse test (vHIT), and the otolith function with subjective visual vertical (SVV) tilt and variability, and cervical and ocular vestibular-evoked myogenic potentials (VEMPs). Patients with EA2 commonly showed abnormal VOR responses at least for one SCC with high-acceleration, high-frequency head impulses (14/16, 88%), and impaired visual-vestibular interaction (7/12, 58%). In response to low acceleration and frequency stimuli, the VOR gains were generally normal. The majority of EA2 patients had impairments in at least one of the otolith function tests (13/16, 81%): SVV tilt or variability (7/14, 50%), oVEMP (8/15, 53%), and cVEMP (4/16, 25%). Vestibular impairments are common in EA2 even during the interictal periods. Selective decrease in the VOR responses during higher acceleration stimuli along with impaired visual-vestibular interaction and otolith function suggests degeneration of the vestibulocerebellum or vestibular nuclei.
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Affiliation(s)
- Jae-Hwan Choi
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Eun Hye Oh
- Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| | - Seo Young Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Hyo Jung Kim
- Research Administration Team, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Seon Kyung Lee
- Dizziness Center, Clinical Neuroscience Center, Department of Neurology, Seoul National University Bundang Hospital, 173-82 Gumi-ro, Bundang-gu, Seongnam, Gyeonggi-do, 13620, South Korea
| | - Jeong Yoon Choi
- Dizziness Center, Clinical Neuroscience Center, Department of Neurology, Seoul National University Bundang Hospital, 173-82 Gumi-ro, Bundang-gu, Seongnam, Gyeonggi-do, 13620, South Korea
| | - Ji-Soo Kim
- Dizziness Center, Clinical Neuroscience Center, Department of Neurology, Seoul National University Bundang Hospital, 173-82 Gumi-ro, Bundang-gu, Seongnam, Gyeonggi-do, 13620, South Korea.
| | - Kwang-Dong Choi
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea. .,Department of Neurology, College of Medicine, Pusan National University Hospital, 1-10 Ami-dong, Seo-gu, Busan, 49241, South Korea.
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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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Muth C, Teufel J, Schöls L, Synofzik M, Franke C, Timmann D, Mansmann U, Strupp M. Fampridine and Acetazolamide in EA2 and Related Familial EA: A Prospective Randomized Placebo-Controlled Trial. Neurol Clin Pract 2021; 11:e438-e446. [PMID: 34484942 DOI: 10.1212/cpj.0000000000001017] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/22/2020] [Indexed: 11/15/2022]
Abstract
Objective To determine the efficacy and safety of the treatment with prolonged-release 4-aminopyridine (fampridine) and acetazolamide for patients with episodic ataxia type 2 (EA2), patients with EA2 were treated with a random sequence of fampridine, acetazolamide, and placebo in a 3-period crossover trial. Methods A total of 30 patients with EA2 (8 female; aged 20-71 years; 18 genetically confirmed, 4 with a positive family history, 8 with the clinical diagnosis) were enrolled in this phase III, randomized, double-blind, placebo-controlled, 3-period crossover trial. Each period lasted 12 weeks with a 4-week washout period. Each patient received a random sequence of 20 mg/d fampridine, 750 mg/d acetazolamide, and placebo. The primary end point was the number of attacks during the last 30 days within the 12-week treatment period. Participants, caregivers, and those assessing the outcomes were blinded to the intervention. Results Compared with placebo, fampridine reduced the number of attacks to 63% (95% CI 54%-74%) and acetazolamide to 52% (95% CI 46%-60%). A total of 39 (26.5%) adverse events were observed under treatment with fampridine (mostly tingling paresthesia and fatigue), 66 (44.9%) happened under acetazolamide (mostly taste disturbance and gastrointestinal complaints), and 42 (28.6%) under placebo (mostly gastrointestinal complaints). Conclusion Both fampridine and acetazolamide significantly reduce the number of attacks in patients with EA2 and related EA in comparison to placebo. Fampridine 10 mg twice daily had fewer side effects than acetazolamide 250 mg 3 times daily. The trial was registered with DRKS.de (DRKS00005258) and EudraCT (2013-000107-17). This study was supported by the Federal Ministry of Education and Research (BMBF) (grant number 01EO0901). Fampridine (study medication) was provided by Biogen Idec. Classification of Evidence Class II evidence.
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Affiliation(s)
- Carolin Muth
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Julian Teufel
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Ludger Schöls
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Matthis Synofzik
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Christiana Franke
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Dagmar Timmann
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Ulrich Mansmann
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders (DSGZ) (CM, JT, M. Strupp), Ludwig Maximilians University, Munich, LMU University Hospital, Campus Grosshadern; Department of Neurology and Hertie-Institute for Clinical Brain Research (LS, M. Synofzik), Eberhard Karls University and German Center for Neurodegenerative Diseases (DZNE), Tübingen; Department of Neurology (CF), Charité-Universitätsmedizin Berlin, Berlin, Germany, Formerly Department of Neurology, University of Dresden; Department of Neurology (DT), Essen University Hospital, University of Duisburg-Essen; and Department of Medical Information Sciences (UM), Biometry, and Epidemiology (IBE), Ludwig Maximilian University, Munich, Germany
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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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Demystifying the spontaneous phenomena of motor hyperexcitability. Clin Neurophysiol 2021; 132:1830-1844. [PMID: 34130251 DOI: 10.1016/j.clinph.2021.03.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/18/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
Possessing a discrete functional repertoire, the anterior horn cell can be in one of two electrophysiological states: on or off. Usually under tight regulatory control by the central nervous system, a hierarchical network of these specialist neurons ensures muscular strength is coordinated, gradated and adaptable. However, spontaneous activation of these cells and their axons can result in abnormal muscular twitching. The muscular twitch is the common building block of several distinct clinical patterns, namely fasciculation, myokymia and neuromyotonia. When attempting to distinguish these entities electromyographically, their unique temporal and morphological profiles must be appreciated. Detection and quantification of burst duration, firing frequency, multiplet patterns and amplitude are informative. A common feature is their persistence during sleep. In this review, we explain the accepted terminology used to describe the spontaneous phenomena of motor hyperexcitability, highlighting potential pitfalls amidst a bemusing and complex collection of overlapping terms. We outline the relevance of these findings within the context of disease, principally amyotrophic lateral sclerosis, Isaacs syndrome and Morvan syndrome. In addition, we highlight the use of high-density surface electromyography, suggesting that more widespread use of this non-invasive technique is likely to provide an enhanced understanding of these motor hyperexcitability syndromes.
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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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Becker-Bense S, Huppert D. [Less common, but clinically important episodic vertigo syndromes]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2021; 89:221-232. [PMID: 33652478 DOI: 10.1055/a-1353-4893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
ZusammenfassungDie Differentialdiagnostik der selteneren, episodischen Schwindelsyndrome kann im klinischen Alltag eine Herausforderung darstellen, insbesondere wenn sie keine im Intervall messbaren Befunde in der neuro-ophthalmologischen oder -otologischen Routinediagnostik hinterlassen. Ursächlich für diese episodischen Schwindelsyndrome können physiologische Reaktionen aufgrund intersensorischer Inkongruenzen oder angeborene bzw. erworbene neuroanatomische/neurophysiologische Varianten sein, die zu vestibulären Reizsyndromen führen. In dieser Übersicht fokussieren wir auf die folgenden, aus unserer Sicht wichtigen vestibulären Syndrome: Bewegungskrankheit, Mal de Debarquement Syndrom, Visuelle Höhenintoleranz, Vestibularisparoxysmie, Zervikaler Schwindel, Episodische Ataxie Typ II und Syndrome eines dritten mobilen Fensters wie das Syndrom der Dehiszenz des superioren Bogengangs. Die Ausprägung reicht von milden Symptomen mit geringer Belastung bis hin zu schweren Krankheitsbildern mit relevanter Alltagseinschränkung. Sie können vom Kindes- oder Jugendalter bis ins Senium auftreten, teilweise mit abweichender Symptomatik. Durch gezielte Anamnese und ggf. erweiterte vestibuläre Diagnostik in einem spezialisierten Zentrum lassen sich diese Syndrome oft klar herausarbeiten und einer erfolgreichen Therapie zuführen.
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Affiliation(s)
- Sandra Becker-Bense
- Deutsches Schwindel- und Gleichgewichtszentrum (DSGZ), Ludwig-Maximilians-Universität München Deutschland
| | - Doreen Huppert
- Deutsches Schwindel- und Gleichgewichtszentrum (DSGZ), Ludwig-Maximilians-Universität München Deutschland
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Phang MWL, Lew SY, Chung I, Lim WKS, Lim LW, Wong KH. Therapeutic roles of natural remedies in combating hereditary ataxia: A systematic review. Chin Med 2021; 16:15. [PMID: 33509239 PMCID: PMC7841890 DOI: 10.1186/s13020-020-00414-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/17/2020] [Accepted: 12/11/2020] [Indexed: 12/30/2022] Open
Abstract
Background Hereditary ataxia (HA) represents a group of genetically heterogeneous neurodegenerative diseases caused by dysfunction of the cerebellum or disruption of the connection between the cerebellum and other areas of the central nervous system. Phenotypic manifestation of HA includes unsteadiness of stance and gait, dysarthria, nystagmus, dysmetria and complaints of clumsiness. There are no specific treatments for HA. Management strategies provide supportive treatment to reduce symptoms. Objectives This systematic review aimed to identify, evaluate and summarise the published literature on the therapeutic roles of natural remedies in the treatment of HA to provide evidence for clinical practice. Methods A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Web of Science, PubMed and Science Direct Scopus were thoroughly searched for relevant published articles from June 2007 to July 2020. Results Ten pre-clinical and two clinical studies were eligible for inclusion in this systematic review. We identified the therapeutic roles of medicinal plants Brassica napus, Gardenia jasminoides, Gastrodia elata, Ginkgo biloba, Glycyrrhiza inflata, Paeonia lactiflora, Pueraria lobata and Rehmannia glutinosa; herbal formulations Shaoyao Gancao Tang and Zhengan Xifeng Tang; and medicinal mushroom Hericium erinaceus in the treatment of HA. In this review, we evaluated the mode of actions contributing to their therapeutic effects, including activation of the ubiquitin–proteasome system, activation of antioxidant pathways, maintenance of intracellular calcium homeostasis and regulation of chaperones. We also briefly highlighted the integral cellular signalling pathways responsible for orchestrating the mode of actions. Conclusion We reviewed the therapeutic roles of natural remedies in improving or halting the progression of HA, which warrant further study for applications into clinical practice.
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Affiliation(s)
- Michael Weng Lok Phang
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Ivy Chung
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - William Kiong-Seng Lim
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Kuching, Sarawak, 94300, Malaysia
| | - Lee Wei Lim
- Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China.
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia.
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Neural Networks in Health and Disease. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11470-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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40
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Yeow SQZ, Loh KWZ, Soong TW. Calcium Channel Splice Variants and Their Effects in Brain and Cardiovascular Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:67-86. [DOI: 10.1007/978-981-16-4254-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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41
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Passi GR, Mohammad SS. Dominant SCN2A mutation with variable phenotype in two generations. Brain Dev 2021; 43:166-169. [PMID: 32893078 DOI: 10.1016/j.braindev.2020.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND SCN2A mutations are some of the commonest causes of neurodevelopmental disorders including epilepsy, movement disorders, autism spectrum disorder, intellectual disability and rarely episodic ataxia. CASE REPORT We present a patient with a dominantly inherited SCN2A mutation presenting as episodic ataxia in a boy and episodic hemiplegia in his father. We have briefly reviewed the literature of SCN2A mutations presenting with episodic ataxia. CONCLUSION Our report has expanded the phenotype for SCN2A mutations.
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Affiliation(s)
- Gouri Rao Passi
- Department of Pediatrics, Choithram Hospital & Research Centre, Indore, India.
| | - Shekeeb S Mohammad
- Discipline of Child and Adolescent Health, Children's Hospital at Westmead Clinical School, University of Sydney, Australia.
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Kim MJ, Yum MS, Seo GH, Lee Y, Jang HN, Ko TS, Lee BH. Clinical Application of Whole Exome Sequencing to Identify Rare but Remediable Neurologic Disorders. J Clin Med 2020; 9:jcm9113724. [PMID: 33233562 PMCID: PMC7699758 DOI: 10.3390/jcm9113724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 12/17/2022] Open
Abstract
Background: The aim of this study was to describe the application of whole exome sequencing (WES) in the accurate genetic diagnosis and personalized treatment of extremely rare neurogenetic disorders. Methods: From 2017 to 2019, children with neurodevelopmental symptoms were evaluated using WES in the pediatric neurology clinic and medical genetics center. The clinical presentation, laboratory findings including the genetic results from WES, and diagnosis-based treatment and outcomes of the four patients are discussed. Results: A total of 376 children with neurodevelopmental symptom were evaluated by WES, and four patients (1.1%) were diagnosed with treatable neurologic disorders. Patient 1 (Pt 1) showed global muscle hypotonia, dysmorphic facial features, and multiple anomalies beginning in the perinatal period. Pt 1 was diagnosed with congenital myasthenic syndrome 22 of PREPL deficiency. Pt 2 presented with hypotonia and developmental arrest and was diagnosed with autosomal recessive dopa-responsive dystonia due to TH deficiency. Pt 3, who suffered from intractable epilepsy and progressive cognitive decline, was diagnosed with epileptic encephalopathy 47 with a heterozygous FGF12 mutation. Pt 4 presented with motor delay and episodic ataxia and was diagnosed with episodic ataxia type II (heterozygous CACNA1A mutation). The patients’ major neurologic symptoms were remarkably relieved with pyridostigmine (Pt 1), levodopa (Pt 2), sodium channel blocker (Pt 3), and acetazolamide (Pt 4), and most patients regained developmental milestones in the follow-up period (0.4 to 3 years). Conclusions: The early application of WES helps in the identification of extremely rare genetic diseases, for which effective treatment modalities exist. Ultimately, WES resulted in optimal clinical outcomes of affected patients.
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Affiliation(s)
- Min-Jee Kim
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Mi-Sun Yum
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
- Correspondence: ; Tel.: +82-2-3010-3386; Fax: +82-2-3010-3356
| | - Go Hun Seo
- 3billion Inc., Seoul 06193, Korea; (G.H.S.); (B.H.L.)
| | - Yena Lee
- Department of Genetics, Asan Medical Center, Ulsan University College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea;
| | - Han Na Jang
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Tae-Sung Ko
- Department of Pediatrics, Asan Medical Center Children’s Hospital, Ulsan University College of Medicine 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul 05505, Korea; (M.-J.K.); (H.N.J.); (T.-S.K.)
| | - Beom Hee Lee
- 3billion Inc., Seoul 06193, Korea; (G.H.S.); (B.H.L.)
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Saathoff Y, Biskup S, Funke C, Roth C. New Nonsense Variant c.2983G>T; p.Glu995* in the CACNA1A Gene Causes Progressive Autosomal Dominant Ataxia. J Mov Disord 2020; 14:70-74. [PMID: 33121221 PMCID: PMC7840235 DOI: 10.14802/jmd.20082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/27/2020] [Indexed: 11/24/2022] Open
Abstract
The genetic testing of hereditary ataxias includes screening for CAG-repeat expansions as well as pathogenic variants and nontranslated oligonucleotide expansion, which can cause spinocerebellar ataxia (SCA). Genotype-phenotype correlations of several SCA subtypes are difficult to establish, and the underlying mechanisms remain unclear. Here, we report a 58-year-old male patient who presented with severe generalized ataxia, horizontal gaze-evoked nystagmus, cognitive impairment and a positive family history of gait difficulties. Genetic panel diagnostics revealed a new nonsense pathogenic variant in the CACNA1A gene (c.2983G>T; p. Glu995*) that segregated with the phenotype in three clinically affected family members. This gene is related to SCA type 6 (SCA6), episodic ataxia type 2, familial hemiplegic migraine type 1, among others. When it is supported by the clinical findings and family history, additional DNA sequencing beyond fragment length analysis should be performed.
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Affiliation(s)
- Yannic Saathoff
- Department of Neurology and Neurophysiology, DRK-Kliniken Nordhessen, Kassel, Germany
| | - Saskia Biskup
- Center for Genomics and Transcriptomics (CeGaT) GmbH, Tuebingen, Germany.,Practice for Human Genetics, Tuebingen, Germany
| | | | - Christian Roth
- Department of Neurology and Neurophysiology, DRK-Kliniken Nordhessen, Kassel, Germany.,Department of Neurology, University of Marburg, Marburg, Germany
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A Common Kinetic Property of Mutations Linked to Episodic Ataxia Type 1 Studied in the Shaker Kv Channel. Int J Mol Sci 2020; 21:ijms21207602. [PMID: 33066705 PMCID: PMC7589002 DOI: 10.3390/ijms21207602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 12/21/2022] Open
Abstract
(1) Background: Episodic ataxia type 1 is caused by mutations in the KCNA1 gene encoding for the voltage-gated potassium channel Kv1.1. There have been many mutations in Kv1.1 linked to episodic ataxia reported and typically investigated by themselves or in small groups. The aim of this article is to determine whether we can define a functional parameter common to all Kv1.1 mutants that have been linked to episodic ataxia. (2) Methods: We introduced the disease mutations linked to episodic ataxia in the drosophila analog of Kv1.1, the Shaker Kv channel, and expressed the channels in Xenopus oocytes. Using the cut-open oocyte technique, we characterized the gating and ionic currents. (3) Results: We found that the episodic ataxia mutations variably altered the different gating mechanisms described for Kv channels. The common characteristic was a conductance voltage relationship and inactivation shifted to less polarized potentials. (4) Conclusions: We suggest that a combination of a prolonged action potential and slowed and incomplete inactivation leads to development of ataxia when Kv channels cannot follow or adapt to high firing rates.
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Penkava J, Ledderose S, Chahrokh-Zadeh S, Munzig A, Eulenburg Z, Huppert D, Strupp M, Becker-Bense S. A novel pathogenic CACNA1A variant causing episodic ataxia type 2 (EA2) spectrum phenotype in four family members and a novel combined therapy. J Neurol 2020; 267:181-184. [PMID: 32910250 PMCID: PMC7718184 DOI: 10.1007/s00415-020-10190-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/18/2020] [Accepted: 08/26/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Josef Penkava
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, Munich, Germany.
| | - S Ledderose
- Department of Pathology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - S Chahrokh-Zadeh
- Center for Human Genetics and Laboratory Diagnostics (CHGLD), Martinsried, Germany
| | - A Munzig
- Center for Human Genetics and Laboratory Diagnostics (CHGLD), Martinsried, Germany
| | - Zu Eulenburg
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, Munich, Germany
| | - D Huppert
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, Munich, Germany
| | - M Strupp
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, Munich, Germany.,Department of Neurology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - S Becker-Bense
- German Center for Vertigo and Balance Disorders (DSGZ), Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, Munich, Germany
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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: 20] [Impact Index Per Article: 5.0] [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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Jaudon F, Baldassari S, Musante I, Thalhammer A, Zara F, Cingolani LA. Targeting Alternative Splicing as a Potential Therapy for Episodic Ataxia Type 2. Biomedicines 2020; 8:E332. [PMID: 32899500 PMCID: PMC7555146 DOI: 10.3390/biomedicines8090332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/26/2022] Open
Abstract
Episodic ataxia type 2 (EA2) is an autosomal dominant neurological disorder characterized by paroxysmal attacks of ataxia, vertigo, and nausea that usually last hours to days. It is caused by loss-of-function mutations in CACNA1A, the gene encoding the pore-forming α1 subunit of P/Q-type voltage-gated Ca2+ channels. Although pharmacological treatments, such as acetazolamide and 4-aminopyridine, exist for EA2, they do not reduce or control the symptoms in all patients. CACNA1A is heavily spliced and some of the identified EA2 mutations are predicted to disrupt selective isoforms of this gene. Modulating splicing of CACNA1A may therefore represent a promising new strategy to develop improved EA2 therapies. Because RNA splicing is dysregulated in many other genetic diseases, several tools, such as antisense oligonucleotides, trans-splicing, and CRISPR-based strategies, have been developed for medical purposes. Here, we review splicing-based strategies used for genetic disorders, including those for Duchenne muscular dystrophy, spinal muscular dystrophy, and frontotemporal dementia with Parkinsonism linked to chromosome 17, and discuss their potential applicability to EA2.
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Affiliation(s)
- Fanny Jaudon
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Simona Baldassari
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
| | - Ilaria Musante
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
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Muro García I, Toribio-Díaz M, Quintas S. Episodic ataxia: a 20-year diagnostic delay. NEUROLOGÍA (ENGLISH EDITION) 2020. [DOI: 10.1016/j.nrleng.2019.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Muro García I, Toribio-Díaz ME, Quintas S. Episodic ataxia: A 20-year diagnostic delay. Neurologia 2020; 35:500-501. [PMID: 31047732 DOI: 10.1016/j.nrl.2019.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/06/2019] [Accepted: 02/25/2019] [Indexed: 10/26/2022] Open
Affiliation(s)
- I Muro García
- Servicio de Neurología, Hospital Universitario de la Princesa, Madrid, España
| | - M E Toribio-Díaz
- Sección de Neurología, Servicio de Medicina Interna, Hospital Universitario del Henares, Coslada, Madrid, España
| | - S Quintas
- Servicio de Neurología, Hospital Universitario de la Princesa, Madrid, España.
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Heyne HO, Baez-Nieto D, Iqbal S, Palmer DS, Brunklaus A, May P, Johannesen KM, Lauxmann S, Lemke JR, Møller RS, Pérez-Palma E, Scholl UI, Syrbe S, Lerche H, Lal D, Campbell AJ, Wang HR, Pan J, Daly MJ. Predicting functional effects of missense variants in voltage-gated sodium and calcium channels. Sci Transl Med 2020; 12:eaay6848. [PMID: 32801145 DOI: 10.1126/scitranslmed.aay6848] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/20/2019] [Accepted: 07/22/2020] [Indexed: 12/30/2022]
Abstract
Malfunctions of voltage-gated sodium and calcium channels (encoded by SCNxA and CACNA1x family genes, respectively) have been associated with severe neurologic, psychiatric, cardiac, and other diseases. Altered channel activity is frequently grouped into gain or loss of ion channel function (GOF or LOF, respectively) that often corresponds not only to clinical disease manifestations but also to differences in drug response. Experimental studies of channel function are therefore important, but laborious and usually focus only on a few variants at a time. On the basis of known gene-disease mechanisms of 19 different diseases, we inferred LOF (n = 518) and GOF (n = 309) likely pathogenic variants from the disease phenotypes of variant carriers. By training a machine learning model on sequence- and structure-based features, we predicted LOF or GOF effects [area under the receiver operating characteristics curve (ROC) = 0.85] of likely pathogenic missense variants. Our LOF versus GOF prediction corresponded to molecular LOF versus GOF effects for 87 functionally tested variants in SCN1/2/8A and CACNA1I (ROC = 0.73) and was validated in exome-wide data from 21,703 cases and 128,957 controls. We showed respective regional clustering of inferred LOF and GOF nucleotide variants across the alignment of the entire gene family, suggesting shared pathomechanisms in the SCNxA/CACNA1x family genes.
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Affiliation(s)
- Henrike O Heyne
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 5WR36M Helsinki, Finland
| | - David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sumaiya Iqbal
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Center for Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Duncan S Palmer
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Andreas Brunklaus
- Paediatric Neurosciences Research Group, Royal Hospital for Sick Children, Glasgow G51 4TF, UK
- School of Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, Belvaux, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Treatment, Danish Epilepsy Centre, 4293 Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, 5230 Odense, Denmark
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Treatment, Danish Epilepsy Centre, 4293 Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, 5230 Odense, Denmark
| | - Eduardo Pérez-Palma
- Cologne Center for Genomics (CCG), University of Cologne, 50923, Germany
- Genomic Medicine Institute, Lemer Research Institute Cleveland Clinic, OH G92J47, USA
| | - Ute I Scholl
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Nephrology and Medical Intensive Care and BIH Center for Regenerative Therapies, 10178 Berlin, Germany
- Berlin Institute of Health (BIH), 10178 Berlin, Germany
| | - Steffen Syrbe
- Division of Pediatric Epileptology, Center for Paediatrics and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Dennis Lal
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Cologne Center for Genomics (CCG), University of Cologne, 50923, Germany
- Genomic Medicine Institute, Lemer Research Institute Cleveland Clinic, OH G92J47, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH G92J47, USA
| | - Arthur J Campbell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Center for Development of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Hao-Ran Wang
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jen Pan
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Mark J Daly
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 5WR36M Helsinki, Finland
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