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Falsaperla R, Criscione R, Cimino C, Pisani F, Ruggieri M. KCNQ2-Related Epilepsy: Genotype-Phenotype Relationship with Tailored Antiseizure Medication (ASM)-A Systematic Review. Neuropediatrics 2023; 54:297-307. [PMID: 36948217 DOI: 10.1055/a-2060-4576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
BACKGROUND Autosomal dominant mutations of the KCNQ2 gene can cause two epileptic disorders: benign familial neonatal seizures (BFNS) and developmental epileptic encephalopathy (DEE). This systematic review aims to identify the best reported therapy for these patients, relating to phenotype, neurodevelopmental outcome, and an eventual correlation between phenotype and genotype. METHODS We searched on PubMed using the search terms "KCNQ2" AND "therapy" and "KCNQ2" AND "treatment"; we found 304 articles. Of these, 29 met our criteria. We collected the data from 194 patients. All 29 articles were retrospective studies. RESULTS In all, 104 patients were classified as DEE and 90 as BFNS. After treatment began, 95% of BFNS patients became seizure free, whereas the seizures stopped only in 73% of those with DEE. Phenobarbital and sodium channel blockers were the most used treatment in BFNS. Most of the DEE patients (95%) needed polytherapy for seizure control and even that did not prevent subsequent developmental impairment (77%).Missense mutations were discovered in 96% of DEE patients; these were less common in BFNS (50%), followed by large deletion (16%), truncation (16%), splice donor site (10%), and frameshift (7%). CONCLUSION Phenobarbital or carbamazepine appears to be the most effective antiseizure medication for children with a "benign" variant. On the contrary, polytherapy is often needed for DEE patients, even if it does not seem to improve neurological outcomes. In DEE patients, most mutations were located in S4 and S6 helix, which could serve as a potential target for the development of more specific treatment in the future.
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Affiliation(s)
- Raffaele Falsaperla
- Neonatal Intensive Care Unit and Neonatal Accompaniment Unit, Azienda Ospedaliero-Universitaria Policlinico "Rodolico-San Marco", San Marco Hospital, University of Catania, Catania, Italy
- Unit of Clinical Paediatrics, Azienda Ospedaliero-Universitaria Policlinico, "Rodolico-San Marco", San Marco Hospital, Catania, Italy
| | - Roberta Criscione
- Neonatal Intensive Care Unit and Neonatal Accompaniment Unit, Azienda Ospedaliero-Universitaria Policlinico "Rodolico-San Marco", Postgraduate Training Program in Pediatrics, University of Catania, Catania, Italy
| | - Carla Cimino
- Neonatal Intensive Care Unit and Neonatal Accompaniment Unit, Azienda Ospedaliero-Universitaria Policlinico "Rodolico-San Marco", San Marco Hospital, University of Catania, Catania, Italy
| | - Francesco Pisani
- Child Neuropsychiatry Unit, Human Neuroscience Department, Sapienza University of Rome, Italy
| | - Martino Ruggieri
- Unit of Clinical Pediatrics, Department of Clinical and Experimental Medicine, University of Catania, AOU "Policlinico", PO "G. Rodolico", Catania, Italy
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2
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Ahmad SF, Ahmad KA, Ng YT. Neonatal Epileptic Encephalopathies. Semin Pediatr Neurol 2021; 37:100880. [PMID: 33892847 DOI: 10.1016/j.spen.2021.100880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/07/2021] [Accepted: 02/20/2021] [Indexed: 11/26/2022]
Abstract
The majority of neonatal seizures are related to common diagnoses, including hypoxic-ischemic encephalopathy and intraventricular hemorrhage. While relatively uncommon, neonatal epileptic encephalopathies represent an important group of neonatal seizure disorders that require immediate diagnosis and intervention. In this review, we provide a summary of the benign and severe neonatal epilepsy syndromes. While benign epilepsy syndromes have favorable prognoses, rapid and accurate diagnosis may prevent an unnecessarily long course of antiseizure medications. The severe epilepsy syndromes may be related to a number of underlying genetic disorders and often carry a poor prognosis. Herein we review diagnostic and therapeutic strategies, and provide a set or algorithms for said purposes.
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Affiliation(s)
- Samiya Fatima Ahmad
- Department of Pediatrics, Baylor College of Medicine, San Antonio, TX; The Children's Hospital of San Antonio, San Antonio, TX.
| | - Kaashif Aqeeb Ahmad
- Department of Pediatrics, Baylor College of Medicine, San Antonio, TX; The Children's Hospital of San Antonio, San Antonio, TX; Pediatrix Medical Group of San Antonio, San Antonio, TX
| | - Yu-Tze Ng
- Department of Pediatrics, Baylor College of Medicine, San Antonio, TX; The Children's Hospital of San Antonio, San Antonio, TX
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3
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Singh S, Singh TG, Rehni AK. An Insight into Molecular Mechanisms and Novel Therapeutic Approaches in Epileptogenesis. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 19:750-779. [PMID: 32914725 DOI: 10.2174/1871527319666200910153827] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 11/22/2022]
Abstract
Epilepsy is the second most common neurological disease with abnormal neural activity involving the activation of various intracellular signalling transduction mechanisms. The molecular and system biology mechanisms responsible for epileptogenesis are not well defined or understood. Neuroinflammation, neurodegeneration and Epigenetic modification elicit epileptogenesis. The excessive neuronal activities in the brain are associated with neurochemical changes underlying the deleterious consequences of excitotoxicity. The prolonged repetitive excessive neuronal activities extended to brain tissue injury by the activation of microglia regulating abnormal neuroglia remodelling and monocyte infiltration in response to brain lesions inducing axonal sprouting contributing to neurodegeneration. The alteration of various downstream transduction pathways resulted in intracellular stress responses associating endoplasmic reticulum, mitochondrial and lysosomal dysfunction, activation of nucleases, proteases mediated neuronal death. The recently novel pharmacological agents modulate various receptors like mTOR, COX-2, TRK, JAK-STAT, epigenetic modulators and neurosteroids are used for attenuation of epileptogenesis. Whereas the various molecular changes like the mutation of the cell surface, nuclear receptor and ion channels focusing on repetitive episodic seizures have been explored by preclinical and clinical studies. Despite effective pharmacotherapy for epilepsy, the inadequate understanding of precise mechanisms, drug resistance and therapeutic failure are the current fundamental problems in epilepsy. Therefore, the novel pharmacological approaches evaluated for efficacy on experimental models of epilepsy need to be identified and validated. In addition, we need to understand the downstream signalling pathways of new targets for the treatment of epilepsy. This review emphasizes on the current state of novel molecular targets as therapeutic approaches and future directions for the management of epileptogenesis. Novel pharmacological approaches and clinical exploration are essential to make new frontiers in curing epilepsy.
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Affiliation(s)
- Shareen Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | | | - Ashish Kumar Rehni
- Cerebral Vascular Disease Research Laboratories, Department of Neurology and Neuroscience Program, University of Miami School of Medicine, Miami, Florida 33101, United States
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4
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Maqoud F, Scala R, Hoxha M, Zappacosta B, Tricarico D. ATP-sensitive potassium channel subunits in the neuroinflammation: novel drug targets in neurodegenerative disorders. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2021; 21:130-149. [PMID: 33463481 DOI: 10.2174/1871527320666210119095626] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/07/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022]
Abstract
Arachidonic acids and its metabolites modulate plenty of ligand-gated, voltage-dependent ion channels, and metabolically regulated potassium channels including ATP-sensitive potassium channels (KATP). KATP channels are hetero-multimeric complexes of sulfonylureas receptors (SUR1, SUR2A or SUR2B) and the pore-forming subunits (Kir6.1 and Kir6.2) likewise expressed in the pre-post synapsis of neurons and inflammatory cells, thereby affecting their proliferation and activity. KATP channels are involved in amyloid-β (Aβ)-induced pathology, therefore emerging as therapeutic targets against Alzheimer's and related diseases. The modulation of these channels can represent an innovative strategy for the treatment of neurodegenerative disorders; nevertheless, the currently available drugs are not selective for brain KATP channels and show contrasting effects. This phenomenon can be a consequence of the multiple physiological roles of the different varieties of KATP channels. Openings of cardiac and muscular KATP channel subunits, is protective against caspase-dependent atrophy in these tissues and some neurodegenerative disorders, whereas in some neuroinflammatory diseases benefits can be obtained through the inhibition of neuronal KATP channel subunits. For example, glibenclamide exerts an anti-inflammatory effect in respiratory, digestive, urological, and central nervous system (CNS) diseases, as well as in ischemia-reperfusion injury associated with abnormal SUR1-Trpm4/TNF-α or SUR1-Trpm4/ Nos2/ROS signaling. Despite this strategy is promising, glibenclamide may have limited clinical efficacy due to its unselective blocking action of SUR2A/B subunits also expressed in cardiovascular apparatus with pro-arrhythmic effects and SUR1 expressed in pancreatic beta cells with hypoglycemic risk. Alternatively, neuronal selective dual modulators showing agonist/antagonist actions on KATP channels can be an option.
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Affiliation(s)
- Fatima Maqoud
- Department of Pharmacy-Pharmaceutical Science, University of Bari Aldo Moro, via Orabona 4, 70125-I. Italy
| | - Rosa Scala
- Department of Pharmacy-Pharmaceutical Science, University of Bari Aldo Moro, via Orabona 4, 70125-I. Italy
| | - Malvina Hoxha
- Department of Chemical-Toxicological and Pharmacological Evaluation of Drugs, Faculty of Pharmacy, "Catholic University Our Lady of Good Counsel", Tirana. Albania
| | - Bruno Zappacosta
- Department of Chemical-Toxicological and Pharmacological Evaluation of Drugs, Faculty of Pharmacy, "Catholic University Our Lady of Good Counsel", Tirana. Albania
| | - Domenico Tricarico
- Department of Pharmacy-Pharmaceutical Science, University of Bari Aldo Moro, via Orabona 4, 70125-I. Italy
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Goto A, Ishii A, Shibata M, Ihara Y, Cooper EC, Hirose S. Characteristics of
KCNQ
2
variants causing either benign neonatal epilepsy or developmental and epileptic encephalopathy. Epilepsia 2019; 60:1870-1880. [DOI: 10.1111/epi.16314] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/23/2019] [Accepted: 07/23/2019] [Indexed: 12/01/2022]
Affiliation(s)
- Ayako Goto
- Department of Pediatrics School of Medicine Fukuoka University Fukuoka Japan
| | - Atsushi Ishii
- Department of Pediatrics School of Medicine Fukuoka University Fukuoka Japan
| | - Mami Shibata
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy Fukuoka University Fukuoka Japan
| | - Yukiko Ihara
- Department of Pediatrics School of Medicine Fukuoka University Fukuoka Japan
| | - Edward C. Cooper
- Department of Neurology Baylor College of Medicine Houston Texas
| | - Shinichi Hirose
- Department of Pediatrics School of Medicine Fukuoka University Fukuoka Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy Fukuoka University Fukuoka Japan
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6
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Spagnoli C, Salerno GG, Iodice A, Frattini D, Pisani F, Fusco C. KCNQ2 encephalopathy: A case due to a de novo deletion. Brain Dev 2018; 40:65-68. [PMID: 28728838 DOI: 10.1016/j.braindev.2017.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 06/15/2017] [Accepted: 06/30/2017] [Indexed: 11/24/2022]
Abstract
KCNQ2 encephalopathy is characterized by severely abnormal EEG, neonatal-onset epilepsy and developmental delay. It is caused by mutations (typically missense) in the KCNQ2 gene, encoding the voltage gated potassium channel Kv7.2 and leading to a negative-dominant effect. We present one case experiencing recurrent neonatal seizures with changing hemispheres of origin, reminiscent of epilepsy of infancy with migrating focal seizures. At 9months of age the patient is still seizure-free on carbamazepine, although he is developing a spastic-dystonic tetraplegia with severe dysphagia. He harbors a de novo deletion (c.913_915del [p.Phe305del)]), only described once in a couple of severely affected twins, and leading to the deletion of a phenylalanine residue in the pore domain of the channel. In conclusion, our case is the second described with encephalopathy due to this specific deletion (the one and only deletion so far reported in KCNQ2 encephalopathy). Thus, deletion is a newly described mechanism highlighting how not only missense mutations but also deletions in the channel hot spots can lead to a severe phenotype. Furthermore he presented ictal EEG features similar to epilepsy of infancy with migrating focal seizures not previously described.
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Affiliation(s)
- Carlotta Spagnoli
- Department of Pediatrics, Child Neurology Unit, Santa Maria Nuova Hospital, viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Grazia Gabriella Salerno
- Department of Pediatrics, Child Neurology Unit, Santa Maria Nuova Hospital, viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Alessandro Iodice
- Department of Pediatrics, Child Neurology Unit, Santa Maria Nuova Hospital, viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Daniele Frattini
- Department of Pediatrics, Child Neurology Unit, Santa Maria Nuova Hospital, viale Risorgimento 80, 42123 Reggio Emilia, Italy.
| | - Francesco Pisani
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, via Gramsci, 14, 43123 Parma, Italy.
| | - Carlo Fusco
- Department of Pediatrics, Child Neurology Unit, Santa Maria Nuova Hospital, viale Risorgimento 80, 42123 Reggio Emilia, Italy.
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7
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Štěrbová K, Laššuthová P, Perníková I, Beran M, Neupauerová J, Kršek P, Seeman P. KCNQ2 Mutation Explains the Etiology of Chloral Hydrate-Responsive Ohtahara Syndrome. Pediatr Neurol 2017; 67:e3-e4. [PMID: 28065823 DOI: 10.1016/j.pediatrneurol.2016.11.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/21/2016] [Accepted: 11/24/2016] [Indexed: 11/19/2022]
Affiliation(s)
- Katalin Štěrbová
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic
| | - Petra Laššuthová
- DNA Laboratory, Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic.
| | - Ivana Perníková
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic
| | - Michal Beran
- Department of Forensic Medicine, Bulovka Hospital, Prague, Czech Republic
| | - Jana Neupauerová
- DNA Laboratory, Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic
| | - Pavel Kršek
- Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic
| | - Pavel Seeman
- DNA Laboratory, Department of Child Neurology, 2nd Faculty of Medicine, Charles University and Motol Hospital, Prague, Czech Republic
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8
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Millichap JJ, Park KL, Tsuchida T, Ben-Zeev B, Carmant L, Flamini R, Joshi N, Levisohn PM, Marsh E, Nangia S, Narayanan V, Ortiz-Gonzalez XR, Patterson MC, Pearl PL, Porter B, Ramsey K, McGinnis EL, Taglialatela M, Tracy M, Tran B, Venkatesan C, Weckhuysen S, Cooper EC. KCNQ2 encephalopathy: Features, mutational hot spots, and ezogabine treatment of 11 patients. NEUROLOGY-GENETICS 2016; 2:e96. [PMID: 27602407 PMCID: PMC4995058 DOI: 10.1212/nxg.0000000000000096] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/06/2016] [Indexed: 11/15/2022]
Abstract
Objective: To advance the understanding of KCNQ2 encephalopathy genotype–phenotype relationships and to begin to assess the potential of selective KCNQ channel openers as targeted treatments. Methods: We retrospectively studied 23 patients with KCNQ2 encephalopathy, including 11 treated with ezogabine (EZO). We analyzed the genotype–phenotype relationships in these and 70 previously described patients. Results: The mean seizure onset age was 1.8 ± 1.6 (SD) days. Of the 20 EEGs obtained within a week of birth, 11 showed burst suppression. When new seizure types appeared in infancy (15 patients), the most common were epileptic spasms (n = 8). At last follow-up, seizures persisted in 9 patients. Development was delayed in all, severely in 14. The KCNQ2 variants identified introduced amino acid missense changes or, in one instance, a single residue deletion. They were clustered in 4 protein subdomains predicted to poison tetrameric channel functions. EZO use (assessed by the treating physicians and parents) was associated with improvement in seizures and/or development in 3 of the 4 treated before 6 months of age, and 2 of the 7 treated later; no serious side effects were observed. Conclusions: KCNQ2 variants cause neonatal-onset epileptic encephalopathy of widely varying severity. Pathogenic variants in epileptic encephalopathy are clustered in “hot spots” known to be critical for channel activity. For variants causing KCNQ2 channel loss of function, EZO appeared well tolerated and potentially beneficial against refractory seizures when started early. Larger, prospective studies are needed to enable better definition of prognostic categories and more robust testing of novel interventions. Classification of evidence: This study provides Class IV evidence that EZO is effective for refractory seizures in patients with epilepsy due to KCNQ2 encephalopathy.
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Affiliation(s)
| | - Kristen L Park
- Authors' affiliations are listed at the end of the article
| | - Tammy Tsuchida
- Authors' affiliations are listed at the end of the article
| | | | - Lionel Carmant
- Authors' affiliations are listed at the end of the article
| | - Robert Flamini
- Authors' affiliations are listed at the end of the article
| | - Nishtha Joshi
- Authors' affiliations are listed at the end of the article
| | | | - Eric Marsh
- Authors' affiliations are listed at the end of the article
| | - Srishti Nangia
- Authors' affiliations are listed at the end of the article
| | | | | | | | | | - Brenda Porter
- Authors' affiliations are listed at the end of the article
| | - Keri Ramsey
- Authors' affiliations are listed at the end of the article
| | | | | | - Molly Tracy
- Authors' affiliations are listed at the end of the article
| | - Baouyen Tran
- Authors' affiliations are listed at the end of the article
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9
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Møller RS, Larsen LHG, Johannesen KM, Talvik I, Talvik T, Vaher U, Miranda MJ, Farooq M, Nielsen JEK, Svendsen LL, Kjelgaard DB, Linnet KM, Hao Q, Uldall P, Frangu M, Tommerup N, Baig SM, Abdullah U, Born AP, Gellert P, Nikanorova M, Olofsson K, Jepsen B, Marjanovic D, Al-Zehhawi LIK, Peñalva SJ, Krag-Olsen B, Brusgaard K, Hjalgrim H, Rubboli G, Pal DK, Dahl HA. Gene Panel Testing in Epileptic Encephalopathies and Familial Epilepsies. Mol Syndromol 2016; 7:210-219. [PMID: 27781031 DOI: 10.1159/000448369] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In recent years, several genes have been causally associated with epilepsy. However, making a genetic diagnosis in a patient can still be difficult, since extensive phenotypic and genetic heterogeneity has been observed in many monogenic epilepsies. This study aimed to analyze the genetic basis of a wide spectrum of epilepsies with age of onset spanning from the neonatal period to adulthood. A gene panel targeting 46 epilepsy genes was used on a cohort of 216 patients consecutively referred for panel testing. The patients had a range of different epilepsies from benign neonatal seizures to epileptic encephalopathies (EEs). Potentially causative variants were evaluated by literature and database searches, submitted to bioinformatic prediction algorithms, and validated by Sanger sequencing. If possible, parents were included for segregation analysis. We identified a presumed disease-causing variant in 49 (23%) of the 216 patients. The variants were found in 19 different genes including SCN1A, STXBP1, CDKL5, SCN2A, SCN8A, GABRA1, KCNA2, and STX1B. Patients with neonatal-onset epilepsies had the highest rate of positive findings (57%). The overall yield for patients with EEs was 32%, compared to 17% among patients with generalized epilepsies and 16% in patients with focal or multifocal epilepsies. By the use of a gene panel consisting of 46 epilepsy genes, we were able to find a disease-causing genetic variation in 23% of the analyzed patients. The highest yield was found among patients with neonatal-onset epilepsies and EEs.
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Affiliation(s)
- Rikke S Møller
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | | | - Katrine M Johannesen
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Inga Talvik
- Tallinn Children's Hospital, Tallinn, Estonia; Tartu University Hospital, Children's Clinic, Tartu, Estonia
| | - Tiina Talvik
- Tartu University Hospital, Children's Clinic, Tartu, Estonia; Department of Paediatrics, University of Tartu, Tartu, Estonia
| | - Ulvi Vaher
- Tartu University Hospital, Children's Clinic, Tartu, Estonia; Department of Paediatrics, University of Tartu, Tartu, Estonia
| | - Maria J Miranda
- Department of Pediatrics, Pediatric Neurology, Herlev University Hospital, Copenhagen University, Herlev, Denmark
| | - Muhammad Farooq
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark; Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Jens E K Nielsen
- Department of Clinical Medicine, Section of Gynaecology, Obstetrics and Paediatrics, Roskilde Hospital, Roskilde, Denmark
| | | | | | - Karen M Linnet
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | - Qin Hao
- Amplexa Genetics, Odense, Denmark
| | - Peter Uldall
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Mimoza Frangu
- Department of Pediatrics, Holbæk Hospital, Holbæk, Denmark
| | - Niels Tommerup
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark
| | - Shahid M Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Uzma Abdullah
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark; Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Alfred P Born
- Department of Paediatrics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pia Gellert
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Marina Nikanorova
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Kern Olofsson
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Birgit Jepsen
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | | | - Lana I K Al-Zehhawi
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Bente Krag-Olsen
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Helle Hjalgrim
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Guido Rubboli
- Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark
| | - Deb K Pal
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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10
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Ihara Y, Tomonoh Y, Deshimaru M, Zhang B, Uchida T, Ishii A, Hirose S. Retigabine, a Kv7.2/Kv7.3-Channel Opener, Attenuates Drug-Induced Seizures in Knock-In Mice Harboring Kcnq2 Mutations. PLoS One 2016; 11:e0150095. [PMID: 26910900 PMCID: PMC4766199 DOI: 10.1371/journal.pone.0150095] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 02/09/2016] [Indexed: 12/30/2022] Open
Abstract
The hetero-tetrameric voltage-gated potassium channel Kv7.2/Kv7.3, which is encoded by KCNQ2 and KCNQ3, plays an important role in limiting network excitability in the neonatal brain. Kv7.2/Kv7.3 dysfunction resulting from KCNQ2 mutations predominantly causes self-limited or benign epilepsy in neonates, but also causes early onset epileptic encephalopathy. Retigabine (RTG), a Kv7.2/ Kv7.3-channel opener, seems to be a rational antiepileptic drug for epilepsies caused by KCNQ2 mutations. We therefore evaluated the effects of RTG on seizures in two strains of knock-in mice harboring different Kcnq2 mutations, in comparison to the effects of phenobarbital (PB), which is the first-line antiepileptic drug for seizures in neonates. The subjects were heterozygous knock-in mice (Kcnq2Y284C/+ and Kcnq2A306T/+) bearing the Y284C or A306T Kcnq2 mutation, respectively, and their wild-type (WT) littermates, at 63–100 days of age. Seizures induced by intraperitoneal injection of kainic acid (KA, 12mg/kg) were recorded using a video-electroencephalography (EEG) monitoring system. Effects of RTG on KA-induced seizures of both strains of knock-in mice were assessed using seizure scores from a modified Racine’s scale and compared with those of PB. The number and total duration of spike bursts on EEG and behaviors monitored by video recording were also used to evaluate the effects of RTG and PB. Both Kcnq2Y284C/+ and Kcnq2A306T/+ mice showed significantly more KA-induced seizures than WT mice. RTG significantly attenuated KA-induced seizure activities in both Kcnq2Y284C/+ and Kcnq2A306T/+ mice, and more markedly than PB. This is the first reported evidence of RTG ameliorating KA-induced seizures in knock-in mice bearing mutations of Kcnq2, with more marked effects than those observed with PB. RTG or other Kv7.2-channel openers may be considered as first-line antiepileptic treatments for epilepsies resulting from KCNQ2 mutations.
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Affiliation(s)
- Yukiko Ihara
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Yuko Tomonoh
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Masanobu Deshimaru
- Department of Chemistry, Faculty of Science, Fukuoka University, Fukuoka, Japan
| | - Bo Zhang
- Department of Biochemistry, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Taku Uchida
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka City, Japan
| | - Atsushi Ishii
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Shinichi Hirose
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka City, Japan
- * E-mail:
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11
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Wolfart J, Laker D. Homeostasis or channelopathy? Acquired cell type-specific ion channel changes in temporal lobe epilepsy and their antiepileptic potential. Front Physiol 2015; 6:168. [PMID: 26124723 PMCID: PMC4467176 DOI: 10.3389/fphys.2015.00168] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/19/2015] [Indexed: 01/16/2023] Open
Abstract
Neurons continuously adapt the expression and functionality of their ion channels. For example, exposed to chronic excitotoxicity, neurons homeostatically downscale their intrinsic excitability. In contrast, the “acquired channelopathy” hypothesis suggests that proepileptic channel characteristics develop during epilepsy. We review cell type-specific channel alterations under different epileptic conditions and discuss the potential of channels that undergo homeostatic adaptations, as targets for antiepileptic drugs (AEDs). Most of the relevant studies have been performed on temporal lobe epilepsy (TLE), a widespread AED-refractory, focal epilepsy. The TLE patients, who undergo epilepsy surgery, frequently display hippocampal sclerosis (HS), which is associated with degeneration of cornu ammonis subfield 1 pyramidal cells (CA1 PCs). Although the resected human tissue offers insights, controlled data largely stem from animal models simulating different aspects of TLE and other epilepsies. Most of the cell type-specific information is available for CA1 PCs and dentate gyrus granule cells (DG GCs). Between these two cell types, a dichotomy can be observed: while DG GCs acquire properties decreasing the intrinsic excitability (in TLE models and patients with HS), CA1 PCs develop channel characteristics increasing intrinsic excitability (in TLE models without HS only). However, thorough examination of data on these and other cell types reveals the coexistence of protective and permissive intrinsic plasticity within neurons. These mechanisms appear differentially regulated, depending on the cell type and seizure condition. Interestingly, the same channel molecules that are upregulated in DG GCs during HS-related TLE, appear as promising targets for future AEDs and gene therapies. Hence, GCs provide an example of homeostatic ion channel adaptation which can serve as a primer when designing novel anti-epileptic strategies.
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Affiliation(s)
- Jakob Wolfart
- Oscar Langendorff Institute of Physiology, University of Rostock Rostock, Germany
| | - Debora Laker
- Oscar Langendorff Institute of Physiology, University of Rostock Rostock, Germany
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Shimatani Y, Nodera H, Shibuta Y, Miyazaki Y, Misawa S, Kuwabara S, Kaji R. Abnormal gating of axonal slow potassium current in cramp-fasciculation syndrome. Clin Neurophysiol 2015; 126:1246-1254. [DOI: 10.1016/j.clinph.2014.09.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/30/2014] [Accepted: 09/03/2014] [Indexed: 12/13/2022]
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13
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Ishii A, Kanaumi T, Sohda M, Misumi Y, Zhang B, Kakinuma N, Haga Y, Watanabe K, Takeda S, Okada M, Ueno S, Kaneko S, Takashima S, Hirose S. Association of nonsense mutation in GABRG2 with abnormal trafficking of GABAA receptors in severe epilepsy. Epilepsy Res 2014; 108:420-32. [PMID: 24480790 DOI: 10.1016/j.eplepsyres.2013.12.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 12/07/2013] [Accepted: 12/16/2013] [Indexed: 11/29/2022]
Abstract
Mutations in GABRG2, which encodes the γ2 subunit of GABAA receptors, can cause both genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome. Most GABRG2 truncating mutations associated with Dravet syndrome result in premature termination codons (PTCs) and are stably translated into mutant proteins with potential dominant-negative effects. This study involved search for mutations in candidate genes for Dravet syndrome, namely SCN1A, 2A, 1B, 2B, GABRA1, B2, and G2. A heterozygous nonsense mutation (c.118C>T, p.Q40X) in GABRG2 was identified in dizygotic twin girls with Dravet syndrome and their apparently healthy father. Electrophysiological studies with the reconstituted GABAA receptors in HEK cells showed reduced GABA-induced currents when mutated γ2 DNA was cotransfected with wild-type α1 and β2 subunits. In this case, immunohistochemistry using antibodies to the α1 and γ2 subunits of GABAA receptor showed granular staining in the soma. In addition, microinjection of mutated γ2 subunit cDNA into HEK cells severely inhibited intracellular trafficking of GABAA receptor subunits α1 and β2, and retention of these proteins in the endoplasmic reticulum. The mutated γ2 subunit-expressing neurons also showed impaired axonal transport of the α1 and β2 subunits. Our findings suggested that different phenotypes of epilepsy, e.g., GEFS+ and Dravet syndrome (which share similar abnormalities in causative genes) are likely due to impaired axonal transport associated with the dominant-negative effects of GABRG2.
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Affiliation(s)
- Atsushi Ishii
- Department of Pediatrics, Fukuoka University, Fukuoka, Japan; Central Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Takeshi Kanaumi
- Department of Pediatrics, Fukuoka University, Fukuoka, Japan; Central Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Miwa Sohda
- Division of Oral Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yoshio Misumi
- Department of Cell Biology, Fukuoka University, Fukuoka, Japan
| | - Bo Zhang
- Department of Biochemistry, Fukuoka University, Fukuoka, Japan
| | - Naoto Kakinuma
- Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Yoshiko Haga
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kazuyoshi Watanabe
- Faculty of Health and Medical Sciences, Aichi Shukutoku University, Nagakute, Japan
| | - Sen Takeda
- Department of Anatomy and Cell Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Motohiro Okada
- Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Shinya Ueno
- Rehabilitation Medicine, Institute of Brain Science, Japan
| | - Sunao Kaneko
- Department of Neuropsychiatry, Hirosaki University, Hirosaki, Japan; North Tohoku Epilepsy Center, Minato Hospital, Hachinohe, Japan
| | - Sachio Takashima
- Yanagawa Institute for Developmental Disabilities, Child Neurology, International University of Health and Welfare, Yanagawa, Japan
| | - Shinichi Hirose
- Department of Pediatrics, Fukuoka University, Fukuoka, Japan; Central Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan.
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Shah NH, Aizenman E. Voltage-gated potassium channels at the crossroads of neuronal function, ischemic tolerance, and neurodegeneration. Transl Stroke Res 2013; 5:38-58. [PMID: 24323720 DOI: 10.1007/s12975-013-0297-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/14/2013] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
Voltage-gated potassium (Kv) channels are widely expressed in the central and peripheral nervous system and are crucial mediators of neuronal excitability. Importantly, these channels also actively participate in cellular and molecular signaling pathways that regulate the life and death of neurons. Injury-mediated increased K(+) efflux through Kv2.1 channels promotes neuronal apoptosis, contributing to widespread neuronal loss in neurodegenerative disorders such as Alzheimer's disease and stroke. In contrast, some forms of neuronal activity can dramatically alter Kv2.1 channel phosphorylation levels and influence their localization. These changes are normally accompanied by modifications in channel voltage dependence, which may be neuroprotective within the context of ischemic injury. Kv1 and Kv7 channel dysfunction leads to neuronal hyperexcitability that critically contributes to the pathophysiology of human clinical disorders such as episodic ataxia and epilepsy. This review summarizes the neurotoxic, neuroprotective, and neuroregulatory roles of Kv channels and highlights the consequences of Kv channel dysfunction on neuronal physiology. The studies described in this review thus underscore the importance of normal Kv channel function in neurons and emphasize the therapeutic potential of targeting Kv channels in the treatment of a wide range of neurological diseases.
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Affiliation(s)
- Niyathi Hegde Shah
- Department of Neurobiology, University of Pittsburgh School of Medicine, 3500 Terrace Street, E1456 BST, Pittsburgh, PA, 15261, USA,
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Ishii A, Yasumoto S, Ihara Y, Inoue T, Fujita T, Nakamura N, Ohfu M, Yamashita Y, Takatsuka H, Taga T, Miyata R, Ito M, Tsuchiya H, Matsuoka T, Kitao T, Murakami K, Lee WT, Kaneko S, Hirose S. Genetic analysis of PRRT2 for benign infantile epilepsy, infantile convulsions with choreoathetosis syndrome, and benign convulsions with mild gastroenteritis. Brain Dev 2013; 35:524-30. [PMID: 23073245 DOI: 10.1016/j.braindev.2012.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 09/05/2012] [Accepted: 09/11/2012] [Indexed: 11/18/2022]
Abstract
PURPOSE PRRT2 mutations were recently identified in benign familial infantile epilepsy (BFIE) and infantile convulsions with paroxysmal choreoathetosis (ICCA) but no abnormalities have so far been identified in their phenotypically similar seizure disorder of benign convulsions with mild gastroenteritis (CwG), while mutations in KCNQ2 and KCNQ3 have been recognized in benign familial neonatal epilepsy (BFNE). The aim of this study was to identify PRRT2 mutations in infantile convulsions in Asian families with BFIE and ICCA, CwG and BFNE. METHODS We recruited 26 unrelated Japanese affected with either BFIE or non-familial benign infantile seizures and their families, including three families with ICCA. A total of 17 Japanese and Taiwanese with CwG, 50 Japanese with BFNE and 96 healthy volunteers were also recruited. Mutations of PRRT2 were sought using direct sequencing. RESULTS Heterozygous truncation mutation (c.649dupC) was identified in 15 of 26 individuals with benign infantile epilepsy (52.1%). All three families of ICCA harbored the same mutation (100%). Another novel mutation (c.1012+2dupT) was found in the proband of a family with BFIE. However, no PRRT2 mutation was found in either CwG or BFNE. CONCLUSIONS The results confirm that c.649dupC, a truncating mutation of PRRT2, is a hotspot mutation resulting in BFIE or ICCA regardless of the ethnic background. In contrast, PRRT2 mutations do not seem to be associated with CwG or BFNE. Screening for PRRT2 mutation might be useful in early-stage differentiation of BFIE from CwG.
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Affiliation(s)
- Atsushi Ishii
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
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Zhou XH, Hui ZY, Shi RM, Song HX, Zhang W, Liu L. Site-directed mutagenesis of neonatal convulsions associated KCNQ2 gene and its protein expression. Transl Pediatr 2012; 1:91-8. [PMID: 26835270 PMCID: PMC4728876 DOI: 10.3978/j.issn.2224-4336.2012.03.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE To study the protocol of construction of a KCNQ2-c.812G>T mutant and its eukaryotic expression vector, the c.812G>T (p.G271V) mutation, which was detected in a Chinese pedigree of benign familial infantile convulsions (BFIC), and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells. METHODS A KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules. RESULTS Direct sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells. CONCLUSIONS Successful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.
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Affiliation(s)
- Xi-Hui Zhou
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
| | - Zhi-Yan Hui
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
| | - Rui-Ming Shi
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
| | - Hong-Xia Song
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
| | - Wei Zhang
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
| | - Li Liu
- Department of Neonatology, First Affiliated Hospital, Medical College of Xi'an Jiaotong University, Xi'an 710061, China
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Ishii A, Miyajima T, Kurahashi H, Wang JW, Yasumoto S, Kaneko S, Hirose S. KCNQ2 abnormality in BECTS: benign childhood epilepsy with centrotemporal spikes following benign neonatal seizures resulting from a mutation of KCNQ2. Epilepsy Res 2012; 102:122-5. [PMID: 22884718 DOI: 10.1016/j.eplepsyres.2012.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 07/08/2012] [Indexed: 11/19/2022]
Abstract
The molecular pathogenesis of benign childhood epilepsy with centrotemporal spikes (BECTS) remains unclear whereas mutations of the KCNQ2 and KCNQ3 genes have been identified as causes of benign familial neonatal convulsions. We report here a girl with benign neonatal convulsions followed by BECTS, for whom a mutation of KCNQ2 was identified. This case may provide the clue to the understanding of the molecular pathogenesis of BECTS.
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Affiliation(s)
- Atsushi Ishii
- Department of Pediatrics, Fukuoka University, Fukuoka, Japan
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Abstract
A major challenge in epilepsy research is to unravel the complex genetic mechanisms underlying both common and rare forms of epilepsy, as well as the genetic determinants of response to treatment. To accelerate progress in this area, the National Institute of Neurological Disorders and Stroke (NINDS) recently offered funding for the creation of a “Center without Walls” to focus on the genetics of human epilepsy. This article describes Epi4K, the collaborative study supported through this grant mechanism and having the aim of analyzing the genomes of a minimum 4,000 subjects with highly selected and well-characterized epilepsy.
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Affiliation(s)
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- Center for Human Genome Variation, Duke University, Durham, North Carolina 27708, USA
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Miceli F, Soldovieri MV, Iannotti FA, Barrese V, Ambrosino P, Martire M, Cilio MR, Taglialatela M. The Voltage-Sensing Domain of K(v)7.2 Channels as a Molecular Target for Epilepsy-Causing Mutations and Anticonvulsants. Front Pharmacol 2011; 2:2. [PMID: 21687499 PMCID: PMC3108560 DOI: 10.3389/fphar.2011.00002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 01/13/2011] [Indexed: 11/30/2022] Open
Abstract
Understanding the molecular mechanisms underlying voltage-dependent gating in voltage-gated ion channels (VGICs) has been a major effort over the last decades. In recent years, changes in the gating process have emerged as common denominators for several genetically determined channelopathies affecting heart rhythm (arrhythmias), neuronal excitability (epilepsy, pain), or skeletal muscle contraction (periodic paralysis). Moreover, gating changes appear as the main molecular mechanism by which several natural toxins from a variety of species affect ion channel function. In this work, we describe the pathophysiological and pharmacological relevance of the gating process in voltage-gated K+ channels encoded by the Kv7 gene family. After reviewing the current knowledge on the molecular mechanisms and on the structural models of voltage-dependent gating in VGICs, we describe the physiological relevance of these channels, with particular emphasis on those formed by Kv7.2–Kv7.5 subunits having a well-established role in controlling neuronal excitability in humans. In fact, genetically determined alterations in Kv7.2 and Kv7.3 genes are responsible for benign familial neonatal convulsions, a rare seizure disorder affecting newborns, and the pharmacological activation of Kv7.2/3 channels can exert antiepileptic activity in humans. Both mutation-triggered channel dysfunction and drug-induced channel activation can occur by impeding or facilitating, respectively, channel sensitivity to membrane voltage and can affect overlapping molecular sites within the voltage-sensing domain of these channels. Thus, understanding the molecular steps involved in voltage-sensing in Kv7 channels will allow to better define the pathogenesis of rare human epilepsy, and to design innovative pharmacological strategies for the treatment of epilepsies and, possibly, other human diseases characterized by neuronal hyperexcitability.
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Affiliation(s)
- Francesco Miceli
- Division of Neurology, IRCCS Bambino Gesù Children's Hospital Rome, Italy
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Ishii A, Zhang B, Kaneko S, Hirose S. Positive association between benign familial infantile convulsions and LGI4. Brain Dev 2010; 32:538-43. [PMID: 19815358 DOI: 10.1016/j.braindev.2009.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 09/04/2009] [Accepted: 09/07/2009] [Indexed: 11/25/2022]
Abstract
PURPOSE LGI4 is located in 19q13.11, where the locus of benign familial infantile convulsions (BFIC) has been mapped. LGI4 belongs to a family of proteins with the epilepsy-associated repeat (EAR) domain and is associated with various epilepsies. We investigated whether LGI4 is a candidate gene for BFIC. METHODS Fifteen patients with BFIC were examined for mutations and/or polymorphisms of LGI4 by using a direct sequencing method. RESULTS Several frequent polymorphisms were identified. The genotype frequency distribution of c.1722G/A polymorphism was significantly different between patients with BFIC and control subjects (p<0.05). Logistic regression analysis showed that the G allele of c.1722G/A polymorphism had significant recessive effects on the increased relative risk for BFIC (p<0.05). There was no association between c.1722G/A polymorphism and benign familial neonatal convulsion, an epilepsy phenotype similar to BFIC but genetically distinguished from BFIC. DISCUSSION The positive genotypic association between BFIC and c.1722G/A polymorphism suggests that LGI4 might contribute to the susceptibility to BFIC.
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Affiliation(s)
- Atsushi Ishii
- Department of Pediatrics, School of Medicine, Fukuoka University, Jonanku, Fukuoka, Japan
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Ottman R, Hirose S, Jain S, Lerche H, Lopes-Cendes I, Noebels JL, Serratosa J, Zara F, Scheffer IE. Genetic testing in the epilepsies--report of the ILAE Genetics Commission. Epilepsia 2010; 51:655-70. [PMID: 20100225 DOI: 10.1111/j.1528-1167.2009.02429.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this report, the International League Against Epilepsy (ILAE) Genetics Commission discusses essential issues to be considered with regard to clinical genetic testing in the epilepsies. Genetic research on the epilepsies has led to the identification of more than 20 genes with a major effect on susceptibility to idiopathic epilepsies. The most important potential clinical application of these discoveries is genetic testing: the use of genetic information, either to clarify the diagnosis in people already known or suspected to have epilepsy (diagnostic testing), or to predict onset of epilepsy in people at risk because of a family history (predictive testing). Although genetic testing has many potential benefits, it also has potential harms, and assessment of these potential benefits and harms in particular situations is complex. Moreover, many treating clinicians are unfamiliar with the types of tests available, how to access them, how to decide whether they should be offered, and what measures should be used to maximize benefit and minimize harm to their patients. Because the field is moving rapidly, with new information emerging practically every day, we present a framework for considering the clinical utility of genetic testing that can be applied to many different syndromes and clinical contexts. Given the current state of knowledge, genetic testing has high clinical utility in few clinical contexts, but in some of these it carries implications for daily clinical practice.
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Affiliation(s)
- Ruth Ottman
- G. H. Sergievsky Center and Department of Epidemiology, Columbia University, New York, NY, USA.
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Abstract
Genetic factors play an increasingly recognized role in idiopathic epilepsies. Since 1995, positional cloning strategies in multi-generational families with autosomal dominant transmission have revealed 11 genes (KCNQ2, KCNQ3, CHRNA4, CHRNA2, CHRNB2, SCN1B, SCN1A, SCN2A, GABRG2, GABRA1, and LGI1) and numerous loci for febrile seizures and epilepsies. To date, all genes with the exception of LGI1 (leucine-rich glioma inactivated 1), encode neuronal ion channel or neurotransmitter receptor subunits. Molecular approaches have revealed great genetic heterogeneity, with the vast majority of genes remaining to be identified. One of the major challenges is now to understand phenotype-genotype correlations. This review focuses on the current knowledge on the molecular basis of these rare Mendelian autosomal dominant forms of idiopathic epilepsies.
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Affiliation(s)
- Stéphanie Baulac
- UPMC/Inserm, UMR_S975, Cricm, F-75013, Bâtiment Pharmacie, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France.
| | - Michel Baulac
- UPMC/Inserm, UMR_S975, Cricm, F-75013, Bâtiment Pharmacie, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France; Center for Epilepsy, AP-HP, Bâtiment Paul Casteigne Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France
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Neutralization of a unique, negatively-charged residue in the voltage sensor of KV7.2 subunits in a sporadic case of benign familial neonatal seizures. Neurobiol Dis 2009; 34:501-10. [DOI: 10.1016/j.nbd.2009.03.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 02/24/2009] [Accepted: 03/18/2009] [Indexed: 01/06/2023] Open
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