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Kurekci F, Akif Kilic M, Akbas S, Avci R, Oney C, Dilruba Aslanger A, Maras Genc H, Aydinli N, Pembegul Yildiz E. Voltage-gated sodium channel epilepsies in a tertiary care center: Phenotypic spectrum with correlation to predicted functional effects. Epilepsy Behav 2024; 158:109930. [PMID: 38964184 DOI: 10.1016/j.yebeh.2024.109930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 06/27/2024] [Accepted: 06/29/2024] [Indexed: 07/06/2024]
Abstract
BACKGROUND Variants in sodium channel genes (SCN) are strongly associated with epilepsy phenotypes. Our aim in this study to evaluate the genotype and phenotype correlation of patients with SCN variants in our tertiary care center. METHODS In this retrospective study, patients with SCN variants and epilepsy who were followed up at our clinic between 2018 and 2022 were evaluated. Our study discussed the demographics of the patients, the seizure types, the age of seizure onset, the SCN variants, the domains and the functions of the variants, the magnetic resonance imaging findings, the motor, cognitive, and psychiatric comorbidities, and the response to anti-seizure medication. Genetic testing was conducted using a next-generation sequencing gene panel (epilepsy panel) or a whole-exome sequencing. For evaluating variant function, we used a prediction tool (https://funnc.shinyapps.io/shinyappweb/ site). To assess protein domains, we used the PER viewer (http://per.broadinstitute.org/). RESULTS Twenty-three patients with SCN variants and epilepsy have been identified. Sixteen patients had variants in the SCN1A, six patients had variants in the SCN2A, and one patient had a variant in the SCN3A. Two novel SCN1A variants and two novel SCN2A variants were identified. The analysis revealed 14/23 missense, 6/23 nonsense, 2/23 frameshift, and 1/23 splice site variants in the SCN. There are seven variants predicted to be gain-of-function and 13 predicted to be loss-of-function. Among 23 patients; 11 had Dravet Syndrome, 6 had early infantile developmental and epileptic encephalopathy, three had genetic epilepsy with febrile seizures plus spectrum disorder, one had self-limited familial neonatal-infantile epilepsy, one had self-limited infantile epilepsy and one had infantile childhood development epileptic encephalopathy. CONCLUSION Our cohort consists of mainly SCN1 variants, most of them were predicted to be loss of function. Dravet syndrome was the most common phenotype. The prediction tool used in our study demonstrated overall compatibility with clinical findings. Due to the diverse clinical manifestations of variant functions, it may assist in guiding medication selection and predicting outcomes. We believe that such a tool will help the clinician in both prognosis prediction and solving therapeutic challenges in this group where refractory seizures are common.
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Affiliation(s)
- Fulya Kurekci
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye.
| | - Mehmet Akif Kilic
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Sinan Akbas
- Department of Medical Genetics, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Rıdvan Avci
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Ceyda Oney
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Ayca Dilruba Aslanger
- Department of Medical Genetics, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Hulya Maras Genc
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Nur Aydinli
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
| | - Edibe Pembegul Yildiz
- Department of Pediatrics, Division of Pediatric Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkiye
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Shin HJ, Ko A, Kim SH, Lee JS, Kang HC. Unusual Voltage-Gated Sodium and Potassium Channelopathies Related to Epilepsy. J Clin Neurol 2024; 20:402-411. [PMID: 38951973 PMCID: PMC11220354 DOI: 10.3988/jcn.2023.0435] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/03/2024] [Accepted: 01/23/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND AND PURPOSE There is extensive literature on monogenic epilepsies caused by mutations in familiar channelopathy genes such as SCN1A. However, information on other less-common channelopathy genes is scarce. This study aimed to explore the genetic and clinical characteristics of patients diagnosed with unusual voltage-gated sodium and potassium channelopathies related to epilepsy. METHODS This observational, retrospective study analyzed pediatric patients with epilepsy who carried pathogenic variants of unusual voltage-gated sodium and potassium channelopathy genes responsible for seizure-associated phenotypes. Targeted next-generation sequencing (NGS) panel tests were performed between November 2016 and June 2022 at Severance Children's Hospital, Seoul, South Korea. Clinical characteristics and the treatment responses to different types of antiseizure medications were further analyzed according to different types of gene mutation. RESULTS This study included 15 patients with the following unusual voltage-gated sodium and potassium channelopathy genes: SCN3A (n=1), SCN4A (n=1), KCNA1 (n=1), KCNA2 (n=4), KCNB1 (n=6), KCNC1 (n=1), and KCNMA1 (n=1). NGS-based genetic testing identified 13 missense mutations (87%), 1 splice-site variant (7%), and 1 copy-number variant (7%). Developmental and epileptic encephalopathy was diagnosed in nine (60%) patients. Seizure freedom was eventually achieved in eight (53%) patients, whereas seizures persisted in seven (47%) patients. CONCLUSIONS Our findings broaden the genotypic and phenotypic spectra of less-common voltage-gated sodium and potassium channelopathies associated with epilepsy.
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Affiliation(s)
- Hui Jin Shin
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Ara Ko
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Se Hee Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
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Rusina E, Simonti M, Duprat F, Cestèle S, Mantegazza M. Voltage-gated sodium channels in genetic epilepsy: up and down of excitability. J Neurochem 2023. [PMID: 37654020 DOI: 10.1111/jnc.15947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 09/02/2023]
Abstract
The past two decades have witnessed a wide range of studies investigating genetic variants of voltage-gated sodium (NaV ) channels, which are involved in a broad spectrum of diseases, including several types of epilepsy. We have reviewed here phenotypes and pathological mechanisms of genetic epilepsies caused by variants in NaV α and β subunits, as well as of some relevant interacting proteins (FGF12/FHF1, PRRT2, and Ankyrin-G). Notably, variants of all these genes can induce either gain- or loss-of-function of NaV leading to either neuronal hyperexcitability or hypoexcitability. We present the results of functional studies obtained with different experimental models, highlighting that they should be interpreted considering the features of the experimental system used. These systems are models, but they have allowed us to better understand pathophysiological issues, ameliorate diagnostics, orientate genetic counseling, and select/develop therapies within a precision medicine framework. These studies have also allowed us to gain insights into the physiological roles of different NaV channels and of the cells that express them. Overall, our review shows the progress that has been made, but also the need for further studies on aspects that have not yet been clarified. Finally, we conclude by highlighting some significant themes of general interest that can be gleaned from the results of the work of the last two decades.
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Affiliation(s)
- Evgeniia Rusina
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Martina Simonti
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Fabrice Duprat
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Massimo Mantegazza
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
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Zidar N, Tomašič T, Kikelj D, Durcik M, Tytgat J, Peigneur S, Rogers M, Haworth A, Kirby RW. New aryl and acylsulfonamides as state-dependent inhibitors of Na v1.3 voltage-gated sodium channel. Eur J Med Chem 2023; 258:115530. [PMID: 37329714 DOI: 10.1016/j.ejmech.2023.115530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/19/2023]
Abstract
Voltage-gated sodium channels (Navs) play an essential role in neurotransmission, and their dysfunction is often a cause of various neurological disorders. The Nav1.3 isoform is found in the CNS and upregulated after injury in the periphery, but its role in human physiology has not yet been fully elucidated. Reports suggest that selective Nav1.3 inhibitors could be used as novel therapeutics to treat pain or neurodevelopmental disorders. Few selective inhibitors of this channel are known in the literature. In this work, we report the discovery of a new series of aryl and acylsulfonamides as state-dependent inhibitors of Nav1.3 channels. Using a ligand-based 3D similarity search and subsequent hit optimization, we identified and prepared a series of 47 novel compounds and tested them on Nav1.3, Nav1.5, and a selected subset also on Nav1.7 channels in a QPatch patch-clamp electrophysiology assay. Eight compounds had an IC50 value of less than 1 μM against the Nav1.3 channel inactivated state, with one compound displaying an IC50 value of 20 nM, whereas activity against the inactivated state of the Nav1.5 channel and Nav1.7 channel was approximately 20-fold weaker. None of the compounds showed use-dependent inhibition of the cardiac isoform Nav1.5 at a concentration of 30 μM. Further selectivity testing of the most promising hits was measured using the two-electrode voltage-clamp method against the closed state of the Nav1.1-Nav1.8 channels, and compound 15b displayed small, yet selective, effects against the Nav1.3 channel, with no activity against the other isoforms. Additional selectivity testing of promising hits against the inactivated state of the Nav1.3, Nav1.7, and Nav1.8 channels revealed several compounds with robust and selective activity against the inactivated state of the Nav1.3 channel among the three isoforms tested. Moreover, the compounds were not cytotoxic at a concentration of 50 μM, as demonstrated by the assay in human HepG2 cells (hepatocellular carcinoma cells). The novel state-dependent inhibitors of Nav1.3 discovered in this work provide a valuable tool to better evaluate this channel as a potential drug target.
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Affiliation(s)
- Nace Zidar
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, 1000, Ljubljana, Slovenia.
| | - Tihomir Tomašič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, 1000, Ljubljana, Slovenia
| | - Danijel Kikelj
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, 1000, Ljubljana, Slovenia
| | - Martina Durcik
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, 1000, Ljubljana, Slovenia
| | - Jan Tytgat
- University of Leuven (KU Leuven), Toxicology & Pharmacology, O&N2, PO Box 922, Herestraat 49, 3000, Leuven, Belgium
| | - Steve Peigneur
- University of Leuven (KU Leuven), Toxicology & Pharmacology, O&N2, PO Box 922, Herestraat 49, 3000, Leuven, Belgium
| | - Marc Rogers
- Metrion Biosciences Limited, Building 2, Granta Centre, Granta Park, Great Abington, Cambridge, CB21 6AL, UK
| | - Alexander Haworth
- Metrion Biosciences Limited, Building 2, Granta Centre, Granta Park, Great Abington, Cambridge, CB21 6AL, UK
| | - Robert W Kirby
- Metrion Biosciences Limited, Building 2, Granta Centre, Granta Park, Great Abington, Cambridge, CB21 6AL, UK
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Kanduc D. Exposure to SARS-CoV-2 and Infantile Diseases. Glob Med Genet 2023; 10:72-78. [PMID: 37144240 PMCID: PMC10154082 DOI: 10.1055/s-0043-1768699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
Background and Aim Immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in newborns and children after prophylactic immunization is currently a relevant research topic. The present study analyzes the issue by examining the possibility that the anti-SARS-CoV-2 immune responses are not uniquely directed against the virus but can-via molecular mimicry and the consequent cross-reactivity-also hit human proteins involved in infantile diseases. Methods Human proteins that-if altered-associate with infantile disorders were searched for minimal immune pentapeptide determinants shared with SARS-CoV-2 spike glycoprotein (gp). Then, the shared pentapeptides were analyzed for immunologic potential and immunologic imprinting phenomena. Results Comparative sequence analysis shows that: (1) numerous pentapeptides (namely, 54) are common to SARS-CoV-2 spike gp and human proteins that, when altered, are linked to infantile diseases; (2) all the shared peptides have an immunologic potential since they are present in experimentally validated SARS-CoV-2 spike gp-derived epitopes; and (3) many of the shared peptides are also hosted in infectious pathogens to which children can have already been exposed, thus making immunologic imprint phenomena feasible. Conclusion Molecular mimicry and the consequent cross-reactivity can represent the mechanism that connects exposure to SARS-CoV-2 and various pediatric diseases, with a fundamental role of the immunologic memory and the history of the child's infections in determining and specifying the immune response and the pathologic autoimmune sequela.
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Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
- Address for correspondence Darja Kanduc, PhD Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari70126 BariItaly
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Structure and Function of Sodium Channel Nav1.3 in Neurological Disorders. Cell Mol Neurobiol 2023; 43:575-584. [PMID: 35332400 DOI: 10.1007/s10571-022-01211-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 03/07/2022] [Indexed: 11/03/2022]
Abstract
Nav1.3, encoded by the SCN3A gene, is a voltage-gated sodium channel on the cell membrane. It is expressed abundantly in the fetal brain but little in the normal adult brain. It is involved in the generation and conduction of action potentials in excitable cells. Nav1.3 plays an important role in many neurological diseases. The aim of this review is to summarize new findings about Nav1.3 in the field of neurology. Many mutations of SCN3A can lead to neuronal hyperexcitability and then cause epilepsy. The rapid recovery from inactivation and slow closed-state inactivation kinetics of Nav1.3 leads to a reduced activation threshold of the channel and a high frequency of firing of neurons. Hyperactivity of Nav1.3 also induces increased excitability of sensory neurons, a lower nociceptive threshold, and neuropathic pain. This review summarizes the structure and the function of Nav1.3 and focuses on its relationship with epilepsy and neuropathic pain.
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Duc NM, Thu NTM, Bui CB, Hoa G, Le Trung Hieu N. Genotype and phenotype characteristics of West syndrome in 20 Vietnamese children: Two novel variants detected by next-generation sequencing. Epilepsy Res 2023; 190:107094. [PMID: 36689859 DOI: 10.1016/j.eplepsyres.2023.107094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
BACKGROUND In children with West syndrome (WS), whose treatment is challenging due to drug resistance and poor prognosis, investigation of genetic etiology and genotype-phenotype characteristics might assist in treatment optimization and genetic counseling. OBJECTIVE In this study, we aimed to present the results of genetic analysis and the corresponding phenotypes in a cohort of twenty children with WS in Vietnam. METHODS Our study was designed as a single-institution retrospective case series, in which consecutive sampling was used to select WS children having undergone genetic testing. Identified variants were investigated individually or as a variant combination by bioinformatics platforms. Clinical data were used to establish the genotype-phenotype correlation and compare clinical characteristics between groups of genetic causes and unknown causes. RESULTS Genetic testing identified at least one variant in 17/20 children. According to ACMG 2015, of all variants, one variant (3.9%) was classified as a benign variant, 16 variants (61.5%) were variants of uncertain significance, 4 (15.4%) were likely pathogenic variants, and 5 (19.2%) were pathogenic variants. These 26 variants belonged to 21 genes, of which eight candidate genes were CREBBP, MED25, HDAC8, SCN3A, ABCD1, TSC2, COL4A1, and NDUFA10. Two novel variants of SCN3A and TSC2 were found. Predicted pathogenic variant combinations were identified in two cases. Compared to three children of unknown etiology, five children with genetic causes had a higher rate of abnormal brain structures, developmental delay, and treatment resistance. CONCLUSIONS WS has a genetically heterogeneous etiology, and some cases might be polygenically susceptible. Our findings expand the disease's genotype-phenotype spectrum and support previous literature results that genetic etiology poses an unfavorable outcome in WS.
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Affiliation(s)
- Nguyen Minh Duc
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam.
| | - Nguyen Thuy Minh Thu
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam; Neurology Department, Children Hospital 2, Ho Chi Minh City 70000, Vietnam.
| | - Chi-Bao Bui
- School of Medicine, Vietnam National University, Ho Chi Minh City 70701, Vietnam.
| | - Giang Hoa
- Medical Genetics Institute, Ho Chi Minh City 70000, Vietnam.
| | - Nguyen Le Trung Hieu
- Neurology Department, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City 70000, Vietnam; Neurology Department, Children Hospital 2, Ho Chi Minh City 70000, Vietnam.
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Johannesen KM, Gardella E, Ahring PK, Møller RS. De novo SCN3A missense variant associated with self-limiting generalized epilepsy with fever sensitivity. Eur J Med Genet 2022; 65:104577. [DOI: 10.1016/j.ejmg.2022.104577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 05/09/2022] [Accepted: 07/20/2022] [Indexed: 11/28/2022]
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A nutraceutical product, extracted from Cannabis sativa, modulates voltage-gated sodium channel function. J Cannabis Res 2022; 4:30. [PMID: 35689251 PMCID: PMC9185959 DOI: 10.1186/s42238-022-00136-x] [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: 07/16/2021] [Accepted: 05/08/2022] [Indexed: 11/24/2022] Open
Abstract
Background Purified cannabidiol (CBD), a non-psychoactive phytocannabinoid, has gained regulatory approval to treat intractable childhood epilepsies. Despite this, artisanal and commercial CBD-dominant hemp-based products continue to be used by epilepsy patients. Notably, the CBD doses used in these latter products are much lower than that found to be effective in reducing seizures in clinical trials with purified CBD. This might be because these CBD-dominant hemp products contain other bioactive compounds, including phytocannabinoids and terpenes, which may exert unique effects on epilepsy-relevant drug targets. Voltage-gated sodium (NaV) channels are vital for initiation of neuronal action potential propagation and genetic mutations in these channels result in epilepsy phenotypes. Recent studies suggest that NaV channels are inhibited by purified CBD. However, the effect of cannabis-based products on the function of NaV channels is unknown. Methods Using automated-planar patch-clamp technology, we profile a hemp-derived nutraceutical product (NP) against human NaV1.1–NaV1.8 expressed in mammalian cells to examine effects on the biophysical properties of channel conductance, steady-state fast inactivation and recovery from fast inactivation. Results NP modifies peak current amplitude of the NaV1.1–NaV1.7 subtypes and has variable effects on the biophysical properties for all channel subtypes tested. NP potently inhibits NaV channels revealing half-maximal inhibitory concentration (IC50) values of between 1.6 and 4.2 μg NP/mL. Purified CBD inhibits NaV1.1, NaV1.2, NaV1.6 and NaV1.7 to reveal IC50 values in the micromolar range. The CBD content of the product equates to IC50 values (93–245 nM), which are at least an order of magnitude lower than purified CBD. Unlike NP, hemp seed oil vehicle alone did not inhibit NaV channels, suggesting that the inhibitory effects of NP are independent of hemp seed oil. Conclusions This CBD-dominant NP potently inhibits NaV channels. Future study of the individual elements of NP, including phytocannabinoids and terpenes, may reveal a potent individual component or that its components interact to modulate NaV channels. Supplementary Information The online version contains supplementary material available at 10.1186/s42238-022-00136-x.
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Lo J, Forst AL, Warth R, Zdebik AA. EAST/SeSAME Syndrome and Beyond: The Spectrum of Kir4.1- and Kir5.1-Associated Channelopathies. Front Physiol 2022; 13:852674. [PMID: 35370765 PMCID: PMC8965613 DOI: 10.3389/fphys.2022.852674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/13/2022] Open
Abstract
In 2009, two groups independently linked human mutations in the inwardly rectifying K+ channel Kir4.1 (gene name KCNJ10) to a syndrome affecting the central nervous system (CNS), hearing, and renal tubular salt reabsorption. The autosomal recessive syndrome has been named EAST (epilepsy, ataxia, sensorineural deafness, and renal tubulopathy) or SeSAME syndrome (seizures, sensorineural deafness, ataxia, intellectual disability, and electrolyte imbalance), accordingly. Renal dysfunction in EAST/SeSAME patients results in loss of Na+, K+, and Mg2+ with urine, activation of the renin-angiotensin-aldosterone system, and hypokalemic metabolic alkalosis. Kir4.1 is highly expressed in affected organs: the CNS, inner ear, and kidney. In the kidney, it mostly forms heteromeric channels with Kir5.1 (KCNJ16). Biallelic loss-of-function mutations of Kir5.1 can also have disease significance, but the clinical symptoms differ substantially from those of EAST/SeSAME syndrome: although sensorineural hearing loss and hypokalemia are replicated, there is no alkalosis, but rather acidosis of variable severity; in contrast to EAST/SeSAME syndrome, the CNS is unaffected. This review provides a framework for understanding some of these differences and will guide the reader through the growing literature on Kir4.1 and Kir5.1, discussing the complex disease mechanisms and the variable expression of disease symptoms from a molecular and systems physiology perspective. Knowledge of the pathophysiology of these diseases and their multifaceted clinical spectrum is an important prerequisite for making the correct diagnosis and forms the basis for personalized therapies.
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Affiliation(s)
- Jacky Lo
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Anna-Lena Forst
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Richard Warth
- Medical Cell Biology, Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Anselm A. Zdebik
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Centre for Nephrology, University College London, London, United Kingdom
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Structural basis for modulation of human NaV1.3 by clinical drug and selective antagonist. Nat Commun 2022; 13:1286. [PMID: 35277491 PMCID: PMC8917200 DOI: 10.1038/s41467-022-28808-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/04/2022] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium (NaV) channels play fundamental roles in initiating and propagating action potentials. NaV1.3 is involved in numerous physiological processes including neuronal development, hormone secretion and pain perception. Here we report structures of human NaV1.3/β1/β2 in complex with clinically-used drug bulleyaconitine A and selective antagonist ICA121431. Bulleyaconitine A is located around domain I-II fenestration, providing the detailed view of the site-2 neurotoxin binding site. It partially blocks ion path and expands the pore-lining helices, elucidating how the bulleyaconitine A reduces peak amplitude but improves channel open probability. In contrast, ICA121431 preferentially binds to activated domain IV voltage-sensor, consequently strengthens the Ile-Phe-Met motif binding to its receptor site, stabilizes the channel in inactivated state, revealing an allosterically inhibitory mechanism of NaV channels. Our results provide structural details of distinct small-molecular modulators binding sites, elucidate molecular mechanisms of their action on NaV channels and pave a way for subtype-selective therapeutic development. NaV1.3 is involved in neuronal development, hormone secretion and pain perception. Here, the authors elucidate the molecular mechanism for modulation of NaV1.3 by a site-2 neurotoxin bulleyaconitine A and a subtype selective antagonist ICA121431.
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Xu C, Zhang Y, Gozal D, Carney P. Channelopathy of Dravet Syndrome and Potential Neuroprotective Effects of Cannabidiol. J Cent Nerv Syst Dis 2021; 13:11795735211048045. [PMID: 34992485 PMCID: PMC8724990 DOI: 10.1177/11795735211048045] [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] [Indexed: 12/19/2022] Open
Abstract
Dravet syndrome (DS) is a channelopathy, neurodevelopmental, epileptic encephalopathy characterized by seizures, developmental delay, and cognitive impairment that includes susceptibility to thermally induced seizures, spontaneous seizures, ataxia, circadian rhythm and sleep disorders, autistic-like behaviors, and premature death. More than 80% of DS cases are linked to mutations in genes which encode voltage-gated sodium channel subunits, SCN1A and SCN1B, which encode the Nav1.1α subunit and Nav1.1β1 subunit, respectively. There are other gene mutations encoding potassium, calcium, and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels related to DS. One-third of patients have pharmacoresistance epilepsy. DS is unresponsive to standard therapy. Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been introduced for treating DS because of its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. However, the etiological channelopathiological mechanism of DS and action mechanism of CBD on the channels are unclear. In this review, we summarize evidence of the direct and indirect action mechanism of sodium, potassium, calcium, and HCN channels in DS, especially sodium subunits. Some channels' loss-of-function or gain-of-function in inhibitory or excitatory neurons determine the balance of excitatory and inhibitory are associated with DS. A great variety of mechanisms of CBD anticonvulsant effects are focused on modulating these channels, especially sodium, calcium, and potassium channels, which will shed light on ionic channelopathy of DS and the precise molecular treatment of DS in the future.
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Affiliation(s)
- Changqing Xu
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Yumin Zhang
- Department of Anatomy, Physiology and Genetics; Department of Neuroscience, Uniformed Services University School of Medicine, Bethesda, MD, USA
| | - David Gozal
- Department of Child Health and the Child Health Research Institute, School of Medicine, University of Missouri, Columbia, MO, USA
| | - Paul Carney
- Departments of Child Health and Neurology, School of Medicine, University of Missouri, Columbia, MO, USA
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13
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Wong JC, Butler KM, Shapiro L, Thelin JT, Mattison KA, Garber KB, Goldenberg PC, Kubendran S, Schaefer GB, Escayg A. Pathogenic in-Frame Variants in SCN8A: Expanding the Genetic Landscape of SCN8A-Associated Disease. Front Pharmacol 2021; 12:748415. [PMID: 34867351 PMCID: PMC8635767 DOI: 10.3389/fphar.2021.748415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/21/2021] [Indexed: 01/11/2023] Open
Abstract
Numerous SCN8A mutations have been identified, of which, the majority are de novo missense variants. Most mutations result in epileptic encephalopathy; however, some are associated with less severe phenotypes. Mouse models generated by knock-in of human missense SCN8A mutations exhibit seizures and a range of behavioral abnormalities. To date, there are only a few Scn8a mouse models with in-frame deletions or insertions, and notably, none of these mouse lines exhibit increased seizure susceptibility. In the current study, we report the generation and characterization of two Scn8a mouse models (ΔIRL/+ and ΔVIR/+) carrying overlapping in-frame deletions within the voltage sensor of domain 4 (DIVS4). Both mouse lines show increased seizure susceptibility and infrequent spontaneous seizures. We also describe two unrelated patients with the same in-frame SCN8A deletion in the DIV S5-S6 pore region, highlighting the clinical relevance of this class of mutations.
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Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kameryn M Butler
- Department of Human Genetics, Emory University, Atlanta, GA, United States.,Greenwood Genetic Center, Greenwood, SC, United States
| | - Lindsey Shapiro
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Jacquelyn T Thelin
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kari A Mattison
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Kathryn B Garber
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Paula C Goldenberg
- Department of Pediatrics and Medical Genetics, Harvard Medical School, Boston, MA, United States
| | - Shobana Kubendran
- Department of Pediatrics, Kansas University School of Medicine-Wichita, Wichita, KS, United States
| | - G Bradley Schaefer
- University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, United States
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14
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Bagheri S, Haddadi R, Saki S, Kourosh-Arami M, Komaki A. The effect of sodium channels on neurological/neuronal disorders: A systematic review. Int J Dev Neurosci 2021; 81:669-685. [PMID: 34687079 DOI: 10.1002/jdn.10153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/06/2021] [Accepted: 10/19/2021] [Indexed: 12/19/2022] Open
Abstract
Neurological and neuronal disorders are associated with structural, biochemical, or electrical abnormalities in the nervous system. Many neurological diseases have not yet been discovered. Interventions used for the treatment of these disorders include avoidance measures, lifestyle changes, physiotherapy, neurorehabilitation, pain management, medication, and surgery. In the sodium channelopathies, alterations in the structure, expression, and function of voltage-gated sodium channels (VGSCs) are considered as the causes of neurological and neuronal diseases. Online databases, including Scopus, Science Direct, Google Scholar, and PubMed were assessed for studies published between 1977 and 2020 using the keywords of review, sodium channels blocker, neurological diseases, and neuronal diseases. VGSCs consist of one α subunit and two β subunits. These subunits are known to regulate the gating kinetics, functional characteristics, and localization of the ion channel. These channels are involved in cell migration, cellular connections, neuronal pathfinding, and neurite outgrowth. Through the VGSC, the action potential is triggered and propagated in the neurons. Action potentials are physiological functions and passage of impermeable ions. The electrophysiological properties of these channels and their relationship with neurological and neuronal disorders have been identified. Subunit mutations are involved in the development of diseases, such as epilepsy, multiple sclerosis, autism, and Alzheimer's disease. Accordingly, we conducted a review of the link between VGSCs and neurological and neuronal diseases. Also, novel therapeutic targets were introduced for future drug discoveries.
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Affiliation(s)
- Shokufeh Bagheri
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rasool Haddadi
- Department of Pharmacology, School of Pharmacy, Hamadan University of Medical Science, Hamadan, Iran
| | - Sahar Saki
- Vice-Chancellor for Research and Technology, Hamadan University of Medical Science, Hamadan, Iran
| | - Masoumeh Kourosh-Arami
- Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.,Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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15
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Li W, Zhao W, Wang J, Zhang X, Qian X, Gu R, He G. Identification of a novel variant p.Ser606Gly in SCN3A associated with childhood absence epilepsy. Epilepsy Res 2021; 175:106682. [PMID: 34102392 DOI: 10.1016/j.eplepsyres.2021.106682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/14/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
Sodium (Na+) channels are the basis for action potential generation and propagation, which play a key role in the regulation of neuronal excitability. SCN3A is a gene encoding for sodium channel protein type 3 subunit alpha (or known as Nav1.3). This study aimed to explore SCN3A genetic variants in a cohort of childhood absence epilepsy (CAE) via whole exome sequencing. A novel SCN3A missense variant (c.A1816G, p.Ser606Gly) was identified in a patient with CAE. This variant had not been reported in both 1000G and ExAC databases. Bioinformatics analysis revealed that this variant was pathogenic and could transform the protein structure of Nav1.3. The reported phenotypes of SCN3A-related central nerve system disorders included multiple seizure types, polymicrogyria and different degrees of developmental delay/intellectual disability. The patient with p.Ser606Gly variant exhibited typical absence seizures. The MRI and CT scan results were normal, and EEG showed that 3-Hz spike-slow wave discharges. In conclusion, our findings not only broaden the pathogenic spectrum of SCN3A, but also extend the clinical phenotypes of SCN3A-related CAE.
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Affiliation(s)
- Wei Li
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, China
| | - Wenli Zhao
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Jing Wang
- School of Forensic Medicine, Xinxiang Medical University, Xinxiang, China
| | - Xiaoli Zhang
- Department of Neurology, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Xinlai Qian
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.
| | - Renjun Gu
- Department of Neurology, The Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.
| | - Guoyang He
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.
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16
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Ithal D, Sukumaran SK, Bhattacharjee D, Vemula A, Nadella R, Mahadevan J, Sud R, Viswanath B, Purushottam M, Jain S. Exome hits demystified: The next frontier. Asian J Psychiatr 2021; 59:102640. [PMID: 33892377 DOI: 10.1016/j.ajp.2021.102640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022]
Abstract
Severe mental illnesses such as schizophrenia and bipolar disorder have complex inheritance patterns, involving both common and rare variants. Whole exome sequencing is a promising approach to find out the rare genetic variants. We had previously reported several rare variants in multiplex families with severe mental illnesses. The current article tries to summarise the biological processes and pattern of expression of genes harbouring the aforementioned variants, linking them to known clinical manifestations through a methodical narrative review. Of the 28 genes considered for this review from 7 families with multiple affected individuals, 6 genes are implicated in various neuropsychiatric manifestations including some variations in the brain morphology assessed by magnetic resonance imaging. Another 15 genes, though associated with neuropsychiatric manifestations, did not have established brain morphological changes whereas the remaining 7 genes did not have any previously recorded neuropsychiatric manifestations at all. Wnt/b-catenin signaling pathway was associated with 6 of these genes and PI3K/AKT, calcium signaling, ERK, RhoA and notch signaling pathways had at least 2 gene associations. We present a comprehensive review of biological and clinical knowledge about the genes previously reported in multiplex families with severe mental illness. A 'disease in dish approach' can be helpful to further explore the fundamental mechanisms.
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Affiliation(s)
- Dhruva Ithal
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Salil K Sukumaran
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Debanjan Bhattacharjee
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Alekhya Vemula
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Ravi Nadella
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Jayant Mahadevan
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Reeteka Sud
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Biju Viswanath
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
| | - Meera Purushottam
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India.
| | - Sanjeev Jain
- Department of Psychiatry, National Institute of Mental Health and Neuro Sciences, Bengaluru, Karnataka, India
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17
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Ma H, Guo Y, Chen Z, Wang L, Tang Z, Zhang J, Miao Q, Zhai Q. Mutations in the sodium channel genes SCN1A, SCN3A, and SCN9A in children with epilepsy with febrile seizures plus(EFS+). Seizure 2021; 88:146-152. [PMID: 33895391 DOI: 10.1016/j.seizure.2021.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To explore disease-causing gene mutations of epilepsy with febrile seizures plus (EFS+) in Southern Chinese Han population. METHODS Blood samples and clinical data were collected from 49 Southern Han Chinese patients with EFS+. Gene screening was performed using whole-exome sequencing and panel sequencing for 485 epilepsy-related genes. The pathogenicity of variants was evaluated based on ACMG scoring and assessment of clinical concordance. RESULTS We identified 10 putatively causative sodium channel gene variants in 49 patients with EFS+, including 8 variants in SCN1A (R500Q appeared twice), one in SCN3A and one in SCN9A. All these missense mutations were inherited from maternal or paternal and were evaluated to be of uncertain significance according to ACMG. The clinical features of patients were in concordance with the EFS+ phenotype of the mutated SCN1A, SCN3A and SCN9A gene. The clinical phenotypes of 11 probands with these gene variants included febrile seizures plus (FS+, n=7), Dravet Syndrome (n=3), FS+ with focal seizures (n=1). Three probands with SCN1A variants (R500Q located in the non-voltage areas, or G1711D in the pore-forming domain) developed severe Dravet syndrome. The affected individuals with the other 6 SCN1A variants located outside the pore-forming domain showed mild phenotypes. Novel SCN3A variant ((D1688Y) and SCN9A variant (R185H) were identified in two probands respectively and both of the probands had FS+. CONCLUSION The SCN1A, SCN3A, and SCN9A gene mutations might be a pathogenic cause of EFS+ in Southern Chinese Han population.
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Affiliation(s)
- Hongxia Ma
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China; Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong Province, China
| | - Yuxiong Guo
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Zhihong Chen
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Lingan Wang
- Department of Neurology and Rehabilitation, Guangdong Women and Children's Hospital, Guangzhou, Guangdong Province, China
| | - Zhihong Tang
- Department of Pediatrics, Dongguan City Maternal & Child Health Hospital, Dongguan, Guangdong Province, China
| | - Jingwen Zhang
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Qinfei Miao
- Shantou University, Shantou, Guangdong Province, China
| | - Qiongxiang Zhai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China.
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18
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Mantegazza M, Cestèle S, Catterall WA. Sodium channelopathies of skeletal muscle and brain. Physiol Rev 2021; 101:1633-1689. [PMID: 33769100 DOI: 10.1152/physrev.00025.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.
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Affiliation(s)
- Massimo Mantegazza
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France.,INSERM, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France
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19
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Ademuwagun IA, Rotimi SO, Syrbe S, Ajamma YU, Adebiyi E. Voltage Gated Sodium Channel Genes in Epilepsy: Mutations, Functional Studies, and Treatment Dimensions. Front Neurol 2021; 12:600050. [PMID: 33841294 PMCID: PMC8024648 DOI: 10.3389/fneur.2021.600050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/01/2021] [Indexed: 12/19/2022] Open
Abstract
Genetic epilepsy occurs as a result of mutations in either a single gene or an interplay of different genes. These mutations have been detected in ion channel and non-ion channel genes. A noteworthy class of ion channel genes are the voltage gated sodium channels (VGSCs) that play key roles in the depolarization phase of action potentials in neurons. Of huge significance are SCN1A, SCN1B, SCN2A, SCN3A, and SCN8A genes that are highly expressed in the brain. Genomic studies have revealed inherited and de novo mutations in sodium channels that are linked to different forms of epilepsies. Due to the high frequency of sodium channel mutations in epilepsy, this review discusses the pathogenic mutations in the sodium channel genes that lead to epilepsy. In addition, it explores the functional studies on some known mutations and the clinical significance of VGSC mutations in the medical management of epilepsy. The understanding of these channel mutations may serve as a strong guide in making effective treatment decisions in patient management.
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Affiliation(s)
- Ibitayo Abigail Ademuwagun
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Solomon Oladapo Rotimi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Biochemistry, Covenant University, Ota, Nigeria
| | - Steffen Syrbe
- Clinic for Pediatric and Adolescent Medicine, Heidelberg University, Heidelberg, Germany
| | | | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research, Covenant University, Ota, Nigeria
- Department of Computer and Information Sciences, Covenant University, Ota, Nigeria
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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20
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Abstract
Voltage-gated sodium channels (VGSCs) are foundational to excitable cell function: Their coordinated passage of sodium ions into the cell is critical for the generation and propagation of action potentials throughout the nervous system. The classical paradigm of action potential physiology states that sodium passes through the membrane only transiently (1-2 milliseconds), before the channels inactivate and cease to conduct sodium ions. However, in reality, a small fraction of the total sodium current (1%-2%) remains at steady state despite prolonged depolarization. While this persistent sodium current (INaP) contributes to normal physiological functioning of neurons, accumulating evidence indicates a particularly pathogenic role for an elevated INaP in epilepsy (reviewed previously1). Due to significant advances over the past decade of epilepsy research concerning the importance of INaP in sodium channelopathies, this review seeks to summarize recent evidence and highlight promising novel anti-seizure medication strategies through preferentially targeting INaP.
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Affiliation(s)
- Eric R. Wengert
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
| | - Manoj K. Patel
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
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21
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Fasham J, Leslie JS, Harrison JW, Deline J, Williams KB, Kuhl A, Scott Schwoerer J, Cross HE, Crosby AH, Baple EL. No association between SCN9A and monogenic human epilepsy disorders. PLoS Genet 2020; 16:e1009161. [PMID: 33216760 PMCID: PMC7717534 DOI: 10.1371/journal.pgen.1009161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 12/04/2020] [Accepted: 09/28/2020] [Indexed: 11/27/2022] Open
Abstract
Many studies have demonstrated the clinical utility and importance of epilepsy gene panel testing to confirm the specific aetiology of disease, enable appropriate therapeutic interventions, and inform accurate family counselling. Previously, SCN9A gene variants, in particular a c.1921A>T p.(Asn641Tyr) substitution, have been identified as a likely autosomal dominant cause of febrile seizures/febrile seizures plus and other monogenic seizure phenotypes indistinguishable from those associated with SCN1A, leading to inclusion of SCN9A on epilepsy gene testing panels. Here we present serendipitous findings of genetic studies that identify the SCN9A c.1921A>T p.(Asn641Tyr) variant at high frequency in the Amish community in the absence of such seizure phenotypes. Together with findings in UK Biobank these data refute an association of SCN9A with epilepsy, which has important clinical diagnostic implications.
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Affiliation(s)
- James Fasham
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, United Kingdom
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital, Gladstone Road, Exeter, United Kingdom
| | - Joseph S. Leslie
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, United Kingdom
| | - Jamie W. Harrison
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, United Kingdom
- University of Exeter, Department of Biosciences, Exeter, United Kingdom
| | - James Deline
- Center for Special Children, La Farge Medical Clinic-VMH, La Farge, Wisconsin, United States of America
| | - Katie B. Williams
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Ashley Kuhl
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Jessica Scott Schwoerer
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Harold E. Cross
- Department of Ophthalmology, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Andrew H. Crosby
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, United Kingdom
| | - Emma L. Baple
- RILD Wellcome Wolfson Centre, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, United Kingdom
- Peninsula Clinical Genetics Service, Royal Devon & Exeter Hospital, Gladstone Road, Exeter, United Kingdom
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22
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Menezes LFS, Sabiá Júnior EF, Tibery DV, Carneiro LDA, Schwartz EF. Epilepsy-Related Voltage-Gated Sodium Channelopathies: A Review. Front Pharmacol 2020; 11:1276. [PMID: 33013363 PMCID: PMC7461817 DOI: 10.3389/fphar.2020.01276] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/31/2020] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a disease characterized by abnormal brain activity and a predisposition to generate epileptic seizures, leading to neurobiological, cognitive, psychological, social, and economic impacts for the patient. There are several known causes for epilepsy; one of them is the malfunction of ion channels, resulting from mutations. Voltage-gated sodium channels (NaV) play an essential role in the generation and propagation of action potential, and malfunction caused by mutations can induce irregular neuronal activity. That said, several genetic variations in NaV channels have been described and associated with epilepsy. These mutations can affect channel kinetics, modifying channel activation, inactivation, recovery from inactivation, and/or the current window. Among the NaV subtypes related to epilepsy, NaV1.1 is doubtless the most relevant, with more than 1500 mutations described. Truncation and missense mutations are the most observed alterations. In addition, several studies have already related mutated NaV channels with the electrophysiological functioning of the channel, aiming to correlate with the epilepsy phenotype. The present review provides an overview of studies on epilepsy-associated mutated human NaV1.1, NaV1.2, NaV1.3, NaV1.6, and NaV1.7.
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Affiliation(s)
- Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Elias Ferreira Sabiá Júnior
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Lilian Dos Anjos Carneiro
- Faculdade de Medicina, Centro Universitário Euro Americano, Brasília, Brazil.,Faculdade de Medicina, Centro Universitário do Planalto Central, Brasília, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
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23
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Zaman T, Helbig KL, Clatot J, Thompson CH, Kang SK, Stouffs K, Jansen AE, Verstraete L, Jacquinet A, Parrini E, Guerrini R, Fujiwara Y, Miyatake S, Ben‐Zeev B, Bassan H, Reish O, Marom D, Hauser N, Vu T, Ackermann S, Spencer CE, Lippa N, Srinivasan S, Charzewska A, Hoffman‐Zacharska D, Fitzpatrick D, Harrison V, Vasudevan P, Joss S, Pilz DT, Fawcett KA, Helbig I, Matsumoto N, Kearney JA, Fry AE, Goldberg EM. SCN3A
‐Related Neurodevelopmental Disorder: A Spectrum of Epilepsy and Brain Malformation. Ann Neurol 2020; 88:348-362. [DOI: 10.1002/ana.25809] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 05/05/2020] [Accepted: 05/25/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Tariq Zaman
- Division of Neurology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
| | - Katherine L. Helbig
- Division of Neurology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Epilepsy NeuroGenetics Initiative Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
| | - Jérôme Clatot
- Division of Neurology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Epilepsy NeuroGenetics Initiative Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
| | - Christopher H. Thompson
- Department of Pharmacology Northwestern University Feinberg School of Medicine Chicago Illinois USA
| | - Seok Kyu Kang
- Department of Pharmacology Northwestern University Feinberg School of Medicine Chicago Illinois USA
| | - Katrien Stouffs
- Center for Medical Genetics/Research Center for Reproduction and Genetics University Hospital Brussels, Free University of Brussels Brussels Belgium
| | - Anna E. Jansen
- Pediatric Neurology Unit, Department of Pediatrics University Hospital Brussels Brussels Belgium
- Neurogenetics Research Group Free University of Brussels Brussels Belgium
| | | | - Adeline Jacquinet
- Human Genetics Service Sart Tilman University Hospital Center Liege Belgium
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Department of Neuroscience A. Meyer Children's Hospital, University of Florence Florence Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Department of Neuroscience A. Meyer Children's Hospital, University of Florence Florence Italy
| | - Yuh Fujiwara
- Department of Pediatrics Yokohama City University Medical Center Yokohama Japan
| | - Satoko Miyatake
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Bruria Ben‐Zeev
- Pediatric Neurology Unit Edmond and Lili Safra Children's Hospital, Haim Sheba Medical Center Ramat Gan Israel
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
| | - Haim Bassan
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
- Pediatric Neurology & Development Center Shamir Medical Center (Assaf Harofe) Zerifin Israel
| | - Orit Reish
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
- Genetics Institute Shamir Medical Center (Assaf Harofe) Zerifin Zerifin Israel
| | - Daphna Marom
- Sackler School of Medicine Tel Aviv University Tel Aviv Israel
- Genetics Institute Shamir Medical Center (Assaf Harofe) Zerifin Zerifin Israel
| | - Natalie Hauser
- Inova Translational Medicine Institute Inova Health System Fairfax Virginia USA
| | - Thuy‐Anh Vu
- Department of Pediatric Neurology Children's National Medical Center, Washington, District of Columbia, and Pediatric Specialists of Virginia Fairfax Virginia USA
| | - Sally Ackermann
- Division of Paediatric Neurology, Department of Paediatrics and Child Health Red Cross War Memorial Children's Hospital, University of Cape Town Cape Town South Africa
| | - Careni E. Spencer
- Division of Human Genetics, Department of Medicine University of Cape Town, South Africa and Groote Schuur Hospital Cape Town South Africa
| | - Natalie Lippa
- Institute for Genomic Medicine Columbia University Medical Center New York New York USA
| | - Shraddha Srinivasan
- Department of Neurology Columbia University Medical Center New York New York USA
| | | | | | - David Fitzpatrick
- Medical Research Council Human Genetics Unit Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh Edinburgh United Kingdom
| | - Victoria Harrison
- Wessex Clinical Genetics Service Princess Anne Hospital Southampton United Kingdom
| | - Pradeep Vasudevan
- Department of Clinical Genetics University Hospitals Leicester National Health Service Trust Leicester United Kingdom
| | - Shelagh Joss
- West of Scotland Clinical Genetics Service Queen Elizabeth University Hospital Glasgow United Kingdom
| | - Daniela T. Pilz
- West of Scotland Clinical Genetics Service Queen Elizabeth University Hospital Glasgow United Kingdom
- Division of Cancer and Genetics School of Medicine, Cardiff University Cardiff United Kingdom
| | - Katherine A. Fawcett
- Medical Research Council (MRC) Computational Genomics Analysis and Training Programme, MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital Oxford United Kingdom
| | - Ingo Helbig
- Division of Neurology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Epilepsy NeuroGenetics Initiative Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Department of Neurology, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
- Department of Biomedical and Health Informatics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
| | - Naomichi Matsumoto
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama Japan
| | - Jennifer A. Kearney
- Department of Pharmacology Northwestern University Feinberg School of Medicine Chicago Illinois USA
| | - Andrew E. Fry
- Division of Cancer and Genetics School of Medicine, Cardiff University Cardiff United Kingdom
- Institute of Medical Genetics University Hospital of Wales Cardiff United Kingdom
| | - Ethan M. Goldberg
- Division of Neurology, Department of Pediatrics Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Epilepsy NeuroGenetics Initiative Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
- Department of Neurology, Perelman School of Medicine University of Pennsylvania Philadelphia Pennsylvania USA
- Department of Neuroscience Perelman School of Medicine, University of Pennsylvania Philadelphia Pennsylvania USA
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24
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Fatema K, Rahman MM, Faruk O. SCN8A Mutation in Infantile Epileptic Encephalopathy: Report of Two Cases. J Epilepsy Res 2020; 9:147-151. [PMID: 32509551 PMCID: PMC7251340 DOI: 10.14581/jer.19017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/21/2019] [Accepted: 01/09/2020] [Indexed: 12/03/2022] Open
Abstract
Early infantile epileptic encephalopathy type 13 is a severe form of epilepsy caused by mutations in the sodium channel 8 alpha (SCN8A) gene. This gene encodes the neuronal voltage-gated sodium channel which plays vital role in neuronal excitability. Here we present two cases with SCN8A encephalopathy. Both cases had mutation in p.Arg1872Gin the SCN8A gene, which was detected by targeted next generation sequencing. Case 1 was a 14-month old boy, who had a normal birth history with normal development up to 6 months and then developed repeated generalized seizure, which was nonresponsive to multiple antiepileptic drugs. He also had neuroregression and dystonia. His electroencephalogram (EEG) showed progressive background abnormality with burst suppression pattern. His metabolic panel was normal and had partial response to carbamazepine. The second case was for an 11-month old boy with the onset of seizure at the age of 7 months. Seizure was generalized, resistant to multiple antiepileptic drugs. He had developmental delay from beginning, no movement disorder. EEG showed focal discharge from left temporal and occipital region. He showed partial response to oxcarbazepine. Our cases had similarities with the previously reported cases. The detailed discussion of our cases would contribute to early detection and targeted treatment of SCN8A encephalopathy. This also gives special emphasis on a genetic test in infants with intractable epilepsy, movement disorder and developmental delay.
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Affiliation(s)
- Kanij Fatema
- Department of Pediatric Neurology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
| | - Md Mizanur Rahman
- Department of Pediatric Neurology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
| | - Omar Faruk
- Department of Pediatric Neurology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
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25
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Krenn M, Wagner M, Hotzy C, Graf E, Weber S, Brunet T, Lorenz-Depiereux B, Kasprian G, Aull-Watschinger S, Pataraia E, Stogmann E, Zimprich A, Strom TM, Meitinger T, Zimprich F. Diagnostic exome sequencing in non-acquired focal epilepsies highlights a major role of GATOR1 complex genes. J Med Genet 2020; 57:624-633. [PMID: 32086284 DOI: 10.1136/jmedgenet-2019-106658] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The genetic architecture of non-acquired focal epilepsies (NAFEs) becomes increasingly unravelled using genome-wide sequencing datasets. However, it remains to be determined how this emerging knowledge can be translated into a diagnostic setting. To bridge this gap, we assessed the diagnostic outcomes of exome sequencing (ES) in NAFE. METHODS 112 deeply phenotyped patients with NAFE were included in the study. Diagnostic ES was performed, followed by a screen to detect variants of uncertain significance (VUSs) in 15 well-established focal epilepsy genes. Explorative gene prioritisation was used to identify possible novel candidate aetiologies with so far limited evidence for NAFE. RESULTS ES identified pathogenic or likely pathogenic (ie, diagnostic) variants in 13/112 patients (12%) in the genes DEPDC5, NPRL3, GABRG2, SCN1A, PCDH19 and STX1B. Two pathogenic variants were microdeletions involving NPRL3 and PCDH19. Nine of the 13 diagnostic variants (69%) were found in genes of the GATOR1 complex, a potentially druggable target involved in the mammalian target of rapamycin (mTOR) signalling pathway. In addition, 17 VUSs in focal epilepsy genes and 6 rare variants in candidate genes (MTOR, KCNA2, RBFOX1 and SCN3A) were detected. Five patients with reported variants had double hits in different genes, suggesting a possible (oligogenic) role of multiple rare variants. CONCLUSION This study underscores the molecular heterogeneity of NAFE with GATOR1 complex genes representing the by far most relevant genetic aetiology known to date. Although the diagnostic yield is lower compared with severe early-onset epilepsies, the high rate of VUSs and candidate variants suggests a further increase in future years.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Neurogenomics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Christoph Hotzy
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Elisabeth Graf
- Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Sandrina Weber
- Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Theresa Brunet
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany
| | | | - Gregor Kasprian
- Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | | | | | | | | | - Tim M Strom
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technical University Munich, Munich, Bayern, Germany.,Institute of Human Genetics, Helmholtz Center Munich, Neuherberg, Bayern, Germany
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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26
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Inuzuka LM, Macedo-Souza LI, Della-Ripa B, Cabral KSS, Monteiro F, Kitajima JP, de Souza Godoy LF, de Souza Delgado D, Kok F, Garzon E. Neurodevelopmental disorder associated with de novo SCN3A pathogenic variants: two new cases and review of the literature. Brain Dev 2020; 42:211-216. [PMID: 31677917 DOI: 10.1016/j.braindev.2019.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/28/2019] [Accepted: 09/10/2019] [Indexed: 10/25/2022]
Abstract
SCN3A was recently recognized as a gene associated with neurodevelopmental disorder and epilepsy. We present two additional patients with a novel de novo SCN3A pathogenic variant, and a review of all published cases of de novo variants. In one of our patients brain magnetic resonance imaging (MRI) disclosed a severe polymicrogyria and in the other it was normal. The clinical phenotype was characterized by a severe developmental delay and refractory epilepsy in the patient with polymicrogyria and intellectual disability with autistic features and pharmacoresponsive epilepsy in the subject with normal MRI. Polymicrogyria, a disorder of progenitor cells proliferation and migration, is an unanticipated finding for an ion channel dysfunction.
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Affiliation(s)
- Luciana Midori Inuzuka
- Epilepsy Clinic, Hospital Sírio-Libanês, São Paulo, Brazil; Department of Neurology, University of São Paulo School of Medicine, Brazil.
| | | | - Bruno Della-Ripa
- Department of Neurology, University of São Paulo School of Medicine, Brazil.
| | - Katiane S S Cabral
- Department of Neurology, University of São Paulo School of Medicine, Brazil.
| | | | | | | | | | - Fernando Kok
- Mendelics Genomic Analysis, São Paulo, Brazil; Department of Neurology, University of São Paulo School of Medicine, Brazil.
| | - Eliana Garzon
- Epilepsy Clinic, Hospital Sírio-Libanês, São Paulo, Brazil; Department of Neurology, University of São Paulo School of Medicine, Brazil.
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27
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Smith RS, Walsh CA. Ion Channel Functions in Early Brain Development. Trends Neurosci 2020; 43:103-114. [PMID: 31959360 PMCID: PMC7092371 DOI: 10.1016/j.tins.2019.12.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/08/2019] [Accepted: 12/10/2019] [Indexed: 12/12/2022]
Abstract
During prenatal brain development, ion channels are ubiquitous across several cell types, including progenitor cells and migrating neurons but their function has not been clear. In the past, ion channel dysfunction has been primarily studied in the context of postnatal, differentiated neurons that fire action potentials - notably ion channels mutated in the epilepsies - yet data now support a surprising role in prenatal human brain disorders as well. Modern gene discovery approaches have identified defective ion channels in individuals with cerebral cortex malformations, which reflect abnormalities in early-to-middle stages of embryonic development (prior to ubiquitous action potentials). These human genetics studies and recent in utero animal modeling work suggest that precise control of ionic flux (calcium, sodium, and potassium) contributes to in utero developmental processes such as neural proliferation, migration, and differentiation.
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Affiliation(s)
- Richard S Smith
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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28
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Lindstrand A, Eisfeldt J, Pettersson M, Carvalho CMB, Kvarnung M, Grigelioniene G, Anderlid BM, Bjerin O, Gustavsson P, Hammarsjö A, Georgii-Hemming P, Iwarsson E, Johansson-Soller M, Lagerstedt-Robinson K, Lieden A, Magnusson M, Martin M, Malmgren H, Nordenskjöld M, Norling A, Sahlin E, Stranneheim H, Tham E, Wincent J, Ygberg S, Wedell A, Wirta V, Nordgren A, Lundin J, Nilsson D. From cytogenetics to cytogenomics: whole-genome sequencing as a first-line test comprehensively captures the diverse spectrum of disease-causing genetic variation underlying intellectual disability. Genome Med 2019; 11:68. [PMID: 31694722 PMCID: PMC6836550 DOI: 10.1186/s13073-019-0675-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/09/2019] [Indexed: 12/30/2022] Open
Abstract
Background Since different types of genetic variants, from single nucleotide variants (SNVs) to large chromosomal rearrangements, underlie intellectual disability, we evaluated the use of whole-genome sequencing (WGS) rather than chromosomal microarray analysis (CMA) as a first-line genetic diagnostic test. Methods We analyzed three cohorts with short-read WGS: (i) a retrospective cohort with validated copy number variants (CNVs) (cohort 1, n = 68), (ii) individuals referred for monogenic multi-gene panels (cohort 2, n = 156), and (iii) 100 prospective, consecutive cases referred to our center for CMA (cohort 3). Bioinformatic tools developed include FindSV, SVDB, Rhocall, Rhoviz, and vcf2cytosure. Results First, we validated our structural variant (SV)-calling pipeline on cohort 1, consisting of three trisomies and 79 deletions and duplications with a median size of 850 kb (min 500 bp, max 155 Mb). All variants were detected. Second, we utilized the same pipeline in cohort 2 and analyzed with monogenic WGS panels, increasing the diagnostic yield to 8%. Next, cohort 3 was analyzed by both CMA and WGS. The WGS data was processed for large (> 10 kb) SVs genome-wide and for exonic SVs and SNVs in a panel of 887 genes linked to intellectual disability as well as genes matched to patient-specific Human Phenotype Ontology (HPO) phenotypes. This yielded a total of 25 pathogenic variants (SNVs or SVs), of which 12 were detected by CMA as well. We also applied short tandem repeat (STR) expansion detection and discovered one pathologic expansion in ATXN7. Finally, a case of Prader-Willi syndrome with uniparental disomy (UPD) was validated in the WGS data. Important positional information was obtained in all cohorts. Remarkably, 7% of the analyzed cases harbored complex structural variants, as exemplified by a ring chromosome and two duplications found to be an insertional translocation and part of a cryptic unbalanced translocation, respectively. Conclusion The overall diagnostic rate of 27% was more than doubled compared to clinical microarray (12%). Using WGS, we detected a wide range of SVs with high accuracy. Since the WGS data also allowed for analysis of SNVs, UPD, and STRs, it represents a powerful comprehensive genetic test in a clinical diagnostic laboratory setting.
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Affiliation(s)
- Anna Lindstrand
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden. .,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. .,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Jesper Eisfeldt
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Maria Pettersson
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Malin Kvarnung
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Giedre Grigelioniene
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Britt-Marie Anderlid
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Olof Bjerin
- The Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Peter Gustavsson
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Anna Hammarsjö
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Erik Iwarsson
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Maria Johansson-Soller
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Kristina Lagerstedt-Robinson
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Agne Lieden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Måns Magnusson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Marcel Martin
- Department of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Helena Malmgren
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Magnus Nordenskjöld
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ameli Norling
- The Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Ellika Sahlin
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Henrik Stranneheim
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Emma Tham
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Josephine Wincent
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Sofia Ygberg
- The Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Wedell
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Valtteri Wirta
- Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.,Science for Life Laboratory, Department of Microbiology, Tumor and Cell biology, Karolinska Institutet, Stockholm, Sweden
| | - Ann Nordgren
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Johanna Lundin
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Daniel Nilsson
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
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29
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Li J, Gao K, Yan H, Xiangwei W, Liu N, Wang T, Xu H, Lin Z, Xie H, Wang J, Wu Y, Jiang Y. Reanalysis of whole exome sequencing data in patients with epilepsy and intellectual disability/mental retardation. Gene 2019; 700:168-175. [DOI: 10.1016/j.gene.2019.03.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/11/2019] [Accepted: 03/19/2019] [Indexed: 12/13/2022]
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30
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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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31
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Feng Y, Zhang S, Zhang Z, Guo J, Tan Z, Zhu Y, Tao J, Ji YH. Understanding Genotypes and Phenotypes of the Mutations in Voltage- Gated Sodium Channel α Subunits in Epilepsy. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2018; 18:266-272. [PMID: 30370865 DOI: 10.2174/1871527317666181026164825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/16/2018] [Accepted: 05/16/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND & OBJECTIVE Voltage-gated sodium channels (VGSCs) are responsible for the generation and propagation of action potentials in most excitable cells. In general, a VGSC consists of one pore-forming α subunit and two auxiliary β subunits. Genetic alterations in VGSCs genes, including both α and β subunits, are considered to be associated with epileptogenesis as well as seizures. This review aims to summarize the mutations in VGSC α subunits in epilepsy, particularly the pathophysiological and pharmacological properties of relevant VGSC mutants. CONCLUSION The review of epilepsy-associated VGSC α subunits mutants may not only contribute to the understanding of disease mechanism and genetic modifiers, but also provide potential theoretical targets for the precision and individualized medicine for epilepsy.
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Affiliation(s)
- Yijun Feng
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, China
| | - Shuzhang Zhang
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, China
| | - Zhiping Zhang
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, China
| | - Jingkang Guo
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, China
| | - Zhiyong Tan
- Department of Pharmacology and Toxicology and Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Yudan Zhu
- Central Laboratory, Department of Neurology and Neurosurgery, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jie Tao
- Central Laboratory, Department of Neurology and Neurosurgery, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Hua Ji
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, China
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32
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Smith RS, Kenny CJ, Ganesh V, Jang A, Borges-Monroy R, Partlow JN, Hill RS, Shin T, Chen AY, Doan RN, Anttonen AK, Ignatius J, Medne L, Bönnemann CG, Hecht JL, Salonen O, Barkovich AJ, Poduri A, Wilke M, de Wit MCY, Mancini GMS, Sztriha L, Im K, Amrom D, Andermann E, Paetau R, Lehesjoki AE, Walsh CA, Lehtinen MK. Sodium Channel SCN3A (Na V1.3) Regulation of Human Cerebral Cortical Folding and Oral Motor Development. Neuron 2018; 99:905-913.e7. [PMID: 30146301 DOI: 10.1016/j.neuron.2018.07.052] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 06/05/2018] [Accepted: 07/30/2018] [Indexed: 12/29/2022]
Abstract
Channelopathies are disorders caused by abnormal ion channel function in differentiated excitable tissues. We discovered a unique neurodevelopmental channelopathy resulting from pathogenic variants in SCN3A, a gene encoding the voltage-gated sodium channel NaV1.3. Pathogenic NaV1.3 channels showed altered biophysical properties including increased persistent current. Remarkably, affected individuals showed disrupted folding (polymicrogyria) of the perisylvian cortex of the brain but did not typically exhibit epilepsy; they presented with prominent speech and oral motor dysfunction, implicating SCN3A in prenatal development of human cortical language areas. The development of this disorder parallels SCN3A expression, which we observed to be highest early in fetal cortical development in progenitor cells of the outer subventricular zone and cortical plate neurons and decreased postnatally, when SCN1A (NaV1.1) expression increased. Disrupted cerebral cortical folding and neuronal migration were recapitulated in ferrets expressing the mutant channel, underscoring the unexpected role of SCN3A in progenitor cells and migrating neurons.
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Affiliation(s)
- Richard S Smith
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Connor J Kenny
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Vijay Ganesh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ahram Jang
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Rebeca Borges-Monroy
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jennifer N Partlow
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - R Sean Hill
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Taehwan Shin
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Allen Y Chen
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ryan N Doan
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Anna-Kaisa Anttonen
- The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland; Medical and Clinical Genetics, Neuroscience Center and Research Programs Unit, Molecular Neurology, 00014, University of Helsinki, Helsinki, Finland
| | - Jaakko Ignatius
- Department of Clinical Genetics, Turku University Hospital, Turku, 20521, Finland
| | - Livija Medne
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Carsten G Bönnemann
- Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jonathan L Hecht
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Oili Salonen
- Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, 00029 HUS, Helsinki, Finland
| | - A James Barkovich
- Benioff Children's Hospital, Departments of Radiology, Pediatrics, Neurology, and Neurological Surgery, University of California San Francisco, San Francisco, CA 94117, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital and Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Martina Wilke
- Department of Clinical Genetics, Erasmus MC Rotterdam 3015CN, Netherlands
| | - Marie Claire Y de Wit
- Neurogenetics Joint Clinic in Sophia Children's Hospital, Erasmus MC Rotterdam 3015CN, Netherlands
| | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus MC Rotterdam 3015CN, Netherlands
| | - Laszlo Sztriha
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Kiho Im
- Division of Newborn Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Dina Amrom
- Neurogenetics Unit and Epilepsy Research Group, Montreal Neurological Institute and Hospital; and the Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, QC H3A 2B4, Canada
| | - Eva Andermann
- Neurogenetics Unit and Epilepsy Research Group, Montreal Neurological Institute and Hospital; and the Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, QC H3A 2B4, Canada
| | - Ritva Paetau
- Children's Hospital, University of Helsinki and Helsinki University Hospital, 00029 HUS, Helsinki, Finland
| | - Anna-Elina Lehesjoki
- The Folkhälsan Institute of Genetics, 00290 Helsinki, Finland; Medical and Clinical Genetics, Neuroscience Center and Research Programs Unit, Molecular Neurology, 00014, University of Helsinki, Helsinki, Finland
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, and Howard Hughes Medical Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA.
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Zaman T, Helbig I, Božović IB, DeBrosse SD, Bergqvist AC, Wallis K, Medne L, Maver A, Peterlin B, Helbig KL, Zhang X, Goldberg EM. Mutations in SCN3A cause early infantile epileptic encephalopathy. Ann Neurol 2018; 83:703-717. [PMID: 29466837 DOI: 10.1002/ana.25188] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/01/2018] [Accepted: 02/18/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Voltage-gated sodium (Na+ ) channels underlie action potential generation and propagation and hence are central to the regulation of excitability in the nervous system. Mutations in the genes SCN1A, SCN2A, and SCN8A, encoding the Na+ channel pore-forming (α) subunits Nav1.1, 1.2, and 1.6, respectively, and SCN1B, encoding the accessory subunit β1 , are established causes of genetic epilepsies. SCN3A, encoding Nav1.3, is known to be highly expressed in brain, but has not previously been linked to early infantile epileptic encephalopathy. Here, we describe a cohort of 4 patients with epileptic encephalopathy and heterozygous de novo missense variants in SCN3A (p.Ile875Thr in 2 cases, p.Pro1333Leu, and p.Val1769Ala). METHODS All patients presented with treatment-resistant epilepsy in the first year of life, severe to profound intellectual disability, and in 2 cases (both with the variant p.Ile875Thr), diffuse polymicrogyria. RESULTS Electrophysiological recordings of mutant channels revealed prominent gain of channel function, with a markedly increased amplitude of the slowly inactivating current component, and for 2 of 3 mutants (p.Ile875Thr and p.Pro1333Leu), a leftward shift in the voltage dependence of activation to more hyperpolarized potentials. Gain of function was not observed for Nav1.3 variants known or presumed to be inherited (p.Arg1642Cys and p.Lys1799Gln). The antiseizure medications phenytoin and lacosamide selectively blocked slowly inactivating over transient current in wild-type and mutant Nav1.3 channels. INTERPRETATION These findings establish SCN3A as a new gene for infantile epileptic encephalopathy and suggest a potential pharmacologic intervention. These findings also reinforce the role of Nav1.3 as an important regulator of neuronal excitability in the developing brain, while providing additional insight into mechanisms of slow inactivation of Nav1.3. Ann Neurol 2018;83:703-717.
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Affiliation(s)
- Tariq Zaman
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Ingo Helbig
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA.,Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian Albrecht University, Kiel, Germany.,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ivana Babić Božović
- Department of Biology and Medical Genetics, School of Medicine, University of Rijeka, Rijeka, Croatia
| | - Suzanne D DeBrosse
- Departments of Genetics and Genome Sciences, Pediatrics, and Neurology, and Center for Human Genetics, Case Western Reserve University School of Medicine, Cleveland, OH
| | - A Christina Bergqvist
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Kimberly Wallis
- Departments of Genetics and Genome Sciences, Pediatrics, and Neurology, and Center for Human Genetics, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Livija Medne
- Division of Human Genetics, Department of Pediatrics, Individualized Medical Genetics Center, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Aleš Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Katherine L Helbig
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA.,Division of Clinical Genomics, Ambry Genetics, Aliso Viejo, CA
| | - Xiaohong Zhang
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Ethan M Goldberg
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA.,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.,Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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Tumienė B, Maver A, Writzl K, Hodžić A, Čuturilo G, Kuzmanić-Šamija R, Čulić V, Peterlin B. Diagnostic exome sequencing of syndromic epilepsy patients in clinical practice. Clin Genet 2018; 93:1057-1062. [PMID: 29286531 DOI: 10.1111/cge.13203] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 02/04/2023]
Abstract
Although genetic revolution of recent years has vastly expanded a list of genes implicated in epilepsies, complex architecture of epilepsy genetics is still largely unknown, consequently, universally accepted workflows for epilepsy genetic testing in a clinical practice are missing. We present a comprehensive NGS-based diagnostic approach addressing both the clinical and genetic heterogeneity of disorders involving epilepsy or seizures. A bioinformatic panel of 862 epilepsy- or seizure-associated genes was applied to Mendeliome (4813 genes) or whole-exome sequencing data as a first stage, while the second stage included untargeted variant interpretation. Eighty-six consecutive patients with epilepsy or seizures associated with neurodevelopmental disorders and/or congenital malformations were investigated. Of the 86 probands, 42 harbored pathogenic and likely pathogenic variants, giving a diagnostic yield of 49%. Two patients were diagnosed with pathogenic copy number variations and 2 had causative mitochondrial DNA variants. Eleven patients (13%) were diagnosed with diseases with specific treatments. Besides, genomic approach in diagnostics had multiple additional benefits due to mostly non-specific, overlapping, not full-blown phenotypes and abilities to diagnose novel and ultra rare epilepsy-associated diseases. Likely pathogenic variants were identified in SOX5 gene, not previously associated with epilepsy, and UBA5, a recently associated with epilepsy gene.
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Affiliation(s)
- B Tumienė
- Clinical Institute for Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Department of Human and Medical Genetics, Centre for Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - A Maver
- Clinical Institute for Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - K Writzl
- Clinical Institute for Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - A Hodžić
- Clinical Institute for Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - G Čuturilo
- Department of Medical Genetics, University Children's Hospital, Belgrade, Serbia
| | | | - V Čulić
- Department of Pediatrics, University Hospital Split, Split, Croatia
| | - B Peterlin
- Clinical Institute for Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
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35
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Eimon PM, Ghannad-Rezaie M, De Rienzo G, Allalou A, Wu Y, Gao M, Roy A, Skolnick J, Yanik MF. Brain activity patterns in high-throughput electrophysiology screen predict both drug efficacies and side effects. Nat Commun 2018; 9:219. [PMID: 29335539 PMCID: PMC5768723 DOI: 10.1038/s41467-017-02404-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 11/25/2017] [Indexed: 11/26/2022] Open
Abstract
Neurological drugs are often associated with serious side effects, yet drug screens typically focus only on efficacy. We demonstrate a novel paradigm utilizing high-throughput in vivo electrophysiology and brain activity patterns (BAPs). A platform with high sensitivity records local field potentials (LFPs) simultaneously from many zebrafish larvae over extended periods. We show that BAPs from larvae experiencing epileptic seizures or drug-induced side effects have substantially reduced complexity (entropy), similar to reduced LFP complexity observed in Parkinson’s disease. To determine whether drugs that enhance BAP complexity produces positive outcomes, we used light pulses to trigger seizures in a model of Dravet syndrome, an intractable genetic epilepsy. The highest-ranked compounds identified by BAP analysis exhibit far greater anti-seizure efficacy and fewer side effects during subsequent in-depth behavioral assessment. This high correlation with behavioral outcomes illustrates the power of brain activity pattern-based screens and identifies novel therapeutic candidates with minimal side effects. One challenge in drug screening for neurological disorders is how to accurately capture disease pathology and side effects. Here, the authors developed a multi-channel recording platform based on a zebrafish genetic model of epilepsy to screen for antiepileptic drugs.
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Affiliation(s)
- Peter M Eimon
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Mostafa Ghannad-Rezaie
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.,UZH/ETH Irchel Campus, Y17-L76, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Gianluca De Rienzo
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.,Intellimedix, Cambridge, MA, 02139, USA.,Axcella Health, 840 Memorial Dr, Cambridge, MA, 02139, USA
| | - Amin Allalou
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Yuelong Wu
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Mu Gao
- Georgia Institute of Technology, 950 Atlantic Drive, Room 2151, Atlanta, GA, 30332, USA
| | - Ambrish Roy
- Georgia Institute of Technology, 950 Atlantic Drive, Room 2151, Atlanta, GA, 30332, USA
| | - Jeffrey Skolnick
- Georgia Institute of Technology, 950 Atlantic Drive, Room 2151, Atlanta, GA, 30332, USA
| | - Mehmet Fatih Yanik
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA. .,UZH/ETH Irchel Campus, Y17-L76, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
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36
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Symonds JD, Zuberi SM. Genetics update: Monogenetics, polygene disorders and the quest for modifying genes. Neuropharmacology 2017; 132:3-19. [PMID: 29037745 DOI: 10.1016/j.neuropharm.2017.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/19/2022]
Abstract
The genetic channelopathies are a broad collection of diseases. Many ion channel genes demonstrate wide phenotypic pleiotropy, but nonetheless concerted efforts have been made to characterise genotype-phenotype relationships. In this review we give an overview of the factors that influence genotype-phenotype relationships across this group of diseases as a whole, using specific individual channelopathies as examples. We suggest reasons for the limitations observed in these relationships. We discuss the role of ion channel variation in polygenic disease and highlight research that has contributed to unravelling the complex aetiological nature of these conditions. We focus specifically on the quest for modifying genes in inherited channelopathies, using the voltage-gated sodium channels as an example. Epilepsy related to genetic channelopathy is one area in which precision medicine is showing promise. We will discuss the successes and limitations of precision medicine in these conditions. This article is part of the Special Issue entitled 'Channelopathies.'
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Affiliation(s)
- Joseph D Symonds
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
| | - Sameer M Zuberi
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK.
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37
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Wang J, Gao H, Bao X, Zhang Q, Li J, Wei L, Wu X, Chen Y, Yu S. SCN8A mutations in Chinese patients with early onset epileptic encephalopathy and benign infantile seizures. BMC MEDICAL GENETICS 2017; 18:104. [PMID: 28923014 PMCID: PMC5604297 DOI: 10.1186/s12881-017-0460-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/08/2017] [Indexed: 11/23/2022]
Abstract
Background SCN8A mutations have recently been associated with epilepsy and neurodevelopmental disorders. This study aimed to broaden the phenotypic-spectrum of disease related with SCN8A mutations. Methods To identify the pathogenic gene of a Chinese family, in which six members suffered from epilepsy, whole-exome sequencing was performed. In addition, target next-generation sequencing (NGS) was performed on 178 sporadic patients, who had epilepsy of unknown etiology within 6 months after birth. A detailed clinical history was obtained. Results A heterozygous missense mutation of SCN8A was identified in the Chinese family. Six de novo mutations of SCN8A were detected in 6 sporadic patients with epilepsy. In the family, six members developed seizures within a few years after birth. Five of them had milder clinical performance, that they had normal cognition and developmental milestones, and seizure-free was achieved by mono-therapy. The other one affected member presented with refractory epilepsy and developmental regression. She died from sudden unexpected death in epilepsy (SUDEP) at 17-year-old. Clinical features of six sporadic patients with SCN8A mutations were diverse, ranging from severe epileptic encephalopathy to benign epilepsy with normal cognition. Seizures started at the mean age of 3.9 months (from 2 months to 6 months). Seizure-free was achieved in four of them by mono- or multi-antiepileptic drugs. Five of them demonstrated mild or severe psychomotor retardation, whereas the other one was normal in development and intelligence. Conclusions Our findings extend the spectrum of SCN8A mutations and the clinical features of patients with SCN8A mutations. The majority of SCN8A mutations were de novo, inherited mutations from the heterozygous parents can also occur. The phenotypic spectrum of SCN8A mutation varied largely. Most affected patients manifested as refractory epilepsy and severe intellectual disability, only a small number of patients presented with milder clinical patterns. Additionally, our study confirmed that the same mutation can lead to different phenotypes. Electronic supplementary material The online version of this article (10.1186/s12881-017-0460-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jiaping Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Hua Gao
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
| | - Qingping Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Jiarui Li
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Liping Wei
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yan Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Shujie Yu
- Department of Neurology, Harbin Children's Hospital, Harbin, Heilongjiang Province, 150010, China
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38
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Zahir FR, Mwenifumbo JC, Chun HJE, Lim EL, Van Karnebeek CDM, Couse M, Mungall KL, Lee L, Makela N, Armstrong L, Boerkoel CF, Langlois SL, McGillivray BM, Jones SJM, Friedman JM, Marra MA. Comprehensive whole genome sequence analyses yields novel genetic and structural insights for Intellectual Disability. BMC Genomics 2017; 18:403. [PMID: 28539120 PMCID: PMC5442678 DOI: 10.1186/s12864-017-3671-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/29/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Intellectual Disability (ID) is among the most common global disorders, yet etiology is unknown in ~30% of patients despite clinical assessment. Whole genome sequencing (WGS) is able to interrogate the entire genome, providing potential to diagnose idiopathic patients. METHODS We conducted WGS on eight children with idiopathic ID and brain structural defects, and their normal parents; carrying out an extensive data analyses, using standard and discovery approaches. RESULTS We verified de novo pathogenic single nucleotide variants (SNV) in ARID1B c.1595delG and PHF6 c.820C > T, potentially causative de novo two base indels in SQSTM1 c.115_116delinsTA and UPF1 c.1576_1577delinsA, and de novo SNVs in CACNB3 c.1289G > A, and SPRY4 c.508 T > A, of uncertain significance. We report results from a large secondary control study of 2081 exomes probing the pathogenicity of the above genes. We analyzed structural variation by four different algorithms including de novo genome assembly. We confirmed a likely contributory 165 kb de novo heterozygous 1q43 microdeletion missed by clinical microarray. The de novo assembly resulted in unmasking hidden genome instability that was missed by standard re-alignment based algorithms. We also interrogated regulatory sequence variation for known and hypothesized ID genes and present useful strategies for WGS data analyses for non-coding variation. CONCLUSION This study provides an extensive analysis of WGS in the context of ID, providing genetic and structural insights into ID and yielding diagnoses.
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Affiliation(s)
- Farah R Zahir
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada. .,Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. .,Qatar Biomedical Research Institute, Hamad Bin Khalifa University, P.O. Box 34110, Doha, Qatar.
| | - Jill C Mwenifumbo
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada
| | - Hye-Jung E Chun
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada
| | - Emilia L Lim
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada
| | - Clara D M Van Karnebeek
- Department of Pediatrics, Centre for Molecular Medicine & Therapeutics Child & Family Research Institute, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Madeline Couse
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Karen L Mungall
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada
| | - Leora Lee
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Nancy Makela
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Linlea Armstrong
- Provincial Medical Genetics Programme, Children's & Women's Health Centre of British Columbia, Vancouver, BC, V6H 3N1, Canada
| | - Cornelius F Boerkoel
- Provincial Medical Genetics Programme, Children's & Women's Health Centre of British Columbia, Vancouver, BC, V6H 3N1, Canada
| | - Sylvie L Langlois
- Provincial Medical Genetics Programme, Children's & Women's Health Centre of British Columbia, Vancouver, BC, V6H 3N1, Canada
| | - Barbara M McGillivray
- Provincial Medical Genetics Programme, Children's & Women's Health Centre of British Columbia, Vancouver, BC, V6H 3N1, Canada
| | - Steven J M Jones
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada
| | - Jan M Friedman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Marco A Marra
- Canada's Michael Smith Genome Sciences Center, Vancouver, BC, V5Z 4S6, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
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39
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Holland KD, Bouley TM, Horn PS. Comparison and optimization of in silico algorithms for predicting the pathogenicity of sodium channel variants in epilepsy. Epilepsia 2017; 58:1190-1198. [PMID: 28518218 DOI: 10.1111/epi.13798] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2017] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Variants in neuronal voltage-gated sodium channel α-subunits genes SCN1A, SCN2A, and SCN8A are common in early onset epileptic encephalopathies and other autosomal dominant childhood epilepsy syndromes. However, in clinical practice, missense variants are often classified as variants of uncertain significance when missense variants are identified but heritability cannot be determined. Genetic testing reports often include results of computational tests to estimate pathogenicity and the frequency of that variant in population-based databases. The objective of this work was to enhance clinicians' understanding of results by (1) determining how effectively computational algorithms predict epileptogenicity of sodium channel (SCN) missense variants; (2) optimizing their predictive capabilities; and (3) determining if epilepsy-associated SCN variants are present in population-based databases. This will help clinicians better understand the results of indeterminate SCN test results in people with epilepsy. METHODS Pathogenic, likely pathogenic, and benign variants in SCNs were identified using databases of sodium channel variants. Benign variants were also identified from population-based databases. Eight algorithms commonly used to predict pathogenicity were compared. In addition, logistic regression was used to determine if a combination of algorithms could better predict pathogenicity. RESULTS Based on American College of Medical Genetic Criteria, 440 variants were classified as pathogenic or likely pathogenic and 84 were classified as benign or likely benign. Twenty-eight variants previously associated with epilepsy were present in population-based gene databases. The output provided by most computational algorithms had a high sensitivity but low specificity with an accuracy of 0.52-0.77. Accuracy could be improved by adjusting the threshold for pathogenicity. Using this adjustment, the Mendelian Clinically Applicable Pathogenicity (M-CAP) algorithm had an accuracy of 0.90 and a combination of algorithms increased the accuracy to 0.92. SIGNIFICANCE Potentially pathogenic variants are present in population-based sources. Most computational algorithms overestimate pathogenicity; however, a weighted combination of several algorithms increased classification accuracy to >0.90.
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Affiliation(s)
- Katherine D Holland
- Departments of Pediatrics and Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A.,Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.,McMicken College of Arts and Sciences, University of Cincinnati, Cincinnati, Ohio, U.S.A
| | | | - Paul S Horn
- Departments of Pediatrics and Neurology, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A.,Division of Child Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.,McMicken College of Arts and Sciences, University of Cincinnati, Cincinnati, Ohio, U.S.A
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40
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Ion Channel Genes and Epilepsy: Functional Alteration, Pathogenic Potential, and Mechanism of Epilepsy. Neurosci Bull 2017; 33:455-477. [PMID: 28488083 DOI: 10.1007/s12264-017-0134-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/20/2017] [Indexed: 01/29/2023] Open
Abstract
Ion channels are crucial in the generation and modulation of excitability in the nervous system and have been implicated in human epilepsy. Forty-one epilepsy-associated ion channel genes and their mutations are systematically reviewed. In this paper, we analyzed the genotypes, functional alterations (funotypes), and phenotypes of these mutations. Eleven genes featured loss-of-function mutations and six had gain-of-function mutations. Nine genes displayed diversified funotypes, among which a distinct funotype-phenotype correlation was found in SCN1A. These data suggest that the funotype is an essential consideration in evaluating the pathogenicity of mutations and a distinct funotype or funotype-phenotype correlation helps to define the pathogenic potential of a gene.
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41
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Su S, Shao J, Zhao Q, Ren X, Cai W, Li L, Bai Q, Chen X, Xu B, Wang J, Cao J, Zang W. MiR-30b Attenuates Neuropathic Pain by Regulating Voltage-Gated Sodium Channel Nav1.3 in Rats. Front Mol Neurosci 2017; 10:126. [PMID: 28529474 PMCID: PMC5418349 DOI: 10.3389/fnmol.2017.00126] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 04/18/2017] [Indexed: 01/12/2023] Open
Abstract
Nav1.3 is a tetrodotoxin-sensitive isoform among voltage-gated sodium channels that are closely associated with neuropathic pain. It can be up-regulated following nerve injury, but its biological function remains uncertain. MicroRNAs (miRNAs) are endogenous non-coding RNAs that can regulate post-transcriptional gene expression by binding with their target mRNAs. Using Target Scan software, we discovered that SCN3A is the major target of miR-30b, and we then determined whether miR-30b regulated the expression of Nav1.3 by transfecting miR-30b agomir through the stimulation of TNF-α or by transfecting miR-30b antagomir in primary dorsal root ganglion (DRG) neurons. The spinal nerve ligation (SNL) model was used to determine the contribution of miR-30b to neuropathic pain, to evaluate changes in Nav1.3 mRNA and protein expression, and to understand the sensitivity of rats to mechanical and thermal stimuli. Our results showed that miR-30b agomir transfection down-regulated Nav1.3 mRNA stimulated with TNF-α in primary DRG neurons. Moreover, miR-30b overexpression significantly attenuated neuropathic pain induced by SNL, with decreases in the expression of Nav1.3 mRNA and protein both in DRG neurons and spinal cord. Activation of Nav1.3 caused by miR-30b antagomir was identified. These data suggest that miR-30b is involved in the development of neuropathic pain, probably by regulating the expression of Nav1.3, and might be a novel therapeutic target for neuropathic pain. Perspective: This study is the first to explore the important role of miR-30b and Nav1.3 in spinal nerve ligation-induced neuropathic pain, and our evidence may provide new insight for improving therapeutic approaches to pain.
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Affiliation(s)
- Songxue Su
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Jinping Shao
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Qingzan Zhao
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Xiuhua Ren
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Weihua Cai
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Lei Li
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Qian Bai
- Department of Anesthesiology, The Second Affiliated Hospital of Zhengzhou UniversityZhengzhou, China
| | - Xuemei Chen
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Bo Xu
- Department of Anesthesiology, General Hospital of Guangzhou Military Command of People's Liberation ArmyGuangzhou, China
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, BaltimoreMD, USA
| | - Jing Cao
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
| | - Weidong Zang
- Department of Anatomy, Basic Medical Sciences College, Zhengzhou UniversityZhengzhou, China
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42
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Lamar T, Vanoye CG, Calhoun J, Wong JC, Dutton SBB, Jorge BS, Velinov M, Escayg A, Kearney JA. SCN3A deficiency associated with increased seizure susceptibility. Neurobiol Dis 2017; 102:38-48. [PMID: 28235671 DOI: 10.1016/j.nbd.2017.02.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 01/24/2017] [Accepted: 02/20/2017] [Indexed: 11/25/2022] Open
Abstract
Mutations in voltage-gated sodium channels expressed highly in the brain (SCN1A, SCN2A, SCN3A, and SCN8A) are responsible for an increasing number of epilepsy syndromes. In particular, mutations in the SCN3A gene, encoding the pore-forming Nav1.3 α subunit, have been identified in patients with focal epilepsy. Biophysical characterization of epilepsy-associated SCN3A variants suggests that both gain- and loss-of-function SCN3A mutations may lead to increased seizure susceptibility. In this report, we identified a novel SCN3A variant (L247P) by whole exome sequencing of a child with focal epilepsy, developmental delay, and autonomic nervous system dysfunction. Voltage clamp analysis showed no detectable sodium current in a heterologous expression system expressing the SCN3A-L247P variant. Furthermore, cell surface biotinylation demonstrated a reduction in the amount of SCN3A-L247P at the cell surface, suggesting the SCN3A-L247P variant is a trafficking-deficient mutant. To further explore the possible clinical consequences of reduced SCN3A activity, we investigated the effect of a hypomorphic Scn3a allele (Scn3aHyp) on seizure susceptibility and behavior using a gene trap mouse line. Heterozygous Scn3a mutant mice (Scn3a+/Hyp) did not exhibit spontaneous seizures nor were they susceptible to hyperthermia-induced seizures. However, they displayed increased susceptibility to electroconvulsive (6Hz) and chemiconvulsive (flurothyl and kainic acid) induced seizures. Scn3a+/Hyp mice also exhibited deficits in locomotor activity and motor learning. Taken together, these results provide evidence that loss-of-function of SCN3A caused by reduced protein expression or deficient trafficking to the plasma membrane may contribute to increased seizure susceptibility.
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Affiliation(s)
- Tyra Lamar
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Carlos G Vanoye
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jeffrey Calhoun
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | | | - Benjamin S Jorge
- Neuroscience Program, Vanderbilt University, Nashville, TN 37232, USA
| | - Milen Velinov
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA; Albert Einstein College of Medicine, Bronx, NY, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, USA.
| | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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43
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Structure-based assessment of disease-related mutations in human voltage-gated sodium channels. Protein Cell 2017; 8:401-438. [PMID: 28150151 PMCID: PMC5445024 DOI: 10.1007/s13238-017-0372-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/09/2017] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium (Nav) channels are essential for the rapid upstroke of action potentials and the propagation of electrical signals in nerves and muscles. Defects of Nav channels are associated with a variety of channelopathies. More than 1000 disease-related mutations have been identified in Nav channels, with Nav1.1 and Nav1.5 each harboring more than 400 mutations. Nav channels represent major targets for a wide array of neurotoxins and drugs. Atomic structures of Nav channels are required to understand their function and disease mechanisms. The recently determined atomic structure of the rabbit voltage-gated calcium (Cav) channel Cav1.1 provides a template for homology-based structural modeling of the evolutionarily related Nav channels. In this Resource article, we summarized all the reported disease-related mutations in human Nav channels, generated a homologous model of human Nav1.7, and structurally mapped disease-associated mutations. Before the determination of structures of human Nav channels, the analysis presented here serves as the base framework for mechanistic investigation of Nav channelopathies and for potential structure-based drug discovery.
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44
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Chen T, Giri M, Xia Z, Subedi YN, Li Y. Genetic and epigenetic mechanisms of epilepsy: a review. Neuropsychiatr Dis Treat 2017; 13:1841-1859. [PMID: 28761347 PMCID: PMC5516882 DOI: 10.2147/ndt.s142032] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Epilepsy is a common episodic neurological disorder or condition characterized by recurrent epileptic seizures, and genetics seems to play a key role in its etiology. Early linkage studies have localized multiple loci that may harbor susceptibility genes to epilepsy, and mutational analyses have detected a number of mutations involved in both ion channel and nonion channel genes in patients with idiopathic epilepsy. Genome-wide studies of epilepsy have found copy number variants at 2q24.2-q24.3, 7q11.22, 15q11.2-q13.3, and 16p13.11-p13.2, some of which disrupt multiple genes, such as NRXN1, AUTS2, NLGN1, CNTNAP2, GRIN2A, PRRT2, NIPA2, and BMP5, implicated for neurodevelopmental disorders, including intellectual disability and autism. Unfortunately, only a few common genetic variants have been associated with epilepsy. Recent exome-sequencing studies have found some genetic mutations, most of which are located in nonion channel genes such as the LGI1, PRRT2, EFHC1, PRICKLE, RBFOX1, and DEPDC5 and in probands with rare forms of familial epilepsy, and some of these genes are involved with the neurodevelopment. Since epigenetics plays a role in neuronal function from embryogenesis and early brain development to tissue-specific gene expression, epigenetic regulation may contribute to the genetic mechanism of neurodevelopment through which a gene and the environment interacting with each other affect the development of epilepsy. This review focused on the analytic tools used to identify epilepsy and then provided a summary of recent linkage and association findings, indicating the existence of novel genes on several chromosomes for further understanding of the biology of epilepsy.
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Affiliation(s)
- Tian Chen
- Department of Health Management Center, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
| | - Mohan Giri
- National Center for Rheumatic Diseases, Ratopul, Gaushala, Kathmandu, Nepal
| | - Zhenyi Xia
- Department of Thoracic Surgery, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
| | - Yadu Nanda Subedi
- National Center for Rheumatic Diseases, Ratopul, Gaushala, Kathmandu, Nepal
| | - Yan Li
- Department of Health Management Center, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
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45
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Bertrand D, Biton B, Licher T, Chambard JM, Lanneau C, Partiseti M, Lefevre IA. Functional Studies of Sodium Channels: From Target to Compound Identification. ACTA ACUST UNITED AC 2016; 75:9.21.1-9.21.35. [PMID: 27960031 DOI: 10.1002/cpph.14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Over the last six decades, voltage-gated sodium (Nav ) channels have attracted a great deal of scientific and pharmaceutical interest, driving fundamental advances in both biology and technology. The structure and physiological function of these channels have been extensively studied; clinical and genetic data have uncovered their implication in diseases such as epilepsy, arrhythmias, and pain, bringing them into focus as current and future drug targets. While different techniques have been established to record the activity of Nav channels, proper determination of their properties still presents serious challenges, depending upon the experimental conditions and the desired subtype of channel to be characterized. The aim of this unit is to review the characteristics of Nav channels, their properties, the cells in which they can be studied, and the currently available techniques. Topics covered include the determination of Nav -channel biophysical properties as well as the use of toxins to discriminate between subtypes using electrophysiological or optical methods. Perspectives on the development of high-throughput screening assays with their advantages and limitations are also discussed to allow a better understanding of the challenges encountered in voltage-gated sodium channel preclinical drug discovery. © 2016 by John Wiley & Sons, Inc.
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46
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Wang J, Lin ZJ, Liu L, Xu HQ, Shi YW, Yi YH, He N, Liao WP. Epilepsy-associated genes. Seizure 2016; 44:11-20. [PMID: 28007376 DOI: 10.1016/j.seizure.2016.11.030] [Citation(s) in RCA: 275] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/03/2016] [Accepted: 11/30/2016] [Indexed: 10/20/2022] Open
Abstract
Development in genetic technology has led to the identification of an increasing number of genes associated with epilepsy. These discoveries will both provide the basis for including genetic tests in clinical practice and improve diagnosis and treatment of epilepsy. By searching through several databases (OMIM, HGMD, and EpilepsyGene) and recent publications on PubMed, we found 977 genes that are associated with epilepsy. We classified these genes into 4 categories according to the manifestation of epilepsy in phenotypes. We found 84 genes that are considered as epilepsy genes: genes that cause epilepsies or syndromes with epilepsy as the core symptom. 73 genes were listed as neurodevelopment-associated genes: genes associated with both brain-development malformations and epilepsy. Several genes (536) were epilepsy-related: genes associated with both physical or other systemic abnormalities and epilepsy or seizures. We found 284 additional genes putatively associated with epilepsy; this requires further verification. These integrated data will provide new insights useful for both including genetic tests in the clinical practice and evaluating the results of genetic tests. We also summarized the epilepsy-associated genes according to their function, with the goal to better characterize the association between genes and epilepsies and to further understand the mechanisms underlying epilepsy.
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Affiliation(s)
- Jie Wang
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zhi-Jian Lin
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Liu Liu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Hai-Qing Xu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China; Department of Neurology, Affiliated Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Yi-Wu Shi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Na He
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.
| | - Wei-Ping Liao
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.
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47
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Hessel EVS, van Lith HA, Wolterink-Donselaar IG, de Wit M, Groot Koerkamp MJA, Holstege FCP, Kas MJH, Fernandes C, de Graan PNE. Mapping of aFEB3homologous febrile seizure locus on mouse chromosome 2 containing candidate genesScn1aandScn3a. Eur J Neurosci 2016; 44:2950-2957. [DOI: 10.1111/ejn.13420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/10/2016] [Accepted: 08/09/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Ellen V. S. Hessel
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | - Hein A. van Lith
- Division of Animal Welfare & Laboratory Animal Science; Department of Animals in Science & Society; Faculty of Veterinary Medicine and Brain Center Rudolf Magnus; Utrecht University; Utrecht The Netherlands
| | - Inge G. Wolterink-Donselaar
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | - Marina de Wit
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | | | - Frank C. P. Holstege
- Department of Molecular Cancer Research; University Medical Center Utrecht; Utrecht The Netherlands
| | - Martien J. H. Kas
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
- Groningen Institute for Evolutionary Life Sciences; University of Groningen; Groningen The Netherlands
| | - Cathy Fernandes
- Social, Genetic & Developmental Psychiatry Centre; Institute of Psychiatry; Psychology and Neuroscience; King's College London; London UK
| | - Pierre N. E. de Graan
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
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48
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Trujillano D, Bertoli-Avella AM, Kumar Kandaswamy K, Weiss ME, Köster J, Marais A, Paknia O, Schröder R, Garcia-Aznar JM, Werber M, Brandau O, Calvo Del Castillo M, Baldi C, Wessel K, Kishore S, Nahavandi N, Eyaid W, Al Rifai MT, Al-Rumayyan A, Al-Twaijri W, Alothaim A, Alhashem A, Al-Sannaa N, Al-Balwi M, Alfadhel M, Rolfs A, Abou Jamra R. Clinical exome sequencing: results from 2819 samples reflecting 1000 families. Eur J Hum Genet 2016; 25:176-182. [PMID: 27848944 PMCID: PMC5255946 DOI: 10.1038/ejhg.2016.146] [Citation(s) in RCA: 254] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 09/07/2016] [Accepted: 09/23/2016] [Indexed: 02/01/2023] Open
Abstract
We report our results of 1000 diagnostic WES cases based on 2819 sequenced samples from 54 countries with a wide phenotypic spectrum. Clinical information given by the requesting physicians was translated to HPO terms. WES processes were performed according to standardized settings. We identified the underlying pathogenic or likely pathogenic variants in 307 families (30.7%). In further 253 families (25.3%) a variant of unknown significance, possibly explaining the clinical symptoms of the index patient was identified. WES enabled timely diagnosing of genetic diseases, validation of causality of specific genetic disorders of PTPN23, KCTD3, SCN3A, PPOX, FRMPD4, and SCN1B, and setting dual diagnoses by detecting two causative variants in distinct genes in the same patient. We observed a better diagnostic yield in consanguineous families, in severe and in syndromic phenotypes. Our results suggest that WES has a better yield in patients that present with several symptoms, rather than an isolated abnormality. We also validate the clinical benefit of WES as an effective diagnostic tool, particularly in nonspecific or heterogeneous phenotypes. We recommend WES as a first-line diagnostic in all cases without a clear differential diagnosis, to facilitate personal medical care.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Wafaa Eyaid
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Muhammad Talal Al Rifai
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Ahmed Al-Rumayyan
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Waleed Al-Twaijri
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Ali Alothaim
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Department of pathology, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Division of Metabolic and Genetics, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Nouriya Al-Sannaa
- Division of Pediatrics, Johns Hopkins Aramco hospital, Dhahran Health Center, Saudi Aramco, Dhahran, Saudi Arabia
| | - Mohammed Al-Balwi
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Arndt Rolfs
- Centogene AG, Rostock, Germany.,Albrecht-Kossel-Institute for Neuroregeneration, Medical University Rostock, Rostock, Germany
| | - Rami Abou Jamra
- Centogene AG, Rostock, Germany.,Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
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49
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Bao L, Zhang Y, Wang J, Wang H, Dong N, Su X, Xu M, Wang X. Variations of chromosome 2 gene expressions among patients with lung cancer or non-cancer. Cell Biol Toxicol 2016; 32:419-35. [DOI: 10.1007/s10565-016-9343-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/09/2016] [Indexed: 12/15/2022]
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50
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Thuresson AC, Van Buggenhout G, Sheth F, Kamate M, Andrieux J, Clayton Smith J, Soussi Zander C. Whole gene duplication of SCN2A and SCN3A is associated with neonatal seizures and a normal intellectual development. Clin Genet 2016; 91:106-110. [PMID: 27153334 DOI: 10.1111/cge.12797] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/25/2016] [Accepted: 05/03/2016] [Indexed: 11/29/2022]
Abstract
Duplications at 2q24.3 encompassing the voltage-gated sodium channel gene cluster are associated with early onset epilepsy. All cases described in the literature have presented in addition with different degrees of intellectual disability, and have involved neighbouring genes in addition to the sodium channel gene cluster. Here, we report eight new cases with overlapping duplications at 2q24 ranging from 0.05 to 7.63 Mb in size. Taken together with the previously reported cases, our study suggests that having an extra copy of SCN2A has an effect on epilepsy pathogenesis, causing benign familial infantile seizures which eventually disappear at the age of 1-2 years. However, the number of copies of SCN2A does not appear to have an effect on cognitive outcome.
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Affiliation(s)
- A-C Thuresson
- Department of Immunology, Genetics and Pathology, Rudbeck and Science for Life laboratory, Uppsala University, Uppsala, Sweden
| | - G Van Buggenhout
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - F Sheth
- FRIGE's Institute of Human Genetics, Ahmedabad, India
| | - M Kamate
- Department of Pediatric Neurology and Child Development Centre, KLES Prabhakar Kore Hospital, Belgaum, India
| | - J Andrieux
- Laboratoire de Génétique Médicale, Hopital Jeanne de Flandre, CHRU de Lille, Lille, France
| | - J Clayton Smith
- Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre, St Mary's Hospital, Manchester, UK.,Institute of Human Development, University of Manchester, Manchester, UK
| | - C Soussi Zander
- Department of Immunology, Genetics and Pathology, Rudbeck and Science for Life laboratory, Uppsala University, Uppsala, Sweden
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