51
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Saini L, Singanamalla B, Natarajan R, Madaan P. Role of genotype–phenotype correlation in prognostication of a child with a novel potassium channelopathy. J Pediatr Neurosci 2022. [DOI: 10.4103/jpn.jpn_294_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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52
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Costa F, Guardiani C, Giacomello A. Exploring K v 1.2 Channel Inactivation Through MD Simulations and Network Analysis. Front Mol Biosci 2021; 8:784276. [PMID: 34988118 PMCID: PMC8721119 DOI: 10.3389/fmolb.2021.784276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022] Open
Abstract
The KCNA2 gene encodes the K v 1.2 channel, a mammalian Shaker-like voltage-gated K+ channel, whose defections are linked to neuronal deficiency and childhood epilepsy. Despite the important role in the kinetic behavior of the channel, the inactivation remained hereby elusive. Here, we studied the K v 1.2 inactivation via a combined simulation/network theoretical approach that revealed two distinct pathways coupling the Voltage Sensor Domain and the Pore Domain to the Selectivity Filter. Additionally, we mutated some residues implicated in these paths and we explained microscopically their function in the inactivation mechanism by computing a contact map. Interestingly, some pathological residues shown to impair the inactivation lay on the paths. In summary, the presented results suggest two pathways as the possible molecular basis of the inactivation mechanism in the K v 1.2 channel. These pathways are consistent with earlier mutational studies and known mutations involved in neuronal channelopathies.
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Affiliation(s)
| | | | - Alberto Giacomello
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
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53
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Miceli F, Guerrini R, Nappi M, Soldovieri MV, Cellini E, Gurnett CA, Parmeggiani L, Mei D, Taglialatela M. Distinct epilepsy phenotypes and response to drugs in KCNA1 gain- and loss-of function variants. Epilepsia 2021; 63:e7-e14. [PMID: 34778950 PMCID: PMC9299230 DOI: 10.1111/epi.17118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/01/2021] [Accepted: 10/22/2021] [Indexed: 11/29/2022]
Abstract
A wide phenotypic spectrum of neurological diseases is associated with KCNA1 (Kv1.1) variants. To investigate the molecular basis of such a heterogeneous clinical presentation and identify the possible correlation with in vitro phenotypes, we compared the functional consequences of three heterozygous de novo variants (p.P403S, p.P405L, and p.P405S) in Kv1.1 pore region found in four patients with severe developmental and epileptic encephalopathy (DEE), with those of a de novo variant in the voltage sensor (p.A261T) identified in two patients with mild, carbamazepine-responsive, focal epilepsy. Patch-clamp electrophysiology was used to investigate the functional properties of mutant Kv1.1 subunits, both expressed as homomers and heteromers with wild-type Kv1.1 subunits. KCNA1 pore mutations markedly decreased (p. P405S) or fully suppressed (p. P403S, p. P405L) Kv1.1-mediated currents, exerting loss-of-function (LoF) effects. By contrast, channels carrying the p.A261T variant exhibited a hyperpolarizing shift of the activation process, consistent with a gain-of-function (GoF) effect. The present results unveil a novel correlation between in vitro phenotype (GoF vs LoF) and clinical course (mild vs severe) in KCNA1-related phenotypes. The excellent clinical response to carbamazepine observed in the patients carrying the A261T variant suggests an exquisite sensitivity of KCNA1 GoF to sodium channel inhibition that should be further explored.
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Affiliation(s)
- Francesco Miceli
- Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | - Renzo Guerrini
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Mario Nappi
- Department of Neuroscience, University of Naples "Federico II", Naples, Italy
| | | | - Elena Cellini
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Christina A Gurnett
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, USA
| | | | - Davide Mei
- Neuroscience Department, A. Meyer Children's Hospital, University of Florence, Florence, Italy
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54
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Qaiser F, Sadoway T, Yin Y, Zulfiqar Ali Q, Nguyen CM, Shum N, Backstrom I, Marques PT, Tabarestani S, Munhoz RP, Krings T, Pearson CE, Yuen RKC, Andrade DM. Genome sequencing identifies rare tandem repeat expansions and copy number variants in Lennox-Gastaut syndrome. Brain Commun 2021; 3:fcab207. [PMID: 34622207 PMCID: PMC8491034 DOI: 10.1093/braincomms/fcab207] [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: 05/10/2021] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 11/22/2022] Open
Abstract
Epilepsies are a group of common neurological disorders with a substantial
genetic basis. Despite this, the molecular diagnosis of epilepsies remains
challenging due to its heterogeneity. Studies utilizing whole-genome sequencing
may provide additional insights into genetic causes of epilepsies of unknown
aetiology. Whole-genome sequencing was used to evaluate a cohort of adults with
unexplained developmental and epileptic encephalopathies (n
= 30), for whom prior genetic tests, including whole-exome sequencing in
some cases, were negative or inconclusive. Rare single nucleotide variants,
insertions/deletions, copy number variants and tandem repeat expansions were
analysed. Seven pathogenic or likely pathogenic single nucleotide variants, and
two pathogenic deleterious copy number variants were identified in nine patients
(32.1% of the cohort). One of the copy number variants, identified in a
patient with Lennox–Gastaut syndrome, was too small to be detected by
chromosomal microarray techniques. We also identified two tandem repeat
expansions with clinical implications in two other patients with
Lennox–Gastaut syndrome: a CGG repeat expansion in the
5′untranslated region of DIP2B, and a CTG expansion in
ATXN8OS (previously implicated in spinocerebellar ataxia
type 8). Three patients had KCNA2 pathogenic variants. One of
them died of sudden unexpected death in epilepsy. The other two patients had, in
addition to a KCNA2 variant, a second de novo
variant impacting potential epilepsy-relevant genes (KCNIP4 and
UBR5). Overall, whole-genome sequencing provided a genetic
explanation in 32.1% of the total cohort. This is also the first report
of coding and non-coding tandem repeat expansions identified in patients with
Lennox–Gastaut syndrome. This study demonstrates that using whole-genome
sequencing, the examination of multiple types of rare genetic variation,
including those found in the non-coding region of the genome, can help resolve
unexplained epilepsies.
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Affiliation(s)
- Farah Qaiser
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Canada.,Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada.,Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Tara Sadoway
- Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Yue Yin
- Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Quratulain Zulfiqar Ali
- Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Charlotte M Nguyen
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Canada.,Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Natalie Shum
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Canada.,Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Ian Backstrom
- Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Paula T Marques
- Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Sepideh Tabarestani
- Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Renato P Munhoz
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Canada.,Neuromodulation Unit and Ataxia Clinic, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Timo Krings
- Department of Medical Imaging, University of Toronto, Toronto, Canada.,Division of Neuroradiology, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Christopher E Pearson
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Canada.,Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Ryan K C Yuen
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Canada.,Genetics & Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - Danielle M Andrade
- Adult Epilepsy Genetics Research Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, Toronto, Canada.,Division of Neurology, Department of Medicine, University of Toronto, Toronto, Canada.,Epilepsy Program, Krembil Neurosciences Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Canada
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55
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A Novel KCNA2 Variant in a Patient with Non-Progressive Congenital Ataxia and Epilepsy: Functional Characterization and Sensitivity to 4-Aminopyridine. Int J Mol Sci 2021; 22:ijms22189913. [PMID: 34576077 PMCID: PMC8469797 DOI: 10.3390/ijms22189913] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 12/26/2022] Open
Abstract
Kv1.2 channels, encoded by the KCNA2 gene, are localized in the central and peripheral nervous system, where they regulate neuronal excitability. Recently, heterozygous mutations in KCNA2 have been associated with a spectrum of symptoms extending from epileptic encephalopathy, intellectual disability, and cerebellar ataxia. Patients are treated with a combination of antiepileptic drugs and 4-aminopyridine (4-AP) has been recently trialed in specific cases. We identified a novel variant in KCNA2, E236K, in a Serbian proband with non-progressive congenital ataxia and early onset epilepsy, treated with sodium valproate. To ascertain the pathogenicity of E236K mutation and to verify its sensitivity to 4-AP, we transfected HEK 293 cells with Kv1.2 WT or E236K cDNAs and recorded potassium currents through the whole-cell patch-clamp. In silico analysis supported the electrophysiological data. E236K channels showed voltage-dependent activation shifted towards negative potentials and slower kinetics of deactivation and activation compared with Kv1.2 WT. Heteromeric Kv1.2 WT+E236K channels, resembling the condition of the heterozygous patient, confirmed a mixed gain- and loss-of-function (GoF/LoF) biophysical phenotype. 4-AP inhibited both Kv1.2 and E236K channels with similar potency. Homology modeling studies of mutant channels suggested a reduced interaction between the residue K236 in the S2 segment and the gating charges at S4. Overall, the biophysical phenotype of E236K channels correlates with the mild end of the clinical spectrum reported in patients with GoF/LoF defects. The response to 4-AP corroborates existing evidence that KCNA2-disorders could benefit from variant-tailored therapeutic approaches, based on functional studies.
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56
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Hedrich UBS, Lauxmann S, Wolff M, Synofzik M, Bast T, Binelli A, Serratosa JM, Martínez-Ulloa P, Allen NM, King MD, Gorman KM, Zeev BB, Tzadok M, Wong-Kisiel L, Marjanovic D, Rubboli G, Sisodiya SM, Lutz F, Ashraf HP, Torge K, Yan P, Bosselmann C, Schwarz N, Fudali M, Lerche H. 4-Aminopyridine is a promising treatment option for patients with gain-of-function KCNA2-encephalopathy. Sci Transl Med 2021; 13:eaaz4957. [PMID: 34516822 DOI: 10.1126/scitranslmed.aaz4957] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Ulrike B S Hedrich
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Markus Wolff
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, 72076 Tuebingen, Germany.,Department of Pediatric Neurology, Vivantes-Klinikum Neukölln, 12351 Berlin, Germany
| | - Matthis Synofzik
- Department of Neurology and Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Thomas Bast
- Epilepsy Center Kork, 77694 Kehl-Kork, Germany.,Medical Faculty of the University of Freiburg, 79110 Freiburg, Germany
| | - Adrian Binelli
- Department of Pediatric Neurology, Elizalde Children's Hospital, C1270 Buenos Aires, Argentina
| | - José M Serratosa
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS- Fundacio'n Jime'nez Dı'az, UAM, 28040 Madrid, Spain.,Centro de Investigacio'n Biome'dica en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
| | - Pedro Martínez-Ulloa
- Neurology Laboratory and Epilepsy Unit, Department of Neurology, IIS- Fundacio'n Jime'nez Dı'az, UAM, 28040 Madrid, Spain
| | - Nicholas M Allen
- Department of Paediatrics, Clinical Sciences Institute, National University of Ireland Galway, Galway H91 TK33, Ireland
| | - Mary D King
- Department of Neurology and Neurophysiology, Children's Health Ireland at Temple Street, Dublin DO1 YC67, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin DO4 V1W8, Ireland
| | - Kathleen M Gorman
- Department of Neurology and Neurophysiology, Children's Health Ireland at Temple Street, Dublin DO1 YC67, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin DO4 V1W8, Ireland
| | - Bruria Ben Zeev
- Sackler School of Medicine Tel Aviv University, Tel Aviv 6997801, Israel.,Pediatric Neurology Unit, Edmond and Lilly Safra Pediatric Hospital, Sheba Medical Center, 5265601 Ramat Gan, Israel
| | - Michal Tzadok
- Sackler School of Medicine Tel Aviv University, Tel Aviv 6997801, Israel.,Pediatric Neurology Unit, Edmond and Lilly Safra Pediatric Hospital, Sheba Medical Center, 5265601 Ramat Gan, Israel
| | - Lily Wong-Kisiel
- Divisions of Child Neurology & Division of Epilepsy, Department of Neurology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | | | - Guido Rubboli
- Danish Epilepsy Center, Filadelfia, 4293 Dianalund, Denmark.,University of Copenhagen, 1165 Copenhagen, Denmark
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
| | - Florian Lutz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Harshad Pannikkaveettil Ashraf
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Kirsten Torge
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Pu Yan
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Christian Bosselmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Niklas Schwarz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
| | - Monika Fudali
- Department of Neurosurgery, University of Tuebingen, 72076 Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, 72076 Tuebingen, Germany
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57
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Lamothe SM, Kurata HT. Slc7a5 alters Kvβ-mediated regulation of Kv1.2. J Gen Physiol 2021; 152:151687. [PMID: 32311044 PMCID: PMC7335012 DOI: 10.1085/jgp.201912524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/22/2020] [Accepted: 03/13/2020] [Indexed: 01/15/2023] Open
Abstract
The voltage-gated potassium channel Kv1.2 plays a pivotal role in neuronal excitability and is regulated by a variety of known and unknown extrinsic factors. The canonical accessory subunit of Kv1.2, Kvβ, promotes N-type inactivation and cell surface expression of the channel. We recently reported that a neutral amino acid transporter, Slc7a5, alters the function and expression of Kv1.2. In the current study, we investigated the effects of Slc7a5 on Kv1.2 in the presence of Kvβ1.2 subunits. We observed that Slc7a5-induced suppression of Kv1.2 current and protein expression was attenuated with cotransfection of Kvβ1.2. However, gating effects mediated by Slc7a5, including disinhibition and a hyperpolarizing shift in channel activation, were observed together with Kvβ-mediated inactivation, indicating convergent regulation of Kv1.2 by both regulatory proteins. Slc7a5 influenced several properties of Kvβ-induced inactivation of Kv1.2, including accelerated inactivation, a hyperpolarizing shift and greater extent of steady-state inactivation, and delayed recovery from inactivation. These modified inactivation properties were also apparent in altered deactivation of the Kv1.2/Kvβ/Slc7a5 channel complex. Taken together, these findings illustrate a functional interaction arising from simultaneous regulation of Kv1.2 by Kvβ and Slc7a5, leading to powerful effects on Kv1.2 expression, gating, and overall channel function.
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Affiliation(s)
- Shawn M Lamothe
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Harley T Kurata
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
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58
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Abstract
Zusammenfassung
Hintergrund
Aktuell werden in der Epileptologie fast ausschließlich Medikamente eingesetzt, die gegen Anfälle wirken („Antikonvulsiva“). Diese beeinflussen die Pathophysiologie der individuell zugrunde liegenden Epilepsie wenig spezifisch im Sinne von „Antiepileptika“. Darauf zielt aber der Begriff „molekulare Pädiatrie“ ab.
Methodik
Ein großes internationales Netzwerk zum einfachen Erfahrungsaustausch von Klinikern über die Therapie von Kindern mit sehr seltenen genetischen Epilepsien ist das Network for Therapy of Rare Epilepsies (NETRE).
Ergebnisse
NETRE besteht seit 15 Jahren und ist in > 320 Gruppen gegliedert, die mit anderen Forschungsgruppen und Selbsthilfevereinigungen kooperieren. Einige Beispiele für klinische Charakteristika neuer Epilepsiegene werden vorgestellt (z. B. Kauanfälle bei SYNGAP1). Eine genetische Untersuchung kann helfen, eine diagnostische Odyssee, auch eine Fehl- oder Überbehandlung eines Patienten zu vermeiden. Aus den genetischen Befunden ergeben sich bislang nur in Einzelfällen gezielte Therapiemöglichkeiten, und diese bisher meist nur mit geringer Evidenz: z. B. Natriumkanalblocker bei SCN2A-Mutationen mit einer „gain of function“ oder Statine bei SYNGAP1-Mutationen. Epigenetische Faktoren wie „early neuroimpaired twin entity“ (ENITE) sind auch bei genetischen Epilepsien bedeutsam.
Diskussion
Der rasante Fortschritt in der genetischen Grundlagenforschung kommt einem Paradigmenwechsel im Verständnis von Pathophysiologie und klinischen Zeichen v. a. bei im frühen Kindesalter beginnenden Epilepsien gleich. Individualisierte Therapieansätze sind aktuell noch selten. Anamnese, klinische Untersuchung und Erfahrung bleiben wichtig. Ethische, psychologische und wirtschaftliche Aspekte einer breiten genetischen Diagnostik sind zu berücksichtigen.
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59
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Abstract
The presence of unprovoked, recurrent seizures, particularly when drug resistant and associated with cognitive and behavioral deficits, warrants investigation for an underlying genetic cause. This article provides an overview of the major classes of genes associated with epilepsy phenotypes divided into functional categories along with the recommended work-up and therapeutic considerations. Gene discovery in epilepsy supports counseling and anticipatory guidance but also opens the door for precision medicine guiding therapy with a focus on those with disease-modifying effects.
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Affiliation(s)
- Luis A Martinez
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Yi-Chen Lai
- Department of Pediatrics, Section of Pediatric Critical Care Medicine, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - J Lloyd Holder
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA
| | - Anne E Anderson
- Department of Pediatrics, Section of Pediatric Neurology and Developmental Neuroscience, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, 1250 Moursund Drive, Houston, TX 77030, USA.
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60
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Kegele J, Krüger J, Koko M, Lange L, Marco Hernandez AV, Martinez F, Münchau A, Lerche H, Lauxmann S. Genetics of Paroxysmal Dyskinesia: Novel Variants Corroborate the Role of KCNA1 in Paroxysmal Dyskinesia and Highlight the Diverse Phenotypic Spectrum of KCNA1- and SLC2A1-Related Disorders. Front Neurol 2021; 12:701351. [PMID: 34305802 PMCID: PMC8297685 DOI: 10.3389/fneur.2021.701351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/28/2021] [Indexed: 11/21/2022] Open
Abstract
Paroxysmal dyskinesias (PxD) are rare movement disorders with characteristic episodes of involuntary mixed hyperkinetic movements. Scientific efforts and technical advances in molecular genetics have led to the discovery of a variety of genes associated with PxD; however, clinical and genetic information of rarely affected genes or infrequent variants is often limited. In our case series, we present two individuals with PxD including one with classical paroxysmal kinesigenic dyskinesia, who carry new likely pathogenic de novo variants in KCNA1 (p.Gly396Val and p.Gly396Arg). The gene has only recently been discovered to be causative for familial paroxysmal kinesigenic dyskinesia. We also provide genetic evidence for pathogenicity of two newly identified disease-causing variants in SLC2A1 (p.Met96Thr and p.Leu231Pro) leading to paroxysmal exercise-induced dyskinesia. Since clinical information of carriers of variants in known disease-causing genes is often scarce, we encourage to share clinical data of individuals with rare or novel (likely) pathogenic variants to improve disease understanding.
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Affiliation(s)
- Josua Kegele
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Johanna Krüger
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Lara Lange
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | | | - Francisco Martinez
- Neuropediatrics Section, Hospital Universitari i Politècnic La Fe, Valencia, Spain
- Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Alexander Münchau
- Institute of Systems Motor Science, University of Lübeck, Lübeck, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Stephan Lauxmann
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
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61
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Miao P, Tang S, Ye J, Tang J, Wang J, Zheng C, Li Y, Feng J. Differential Functional Changes of Nav1.2 Channel Causing SCN2A-Related Epilepsy and Status Epilepticus During Slow Sleep. Front Neurol 2021; 12:653517. [PMID: 34093402 PMCID: PMC8170409 DOI: 10.3389/fneur.2021.653517] [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: 01/14/2021] [Accepted: 03/24/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Nav1.2 encoded by the SCN2A gene is a brain-expressed voltage-gated sodium channel known to be associated with neurodevelopment disorders ranging from benign familial neonatal infantile seizures (BFIS) to developmental and epileptic encephalopathy (DEE) and autism spectrum disorder. Interestingly, status epilepticus during slow sleep (ESES), which aggravates cognitive impairment, has been found in SCN2A-related epilepsy. However, the functional features and the relationship between SCN2A and ESES have not been researched. Method: We herein investigated the functional consequences of an unpublished de novo V911A and the other two published variants in patients with SCN2A-related disorder and ESES by whole-cell patch-clamp studies in transfected HEK293T cells. Results: The unpublished V911A and published K1933M variants detected in patients with DEE exhibited a profound gain-of-functional (GOF) change. Another published BFIS variant S863F significantly reduced current density as a loss-of-functional (LOF) change. The refractory epilepsy in the patient with V911A was controlled by using the precise treatment of oxcarbazepine (OXC) since the age of 3 months. ESES was found at 18 months during the seizure-free period. We finally chose an aggressive treatment for eliminating ESES by using methylprednisolone combined with levetiracetam and nitrazepam instead of the precise treatment of OXC. Conclusion: Both GOF and LOF variants in the SCN2A gene can lead to ESES among the phenotypes of DEE and BFIS. We should monitor the electroencephalogram regularly in the patients with SCN2A-related epilepsy even during their seizure-free period.
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Affiliation(s)
- Pu Miao
- Pediatric Department, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Siyang Tang
- National Health Center and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, National Clinical Research Center for Child Health, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jia Ye
- National Health Center and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, National Clinical Research Center for Child Health, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jihong Tang
- Department of Neurology, Children's Hospital of Soochow University, Suzhou, China
| | - Jianda Wang
- Pediatric Department, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chaoguang Zheng
- Pediatric Department, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuezhou Li
- National Health Center and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, National Clinical Research Center for Child Health, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Feng
- Pediatric Department, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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Abe‐Hatano C, Iida A, Kosugi S, Momozawa Y, Terao C, Ishikawa K, Okubo M, Hachiya Y, Nishida H, Nakamura K, Miyata R, Murakami C, Takahashi K, Hoshino K, Sakamoto H, Ohta S, Kubota M, Takeshita E, Ishiyama A, Nakagawa E, Sasaki M, Kato M, Matsumoto N, Kamatani Y, Kubo M, Takahashi Y, Natsume J, Inoue K, Goto Y. Whole genome sequencing of 45 Japanese patients with intellectual disability. Am J Med Genet A 2021; 185:1468-1480. [PMID: 33624935 PMCID: PMC8247954 DOI: 10.1002/ajmg.a.62138] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/23/2020] [Accepted: 02/06/2021] [Indexed: 02/06/2023]
Abstract
Intellectual disability (ID) is characterized by significant limitations in both intellectual functioning and adaptive behaviors, originating before the age of 18 years. However, the genetic etiologies of ID are still incompletely elucidated due to the wide range of clinical and genetic heterogeneity. Whole genome sequencing (WGS) has been applied as a single-step clinical diagnostic tool for ID because it detects genetic variations with a wide range of resolution from single nucleotide variants (SNVs) to structural variants (SVs). To explore the causative genes for ID, we employed WGS in 45 patients from 44 unrelated Japanese families and performed a stepwise screening approach focusing on the coding variants in the genes. Here, we report 12 pathogenic and likely pathogenic variants: seven heterozygous variants of ADNP, SATB2, ANKRD11, PTEN, TCF4, SPAST, and KCNA2, three hemizygous variants of SMS, SLC6A8, and IQSEC2, and one homozygous variant in AGTPBP1. Of these, four were considered novel. Furthermore, a novel 76 kb deletion containing exons 1 and 2 in DYRK1A was identified. We confirmed the clinical and genetic heterogeneity and high frequency of de novo causative variants (8/12, 66.7%). This is the first report of WGS analysis in Japanese patients with ID. Our results would provide insight into the correlation between novel variants and expanded phenotypes of the disease.
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Affiliation(s)
- Chihiro Abe‐Hatano
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Aritoshi Iida
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
| | - Shunichi Kosugi
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Yukihide Momozawa
- Laboratory for Genotyping DevelopmentRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Chikashi Terao
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
- Clinical Research CenterShizuoka General HospitalShizuokaJapan
- The Department of Applied GeneticsThe School of Pharmaceutical Sciences, University of ShizuokaShizuokaJapan
| | - Keiko Ishikawa
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
| | - Mariko Okubo
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Yasuo Hachiya
- Department of NeuropediatricsTokyo Metropolitan Neurological HospitalTokyoJapan
| | - Hiroya Nishida
- Department of NeuropediatricsTokyo Metropolitan Neurological HospitalTokyoJapan
| | - Kazuyuki Nakamura
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
| | - Rie Miyata
- Department of PediatricsTokyo‐Kita Medical CenterTokyoJapan
| | - Chie Murakami
- Department of PediatricsKitakyusyu Children's Rehabilitation CenterFukuokaJapan
| | - Kan Takahashi
- Department of PediatricsOme Municipal General HospitalTokyoJapan
| | - Kyoko Hoshino
- Department of PediatricsMinami Wakayama Medical CenterWakayamaJapan
| | - Haruko Sakamoto
- Department of NeonatologyJapanese Red Cross Osaka HospitalOsakaJapan
| | - Sayaka Ohta
- Division of NeurologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Masaya Kubota
- Division of NeurologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Eri Takeshita
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Akihiko Ishiyama
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Eiji Nakagawa
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Masayuki Sasaki
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryTokyoJapan
| | - Mitsuhiro Kato
- Department of PediatricsYamagata University Faculty of MedicineYamagataJapan
- Department of PediatricsShowa University School of MedicineTokyoJapan
| | - Naomichi Matsumoto
- Department of Human GeneticsYokohama City University Graduate School of MedicineKanagawaJapan
| | - Yoichiro Kamatani
- Laboratory for Statistical and Translational GeneticsRIKEN Center for Integrative Medical SciencesKanagawaJapan
- Department of Computational Biology and Medical SciencesGraduate School of Frontier Sciences, The University of TokyoTokyoJapan
| | - Michiaki Kubo
- Laboratory for Genotyping DevelopmentRIKEN Center for Integrative Medical SciencesKanagawaJapan
| | - Yoshiyuki Takahashi
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Jun Natsume
- Department of PediatricsNagoya University Graduate School of MedicineAichiJapan
| | - Ken Inoue
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
| | - Yu‐Ichi Goto
- Department of Mental Retardation and Birth Defect ResearchNational Institute of Neuroscience, National Center of Neurology and PsychiatryTokyoJapan
- Medical Genome CenterNational Center of Neurology and PsychiatryTokyoJapan
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63
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Sun H, Shen XR, Fang ZB, Jiang ZZ, Wei XJ, Wang ZY, Yu XF. Next-Generation Sequencing Technologies and Neurogenetic Diseases. Life (Basel) 2021; 11:life11040361. [PMID: 33921670 PMCID: PMC8072598 DOI: 10.3390/life11040361] [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: 01/25/2021] [Revised: 04/05/2021] [Accepted: 04/16/2021] [Indexed: 12/18/2022] Open
Abstract
Next-generation sequencing (NGS) technology has led to great advances in understanding the causes of Mendelian and complex neurological diseases. Owing to the complexity of genetic diseases, the genetic factors contributing to many rare and common neurological diseases remain poorly understood. Selecting the correct genetic test based on cost-effectiveness, coverage area, and sequencing range can improve diagnosis, treatments, and prevention. Whole-exome sequencing and whole-genome sequencing are suitable methods for finding new mutations, and gene panels are suitable for exploring the roles of specific genes in neurogenetic diseases. Here, we provide an overview of the classifications, applications, advantages, and limitations of NGS in research on neurological diseases. We further provide examples of NGS-based explorations and insights of the genetic causes of neurogenetic diseases, including Charcot-Marie-Tooth disease, spinocerebellar ataxias, epilepsy, and multiple sclerosis. In addition, we focus on issues related to NGS-based analyses, including interpretations of variants of uncertain significance, de novo mutations, congenital genetic diseases with complex phenotypes, and single-molecule real-time approaches.
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Affiliation(s)
| | | | | | | | | | | | - Xue-Fan Yu
- Correspondence: ; Tel.: +86-157-5430-1836
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64
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Gong P, Xue J, Jiao X, Zhang Y, Yang Z. Genetic Etiologies in Developmental and/or Epileptic Encephalopathy With Electrical Status Epilepticus During Sleep: Cohort Study. Front Genet 2021; 12:607965. [PMID: 33897753 PMCID: PMC8060571 DOI: 10.3389/fgene.2021.607965] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/02/2021] [Indexed: 11/30/2022] Open
Abstract
Background Recently, the electroencephalogram pattern of electrical status epilepticus during sleep (ESES) had been reported in some genetic disorders, and most of them were noted with developmental and epileptic encephalopathy (DEE) or epileptic encephalopathy (EE). This study aimed to determine the genetic etiologies and clinical characteristics of ESES in DEE/EE. Methods We performed a cohort study in cases of DEE or EE with ESES. Tio-based genetic testing was performed in 74 cases and was analyzed to identify underlying variants. Results Pathogenic or likely pathogenic variants were identified in 17/74 cases, including KCNQ2 (n = 6), KCNA2 (n = 5), GRIN2A (n = 3), SLC9A6 (n = 1), HIVEP2 (n = 1), and RARS2 (n = 1). Eleven were boys. The median age at seizure onset was 6 months. ESES occurred at the mean age of 2.0 ± 1.2 years, predominant in the Rolandic region in 14 years. Twelve of 17 cases had the first stage of different epilepsy preceding ESES: 2/12 were diagnosed as Ohtahara syndrome, 2/12 were diagnosed as infantile spasms, 3/12 were diagnosed as DEE, and 5/12 were diagnosed as EE without the epileptic syndrome. Conclusion Monogenic variants explained over 20% of DEE/EE with ESES. ESES could be an age-related feature in genetic disorders and occurred after the first stage of different epilepsy. Both age-related factors and genetic etiology were suggested to play a role in the occurrence of ESES in genetic DEE/EE.
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Affiliation(s)
- Pan Gong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jiao Xue
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xianru Jiao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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Nikitin ES, Vinogradova LV. Potassium channels as prominent targets and tools for the treatment of epilepsy. Expert Opin Ther Targets 2021; 25:223-235. [PMID: 33754930 DOI: 10.1080/14728222.2021.1908263] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION K+ channels are of great interest to epilepsy research as mutations in their genes are found in humans with inherited epilepsy. At the level of cellular physiology, K+ channels control neuronal intrinsic excitability and are the main contributors to membrane repolarization of active neurons. Recently, a genetically modified voltage-dependent K+ channel has been patented as a remedy for epileptic seizures. AREAS COVERED We review the role of potassium channels in excitability, clinical and experimental evidence for the association of potassium channelopathies with epilepsy, the targeting of K+ channels by drugs, and perspectives of gene therapy in epilepsy with the expression of extra K+ channels in the brain. EXPERT OPINION Control over K+ conductance is of great potential benefit for the treatment of epilepsy. Nowadays, gene therapy affecting K+ channels is one of the most promising approaches to treat pharmacoresistant focal epilepsy.
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Affiliation(s)
- E S Nikitin
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - L V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
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66
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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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67
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Refining Genotypes and Phenotypes in KCNA2-Related Neurological Disorders. Int J Mol Sci 2021; 22:ijms22062824. [PMID: 33802230 PMCID: PMC7999221 DOI: 10.3390/ijms22062824] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 02/06/2023] Open
Abstract
Pathogenic variants in KCNA2, encoding for the voltage-gated potassium channel Kv1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of KCNA2-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel KCNA2 variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)–valine(406)–proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of KCNA2-related disorders. Our study provides further insights into the clinical spectrum, genotype–phenotype correlation, variability, and predicted functional impact of KCNA2 variants.
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68
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Klee EW, Cousin MA, Pinto E Vairo F, Morales-Rosado JA, Macke EL, Jenkinson WG, Ferrer A, Schultz-Rogers LE, Olson RJ, Oliver GR, Sigafoos AN, Schwab TL, Zimmermann MT, Urrutia RA, Kaiwar C, Gupta A, Blackburn PR, Boczek NJ, Prochnow CA, Lowy RJ, Mulvihill LA, McAllister TM, Aoudia SL, Kruisselbrink TM, Gunderson LB, Kemppainen JL, Fisher LJ, Tarnowski JM, Hager MM, Kroc SA, Bertsch NL, Agre KE, Jackson JL, Macklin-Mantia SK, Murphree MI, Rust LM, Summer Bolster JM, Beck SA, Atwal PS, Ellingson MS, Barnett SS, Rasmussen KJ, Lahner CA, Niu Z, Hasadsri L, Ferber MJ, Marcou CA, Clark KJ, Pichurin PN, Deyle DR, Morava-Kozicz E, Gavrilova RH, Dhamija R, Wierenga KJ, Lanpher BC, Babovic-Vuksanovic D, Farrugia G, Schimmenti LA, Stewart AK, Lazaridis KN. Impact of integrated translational research on clinical exome sequencing. Genet Med 2021; 23:498-507. [PMID: 33144682 DOI: 10.1038/s41436-020-01005-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 02/07/2023] Open
Abstract
PURPOSE Exome sequencing often identifies pathogenic genetic variants in patients with undiagnosed diseases. Nevertheless, frequent findings of variants of uncertain significance necessitate additional efforts to establish causality before reaching a conclusive diagnosis. To provide comprehensive genomic testing to patients with undiagnosed disease, we established an Individualized Medicine Clinic, which offered clinical exome testing and included a Translational Omics Program (TOP) that provided variant curation, research activities, or research exome sequencing. METHODS From 2012 to 2018, 1101 unselected patients with undiagnosed diseases received exome testing. Outcomes were reviewed to assess impact of the TOP and patient characteristics on diagnostic rates through descriptive and multivariate analyses. RESULTS The overall diagnostic yield was 24.9% (274 of 1101 patients), with 174 (15.8% of 1101) diagnosed on the basis of clinical exome sequencing alone. Four hundred twenty-three patients with nondiagnostic or without access to clinical exome sequencing were evaluated by the TOP, with 100 (9% of 1101) patients receiving a diagnosis, accounting for 36.5% of the diagnostic yield. The identification of a genetic diagnosis was influenced by the age at time of testing and the disease phenotype of the patient. CONCLUSION Integration of translational research activities into clinical practice of a tertiary medical center can significantly increase the diagnostic yield of patients with undiagnosed disease.
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Affiliation(s)
- Eric W Klee
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA. .,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA. .,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
| | - Margot A Cousin
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Filippo Pinto E Vairo
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Joel A Morales-Rosado
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Erica L Macke
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - W Garrett Jenkinson
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Alejandro Ferrer
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Laura E Schultz-Rogers
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Rory J Olson
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Gavin R Oliver
- Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Ashley N Sigafoos
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Tanya L Schwab
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Michael T Zimmermann
- Bioinformatics Research and Development Laboratory, Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Raul A Urrutia
- Division of Research, Department of Surgery and the Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Charu Kaiwar
- Center for Individualized Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Aditi Gupta
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Patrick R Blackburn
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Nicole J Boczek
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Carri A Prochnow
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Rebecca J Lowy
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Lindsay A Mulvihill
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Tammy M McAllister
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Stacy L Aoudia
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Teresa M Kruisselbrink
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | | | - Jennifer L Kemppainen
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Laura J Fisher
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | | | - Megan M Hager
- Department of Clinical Genomics, Mayo Clinic, Scottsdale, AZ, USA
| | - Sarah A Kroc
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Nicole L Bertsch
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Katherine E Agre
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Laura M Rust
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | | | - Scott A Beck
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Paldeep S Atwal
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA.,Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, USA
| | - Marissa S Ellingson
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Sarah S Barnett
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Kristen J Rasmussen
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Carrie A Lahner
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Zhiyv Niu
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Linda Hasadsri
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Matthew J Ferber
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Cherisse A Marcou
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Karl J Clark
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Pavel N Pichurin
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - David R Deyle
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Eva Morava-Kozicz
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Ralitza H Gavrilova
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Radhika Dhamija
- Center for Individualized Medicine, Mayo Clinic, Scottsdale, AZ, USA.,Department of Clinical Genomics, Mayo Clinic, Scottsdale, AZ, USA
| | - Klaas J Wierenga
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA.,Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, USA
| | - Brendan C Lanpher
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Dusica Babovic-Vuksanovic
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Gianrico Farrugia
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Division of Gastroenterology and Hepatology, College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Lisa A Schimmenti
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA.,Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | | | - Konstantinos N Lazaridis
- Center for Individualized Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA. .,Division of Gastroenterology and Hepatology, College of Medicine, Mayo Clinic, Rochester, MN, USA.
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Morrison-Levy N, Borlot F, Jain P, Whitney R. Early-Onset Developmental and Epileptic Encephalopathies of Infancy: An Overview of the Genetic Basis and Clinical Features. Pediatr Neurol 2021; 116:85-94. [PMID: 33515866 DOI: 10.1016/j.pediatrneurol.2020.12.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 12/19/2022]
Abstract
Our current knowledge of genetically determined forms of epilepsy has shortened the diagnostic pathway usually experienced by the families of infants diagnosed with early-onset developmental and epileptic encephalopathies. Genetic causes can be found in up to 80% of infants presenting with early-onset developmental and epileptic encephalopathies, often in the context of an uneventful perinatal history and with no clear underlying brain abnormalities. Although current disease-specific therapies remain limited and patient outcomes are often guarded, a genetic diagnosis may lead to early therapeutic intervention using new and/or repurposed therapies. In this review, an overview of epilepsy genetics, the indications for genetic testing in infants, the advantages and limitations of each test, and the challenges and ethical implications of genetic testing are discussed. In addition, the following causative genes associated with early-onset developmental and epileptic encephalopathies are discussed in detail: KCNT1, KCNQ2, KCNA2, SCN2A, SCN8A, STXBP1, CDKL5, PIGA, SPTAN1, and GNAO1. The epilepsy phenotypes, comorbidities, electroencephalgraphic findings, neuroimaging findings, and potential targeted therapies for each gene are reviewed.
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Affiliation(s)
| | - Felippe Borlot
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Puneet Jain
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Robyn Whitney
- Division of Neurology, Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada.
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Kuchenbuch M, Nabbout R, Yochum M, Sauleau P, Modolo J, Wendling F, Benquet P. In silico model reveals the key role of GABA in KCNT1-epilepsy in infancy with migrating focal seizures. Epilepsia 2021; 62:683-697. [PMID: 33617692 DOI: 10.1111/epi.16834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/08/2020] [Accepted: 01/18/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE This study was undertaken to investigate how gain of function (GOF) of slack channel due to a KCNT1 pathogenic variant induces abnormal neuronal cortical network activity and generates specific electroencephalographic (EEG) patterns of epilepsy in infancy with migrating focal seizures. METHODS We used detailed microscopic computational models of neurons to explore the impact of GOF of slack channel (explicitly coded) on each subtype of neurons and on a cortical micronetwork. Then, we adapted a thalamocortical macroscopic model considering results obtained in detailed models and immature properties related to epileptic brain in infancy. Finally, we compared simulated EEGs resulting from the macroscopic model with interictal and ictal patterns of affected individuals using our previously reported EEG markers. RESULTS The pathogenic variants of KCNT1 strongly decreased the firing rate properties of γ-aminobutyric acidergic (GABAergic) interneurons and, to a lesser extent, those of pyramidal cells. This change led to hyperexcitability with increased synchronization in a cortical micronetwork. At the macroscopic scale, introducing slack GOF effect resulted in epilepsy of infancy with migrating focal seizures (EIMFS) EEG interictal patterns. Increased excitation-to-inhibition ratio triggered seizure, but we had to add dynamic depolarizing GABA between somatostatin-positive interneurons and pyramidal cells to obtain migrating seizure. The simulated migrating seizures were close to EIMFS seizures, with similar values regarding the delay between the different ictal activities (one of the specific EEG markers of migrating focal seizures due to KCNT1 pathogenic variants). SIGNIFICANCE This study illustrates the interest of biomathematical models to explore pathophysiological mechanisms bridging the gap between the functional effect of gene pathogenic variants and specific EEG phenotype. Such models can be complementary to in vitro cellular and animal models. This multiscale approach provides an in silico framework that can be further used to identify candidate innovative therapies.
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Affiliation(s)
- Mathieu Kuchenbuch
- LTSI-U1099, Université de Rennes 1, INSERM, Rennes, France.,Department of Pediatric Neurology, Reference Center for Rare Epilepsies, Hôpital Necker-Enfants malades, member of European Network EPICARE, Paris, France.,Laboratory of Translational Research for Neurological Disorders (UMR 1163), IHU Imagine Institute of Genetic Diseases, INSERM, University of Paris, Paris, France
| | - Rima Nabbout
- Department of Pediatric Neurology, Reference Center for Rare Epilepsies, Hôpital Necker-Enfants malades, member of European Network EPICARE, Paris, France.,Laboratory of Translational Research for Neurological Disorders (UMR 1163), IHU Imagine Institute of Genetic Diseases, INSERM, University of Paris, Paris, France
| | - Maxime Yochum
- LTSI-U1099, Université de Rennes 1, INSERM, Rennes, France
| | - Paul Sauleau
- CHU de Rennes (Department of Neurophysiology), "Behavior and Basal Ganglia" Research Unit (EA4712), University of Rennes, Rennes, France
| | - Julien Modolo
- LTSI-U1099, Université de Rennes 1, INSERM, Rennes, France
| | | | - Pascal Benquet
- LTSI-U1099, Université de Rennes 1, INSERM, Rennes, France
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71
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Simkin D, Marshall KA, Vanoye CG, Desai RR, Bustos BI, Piyevsky BN, Ortega JA, Forrest M, Robertson GL, Penzes P, Laux LC, Lubbe SJ, Millichap JJ, George AL, Kiskinis E. Dyshomeostatic modulation of Ca 2+-activated K + channels in a human neuronal model of KCNQ2 encephalopathy. eLife 2021; 10:64434. [PMID: 33544076 PMCID: PMC7864629 DOI: 10.7554/elife.64434] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/20/2021] [Indexed: 12/22/2022] Open
Abstract
Mutations in KCNQ2, which encodes a pore-forming K+ channel subunit responsible for neuronal M-current, cause neonatal epileptic encephalopathy, a complex disorder presenting with severe early-onset seizures and impaired neurodevelopment. The condition is exceptionally difficult to treat, partially because the effects of KCNQ2 mutations on the development and function of human neurons are unknown. Here, we used induced pluripotent stem cells (iPSCs) and gene editing to establish a disease model and measured the functional properties of differentiated excitatory neurons. We find that patient iPSC-derived neurons exhibit faster action potential repolarization, larger post-burst afterhyperpolarization and a functional enhancement of Ca2+-activated K+ channels. These properties, which can be recapitulated by chronic inhibition of M-current in control neurons, facilitate a burst-suppression firing pattern that is reminiscent of the interictal electroencephalography pattern in patients. Our findings suggest that dyshomeostatic mechanisms compound KCNQ2 loss-of-function leading to alterations in the neurodevelopmental trajectory of patient iPSC-derived neurons.
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Affiliation(s)
- Dina Simkin
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Kelly A Marshall
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Carlos G Vanoye
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Reshma R Desai
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Bernabe I Bustos
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Brandon N Piyevsky
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Juan A Ortega
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Marc Forrest
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Center for Autism and Neurodevelopment, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Gabriella L Robertson
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Peter Penzes
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Center for Autism and Neurodevelopment, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Linda C Laux
- Epilepsy Center and Division of Neurology, Departments of Pediatrics and Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Steven J Lubbe
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - John J Millichap
- Epilepsy Center and Division of Neurology, Departments of Pediatrics and Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Alfred L George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, United States
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72
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Deep phenotyping unstructured data mining in an extensive pediatric database to unravel a common KCNA2 variant in neurodevelopmental syndromes. Genet Med 2021; 23:968-971. [PMID: 33500571 PMCID: PMC8105164 DOI: 10.1038/s41436-020-01039-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 01/08/2023] Open
Abstract
Purpose Electronic health records are gaining popularity to detect and propose interdisciplinary treatments for patients with similar medical histories, diagnoses, and outcomes. These files are compiled by different nonexperts and expert clinicians. Data mining in these unstructured data is a transposable and sustainable methodology to search for patients presenting a high similitude of clinical features. Methods Exome and targeted next-generation sequencing bioinformatics analyses were performed at the Imagine Institute. Similarity Index (SI), an algorithm based on a vector space model (VSM) that exploits concepts extracted from clinical narrative reports was used to identify patients with highly similar clinical features. Results Here we describe a case of “automated diagnosis” indicated by Dr. Warehouse, a biomedical data warehouse oriented toward clinical narrative reports, developed at Necker Children’s Hospital using around 500,000 patients’ records. Through the use of this warehouse, we were able to match and identify two patients sharing very specific clinical neonatal and childhood features harboring the same de novo variant in KCNA2. Conclusion This innovative application of database clustering clinical features could advance identification of patients with rare and common genetic conditions and detect with high accuracy the natural history of patients harboring similar genetic pathogenic variants.
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73
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Timäus C, von Gottberg P, Hirschel S, Lange C, Wiltfang J, Hansen N. KCNA2 Autoimmunity in Progressive Cognitive Impairment: Case Series and Literature Review. Brain Sci 2021; 11:89. [PMID: 33445475 PMCID: PMC7826663 DOI: 10.3390/brainsci11010089] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 12/31/2022] Open
Abstract
Autoimmune dementia is a novel and expanding field which subsumes neuropsychiatric disorders with predominant cognitive impairments due to an underlying autoimmune etiology. Progressive dementias with atypical clinical presentation should trigger a thorough diagnostic approach including testing for neural surface and intracellular antibodies to avoid a delay in accurate diagnosis and initiating appropriate therapy. Here, we present two emerging cases of progressive dementia with co-existing serum autoantibodies against the KCNA2 (potassium voltage-gated channel subfamily A member 2) subunit. We found various cognitive deficits with dominant impairments in the memory domain, particularly in delayed recall. One patient presented a subacute onset of then-persisting cognitive deficits, while the other patient's cognitive impairments progressed more chronically and fluctuated. Cognitive impairments coincided with additional neuropsychiatric symptoms. Both had a potential paraneoplastic background according to their medical history and diagnostic results. We discuss the potential role of KCNA2 autoantibodies in these patients and in general by reviewing the literature. The pathogenetic role of KCNA2 antibodies in cognitive impairment is not well delineated; clinical presentations are heterogeneous, and thus a causal link between antibodies remains questionable. Current evidence indicates an intracellular rather than extracellular epitope. We strongly suggest additional prospective studies to explore KCNA2 antibodies in specifically-defined cohorts of cognitively impaired patients via a systematic assessment of clinical, neuropsychological, neuroimaging, as well as laboratory and CSF (cerebrospinal fluid) parameters, and antibody studies to (1) determine the epitope's location (intracellular vs. extracellular), (2) the mode of action, and (3) seek co-existing, novel pathogenetic autoantibodies in sera and CSF.
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Affiliation(s)
- Charles Timäus
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Philipp von Gottberg
- Department of Neuroradiology, University Medical Center Goettingen, Robert-Koch-Str. 40, 37075 Goettingen, Germany;
| | - Sina Hirschel
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Claudia Lange
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
| | - Jens Wiltfang
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Goettingen, Germany
- Neurosciences and Signaling Group, Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, 3810-193 Aveiro, Portugal
| | - Niels Hansen
- Department of Psychiatry and Psychotherapy, University of Goettingen, Von-Siebold-Str. 5, 37075 Goettingen, Germany; (S.H.); (C.L.); (J.W.); (N.H.)
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74
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Generation of a human iPSC line from an epileptic encephalopathy patient with electrical status epilepticus during sleep carrying KCNA2 (p.P405L) mutation. Stem Cell Res 2020; 49:102080. [PMID: 33232902 DOI: 10.1016/j.scr.2020.102080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 11/22/2022] Open
Abstract
Mutations in KCNA2 gene, encoding for the voltage-gated K+ channel Kv1.2, has been reported to be associated with epilepsy disorders. This channel is mainly expressed in the central nervous system and plays an important role in neuronal excitability and neurotransmitter release. Herein, we generated an induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells of an eight-year-old girl with epileptic encephalopathy and electrical status epilepticus during sleep carrying a mutation (c.1214C > T, p.Pro405Leu) in KCNA2. These iPSCs exhibited stable amplification, expressed pluripotent markers, and differentiated spontaneously into three germ layers in vitro.
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75
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Lamothe SM, Sharmin N, Silver G, Satou M, Hao Y, Tateno T, Baronas VA, Kurata HT. Control of Slc7a5 sensitivity by the voltage-sensing domain of Kv1 channels. eLife 2020; 9:54916. [PMID: 33164746 PMCID: PMC7690953 DOI: 10.7554/elife.54916] [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: 01/06/2020] [Accepted: 11/06/2020] [Indexed: 01/13/2023] Open
Abstract
Many voltage-dependent ion channels are regulated by accessory proteins. We recently reported powerful regulation of Kv1.2 potassium channels by the amino acid transporter Slc7a5. In this study, we report that Kv1.1 channels are also regulated by Slc7a5, albeit with different functional outcomes. In heterologous expression systems, Kv1.1 exhibits prominent current enhancement ('disinhibition') with holding potentials more negative than −120 mV. Knockdown of endogenous Slc7a5 leads to larger Kv1.1 currents and strongly attenuates the disinhibition effect, suggesting that Slc7a5 regulation of Kv1.1 involves channel inhibition that can be reversed by supraphysiological hyperpolarizing voltages. We investigated chimeric combinations of Kv1.1 and Kv1.2, demonstrating that exchange of the voltage-sensing domain controls the sensitivity and response to Slc7a5, and localize a specific position in S1 with prominent effects on Slc7a5 sensitivity. Overall, our study highlights multiple Slc7a5-sensitive Kv1 subunits, and identifies the voltage-sensing domain as a determinant of Slc7a5 modulation of Kv1 channels.
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Affiliation(s)
- Shawn M Lamothe
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Nazlee Sharmin
- School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, School of Dentistry, Edmonton Clinic Health Academy (ECHA), Edmonton, Canada
| | - Grace Silver
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Motoyasu Satou
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Tochigi, Japan.,Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Yubin Hao
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Toru Tateno
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Victoria A Baronas
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
| | - Harley T Kurata
- Department of Pharmacology, Alberta Diabetes Institute, University of Alberta, Edmonton, Canada
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76
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Pantazis A, Kaneko M, Angelini M, Steccanella F, Westerlund AM, Lindström SH, Nilsson M, Delemotte L, Saitta SC, Olcese R. Tracking the motion of the K V1.2 voltage sensor reveals the molecular perturbations caused by a de novo mutation in a case of epilepsy. J Physiol 2020; 598:5245-5269. [PMID: 32833227 PMCID: PMC8923147 DOI: 10.1113/jp280438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/14/2020] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS KV1.2 channels, encoded by the KCNA2 gene, regulate neuronal excitability by conducting K+ upon depolarization. A new KCNA2 missense variant was discovered in a patient with epilepsy, causing amino acid substitution F302L at helix S4, in the KV1.2 voltage-sensing domain. Immunocytochemistry and flow cytometry showed that F302L does not impair KCNA2 subunit surface trafficking. Molecular dynamics simulations indicated that F302L alters the exposure of S4 residues to membrane lipids. Voltage clamp fluorometry revealed that the voltage-sensing domain of KV1.2-F302L channels is more sensitive to depolarization. Accordingly, KV1.2-F302L channels opened faster and at more negative potentials; however, they also exhibited enhanced inactivation: that is, F302L causes both gain- and loss-of-function effects. Coexpression of KCNA2-WT and -F302L did not fully rescue these effects. The proband's symptoms are more characteristic of patients with loss of KCNA2 function. Enhanced KV1.2 inactivation could lead to increased synaptic release in excitatory neurons, steering neuronal circuits towards epilepsy. ABSTRACT An exome-based diagnostic panel in an infant with epilepsy revealed a previously unreported de novo missense variant in KCNA2, which encodes voltage-gated K+ channel KV1.2. This variant causes substitution F302L, in helix S4 of the KV1.2 voltage-sensing domain (VSD). F302L does not affect KCNA2 subunit membrane trafficking. However, it does alter channel functional properties, accelerating channel opening at more hyperpolarized membrane potentials, indicating gain of function. F302L also caused loss of KV1.2 function via accelerated inactivation onset, decelerated recovery and shifted inactivation voltage dependence to more negative potentials. These effects, which are not fully rescued by coexpression of wild-type and mutant KCNA2 subunits, probably result from the enhancement of VSD function, as demonstrated by optically tracking VSD depolarization-evoked conformational rearrangements. In turn, molecular dynamics simulations suggest altered VSD exposure to membrane lipids. Compared to other encephalopathy patients with KCNA2 mutations, the proband exhibits mild neurological impairment, more characteristic of patients with KCNA2 loss of function. Based on this information, we propose a mechanism of epileptogenesis based on enhanced KV1.2 inactivation leading to increased synaptic release preferentially in excitatory neurons, and hence the perturbation of the excitatory/inhibitory balance of neuronal circuits.
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Affiliation(s)
- Antonios Pantazis
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
- Wallenberg Center for Molecular Medicine, Linköping University, Linköping, Sweden
| | - Maki Kaneko
- Center for Personalized Medicine, Children's Hospital, Los Angeles, Los Angeles, CA, USA
- Division of Genomic Medicine, Department of Pathology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Marina Angelini
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Federica Steccanella
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Annie M Westerlund
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Sarah H Lindström
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Michelle Nilsson
- Division of Neurobiology, Department of Biomedical and Clinical Sciences (BKV), Linköping University, Linköping, Sweden
| | - Lucie Delemotte
- Science for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, Solna, Sweden
| | - Sulagna C Saitta
- Department of Obstetrics and Gynecology and Division of Medical Genetics, Department of Pediatrics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Riccardo Olcese
- Division of Molecular Medicine, Department of Anesthesiology & Perioperative Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Department of Physiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
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77
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Hyperkalemic Periodic Paralysis: Case Report with a SCNA4 Gene Mutation and Literature Review. Case Rep Genet 2020; 2020:8843410. [PMID: 33123387 PMCID: PMC7585666 DOI: 10.1155/2020/8843410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/18/2020] [Accepted: 09/23/2020] [Indexed: 11/24/2022] Open
Abstract
Hyperkalemic periodic paralysis is a rare musculoskeletal disorder characterized by episodic muscle weakness associated with hyperkalemia. It is a channelopathy associated with point mutations in the SCNA4 gene, with an autosomal dominant pattern of inheritance. We report the case of a 39-year-old patient with a picture with onset at six years of age, consisting of episodes of weakness caused by physical activity and intercurrent infectious processes, in whom a point mutation was found in the SCNA4 gene, not previously reported in the literature.
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78
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Matricardi S, De Liso P, Freri E, Costa P, Castellotti B, Magri S, Gellera C, Granata T, Musante L, Lesca G, Oertel J, Craiu D, Hammer TB, Møller RS, Barisic N, Abou Jamra R, Polster T, Vigevano F, Marini C. Neonatal developmental and epileptic encephalopathy due to autosomal recessive variants in
SLC13A5
gene. Epilepsia 2020; 61:2474-2485. [DOI: 10.1111/epi.16699] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 08/18/2020] [Accepted: 08/31/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Sara Matricardi
- Department of Child Neuropsychiatry Children’s Hospital Ancona Italy
| | - Paola De Liso
- Department of Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children's Hospital Rome Italy
| | - Elena Freri
- Department of Pediatric Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Paola Costa
- Department of Neuropsychiatry Institute for Maternal and Child Health Istituto di Ricovero e Cura a Carattere Scientifico Burlo Garofolo Trieste Italy
| | - Barbara Castellotti
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Stefania Magri
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Foundation Carlo Besta Neurological Institute Milan Italy
| | - Luciana Musante
- Department of Medical Genetics Institute for Maternal and Child Health Istituto di Ricovero e Cura a Carattere Scientifico Burlo Garofolo Trieste Italy
| | - Gaetan Lesca
- Department of Medical Genetics Lyon Civil Hospices Lyon France
| | - Julie Oertel
- Department of Medical Genetics Archet Hospital 2, Nice University Hospital Center Nice France
| | - Dana Craiu
- Department of Clinical Neurosciences Carol Davila University of Medicine and Pharmacy Bucharest Bucharest Romania
- Pediatric Neurology Clinic Alexandru Obregia Hospital Bucharest Romania
| | | | - Rikke S. Møller
- Danish Epilepsy Center Filadelfia Dianalund Denmark
- Institute for Regional Health Services University of Southern Denmark Odense Denmark
| | - Nina Barisic
- Division of Child Neurology Department of Pediatrics Clinical Medical Center Zagreb University of Zagreb Medical School Zagreb Croatia
| | - Rami Abou Jamra
- Institute of Human Genetics University Medical Center Leipzig Leipzig Germany
| | - Tilman Polster
- Pediatric Epileptology Mara HospitalBethel Epilepsy Center Bielefeld Germany
| | - Federico Vigevano
- Department of Neuroscience Istituto di Ricovero e Cura a Carattere Scientifico Bambino Gesù Children's Hospital Rome Italy
| | - Carla Marini
- Department of Child Neuropsychiatry Children’s Hospital Ancona Italy
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79
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Hirose S, Tanaka Y, Shibata M, Kimura Y, Ishikawa M, Higurashi N, Yamamoto T, Ichise E, Chiyonobu T, Ishii A. Application of induced pluripotent stem cells in epilepsy. Mol Cell Neurosci 2020; 108:103535. [DOI: 10.1016/j.mcn.2020.103535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
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80
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Bar C, Kuchenbuch M, Barcia G, Schneider A, Jennesson M, Le Guyader G, Lesca G, Mignot C, Montomoli M, Parrini E, Isnard H, Rolland A, Keren B, Afenjar A, Dorison N, Sadleir LG, Breuillard D, Levy R, Rio M, Dupont S, Negrin S, Danieli A, Scalais E, De Saint Martin A, El Chehadeh S, Chelly J, Poisson A, Lebre A, Nica A, Odent S, Sekhara T, Brankovic V, Goldenberg A, Vrielynck P, Lederer D, Maurey H, Terrone G, Besmond C, Hubert L, Berquin P, Billette de Villemeur T, Isidor B, Freeman JL, Mefford HC, Myers CT, Howell KB, Rodríguez‐Sacristán Cascajo A, Meyer P, Genevieve D, Guët A, Doummar D, Durigneux J, van Dooren MF, de Wit MCY, Gerard M, Marey I, Munnich A, Guerrini R, Scheffer IE, Kabashi E, Nabbout R. Developmental and epilepsy spectrum of
KCNB1
encephalopathy with long‐term outcome. Epilepsia 2020; 61:2461-2473. [DOI: 10.1111/epi.16679] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Claire Bar
- Department of Pediatric Neurology Reference Center for Rare Epilepsies Assistance Publique‐Hôpitaux de Paris (AP‐HP), Necker‐Enfants Malades Hospital Paris France
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
| | - Mathieu Kuchenbuch
- Department of Pediatric Neurology Reference Center for Rare Epilepsies Assistance Publique‐Hôpitaux de Paris (AP‐HP), Necker‐Enfants Malades Hospital Paris France
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
| | - Giulia Barcia
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
- Department of Clinical Genetics AP‐HP, Necker‐Enfants Malades Hospital Paris France
| | - Amy Schneider
- Department of Medicine Epilepsy Research Centre Austin Health University of Melbourne Heidelberg Victoria Australia
| | | | - Gwenaël Le Guyader
- Department of Genetics Poitiers University Hospital CenterPoitiers Cedex France
- EA3808–NEUVACOD Neurovascular and Cognitive Disorders Unit University of Poitiers Poitiers France
| | - Gaetan Lesca
- Department of Genetics Lyon Civil Hospices Lyon France
- NeuroMyoGène Institute National Center for Scientific Research Mixed Unit of Research 5310, National Institute of Health and Medical Research U1217University of LyonClaude Bernard Lyon 1 University Villeurbanne France
| | - Cyril Mignot
- National Institute of Health and Medical Research, U1127 National Center for Scientific Research Mixed Unit of Research 7225 Pierre and Marie Curie University Paris 6 Mixed Unit of Research S1127 Brain and Spine Institute Sorbonne University Paris France
- Department of Genetics Rare Causes of Intellectual Disability Reference Center AP‐HP, Pitié‐Salpêtrière HospitalSorbonne University Paris France
| | - Martino Montomoli
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories Neuroscience Department A. Meyer Children's HospitalUniversity of Florence Florence Italy
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories Neuroscience Department A. Meyer Children's HospitalUniversity of Florence Florence Italy
| | - Hervé Isnard
- Pediatric Neurologist Medical Office Lyon France
| | - Anne Rolland
- Department of Pediatrics Nantes University Hospital Center Nantes France
| | - Boris Keren
- Department of Genetics Rare Causes of Intellectual Disability Reference Center AP‐HP, Pitié‐Salpêtrière HospitalSorbonne University Paris France
| | - Alexandra Afenjar
- Department of Genetics and Medical Embryology Reference Center for Malformations and Congenital Diseases of the Cerebellum and Rare Causes of Intellectual Disabilities Sorbonne UniversityAP‐HP, Trousseau Hospital Paris France
| | - Nathalie Dorison
- Pediatric Neurosurgery Department Rothschild Foundation Hospital Paris France
- Department of Pediatric Neurology AP‐HP, Armand Trousseau HospitalSorbonne University Paris France
| | - Lynette G. Sadleir
- Department of Pediatrics and Child Health University of Otago Wellington New Zealand
| | - Delphine Breuillard
- Department of Pediatric Neurology Reference Center for Rare Epilepsies Assistance Publique‐Hôpitaux de Paris (AP‐HP), Necker‐Enfants Malades Hospital Paris France
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
| | - Raphael Levy
- Department of Pediatric Radiology Necker‐Enfants Malades Hospital Paris France
| | - Marlène Rio
- Department of Clinical Genetics AP‐HP, Necker‐Enfants Malades Hospital Paris France
- Laboratory of Developmental Brain Disorders National Institute of Health and Medical Research Mixed Unit of Research 1163 Imagine InstituteSorbonne University Paris France
| | - Sophie Dupont
- National Institute of Health and Medical Research, U1127 National Center for Scientific Research Mixed Unit of Research 7225 Pierre and Marie Curie University Paris 6 Mixed Unit of Research S1127 Brain and Spine Institute Sorbonne University Paris France
- Epileptology Unit and Rehabilitation Unit AP‐HP, Pitie‐Salpêtrière‐Charles Foix Hospital Paris France
| | - Susanna Negrin
- Epilepsy and Clinical Neurophysiology Unit Scientific InstituteIRCCS E. Medea Treviso Italy
| | - Alberto Danieli
- Epilepsy and Clinical Neurophysiology Unit Scientific InstituteIRCCS E. Medea Treviso Italy
| | - Emmanuel Scalais
- Pediatric Neurology Unit Luxembourg Hospital Center Luxembourg City Luxembourg
| | - Anne De Saint Martin
- Department of Pediatric Neurology Strasbourg University HospitalHautepierre Hospital Strasbourg France
| | - Salima El Chehadeh
- Department of Medical Genetics Strasbourg University HospitalsHautepierre Hospital Strasbourg France
| | - Jamel Chelly
- Department of Medical Genetics Strasbourg University HospitalsHautepierre Hospital Strasbourg France
| | - Alice Poisson
- GénoPsy Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders le Vinatier Hospital Center and EDR‐Psy Team (National Center for Scientific Research and Lyon 1 Claude Bernard University) Villeurbanne France
| | - Anne‐Sophie Lebre
- Reims University Hospital CenterMaison Blanche HospitalBiology Department Reims France
| | - Anca Nica
- Neurology Department Center for Clinical Research (CIC 1414) Rennes University Hospital Rennes France
- Laboratory of Signal ProcessingNational Institute of Health and Medical Research Mixed Unit of Research 1099 Rennes France
| | - Sylvie Odent
- Reference Center for Rare Developmental Abnormalities CLAD‐Ouest Rennes University Hospital Center Rennes France
- National Center for Scientific Research Mixed Unit of Research 6290, Institute of Genetics and Development of Rennes (IGDR)University of Rennes Rennes France
| | - Tayeb Sekhara
- Department of Pediatric Neurology C.H.I.R.E.C Brussels Belgium
| | | | - Alice Goldenberg
- Reference Center for Developmental Anomalies and Malformation Syndromes Rouen University Hospital Center Rouen France
| | - Pascal Vrielynck
- Reference Center for Refractory Epilepsy, Catholic University of Louvain William Lennox Neurological Hospital Ottignies Belgium
| | | | - Hélène Maurey
- Department of Pediatric Neurology AP‐HP, Bicêtre University Hospital Kremlin Bicêtre France
| | - Gaetano Terrone
- Department of Translational Medical Sciences Section of Pediatrics, Child Neurology Unit Federico II University Naples Italy
| | - Claude Besmond
- Translational Genetics National Institute of Health and Medical Research Mixed Unit of Research 1163Imagine InstituteUniversity of Paris Paris France
| | - Laurence Hubert
- Translational Genetics National Institute of Health and Medical Research Mixed Unit of Research 1163Imagine InstituteUniversity of Paris Paris France
| | - Patrick Berquin
- Department of Pediatric Neurology Amiens‐Picardie University Hospital CenterUniversity of Picardy Jules Verne Amiens France
| | | | - Bertrand Isidor
- Department of Clinical Genetics Nantes University Hospital Center Nantes France
| | - Jeremy L. Freeman
- Departments of Neurology and Paediatrics Royal Children's Hospital University of Melbourne Melbourne Victoria Australia
- Murdoch Children’s Research Institute Melbourne Victoria Australia
| | - Heather C. Mefford
- Department of Pediatrics Division of Genetic Medicine University of Washington Seattle Washington United States
| | - Candace T. Myers
- Department of Pediatrics Division of Genetic Medicine University of Washington Seattle Washington United States
| | - Katherine B. Howell
- Departments of Neurology and Paediatrics Royal Children's Hospital University of Melbourne Melbourne Victoria Australia
- Murdoch Children’s Research Institute Melbourne Victoria Australia
| | - Andrés Rodríguez‐Sacristán Cascajo
- Pediatric Neurology Unit Department of Pediatric Virgen Macarena Hospital Seville Spain
- Department of Pediatrics School of Medicine University of Seville Seville Spain
| | - Pierre Meyer
- Department of Pediatric Neurology Montpellier University Hospital Center Montpellier France
- PhyMedExp National Institute of Health and Medical Research, U1046National Center for Scientific Research Mixed Unit of Research 9214University of Montpellier Montpellier France
| | - David Genevieve
- Department of Medical Genetics, Rare Disease, and Personalized Medicine IRMBUniversity of MontpellierNational Institute of Health and Medical ResearchMontpellier University Hospital Center Montpellier France
| | - Agnès Guët
- Department of Pediatrics Louis‐Mourier Hospital Colombes France
| | - Diane Doummar
- Department of Pediatric Neurology AP‐HP, Armand Trousseau HospitalSorbonne University Paris France
| | - Julien Durigneux
- Departments of Neurology and Paediatrics Royal Children's Hospital University of Melbourne Melbourne Victoria Australia
| | - Marieke F. van Dooren
- Department of Clinical Genetics Erasmus University Medical Center Rotterdam the Netherlands
| | - Marie Claire Y. de Wit
- Department of Pediatric Neurology and ENCORE Expertise Center Erasmus University Medical Center Sophia Children’s Hospital Rotterdam the Netherlands
| | - Marion Gerard
- Clinical Genetics Côte de Nacre University Hospital Center Caen France
| | - Isabelle Marey
- Department of Genetics Rare Causes of Intellectual Disability Reference Center AP‐HP, Pitié‐Salpêtrière HospitalSorbonne University Paris France
| | - Arnold Munnich
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
- Department of Clinical Genetics AP‐HP, Necker‐Enfants Malades Hospital Paris France
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories Neuroscience Department A. Meyer Children's HospitalUniversity of Florence Florence Italy
| | - Ingrid E. Scheffer
- Department of Medicine Epilepsy Research Centre Austin Health University of Melbourne Heidelberg Victoria Australia
- Departments of Neurology and Paediatrics Royal Children's Hospital University of Melbourne Melbourne Victoria Australia
- Murdoch Children’s Research Institute Melbourne Victoria Australia
- Florey Institute of Neurosciences and Mental Health Heidelberg Victoria Australia
| | - Edor Kabashi
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
| | - Rima Nabbout
- Department of Pediatric Neurology Reference Center for Rare Epilepsies Assistance Publique‐Hôpitaux de Paris (AP‐HP), Necker‐Enfants Malades Hospital Paris France
- Imagine Institute, Mixed Unit of Research 1163 University of ParisSorbonne University Paris France
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81
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Guzmán-Jiménez DE, Campos JB, Venegas-Vega CA, Sánchez MA, Velasco AL. Familial mesial temporal lobe epilepsy in Mexico: Inheritance pattern and clinical features. Epilepsy Res 2020; 167:106450. [PMID: 32949980 DOI: 10.1016/j.eplepsyres.2020.106450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/11/2020] [Accepted: 08/21/2020] [Indexed: 11/19/2022]
Abstract
PURPOSE The objectives of this study were to determine the inheritance pattern by which familial mesial temporal lobe epilepsy (FMTLE) is segregated in Mexican families, and to identify if there was an association between the clinical characteristics and the inheritance pattern. METHOD We included a total of 25 families with two or more members affected with MTLE during two years and elaborated a family pedigree for each family. The inheritance pattern was classified as autosomal dominant (AD) or autosomal recessive (AR), considering the affected members. We used statistical analysis association and differences between clinical characteristics and inheritance patterns. RESULTS The affected families with the AD pattern were 15.7 fold times more likely to start seizures at 5 years of age or earlier than families with AR pattern, OR = 15.7 (IC 95% = 1.9-128.9). We observed a predominance and greater déjà vu association (64.4% vs 31.3%; p = 0.021), OR = 3.9 (CI 95% = 1.1-13.5) in patients with AD versus AR pattern. Finally, we identified that patients with AD pattern had a likelihood of presenting emotional alterations 5.6 times higher than AR (OR = 5.6, IC = 1.1-27.5). CONCLUSION FMTLE is a heterogeneous syndrome, both phenotypically and genotypically; thus, our findings may be helpful for clinical use to perform an early diagnosis, to provide timely treatment, and to prevent comorbidities associated to this disease. However, in order to identify the possible genetic causes underlying these inheritance patterns, the use of molecular studies is necessary.
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Affiliation(s)
- Diana Elena Guzmán-Jiménez
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico; Programa de Doctorado en Ciencias Biomédicas, División de Estudios de Posgrado, Universidad Nacional Autónoma de México (UNAM), Universidad 3000, 04510, Mexico City, Mexico.
| | - Jaime Berumen Campos
- Medical School, Universidad Nacional Autónoma de México, Mexico City, Mexico; Experimental Medicine Unit, Universidad Nacional Autónoma de México, in the General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Carlos Alberto Venegas-Vega
- Medical School, Universidad Nacional Autónoma de México, Mexico City, Mexico; Genetic Unit, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Mariana Alejandre Sánchez
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Ana Luisa Velasco
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
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82
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Gong P, Jiao X, Zhang Y, Yang Z. Complex Mosaicism of Two Distinct Mutations in a Female Patient With KCNA2-Related Encephalopathy: A Case Report. Front Genet 2020; 11:911. [PMID: 32903602 PMCID: PMC7438874 DOI: 10.3389/fgene.2020.00911] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/22/2020] [Indexed: 12/29/2022] Open
Abstract
KCNA2 gene mutations were described to cause a new molecular entity within the developmental and epileptic or epileptic encephalopathies. Here, we firstly reported a patient with an unusual mosaicism for KCNA2, presenting two distinct mosaic missense mutations at the same loci. Clinical trio-based whole-exome sequencing using next-generation sequencing (NGS) revealed two novel mutations in KCNA2: c.1225A > T [p.(Ile409Phe)] and c.1225A > C [p.(Ile409Leu)]. Both missense mutations were in mosaic status and Sanger sequencing confirmed them as de novo. The affected 5-year-old girl presented as seizures with fever sensitivity, and mild cognitive and behavioral disorders. EEG showed focal centrotemporal epileptiform discharges accompanied by nocturnal focal seizures at the age of slightly older than 5 years, more likely carrying a loss-of-function mutation of KCNA2-related phenotype. Further NGS with a mean coverage of 6950 × showed 26% (mosaic mutation reads/total reads) of the c.1225A > T mutation and 23% of the c.1225A > C mutation. The sum of their allele fractions was close to 50%, approximately equal to a heterozygous variant. The patient had no seizures for 8 months on combination of levetiracetam (18.75 mg/kg/d) and valproate (20 mg/kg/d) till the last follow-up at the age of 5 years and 11 months. Our findings highlighted the two mosaic mutations responsible for the pathogenesis of KCNA2-related encephalopathy. The patient expanded the mutational spectrum of KCNA2-related encephalopathy and provided new insight into the complex genetic disorder.
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Affiliation(s)
- Pan Gong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xianru Jiao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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83
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Lammertse HCA, van Berkel AA, Iacomino M, Toonen RF, Striano P, Gambardella A, Verhage M, Zara F. Homozygous STXBP1 variant causes encephalopathy and gain-of-function in synaptic transmission. Brain 2020; 143:441-451. [PMID: 31855252 PMCID: PMC7009479 DOI: 10.1093/brain/awz391] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/09/2019] [Accepted: 10/29/2019] [Indexed: 11/14/2022] Open
Abstract
Heterozygous mutations in the STXBP1 gene encoding the presynaptic protein MUNC18-1 cause STXBP1 encephalopathy, characterized by developmental delay, intellectual disability and epilepsy. Impaired mutant protein stability leading to reduced synaptic transmission is considered the main underlying pathogenetic mechanism. Here, we report the first two cases carrying a homozygous STXBP1 mutation, where their heterozygous siblings and mother are asymptomatic. Both cases were diagnosed with Lennox-Gastaut syndrome. In Munc18-1 null mouse neurons, protein stability of the disease variant (L446F) is less dramatically affected than previously observed for heterozygous disease mutants. Neurons expressing Munc18L446F showed minor changes in morphology and synapse density. However, patch clamp recordings demonstrated that L446F causes a 2-fold increase in evoked synaptic transmission. Conversely, paired pulse plasticity was reduced and recovery after stimulus trains also. Spontaneous release frequency and amplitude, the readily releasable vesicle pool and the kinetics of short-term plasticity were all normal. Hence, the homozygous L446F mutation causes a gain-of-function phenotype regarding release probability and synaptic transmission while having less impact on protein levels than previously reported (heterozygous) mutations. These data show that STXBP1 mutations produce divergent cellular effects, resulting in different clinical features, while sharing the overarching encephalopathic phenotype (developmental delay, intellectual disability and epilepsy).
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Affiliation(s)
- Hanna C A Lammertse
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Annemiek A van Berkel
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Michele Iacomino
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto G. Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Pasquale Striano
- IRCCS Istituto "G. Gaslini", Genova, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | | | - Matthijs Verhage
- Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), University Medical Center Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, IRCCS Istituto G. Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
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84
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Kessi M, Chen B, Peng J, Tang Y, Olatoutou E, He F, Yang L, Yin F. Intellectual Disability and Potassium Channelopathies: A Systematic Review. Front Genet 2020; 11:614. [PMID: 32655623 PMCID: PMC7324798 DOI: 10.3389/fgene.2020.00614] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/20/2020] [Indexed: 01/15/2023] Open
Abstract
Intellectual disability (ID) manifests prior to adulthood as severe limitations to intellectual function and adaptive behavior. The role of potassium channelopathies in ID is poorly understood. Therefore, we aimed to evaluate the relationship between ID and potassium channelopathies. We hypothesized that potassium channelopathies are strongly associated with ID initiation, and that both gain- and loss-of-function mutations lead to ID. This systematic review explores the burden of potassium channelopathies, possible mechanisms, advancements using animal models, therapies, and existing gaps. The literature search encompassed both PubMed and Embase up to October 2019. A total of 75 articles describing 338 cases were included in this review. Nineteen channelopathies were identified, affecting the following genes: KCNMA1, KCNN3, KCNT1, KCNT2, KCNJ10, KCNJ6, KCNJ11, KCNA2, KCNA4, KCND3, KCNH1, KCNQ2, KCNAB1, KCNQ3, KCNQ5, KCNC1, KCNB1, KCNC3, and KCTD3. Twelve of these genes presented both gain- and loss-of-function properties, three displayed gain-of-function only, three exhibited loss-of-function only, and one had unknown function. How gain- and loss-of-function mutations can both lead to ID remains largely unknown. We identified only a few animal studies that focused on the mechanisms of ID in relation to potassium channelopathies and some of the few available therapeutic options (channel openers or blockers) appear to offer limited efficacy. In conclusion, potassium channelopathies contribute to the initiation of ID in several instances and this review provides a comprehensive overview of which molecular players are involved in some of the most prominent disease phenotypes.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China.,Kilimanjaro Christian Medical University College, Moshi, Tanzania.,Mawenzi Regional Referral Hospital, Moshi, Tanzania
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Yulin Tang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Eleonore Olatoutou
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China.,Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
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85
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Arbini A, Gilmore J, King MD, Gorman KM, Krawczyk J, McInerney V, O'Brien T, Shen S, Allen NM. Generation of three induced pluripotent stem cell (iPSC) lines from a patient with developmental epileptic encephalopathy due to the pathogenic KCNA2 variant c.869T>G; p.Leu290Arg (NUIGi052-A, NUIGi052-B, NUIGi052-C). Stem Cell Res 2020; 46:101853. [PMID: 32540721 DOI: 10.1016/j.scr.2020.101853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 05/21/2020] [Indexed: 10/24/2022] Open
Abstract
De novo pathogenic variants in KCNA2 are implicated in causing a spectrum of human neurological disorders, in particular developmental and epileptic encephalopathies. KCNA2 encodes the voltage-gated delayed rectifier potassium channel Kv1.2, which is vital in regulating neuronal membrane potential and repolarization. In this study, we generated three iPSC lines with non-integrating Sendai viral vectors from dermal fibroblasts of an 11-year old female patient harboring the KCNA2 c.869T>G (p.Leu290Arg) pathogenic variant. The iPSC lines were validated with standardized procedures including the targeted mutation, free of transgene integration, SNP karyotyping, pluripotent gene expression, and differentiation capacity into three embryonic germ layers.
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Affiliation(s)
- Alessia Arbini
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Ireland
| | - James Gilmore
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Ireland
| | - Mary D King
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple St. Children's University Hospital, Dublin 1, Ireland; School of Medicine and Medical Sciences, University College Dublin, Ireland
| | - Kathleen M Gorman
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple St. Children's University Hospital, Dublin 1, Ireland; School of Medicine and Medical Sciences, University College Dublin, Ireland
| | - Janusz Krawczyk
- Department of Haematology, Galway University Hospital, Ireland
| | - Veronica McInerney
- HRB Clinical Research Facility, National University of Ireland Galway, Ireland
| | - Timothy O'Brien
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Ireland
| | - Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Ireland; FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin D02, Ireland.
| | - Nicholas M Allen
- Department of Paediatrics, School of Medicine, National University of Ireland Galway, Ireland; Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Ireland.
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D'Adamo MC, Liantonio A, Conte E, Pessia M, Imbrici P. Ion Channels Involvement in Neurodevelopmental Disorders. Neuroscience 2020; 440:337-359. [PMID: 32473276 DOI: 10.1016/j.neuroscience.2020.05.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/14/2022]
Abstract
Inherited and sporadic mutations in genes encoding for brain ion channels, affecting membrane expression or biophysical properties, have been associated with neurodevelopmental disorders characterized by epilepsy, cognitive and behavioral deficits with significant phenotypic and genetic heterogeneity. Over the years, the screening of a growing number of patients and the functional characterization of newly identified mutations in ion channels genes allowed to recognize new phenotypes and to widen the clinical spectrum of known diseases. Furthermore, advancements in understanding disease pathogenesis at atomic level or using patient-derived iPSCs and animal models have been pivotal to orient therapeutic intervention and to put the basis for the development of novel pharmacological options for drug-resistant disorders. In this review we will discuss major improvements and critical issues concerning neurodevelopmental disorders caused by dysfunctions in brain sodium, potassium, calcium, chloride and ligand-gated ion channels.
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Affiliation(s)
- Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | | | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta; Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy.
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87
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Zhao L, Luo F, Wang A, Zhang J, Wang Y, Zhao L, Wang Z, Pu Q. Quick stabilization of capillary for rapid determination of potassium ions in the blood of epilepsy patients by capillary electrophoresis without sample pretreatment. Electrophoresis 2020; 41:1273-1279. [PMID: 32358896 DOI: 10.1002/elps.202000022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 11/07/2022]
Abstract
Mutations in the potassium channel genes may be linked to the development of epilepsy and affect the blood potassium levels. Therefore, accurate determination of potassium in the blood will be critical to diagnose the cause of epilepsy. CE is a competent technique for the fast detection of multiple ions, but complicated matrices of a blood sample may cause significant variation of migration times and the peak shape. In this work, a procedure for rapid stabilization of the capillary inner surface through preflushing of a blood sample was employed. The process takes only 40 min for a capillary and then it can be used for more than 2 weeks. No pretreatment of the blood sample or other surface modification of the capillary is needed for the analysis. The RSDs of the migration time and peak area were reduced to 1.5 and 5.1% from 12.6 and 14.5%, respectively. The proposed method has been successfully applied to the determination of the potassium contents in the blood sample of patients with epilepsy at different stages. The recoveries of potassium ions in these blood samples are in a range from 86.5 to 104.5%.
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Affiliation(s)
- Litao Zhao
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Fanghong Luo
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Anting Wang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Jing Zhang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Yuanhang Wang
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China
| | - Liangtao Zhao
- TSing Biomedical Research Center, The Second Hospital of Lanzhou University, Lanzhou, P. R. China
| | - Zhaoyan Wang
- School of Pharmacy, Lanzhou University, Lanzhou, P. R. China
| | - Qiaosheng Pu
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China
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88
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D’Adamo MC, Liantonio A, Rolland JF, Pessia M, Imbrici P. Kv1.1 Channelopathies: Pathophysiological Mechanisms and Therapeutic Approaches. Int J Mol Sci 2020; 21:ijms21082935. [PMID: 32331416 PMCID: PMC7215777 DOI: 10.3390/ijms21082935] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/19/2020] [Accepted: 04/20/2020] [Indexed: 12/27/2022] Open
Abstract
Kv1.1 belongs to the Shaker subfamily of voltage-gated potassium channels and acts as a critical regulator of neuronal excitability in the central and peripheral nervous systems. KCNA1 is the only gene that has been associated with episodic ataxia type 1 (EA1), an autosomal dominant disorder characterized by ataxia and myokymia and for which different and variable phenotypes have now been reported. The iterative characterization of channel defects at the molecular, network, and organismal levels contributed to elucidating the functional consequences of KCNA1 mutations and to demonstrate that ataxic attacks and neuromyotonia result from cerebellum and motor nerve alterations. Dysfunctions of the Kv1.1 channel have been also associated with epilepsy and kcna1 knock-out mouse is considered a model of sudden unexpected death in epilepsy. The tissue-specific association of Kv1.1 with other Kv1 members, auxiliary and interacting subunits amplifies Kv1.1 physiological roles and expands the pathogenesis of Kv1.1-associated diseases. In line with the current knowledge, Kv1.1 has been proposed as a novel and promising target for the treatment of brain disorders characterized by hyperexcitability, in the attempt to overcome limited response and side effects of available therapies. This review recounts past and current studies clarifying the roles of Kv1.1 in and beyond the nervous system and its contribution to EA1 and seizure susceptibility as well as its wide pharmacological potential.
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Affiliation(s)
- Maria Cristina D’Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
| | - Antonella Liantonio
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
| | | | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida MDS-2080, Malta; (M.C.D.); (M.P.)
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain Po Box 17666, UAE
| | - Paola Imbrici
- Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 70125 Bari, Italy;
- Correspondence:
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89
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Clinical Spectrum of KCNA1 Mutations: New Insights into Episodic Ataxia and Epilepsy Comorbidity. Int J Mol Sci 2020; 21:ijms21082802. [PMID: 32316562 PMCID: PMC7215408 DOI: 10.3390/ijms21082802] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the KCNA1 gene, which encodes voltage-gated Kv1.1 potassium channel α-subunits, cause a variety of human diseases, complicating simple genotype–phenotype correlations in patients. KCNA1 mutations are primarily associated with a rare neurological movement disorder known as episodic ataxia type 1 (EA1). However, some patients have EA1 in combination with epilepsy, whereas others have epilepsy alone. KCNA1 mutations can also cause hypomagnesemia and paroxysmal dyskinesia in rare cases. Why KCNA1 variants are associated with such phenotypic heterogeneity in patients is not yet understood. In this review, literature databases (PubMed) and public genetic archives (dbSNP and ClinVar) were mined for known pathogenic or likely pathogenic mutations in KCNA1 to examine whether patterns exist between mutation type and disease manifestation. Analyses of the 47 deleterious KCNA1 mutations that were identified revealed that epilepsy or seizure-related variants tend to cluster in the S1/S2 transmembrane domains and in the pore region of Kv1.1, whereas EA1-associated variants occur along the whole length of the protein. In addition, insights from animal models of KCNA1 channelopathy were considered, as well as the possible influence of genetic modifiers on disease expressivity and severity. Elucidation of the complex relationship between KCNA1 variants and disease will enable better diagnostic risk assessment and more personalized therapeutic strategies for KCNA1 channelopathy.
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90
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Dunn PJ, Maher BH, Albury CL, Stuart S, Sutherland HG, Maksemous N, Benton MC, Smith RA, Haupt LM, Griffiths LR. Tiered analysis of whole-exome sequencing for epilepsy diagnosis. Mol Genet Genomics 2020; 295:751-763. [DOI: 10.1007/s00438-020-01657-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 02/19/2020] [Indexed: 12/11/2022]
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91
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Allen NM, Weckhuysen S, Gorman K, King MD, Lerche H. Genetic potassium channel-associated epilepsies: Clinical review of the K v family. Eur J Paediatr Neurol 2020; 24:105-116. [PMID: 31932120 DOI: 10.1016/j.ejpn.2019.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/06/2019] [Indexed: 12/22/2022]
Abstract
Next-generation sequencing has enhanced discovery of many disease-associated genes in previously unexplained epilepsies, mainly in developmental and epileptic encephalopathies and familial epilepsies. We now classify these disorders according to the underlying molecular pathways, which encompass a diverse array of cellular and sub-cellular compartments/signalling processes including voltage-gated ion-channel defects. With the aim to develop and increase the use of precision medicine therapies, understanding the pathogenic mechanisms and consequences of disease-causing variants has gained major relevance in clinical care. The super-family of voltage-gated potassium channels is the largest and most diverse family among the ion channels, encompassing approximately 80 genes. Key potassium channelopathies include those affecting the KV, KCa and Kir families, a significant proportion of which have been implicated in neurological disease. As for other ion channel disorders, different pathogenic variants within any individual voltage-gated potassium channel gene tend to affect channel protein function differently, causing heterogeneous clinical phenotypes. The focus of this review is to summarise recent clinical developments regarding the key voltage-gated potassium (KV) family-related epilepsies, which now encompasses approximately 12 established disease-associated genes, from the KCNA-, KCNB-, KCNC-, KCND-, KCNV-, KCNQ- and KCNH-subfamilies.
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Affiliation(s)
- Nicholas M Allen
- Department of Paediatrics, National University of Ireland, Galway, Ireland; Department of Paediatrics (Neurology), Galway University Hospital, Ireland; Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
| | - Sarah Weckhuysen
- Neurogenetics Group, Center for Molecular Neurology, VIB-University of Antwerp, Antwerp, Belgium; Department of Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Kathleen Gorman
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Mary D King
- Department of Paediatric Neurology & Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin 1, Ireland; University College Dublin School of Medicine and Medical Science, University College, Dublin, Ireland
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research, University of Tubingen, Germany
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92
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Jędrychowska J, Korzh V. Kv2.1 voltage-gated potassium channels in developmental perspective. Dev Dyn 2019; 248:1180-1194. [PMID: 31512327 DOI: 10.1002/dvdy.114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/01/2019] [Accepted: 09/03/2019] [Indexed: 11/11/2022] Open
Abstract
Kv2.1 voltage-gated potassium channels consist of two types of α-subunits: (a) electrically-active Kcnb1 α-subunits and (b) silent or modulatory α-subunits plus β-subunits that, similar to silent α-subunits, also regulate electrically-active subunits. Voltage-gated potassium channels were traditionally viewed, mainly by electrophysiologists, as regulators of the electrical activity of the plasma membrane in excitable cells, a role that is performed by transmembrane protein domains of α-subunits that form the electric pore. Genetic studies revealed a role for this region of α-subunits of voltage-gated potassium channels in human neurodevelopmental disorders, such as epileptic encephalopathy. The N- and C-terminal domains of α-subunits interact to form the cytoplasmic subunit of heterotetrameric potassium channels that regulate electric pores. Subsequent animal studies revealed the developmental functions of Kcnb1-containing voltage-gated potassium channels and illustrated their role during brain development and reproduction. These functions of potassium channels are discussed in this review in the context of regulatory interactions between electrically-active and regulatory subunits.
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Affiliation(s)
- Justyna Jędrychowska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw, Poland
| | - Vladimir Korzh
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
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93
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Verdura E, Fons C, Schlüter A, Ruiz M, Fourcade S, Casasnovas C, Castellano A, Pujol A. Complete loss of KCNA1 activity causes neonatal epileptic encephalopathy and dyskinesia. J Med Genet 2019; 57:132-137. [PMID: 31586945 PMCID: PMC7029237 DOI: 10.1136/jmedgenet-2019-106373] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 11/29/2022]
Abstract
Background Since 1994, over 50 families affected by the episodic ataxia type 1 disease spectrum have been described with mutations in KCNA1, encoding the voltage-gated K+ channel subunit Kv1.1. All of these mutations are either transmitted in an autosomal-dominant mode or found as de novo events. Methods A patient presenting with a severe combination of dyskinesia and neonatal epileptic encephalopathy was sequenced by whole-exome sequencing (WES). A candidate variant was tested using cellular assays and patch-clamp recordings. Results WES revealed a homozygous variant (p.Val368Leu) in KCNA1, involving a conserved residue in the pore domain, close to the selectivity signature sequence for K+ ions (TVGYG). Functional analysis showed that mutant protein alone failed to produce functional channels in homozygous state, while coexpression with wild-type produced no effects on K+ currents, similar to wild-type protein alone. Treatment with oxcarbazepine, a sodium channel blocker, proved effective in controlling seizures. Conclusion This newly identified variant is the first to be reported to act in a recessive mode of inheritance in KCNA1. These findings serve as a cautionary tale for the diagnosis of channelopathies, in which an unreported phenotypic presentation or mode of inheritance for the variant of interest can hinder the identification of causative variants and adequate treatment choice.
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Affiliation(s)
- Edgard Verdura
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Carme Fons
- Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain.,Pediatric Neurology Department, Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona, Catalunya, Spain.,Sant Joan de Déu Research Institute (IRSJD), Esplugues de Llobregat, Barcelona, Catalunya, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Stéphane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain.,Neuromuscular Unit, Neurology Department, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
| | - Antonio Castellano
- Institute of Biomedicine of Seville (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Medical Physiology and Biophysics Departament, Universidad de Sevilla, Sevilla, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain .,Centre for Biomedical Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain.,Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Catalunya, Spain
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94
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Bar C, Barcia G, Jennesson M, Le Guyader G, Schneider A, Mignot C, Lesca G, Breuillard D, Montomoli M, Keren B, Doummar D, Billette de Villemeur T, Afenjar A, Marey I, Gerard M, Isnard H, Poisson A, Dupont S, Berquin P, Meyer P, Genevieve D, De Saint Martin A, El Chehadeh S, Chelly J, Guët A, Scalais E, Dorison N, Myers CT, Mefford HC, Howell KB, Marini C, Freeman JL, Nica A, Terrone G, Sekhara T, Lebre A, Odent S, Sadleir LG, Munnich A, Guerrini R, Scheffer IE, Kabashi E, Nabbout R. Expanding the genetic and phenotypic relevance of
KCNB1
variants in developmental and epileptic encephalopathies: 27 new patients and overview of the literature. Hum Mutat 2019; 41:69-80. [DOI: 10.1002/humu.23915] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/28/2019] [Accepted: 09/09/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Claire Bar
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
| | - Giulia Barcia
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
- Department of genetics, Necker Enfants Malades hospitalAssistance Publique‐Hôpitaux de ParisParis France
| | | | - Gwenaël Le Guyader
- Department of geneticsUniversity hospital PoitiersPoitiers Cedex France
- EA3808‐NEUVACOD Unité Neurovasculaire et Troubles Cognitifs, Pôle Biologie SantéUniversité de PoitiersPoitiers France
| | - Amy Schneider
- Department of Medicine, Epilepsy Research Centre, Austin HealthThe University of MelbourneHeidelberg Victoria Australia
| | - Cyril Mignot
- Institut du Cerveau et de la Moelle épinière, INSERM, U 1127, CNRS UMR 7225Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Paris France
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | - Gaetan Lesca
- Department of geneticsHospices Civils de LyonLyon France
- Neurosciences centre of Lyon, INSERM U1028, UMR CNRS 5292Université Claude Bernard Lyon 1Bron Cedex France
| | - Delphine Breuillard
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
| | - Martino Montomoli
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Boris Keren
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | - Diane Doummar
- Department of Pediatric Neurology, Hôpital Armand TrousseauAP‐HPParis France
| | | | - Alexandra Afenjar
- Département de Génétique et Embryologie Médicale, Pathologies Congénitales du Cervelet‐LeucoDystrophies, Centre de Référence déficiences intellectuelles de causes rares, AP‐HP, Hôpital Armand Trousseau, GRC n°19Sorbonne UniversitéParis France
| | - Isabelle Marey
- Département de Génétique et de Cytogénétique, Centre de Reference Déficience Intellectuelle de Causes Rares, APHP, Hôpital Pitié‐SalpêtrièreGRC UPMC (Déficience Intellectuelle et Autisme)Paris France
| | | | | | - Alice Poisson
- Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Centre Hospitalier le Vinatier and EDR‐Psy TeamCentre National de la Recherche Scientifique & Lyon 1 Claude Bernard UniversityVilleurbanne France
| | - Sophie Dupont
- Institut du Cerveau et de la Moelle épinière, INSERM, U 1127, CNRS UMR 7225Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Paris France
- Epileptology and Rehabilitation department, GH Pitie‐Salpêtrière‐Charles FoixAP‐HPParis France
| | - Patrick Berquin
- Department of pediatric neurology Amiens‐Picardie university hospitalUniversité de Picardie Jules VerneAmiens France
| | - Pierre Meyer
- Department of pediatric neurologyMontpellier university hospitalMontpellier France
- PhyMedExp, U1046 INSERMUMR9214 CNRSMontpellier France
| | - David Genevieve
- Service de génétique clinique et du Département de Génétique Médicale, Maladies Rares et Médecine Personnalisée, Centre de référence maladies rares anomalies du développementCHU MontpellierMontpellier France
| | - Anne De Saint Martin
- Department of Pediatric NeurologyStrasbourg University HospitalStrasbourg France
| | - Salima El Chehadeh
- Department of genetics, Hôpital de HautepierreHôpitaux Universitaires de StrasbourgStrasbourg France
| | - Jamel Chelly
- Department of genetics, Hôpital de HautepierreHôpitaux Universitaires de StrasbourgStrasbourg France
| | - Agnès Guët
- Department of PediatricLouis‐Mourier HospitalColombes France
| | - Emmanuel Scalais
- Department of Pediatric Neurology, Centre Hospitalier de LuxembourgLuxembourg CityLuxembourg City Luxembourg
| | - Nathalie Dorison
- Department of pediatric NeurosurgeryRothschild Foundation HospitalParis France
| | - Candace T. Myers
- Department of PediatricsUniversity of WashingtonSeattle Washington
| | - Heather C. Mefford
- Department of Pediatrics, Division of Genetic MedicineUniversity of WashingtonSeattle Washington
| | - Katherine B. Howell
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- Murdoch Children's Research InstituteMelbourne Victoria Australia
| | - Carla Marini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Jeremy L. Freeman
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- Murdoch Children's Research InstituteMelbourne Victoria Australia
| | - Anca Nica
- Department of Neurology, Center for Clinical Research (CIC 1414)Rennes University HospitalRennes France
| | - Gaetano Terrone
- Department of Translational Medical Sciences, Section of Pediatrics‐Child Neurology UnitFederico II UniversityNaples Italy
| | - Tayeb Sekhara
- Department of Pediatric NeurologyC.H.I.R.E.CBrussels Belgium
| | - Anne‐Sophie Lebre
- Department of genetics, Maison Blanche hospitalUniversity hospital, ReimsReims France
| | - Sylvie Odent
- Reference Centre for Rare Developmental AbnormalitiesCLAD‐Ouest, CHU RennesRennes France
- Institute of genetics and developmentCNRS UMR 6290, Rennes universityRennes France
| | - Lynette G. Sadleir
- Department of Paediatrics and Child HealthUniversity of OtagoWellington New Zealand
| | - Arnold Munnich
- Université Paris Descartes‐Sorbonne Paris CitéParis France
- Department of genetics, Necker Enfants Malades hospitalAssistance Publique‐Hôpitaux de ParisParis France
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A Meyer Children's HospitalUniversity of FlorenceFlorence Italy
| | - Ingrid E. Scheffer
- Department of Medicine, Epilepsy Research Centre, Austin HealthThe University of MelbourneHeidelberg Victoria Australia
- Departments of Neurology and Paediatrics, Royal Children's HospitalUniversity of MelbourneMelbourne Victoria Australia
- The Florey Institute of Neurosciences and Mental HealthHeidelberg Victoria Australia
| | - Edor Kabashi
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
| | - Rima Nabbout
- Department of Pediatric Neurology, Reference Centre for Rare EpilepsiesHôpital Necker‐Enfants MaladesParis France
- Imagine institute, laboratory of Translational Research for Neurological Disorders, INSERM UMR 1163Imagine InstituteParis France
- Université Paris Descartes‐Sorbonne Paris CitéParis France
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Uysal B, Löffler H, Rosa F, Lerche H, Schwarz N. Generation of an induced pluripotent stem cell (iPSC) line (HIHDNEi003-A) from a patient with developmental and epileptic encephalopathy carrying a KCNA2 (p.Thr374Ala) mutation. Stem Cell Res 2019; 40:101543. [PMID: 31465893 DOI: 10.1016/j.scr.2019.101543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/15/2019] [Accepted: 08/19/2019] [Indexed: 10/26/2022] Open
Abstract
De novo mutations in the KCNA2 gene, encoding the voltage-gated potassium channel KV1.2, have been identified to cause early-onset developmental and epileptic encephalopathies (DEE). KV1.2 channels conduct delayed-rectifier type K+ currents and play a crucial role in action potential repolarization. In this study we reprogrammed fibroblasts from a 6-months-old male patient with DEE carrying a de novo point mutation (c.1120A > G, p.Thr374Ala) in KCNA2 to induced pluripotent stem cells. Their pluripotency was verified by the capability to differentiate into all three germ layers and the expression of several pluripotency markers on RNA and protein levels.
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Affiliation(s)
- Betül Uysal
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Heidi Löffler
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Filip Rosa
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Niklas Schwarz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany.
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96
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Dissecting the phenotypic and genetic spectrum of early childhood-onset generalized epilepsies. Seizure 2019; 71:222-228. [PMID: 31401500 DOI: 10.1016/j.seizure.2019.07.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 07/17/2019] [Accepted: 07/31/2019] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Although the genetic and clinical aspects of epilepsy with myoclonic-atonic seizures (MAE) and early onset absence epilepsy (EOAE) have been investigated thoroughly, other early childhood-onset generalized epilepsies that share clinical features with MAE and EOAE have not been characterized. In this study, we aimed to delineate the genetic and phenotypic spectrum of early childhood-onset generalized epilepsies, including MAE and EOAE. METHODS We recruited 61 patients diagnosed with MAE, EOAE, genetic epilepsy with febrile seizure plus (GEFS+) and unclassified generalized epilepsies that shared seizure onset age and seizure types. Genetic causes were investigated through targeted gene panel testing, whole exome sequencing, chromosomal microarray, and single-gene Sanger sequencing. RESULTS We classified 11 patients with MAE, 20 with EOAE, 9 with GEFS + spectrum. Epilepsy syndrome was not specified in the remaining 21 patients. The clinical features were comparable across groups. Nevertheless, patients with EOAE tended to show better developmental and seizure outcomes. A total of 23 pathogenic sequences and copy number variants from 12 genes were identified (23/61, 37.7%). Genetic etiologies were confirmed in 36.4% (4/11) of the MAE group, 45% (9/20) of the EOAE group, 22.2% (2/9) of the GEFS + spectrum, and 38.1% (8/21) of the unclassified group. The most frequently identified genes with pathogenic variants were SLC6A1 (7 patients), SLC2A1 (4 patients), and SYNGAP1 (4 patients). CONCLUSION Early childhood-onset generalized epilepsy appeared to be characterized by an overlapping genetic and phenotypic spectrum. SLC6A1 and SLC2A1 appeared to be important genetic causes of early childhood-onset generalized epilepsy.
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97
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Gataullina S, Bienvenu T, Nabbout R, Huberfeld G, Dulac O. Gene mutations in paediatric epilepsies cause NMDA-pathy, and phasic and tonic GABA-pathy. Dev Med Child Neurol 2019; 61:891-898. [PMID: 30680721 DOI: 10.1111/dmcn.14152] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/20/2018] [Indexed: 12/28/2022]
Abstract
The aim of this study was to disentangle mechanisms of epileptogenesis in monogenic epilepsies in children. We reviewed paediatric monogenic epilepsies excluding brain malformation or an inborn error of metabolism, but including the gene function whether there is loss-of-function or gain-of-function, age at gene expression when available, and associated epilepsy syndrome. Genes for which at least five patients with similar epilepsy phenotype had been reported were selected. Three mechanisms are shared by most monogenic epilepsies: (1) excess of N-methyl-d-aspartate (NMDA) transmission activation (NMDA-pathies); (2) abnormal gamma-aminobutyric acid (GABA) transmission with reduced inhibition (phasic GABA-pathies); and (3) tonic activation of extrasynaptic GABAA receptors by extracellular GABA (tonic GABA-pathies). NMDA-pathies comprise early epileptic encephalopathy with suppression-burst, neonatal/infantile benign seizures, West and Lennox-Gastaut syndromes, and encephalopathy with continuous spike waves in slow sleep, thus brief seizures with major interictal spiking. Phasic GABA-pathies comprise mostly generalized epilepsy with febrile seizures plus and Dravet syndrome, thus long-lasting seizures with mild interictal spiking. Tonic GABA-pathies cause epilepsy with myoclonic-atonic seizures and Angelman syndrome, thus major high-amplitude slow-wave activity. This pathophysiological approach to monogenic epilepsies provides diagnostic clues and helps to guide treatment strategy. WHAT THIS PAPER ADDS: In paediatric monogenic epilepsies, electroclinical patterns point to three main mechanisms: NMDA-pathies, and phasic and tonic GABA-pathies. Antiepileptic treatment choice could be guided by each of these mechanisms.
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Affiliation(s)
- Svetlana Gataullina
- Service d' Explorations Fonctionnelles multidisciplinaires Hôpital Antoine Béclère, AP-HP, Clamart, France.,Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,Service de Pédiatrie, Centre Hospitalier Intercommunal, Montreuil, France
| | - Thierry Bienvenu
- Biochemistry and Molecular Genetics Laboratory, Hôpital Cochin, Paris Centre University Group, Paris, France.,Institut Cochin, Inserm U1016, Paris Descartes University, Paris, France
| | - Rima Nabbout
- Centre de Reference Épilepsies Rares, Necker-Enfants Malades Hospital, Paris, France
| | - Gilles Huberfeld
- Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,Clinical Neurophysiology Department, Pitié-Salpêtrière Hospital, Sorbone University, AP-HP, Paris, France.,Neuroglial Interactions in Cerebral Pathophysiology, Center for Interdisciplinary Research in Biology, Collège de France, CNR UMR 7421, Inserm U1050, Labex MemolifePSL Research University, Paris, France
| | - Olivier Dulac
- Inserm U1129, Infantile Epilepsies and Brain Plasticity, CEA Gif/Yvette, Pôle de Recherche et d'Enseignement Supérieur Sorbonne Paris Cité, Paris Descartes University, Paris, France.,AdPueriVitam, Antony, France
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98
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Schwarz N, Uysal B, Rosa F, Löffler H, Mau-Holzmann UA, Liebau S, Lerche H. Establishment of a human induced pluripotent stem cell (iPSC) line (HIHDNEi002-A) from a patient with developmental and epileptic encephalopathy carrying a KCNA2 (p.Arg297Gln) mutation. Stem Cell Res 2019; 37:101445. [PMID: 31075689 DOI: 10.1016/j.scr.2019.101445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/12/2019] [Accepted: 04/18/2019] [Indexed: 11/18/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEE) can be caused by mutations in the KCNA2 gene, coding for the voltage-gated K+ channel Kv1.2. This ion channel belongs to the delayed rectifier class of potassium channels and plays a role during the repolarization phase of an action potential. In this study we reprogrammed fibroblasts from a 30-year-old male patient with DDE carrying a point mutation (c.890G > A, p.Arg297Gln) in KCNA2 to induced pluripotent stem cells. Pluripotency state of the cells was verified by the capability to differentiate into all three germ layers and the expression of several pluripotency markers on RNA and protein levels.
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Affiliation(s)
- Niklas Schwarz
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany.
| | - Betül Uysal
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Filip Rosa
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Heidi Löffler
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
| | - Ulrike A Mau-Holzmann
- Department of Medical Genetics and Applied Genomics, University of Tuebingen, Germany
| | - Stefan Liebau
- Institute of Neuroanatomy & Developmental Biology, University of Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen, Germany
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99
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Møller RS, Hammer TB, Rubboli G, Lemke JR, Johannesen KM. From next-generation sequencing to targeted treatment of non-acquired epilepsies. Expert Rev Mol Diagn 2019; 19:217-228. [DOI: 10.1080/14737159.2019.1573144] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Rikke S. Møller
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Trine B. Hammer
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
| | - Guido Rubboli
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Johannes R. Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Katrine M. Johannesen
- Department of Epilepsy Genetics and Precision Medicine, The Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
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100
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Canafoglia L, Castellotti B, Ragona F, Freri E, Granata T, Chiapparini L, Gellera C, Scaioli V, Franceschetti S, DiFrancesco JC. Progressive myoclonus epilepsy caused by a gain-of-function KCNA2 mutation. Seizure 2019; 65:106-108. [PMID: 30660924 DOI: 10.1016/j.seizure.2019.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/04/2019] [Accepted: 01/08/2019] [Indexed: 10/27/2022] Open
Affiliation(s)
- Laura Canafoglia
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Luisa Chiapparini
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Vidmer Scaioli
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvana Franceschetti
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
| | - Jacopo C DiFrancesco
- Neurophysiopathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; Department of Neurology, San Gerardo Hospital, School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMi), University of Milano-Bicocca, Monza, Italy
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