1
|
Trinh NHNY, Reid AS, Robertson B. Perioperative considerations for adult patients with Dravet syndrome in regional centres. BMJ Case Rep 2023; 16:e256261. [PMID: 38056933 PMCID: PMC10711814 DOI: 10.1136/bcr-2023-256261] [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] [Indexed: 12/08/2023] Open
Abstract
Dravet syndrome (DS) is a rare and intractable severe form of epilepsy presenting in infancy with frequent prolonged myoclonic seizures and neurodevelopmental impairment, associated with a SCN1A gene mutation. Seizures are often triggered by temperature fluctuations and hyperthermia. This report presents a woman in her late adolescence with DS complicated with intractable catamenial epilepsy, a sex-specific form of epilepsy with seizure activity prominent during phases of the menstrual cycle. The patient underwent general anaesthesia for a hysteroscopy, cervical dilatation and endometrial curettage with Mirena insertion to improve seizure control. Her perioperative care was optimised for seizure prevention with continuation of antiepileptic medications, strict temperature monitoring and control, optimised anaesthetic agents encompassing induction with propofol and fentanyl with maintenance sevoflurane, followed by attentive postoperative care and monitoring. This case demonstrates that general anaesthesia can safely be delivered to adult patients with DS in rural and regional areas with thorough perioperative planning.
Collapse
Affiliation(s)
| | - Amy Susan Reid
- Anaesthesia, Albury Wodonga Health, East Albury, New South Wales, Australia
| | - Barbara Robertson
- Anaesthesia, Albury Wodonga Health, East Albury, New South Wales, Australia
| |
Collapse
|
2
|
Kovačević M, Milićević O, Branković M, Janković M, Novaković I, Sokić D, Ristić A, Shamsani J, Vojvodić N. Novel variants in established epilepsy genes in focal epilepsy. Seizure 2023; 110:146-152. [PMID: 37390664 DOI: 10.1016/j.seizure.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 07/02/2023] Open
Abstract
INTRODUCTION Next generation sequencing (NGS) has greatly expanded our understanding of genetic contributors in multiple epilepsy syndromes, including focal epilepsy. Describing the genetic architecture of common syndromes promises to facilitate the diagnostic process as well as aid in the identification of patients who stand to benefit from genetic testing, but most studies to date have been limited to examining children or adults with intellectual disability. Our aim was to determine the yield of targeted sequencing of 5 established epilepsy genes (DEPDC5, LGI1, SCN1A, GRIN2A, and PCHD19) in an extensively phenotyped cohort of focal epilepsy patients with normal intellectual function or mild intellectual disability, as well as describe novel variants and determine the characteristics of variant carriers. PATIENTS AND METHODS Targeted panel sequencing was performed on 96 patients with a strong clinical suspicion of genetic focal epilepsy. Patients had previously gone through a comprehensive diagnostic epilepsy evaluation in The Neurology Clinic, University Clinical Center of Serbia. Variants of interest (VOI) were classified using the American College of Medical Genetics and the Association for Molecular Pathology criteria. RESULTS Six VOI in eight (8/96, 8.3%) patients were found in our cohort. Four likely pathogenic VOI were determined in six (6/96, 6.2%) patients, two DEPDC5 variants in two patients, one SCN1A variant in two patients and one PCDH19 variant in two patients. One variant of unknown significance (VUS) was found in GRIN2A in one (1/96, 1.0%) patient. Only one VOI in GRIN2A was classified as likely benign. No VOI were detected in LGI1. CONCLUSION Sequencing of only five known epilepsy genes yielded a diagnostic result in 6.2% of our cohort and revealed multiple novel variants. Further research is necessary for a better understanding of the genetic basis in common epilepsy syndromes in patients with normal intellectual function or mild intellectual disability.
Collapse
Affiliation(s)
- Maša Kovačević
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
| | | | | | - Milena Janković
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia
| | - Ivana Novaković
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Dragoslav Sokić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Aleksandar Ristić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Nikola Vojvodić
- Neurology Clinic, University Clinical Center of Serbia, Belgrade, Serbia; Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| |
Collapse
|
3
|
Nagy ZF, Sonkodi B, Pál M, Klivényi P, Széll M. Likely Pathogenic Variants of Cav1.3 and Nav1.1 Encoding Genes in Amyotrophic Lateral Sclerosis Could Elucidate the Dysregulated Pain Pathways. Biomedicines 2023; 11:biomedicines11030933. [PMID: 36979911 PMCID: PMC10046311 DOI: 10.3390/biomedicines11030933] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/12/2023] [Accepted: 03/14/2023] [Indexed: 03/22/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a lethal multisystem neurodegenerative disease associated with progressive loss of motor neurons, leading to death. Not only is the clinical picture of ALS heterogenous, but also the pain sensation due to different types of pain involvement. ALS used to be considered a painless disease, but research has been emerging and depicting a more complex pain representation in ALS. Pain has been detected even a couple years before the symptomatic stage of ALS, referring to primary pain associated with muscle denervation, although secondary pain due to nociceptive causes is also a part of the clinical picture. A new non-contact dying-back injury mechanism theory of ALS recently postulated that the irreversible intrafusal proprioceptive Piezo2 microinjury could be the primary damage, with underlying genetic and environmental risk factors. Moreover, this Piezo2 primary damage is also proposed to dysregulate the primary pain pathways in the spinal dorsal horn in ALS due to the lost imbalanced subthreshold Ca2+ currents, NMDA activation and lost L-type Ca2+ currents, leading to the lost activation of wide dynamic range neurons. Our investigation is the first to show that the likely pathogenic variants of the Cav1.3 encoding CACNA1D gene may play a role in ALS pathology and the associated dysregulation or loss of the pain sensation. Furthermore, our reanalysis also shows that the SCN1A gene might also contribute to the dysregulated pain sensation in ALS. Finally, the absence of pathogenic variants of Piezo2 points toward the new non-contact dying-back injury mechanism theory of ALS. However, molecular and genetic investigations are needed to identify the functionally diverse features of this proposed novel critical pathway.
Collapse
Affiliation(s)
- Zsófia Flóra Nagy
- Department of Medical Genetics, Albert Szent-Györgyi Medical School, University of Szeged, 6725 Szeged, Hungary
| | - Balázs Sonkodi
- Department of Health Sciences and Sport Medicine, Hungarian University of Sports Science, 1123 Budapest, Hungary
- Correspondence:
| | - Margit Pál
- Department of Medical Genetics, Albert Szent-Györgyi Medical School, University of Szeged, 6725 Szeged, Hungary
- ELKH-SZTE Functional Clinical Genetics Research Group, 6720 Szeged, Hungary
| | - Péter Klivényi
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, 6725 Szeged, Hungary
| | - Márta Széll
- Department of Medical Genetics, Albert Szent-Györgyi Medical School, University of Szeged, 6725 Szeged, Hungary
- ELKH-SZTE Functional Clinical Genetics Research Group, 6720 Szeged, Hungary
| |
Collapse
|
4
|
Fang Z, Xie L, Li X, Gui J, Yang X, Han Z, Luo H, Huang D, Chen H, Cheng L, Jiang L. Severe epilepsy phenotype with SCN1A missense variants located outside the sodium channel core region: Relationship between functional results and clinical phenotype. Seizure 2022; 101:109-116. [PMID: 35944423 DOI: 10.1016/j.seizure.2022.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/17/2022] [Accepted: 07/29/2022] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Most SCN1A missense variants located outside the sodium channel core region show a mild phenotype. However, there are exceptions, because of which it is challenging to determine the correlation between genotype and phenotype. In this study, we aimed to determine whether functional study could be used to determine disease severity in cases with such variants, and elucidate possible genotype-phenotype relationships. METHODS Forty-seven patients with SCN1A missense variants were recruited, and one with a Dravet syndrome phenotype with an SCN1A missense variant (c.3811T>C/ p.W1271R) located outside the core region was screened with electrophysiological tests. We also reviewed functional SCN1A studies on patients with inconsistent phenotypes and genotypes, and studied the relationship between electrophysiological measurements and clinical phenotype. RESULTS Patch clamp experiments showed that the W1271R variant caused significantly reduced sodium current, decreased channel voltage sensitivity, loss of channel availability, and prolonged recovery time from inactivation compared with wild type (WT), which ultimately caused a change in loss of function (LOF). Twelve cases of severe SCN1A-related epilepsy with missense variants located outside the channel core region were also included from the functional studies. Nine patients with missense SCN1A variants showed complete (3/9) or partial (6/9) physiological LOF. Two missense SCN1A variants caused physiological gain-and-loss of function (G-LOF), and one caused decreased excitability (DE). CONCLUSIONS Not all missense variants located outside the core region cause a mild phenotype. Although current functional studies in heterologous expression systems do not accurately reflect disease severity caused by SCN1A missense variants, they could be an effective model for generation of data to study the initial effects of SCN1A missense variants.
Collapse
Affiliation(s)
- Zhixu Fang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Lingling Xie
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Xue Li
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Jianxiong Gui
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Xiaoyue Yang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Ziyao Han
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Hanyu Luo
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Dishu Huang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Hengsheng Chen
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Li Cheng
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Li Jiang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China.
| |
Collapse
|
5
|
Genetic therapeutic advancements for Dravet Syndrome. Epilepsy Behav 2022; 132:108741. [PMID: 35653814 DOI: 10.1016/j.yebeh.2022.108741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/03/2022]
Abstract
Dravet Syndrome is a genetic epileptic syndrome characterized by severe and intractable seizures associated with cognitive, motor, and behavioral impairments. The disease is also linked with increased mortality mainly due to sudden unexpected death in epilepsy. Over 80% of cases are due to a de novo mutation in one allele of the SCN1A gene, which encodes the α-subunit of the voltage-gated ion channel NaV1.1. Dravet Syndrome is usually refractory to antiepileptic drugs, which only alleviate seizures to a small extent. Viral, non-viral genetic therapy, and gene editing tools are rapidly enhancing and providing new platforms for more effective, alternative medicinal treatments for Dravet syndrome. These strategies include gene supplementation, CRISPR-mediated transcriptional activation, and the use of antisense oligonucleotides. In this review, we summarize our current knowledge of novel genetic therapies that are currently under development for Dravet syndrome.
Collapse
|
6
|
Shapiro L, Escayg A, Wong JC. Cannabidiol Increases Seizure Resistance and Improves Behavior in an Scn8a Mouse Model. Front Pharmacol 2022; 13:815950. [PMID: 35153788 PMCID: PMC8826257 DOI: 10.3389/fphar.2022.815950] [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: 11/16/2021] [Accepted: 01/04/2022] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated sodium channel genes are an important family of human epilepsy genes. De novo missense mutations in SCN8A (encoding Nav1.6) are associated with a spectrum of clinical presentation, including multiple seizure types, movement disorders, intellectual disability, and behavioral abnormalities such as autism. Patients with SCN8A mutations are often treated with multiple antiepileptic drugs, the most common being sodium channel blockers. Cannabidiol (CBD) has been included as a component of treatment regimens for some SCN8A patients; however, to date, there are no clinical trials that have evaluated the therapeutic potential of CBD in patients with SCN8A mutations. In the current manuscript, we demonstrated a dose-dependent increase in seizure resistance following CBD treatment in mice expressing the human SCN8A mutation R1620L (RL/+). We also found that CBD treatment improved social behavior and reduced hyperactivity in the RL/+ mutants. Our findings suggest that CBD may be beneficial in patients with SCN8A-associated disease.
Collapse
Affiliation(s)
- Lindsey Shapiro
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| | - Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, United States
| |
Collapse
|
7
|
McGinn RJ, Von Stein EL, Summers Stromberg JE, Li Y. Precision medicine in epilepsy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 190:147-188. [DOI: 10.1016/bs.pmbts.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Wu X, Hong L. Calmodulin Interactions with Voltage-Gated Sodium Channels. Int J Mol Sci 2021; 22:ijms22189798. [PMID: 34575961 PMCID: PMC8472079 DOI: 10.3390/ijms22189798] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 02/06/2023] Open
Abstract
Calmodulin (CaM) is a small protein that acts as a ubiquitous signal transducer and regulates neuronal plasticity, muscle contraction, and immune response. It interacts with ion channels and plays regulatory roles in cellular electrophysiology. CaM modulates the voltage-gated sodium channel gating process, alters sodium current density, and regulates sodium channel protein trafficking and expression. Many mutations in the CaM-binding IQ domain give rise to diseases including epilepsy, autism, and arrhythmias by interfering with CaM interaction with the channel. In the present review, we discuss CaM interactions with the voltage-gated sodium channel and modulators involved in CaM regulation, as well as summarize CaM-binding IQ domain mutations associated with human diseases in the voltage-gated sodium channel family.
Collapse
|
10
|
Breu M, Häfele C, Trimmel-Schwahofer P, Schmidt WM, Laconne F, Vodopiutz J, Male C, Dressler A. The relation of etiology based on the 2017 ILAE classification to the effectiveness of the ketogenic diet in drug-resistant epilepsy in childhood. Epilepsia 2021; 62:2814-2825. [PMID: 34453316 PMCID: PMC9290115 DOI: 10.1111/epi.17052] [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: 05/03/2021] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 11/29/2022]
Abstract
Objective To investigate the effectiveness and safety of the ketogenic diet (KD) in drug‐resistant epilepsy in childhood in relation to the new 2017 International League Against Epilepsy (ILAE) classification of etiology. Methods A consecutive cohort of patients treated with the KD were categorized according to the ILAE classification into known (structural, genetic, metabolic, infectious, and immune‐mediated) and unknown etiology. Primary outcome was the frequency of patients achieving seizure freedom with the KD at 3 months, secondary outcomes were seizure reduction >50% at 3 months, and both seizure freedom and seizure reduction >50% at 6, 12 months, and at last follow‐up (LFU), and adverse effects. Outcomes were compared between etiology groups. Results Etiology was known in 70% (129/183). Outcomes did not differ at 3 months (known vs unknown: seizure freedom 28% vs 33%, seizure reduction 62 vs 67%), but seizure freedom was significantly less frequent in known etiology at 6 months (26% vs 43%) and beyond (22% vs 37%). Logistic regression identified duration of epilepsy, number of previous antiseizure medications (ASMs), and age‐appropriate psychomotor development as positive determinants of outcome. Among individual etiology groups, the effectiveness of KD was relatively best for genetic (33% at LFU) and poorest for metabolic etiology (8% at LFU). The small number of patients with infectious and immune‐mediated etiology requires larger numbers in each etiology group to corroborate our results. No differences in type and frequency of adverse effects (in 71%) between etiology groups were observed, requiring medical intervention in 21%. Significance The KD was most effective in genetic and unknown etiology, many unknowns probably represent yet unidentified genetic causes. We recommend consequent diagnostic and genetic work‐up to identify etiologies that respond best to the KD. The KD should be offered early to infants with genetic epilepsy before deterioration of epileptic symptoms and of psychomotor development.
Collapse
Affiliation(s)
- Markus Breu
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Chiara Häfele
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Petra Trimmel-Schwahofer
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University Vienna, Vienna, Austria
| | - Franco Laconne
- Institute for Medical Genetics, Medical University Vienna, Vienna, Austria
| | - Julia Vodopiutz
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Christoph Male
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Anastasia Dressler
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| |
Collapse
|
11
|
Pernici CD, Mensah JA, Dahle EJ, Johnson KJ, Handy L, Buxton L, Smith MD, West PJ, Metcalf CS, Wilcox KS. Development of an antiseizure drug screening platform for Dravet syndrome at the NINDS contract site for the Epilepsy Therapy Screening Program. Epilepsia 2021; 62:1665-1676. [PMID: 34002394 PMCID: PMC8360068 DOI: 10.1111/epi.16925] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Dravet syndrome (DS) is a rare but catastrophic genetic epilepsy, with 80% of patients carrying a mutation in the SCN1A gene. Currently, no antiseizure drug (ASD) exists that adequately controls seizures. In the clinic, individuals with DS often present first with a febrile seizure and, subsequently, generalized tonic-clonic seizures that can continue throughout life. To facilitate the development of ASDs for DS, the contract site of the National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP) has evaluated a mouse model of DS using the conditional knock-in Scn1aA1783V/WT mouse. METHODS Survival rates and temperature thresholds for Scn1aA1783V/WT were determined. Prototype ASDs were administered via intraperitoneal injections at the time-to-peak effect, which was previously determined, prior to the induction of hyperthermia-induced seizures. ASDs were considered effective if they significantly increased the temperature at which Scn1aA1783V/WT mice had seizures. RESULTS Approximately 50% of Scn1aA1783V/WT survive to adulthood and all have hyperthermia-induced seizures. The results suggest that hyperthermia-induced seizures in this model of DS are highly refractory to a battery of ASDs. Exceptions were clobazam, tiagabine, levetiracetam, and the combination of clobazam and valproic acid with add-on stiripentol, which elevated seizure thresholds. SIGNIFICANCE Overall, the data demonstrate that the proposed model for DS is suitable for screening novel compounds for the ability to block hyperthermia-induced seizures and that heterozygous mice can be evaluated repeatedly over the course of several weeks, allowing for higher throughput screening.
Collapse
Affiliation(s)
- Chelsea D. Pernici
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Jeffrey A. Mensah
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - E. Jill Dahle
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Kristina J. Johnson
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Laura Handy
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
| | - Lauren Buxton
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Misty D. Smith
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Peter J. West
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Cameron S. Metcalf
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| | - Karen S. Wilcox
- Epilepsy Therapy Screening Program (ETSP) Contract SiteUniversity of UtahSalt Lake CityUTUSA
- Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUTUSA
| |
Collapse
|
12
|
Takahashi K, Ohba T, Okamoto Y, Noguchi A, Okuda H, Kobayashi H, Harada KH, Koizumi A, Ono K, Takahashi T. E44Q mutation in Na V1.7 in a patient with infantile paroxysmal knee pain: electrophysiological analysis of voltage-dependent sodium current. Heliyon 2021; 7:e07396. [PMID: 34222704 PMCID: PMC8243507 DOI: 10.1016/j.heliyon.2021.e07396] [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: 12/24/2020] [Revised: 01/21/2021] [Accepted: 06/21/2021] [Indexed: 10/31/2022] Open
Abstract
Gain-of-function mutations in voltage-gated sodium channels (NaV1.7, NaV1.8, and NaV1.9) are known causes of inherited pain disorders. Identification and functional assessment of new NaV1.7 mutations could help elucidate the phenotypic spectrum of NaV1.7 channelopathies. We identified a novel NaV1.7 mutation (E44Q in exon 2) that substitutes a glutamic acid residue for glutamine in the cytoplasmic N-terminus of NaV1.7 in a patient with paroxysmal pain attacks during childhood and his family who experienced similar pain episodes. To study the sodium channel's function, we performed electrophysiological recordings. Voltage-clamp recordings revealed that the mutation increased the amplitude of the non-inactivating component of the sodium current, which might facilitate channel opening. These data demonstrate that E44Q is a gain-of-function mutation in NaV1.7, which is consistent with our patient's pain phenotype.
Collapse
Affiliation(s)
- Kiichi Takahashi
- Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| | - Takayoshi Ohba
- Department of Cell Physiology, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| | - Yosuke Okamoto
- Department of Cell Physiology, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| | - Atsuko Noguchi
- Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| | - Hiroko Okuda
- Department of Pain Pharmacogenetics, Kyoto University Graduate School of Medicine, Yoshida Konoe, Sakyo, Kyoto, 606-8501, Japan
| | - Hatasu Kobayashi
- Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan
| | - Kouji H Harada
- Department of Health and Environmental Sciences, Kyoto University Graduate School of Medicine, Yoshida Konoe, Sakyo, Kyoto, 606-8501, Japan
| | - Akio Koizumi
- Institute of Public Health and Welfare Research, 18-13, Uzumasa Tanamori, Ukyo, Kyoto, 616-8141, Japan
| | - Kyoichi Ono
- Department of Cell Physiology, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| | - Tsutomu Takahashi
- Department of Pediatrics, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, Japan
| |
Collapse
|
13
|
Miljanovic N, Hauck SM, van Dijk RM, Di Liberto V, Rezaei A, Potschka H. Proteomic signature of the Dravet syndrome in the genetic Scn1a-A1783V mouse model. Neurobiol Dis 2021; 157:105423. [PMID: 34144125 DOI: 10.1016/j.nbd.2021.105423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 05/14/2021] [Accepted: 06/08/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Dravet syndrome is a rare, severe pediatric epileptic encephalopathy associated with intellectual and motor disabilities. Proteomic profiling in a mouse model of Dravet syndrome can provide information about the molecular consequences of the genetic deficiency and about pathophysiological mechanisms developing during the disease course. METHODS A knock-in mouse model of Dravet syndrome with Scn1a haploinsufficiency was used for whole proteome, seizure, and behavioral analysis. Hippocampal tissue was dissected from two- (prior to epilepsy manifestation) and four- (following epilepsy manifestation) week-old male mice and analyzed using LC-MS/MS with label-free quantification. Proteomic data sets were subjected to bioinformatic analysis including pathway enrichment analysis. The differential expression of selected proteins was confirmed by immunohistochemical staining. RESULTS The findings confirmed an increased susceptibility to hyperthermia-associated seizures, the development of spontaneous seizures, and behavioral alterations in the novel Scn1a-A1873V mouse model of Dravet syndrome. As expected, proteomic analysis demonstrated more pronounced alterations following epilepsy manifestation. In particular, proteins involved in neurotransmitter dynamics, receptor and ion channel function, synaptic plasticity, astrogliosis, neoangiogenesis, and nitric oxide signaling showed a pronounced regulation in Dravet mice. Pathway enrichment analysis identified several significantly regulated pathways at the later time point, with pathways linked to synaptic transmission and glutamatergic signaling dominating the list. CONCLUSION In conclusion, the whole proteome analysis in a mouse model of Dravet syndrome demonstrated complex molecular alterations in the hippocampus. Some of these alterations may have an impact on excitability or may serve a compensatory function, which, however, needs to be further confirmed by future investigations. The proteomic data indicate that, due to the molecular consequences of the genetic deficiency, the pathophysiological mechanisms may become more complex during the course of the disease. As a result, the management of Dravet syndrome may need to consider further molecular and cellular alterations. Ensuing functional follow-up studies, this data set may provide valuable guidance for the future development of novel therapeutic approaches.
Collapse
Affiliation(s)
- Nina Miljanovic
- Institute of Pharmacology, Toxicology & Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany; Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Germany
| | - R Maarten van Dijk
- Institute of Pharmacology, Toxicology & Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Valentina Di Liberto
- Institute of Pharmacology, Toxicology & Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Ali Rezaei
- Institute of Pharmacology, Toxicology & Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany; Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology & Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany.
| |
Collapse
|
14
|
Haigh JL, Adhikari A, Copping NA, Stradleigh T, Wade AA, Catta-Preta R, Su-Feher L, Zdilar I, Morse S, Fenton TA, Nguyen A, Quintero D, Agezew S, Sramek M, Kreun EJ, Carter J, Gompers A, Lambert JT, Canales CP, Pennacchio LA, Visel A, Dickel DE, Silverman JL, Nord AS. Deletion of a non-canonical regulatory sequence causes loss of Scn1a expression and epileptic phenotypes in mice. Genome Med 2021; 13:69. [PMID: 33910599 PMCID: PMC8080386 DOI: 10.1186/s13073-021-00884-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Genes with multiple co-active promoters appear common in brain, yet little is known about functional requirements for these potentially redundant genomic regulatory elements. SCN1A, which encodes the NaV1.1 sodium channel alpha subunit, is one such gene with two co-active promoters. Mutations in SCN1A are associated with epilepsy, including Dravet syndrome (DS). The majority of DS patients harbor coding mutations causing SCN1A haploinsufficiency; however, putative causal non-coding promoter mutations have been identified. METHODS To determine the functional role of one of these potentially redundant Scn1a promoters, we focused on the non-coding Scn1a 1b regulatory region, previously described as a non-canonical alternative transcriptional start site. We generated a transgenic mouse line with deletion of the extended evolutionarily conserved 1b non-coding interval and characterized changes in gene and protein expression, and assessed seizure activity and alterations in behavior. RESULTS Mice harboring a deletion of the 1b non-coding interval exhibited surprisingly severe reductions of Scn1a and NaV1.1 expression throughout the brain. This was accompanied by electroencephalographic and thermal-evoked seizures, and behavioral deficits. CONCLUSIONS This work contributes to functional dissection of the regulatory wiring of a major epilepsy risk gene, SCN1A. We identified the 1b region as a critical disease-relevant regulatory element and provide evidence that non-canonical and seemingly redundant promoters can have essential function.
Collapse
Affiliation(s)
- Jessica L Haigh
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Anna Adhikari
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Nycole A Copping
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Tyler Stradleigh
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - A Ayanna Wade
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Rinaldo Catta-Preta
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Linda Su-Feher
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Iva Zdilar
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Sarah Morse
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Timothy A Fenton
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Anh Nguyen
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Diana Quintero
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Samrawit Agezew
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Michael Sramek
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Ellie J Kreun
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Jasmine Carter
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Andrea Gompers
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Jason T Lambert
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Cesar P Canales
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Len A Pennacchio
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
| | - Axel Visel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
- School of Natural Sciences, University of California, Merced, CA, USA
| | - Diane E Dickel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
| | - Jill L Silverman
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA.
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA.
| | - Alex S Nord
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA.
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA.
| |
Collapse
|
15
|
Bothos E, Ntoumou E, Kelaidoni K, Roukas D, Drakoulis N, Papasavva M, Karakostis FA, Moulos P, Karakostis K. Clinical pharmacogenomics in action: design, assessment and implementation of a novel pharmacogenetic panel supporting drug selection for diseases of the central nervous system (CNS). J Transl Med 2021; 19:151. [PMID: 33858454 PMCID: PMC8048316 DOI: 10.1186/s12967-021-02816-3] [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: 01/12/2021] [Accepted: 04/02/2021] [Indexed: 12/18/2022] Open
Abstract
Background Pharmacogenomics describes the link between gene variations (polymorphisms) and drug responses. In view of the implementation of precision medicine in personalized healthcare, pharmacogenetic tests have recently been introduced in the clinical practice. However, the translational aspects of such tests have been limited due to the lack of robust population-based evidence. Materials In this paper we present a novel pharmacogenetic panel (iDNA Genomics-PGx–CNS or PGx–CNS), consisting of 24 single nucleotide polymorphisms (SNPs) on 13 genes involved in the signaling or/and the metabolism of 28 approved drugs currently administered to treat diseases of the Central Nervous System (CNS). We have tested the PGx–CNS panel on 501 patient-derived DNA samples from a southeastern European population and applied biostatistical analyses on the pharmacogenetic associations involving drug selection, dosing and the risk of adverse drug events (ADEs). Results Results reveal the occurrences of each SNP in the sample and a strong correlation with the European population. Nonlinear principal component analysis strongly indicates co-occurrences of certain variants. The metabolization efficiency (poor, intermediate, extensive, ultra-rapid) and the frequency of clinical useful pharmacogenetic, associations in the population (drug relevance), are also described, along with four exemplar clinical cases illustrating the strong potential of the PGx–CNS panel, as a companion diagnostic assay. It is noted that pharmacogenetic associations involving copy number variations (CNVs) or the HLA gene were not included in this analysis. Conclusions Overall, results illustrate that the PGx–CNS panel is a valuable tool supporting therapeutic medical decisions, urging its broad clinical implementation. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-021-02816-3.
Collapse
Affiliation(s)
- E Bothos
- HybridStat Predictive Analytics, Athens, Greece.,Institute of Communications and Computer Systems, National Technical University of Athens, Athens, Greece
| | - E Ntoumou
- iDNA Genomics Private Company, Evrota 25, Kifissia, 145 64, Athens, Greece
| | - K Kelaidoni
- iDNA Genomics Private Company, Evrota 25, Kifissia, 145 64, Athens, Greece
| | - D Roukas
- Department of Psychiatry, Army Hospital (NIMTS), 417 Veterans, 115 21, Athens, Greece
| | - N Drakoulis
- Research Group of Clinical Pharmacology and Pharmacogenomics, Faculty of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece
| | - M Papasavva
- Research Group of Clinical Pharmacology and Pharmacogenomics, Faculty of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Panepistimiopolis, 15771, Zografou, Greece
| | - F A Karakostis
- Paleoanthropology, Senckenberg Centre for Human Evolution and Palaeoenvironment, Department of Geosciences, University of Tübingen, Tübingen, Germany
| | - P Moulos
- HybridStat Predictive Analytics, Athens, Greece.,Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center 'Alexander Fleming', 34 Fleming str, 16672, Athens, Vari, Greece
| | - K Karakostis
- iDNA Genomics Private Company, Evrota 25, Kifissia, 145 64, Athens, Greece.
| |
Collapse
|
16
|
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.
Collapse
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
| | | |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Satta V, Alonso C, Díez P, Martín-Suárez S, Rubio M, Encinas JM, Fernández-Ruiz J, Sagredo O. Neuropathological Characterization of a Dravet Syndrome Knock-In Mouse Model Useful for Investigating Cannabinoid Treatments. Front Mol Neurosci 2021; 13:602801. [PMID: 33584198 PMCID: PMC7879984 DOI: 10.3389/fnmol.2020.602801] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/30/2020] [Indexed: 12/24/2022] Open
Abstract
Dravet syndrome (DS) is an epileptic syndrome caused by mutations in the Scn1a gene encoding the α1 subunit of the sodium channel Nav1.1, which is associated with febrile seizures that progress to severe tonic-clonic seizures and associated comorbidities. Treatment with cannabidiol has been approved to reduce seizures in DS, but it may also be active against these comorbidities. The aim of this study was to validate a new mouse model of DS having lower mortality than previous models, which may serve to further evaluate therapies for the long-term comorbidities. This new model consists of heterozygous conditional knock-in mice carrying a missense mutation (A1783V) in Scn1a gene expressed exclusively in neurons of the CNS (Syn-Cre/Scn1aWT/A1783V). These mice have been used here to determine the extent and persistence of the behavioral deterioration in different postnatal days (PND), as well as to investigate the alterations that the disease produces in the endocannabinoid system and the contribution of inflammatory events and impaired neurogenesis in the pathology. Syn-Cre/Scn1aWT/A1783V mice showed a strong reduction in hindlimb grasp reflex at PND10, whereas at PND25, they presented spontaneous convulsions and a greater susceptibility to pentylenetetrazole-induced seizures, marked hyperactivity, deficient spatial working memory, lower levels of anxiety, and altered social interaction behavior. These differences disappeared at PND40 and PND60, except the changes in social interaction and anxiety. The analysis of CNS structures associated with these behavioral alterations revealed an elevated glial reactivity in the prefrontal cortex and the dentate gyrus. This was associated in the dentate gyrus with a greater cell proliferation detected with Ki67 immunostaining, whereas double-labeling analyses identified that proliferating cells were GFAP-positive suggesting failed neurogenesis but astrocyte proliferation. The analysis of the endocannabinoid system of Syn-Cre/Scn1aWT/A1783V mice confirmed reductions in CB1 receptors and MAGL and FAAH enzymes, mainly in the cerebellum but also in other areas, whereas CB2 receptors became upregulated in the hippocampus. In conclusion, Syn-Cre/Scn1aWT/A1783V mice showed seizuring susceptibility and several comorbidities (hyperactivity, memory impairment, less anxiety, and altered social behavior), which exhibited a pattern of age expression similar to DS patients. Syn-Cre/Scn1aWT/A1783V mice also exhibited greater glial reactivity and a reactive response in the neurogenic niche, and regional changes in the status of the endocannabinoid signaling, events that could contribute in behavioral impairment.
Collapse
Affiliation(s)
- Valentina Satta
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Cristina Alonso
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Paula Díez
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Soraya Martín-Suárez
- The NSC Cell and Neurogenesis Laboratory, Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Marta Rubio
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Juan M Encinas
- The NSC Cell and Neurogenesis Laboratory, Achucarro Basque Center for Neuroscience, Leioa, Spain.,The University of the Basque Country (UPV/EHU), Leioa, Spain.,IKERBASQUE, The Basque Foundation for Science, Bilbao, Spain
| | - Javier Fernández-Ruiz
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Onintza Sagredo
- Instituto Universitario de Investigación en Neuroquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| |
Collapse
|
19
|
Wong JC, Shapiro L, Thelin JT, Heaton EC, Zaman RU, D'Souza MJ, Murnane KS, Escayg A. Nanoparticle encapsulated oxytocin increases resistance to induced seizures and restores social behavior in Scn1a-derived epilepsy. Neurobiol Dis 2020; 147:105147. [PMID: 33189882 DOI: 10.1016/j.nbd.2020.105147] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/14/2020] [Accepted: 10/23/2020] [Indexed: 02/06/2023] Open
Abstract
Oxytocin (OT) has broad effects in the brain and plays an important role in cognitive, social, and neuroendocrine function. OT has also been identified as potentially therapeutic in neuropsychiatric disorders such as autism and depression, which are often comorbid with epilepsy, raising the possibility that it might confer protection against the behavioral and seizure phenotypes in epilepsy. Dravet syndrome (DS) is an early-life encephalopathy associated with prolonged and recurrent early-life febrile seizures (FSs), treatment-resistant afebrile epilepsy, and cognitive and behavioral deficits. De novo loss-of-function mutations in the voltage-gated sodium channel SCN1A are the main cause of DS, while genetic epilepsy with febrile seizures plus (GEFS+), also characterized by early-life FSs and afebrile epilepsy, is typically caused by inherited mutations that alter the biophysical properties of SCN1A. Despite the wide range of available antiepileptic drugs, many patients with SCN1A mutations do not achieve adequate seizure control or the amelioration of associated behavioral comorbidities. In the current study, we demonstrate that nanoparticle encapsulation of OT conferred robust and sustained protection against induced seizures and restored more normal social behavior in a mouse model of Scn1a-derived epilepsy. These results demonstrate the ability of a nanotechnology formulation to significantly enhance the efficacy of OT. This approach will provide a general strategy to enhance the therapeutic potential of additional neuropeptides in epilepsy and other neurological disorders.
Collapse
Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, United States of America.
| | - Lindsey Shapiro
- Department of Human Genetics, Emory University, Atlanta, GA, United States of America
| | - Jacquelyn T Thelin
- Department of Human Genetics, Emory University, Atlanta, GA, United States of America
| | - Elizabeth C Heaton
- Department of Human Genetics, Emory University, Atlanta, GA, United States of America
| | - Rokon U Zaman
- Department of Pharmaceutical Sciences, Mercer University, Atlanta, GA, United States of America
| | - Martin J D'Souza
- Department of Pharmaceutical Sciences, Mercer University, Atlanta, GA, United States of America
| | - Kevin S Murnane
- Department of Pharmaceutical Sciences, Mercer University, Atlanta, GA, United States of America
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, United States of America
| |
Collapse
|
20
|
CRISPR/dCas9-based Scn1a gene activation in inhibitory neurons ameliorates epileptic and behavioral phenotypes of Dravet syndrome model mice. Neurobiol Dis 2020; 141:104954. [DOI: 10.1016/j.nbd.2020.104954] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/12/2023] Open
|
21
|
Kluckova D, Kolnikova M, Lacinova L, Jurkovicova-Tarabova B, Foltan T, Demko V, Kadasi L, Ficek A, Soltysova A. A Study among the Genotype, Functional Alternations, and Phenotype of 9 SCN1A Mutations in Epilepsy Patients. Sci Rep 2020; 10:10288. [PMID: 32581296 PMCID: PMC7314844 DOI: 10.1038/s41598-020-67215-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/26/2020] [Indexed: 12/14/2022] Open
Abstract
Mutations in the voltage-gated sodium channel Nav1.1 (SCN1A) are linked to various epileptic phenotypes with different severities, however, the consequences of newly identified SCN1A variants on patient phenotype is uncertain so far. The functional impact of nine SCN1A variants, including five novel variants identified in this study, was studied using whole-cell patch-clamp recordings measurement of mutant Nav1.1 channels expressed in HEK293T mammalian cells. E78X, W384X, E1587K, and R1596C channels failed to produce measurable sodium currents, indicating complete loss of channel function. E788K and M909K variants resulted in partial loss of function by exhibiting reduced current density, depolarizing shifts of the activation and hyperpolarizing shifts of the inactivation curves, and slower recovery from inactivation. Hyperpolarizing shifts of the activation and inactivation curves were observed in D249E channels along with slower recovery from inactivation. Slower recovery from inactivation was observed in E78D and T1934I with reduced current density in T1934I channels. Various functional effects were observed with the lack of sodium current being mainly associated with severe phenotypes and milder symptoms with less damaging channel alteration. In vitro functional analysis is thus fundamental for elucidation of the molecular mechanisms of epilepsy, to guide patients' treatment, and finally indicate misdiagnosis of SCN1A related epilepsies.
Collapse
Affiliation(s)
- Daniela Kluckova
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Miriam Kolnikova
- Department of Pediatric Neurology, Comenius University Medical School and National Institute of Children's Diseases, Limbova 1, Bratislava, 833 40, Slovakia
| | - Lubica Lacinova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravská cesta 9, Bratislava, 840 05, Slovakia
| | - Bohumila Jurkovicova-Tarabova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravská cesta 9, Bratislava, 840 05, Slovakia
| | - Tomas Foltan
- Department of Pediatric Neurology, Comenius University Medical School and National Institute of Children's Diseases, Limbova 1, Bratislava, 833 40, Slovakia
| | - Viktor Demko
- Department of Plant Physiology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Ludevit Kadasi
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
- Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05, Bratislava, Slovakia
| | - Andrej Ficek
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Andrea Soltysova
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia.
- Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05, Bratislava, Slovakia.
| |
Collapse
|
22
|
van Loo KMJ, Becker AJ. Transcriptional Regulation of Channelopathies in Genetic and Acquired Epilepsies. Front Cell Neurosci 2020; 13:587. [PMID: 31992970 PMCID: PMC6971179 DOI: 10.3389/fncel.2019.00587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/23/2019] [Indexed: 01/03/2023] Open
Abstract
Epilepsy is a common neurological disorder characterized by recurrent uncontrolled seizures and has an idiopathic “genetic” etiology or a symptomatic “acquired” component. Genetic studies have revealed that many epilepsy susceptibility genes encode ion channels, including voltage-gated sodium, potassium and calcium channels. The high prevalence of ion channels in epilepsy pathogenesis led to the causative concept of “ion channelopathies,” which can be elicited by specific mutations in the coding or promoter regions of genes in genetic epilepsies. Intriguingly, expression changes of the same ion channel genes by augmentation of specific transcription factors (TFs) early after an insult can underlie acquired epilepsies. In this study, we review how the transcriptional regulation of ion channels in both genetic and acquired epilepsies can be controlled, and compare these epilepsy “ion channelopathies” with other neurodevelopmental disorders.
Collapse
Affiliation(s)
- Karen M J van Loo
- Department of Neuropathology, Section for Translational Epilepsy Research, University of Bonn Medical Center, Bonn, Germany
| | - Albert J Becker
- Department of Neuropathology, Section for Translational Epilepsy Research, University of Bonn Medical Center, Bonn, Germany
| |
Collapse
|
23
|
Du J, Simmons S, Brunklaus A, Adiconis X, Hession CC, Fu Z, Li Y, Shema R, Møller RS, Barak B, Feng G, Meisler M, Sanders S, Lerche H, Campbell AJ, McCarroll S, Levin JZ, Lal D. Differential excitatory vs inhibitory SCN expression at single cell level regulates brain sodium channel function in neurodevelopmental disorders. Eur J Paediatr Neurol 2020; 24:129-133. [PMID: 31928904 DOI: 10.1016/j.ejpn.2019.12.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 12/18/2019] [Indexed: 10/25/2022]
Abstract
The four voltage-gated sodium channels SCN1/2/3/8A have been associated with heterogeneous types of developmental disorders, each presenting with disease specific temporal and cell type specific gene expression. Using single-cell RNA sequencing transcriptomic data from humans and mice, we observe that SCN1A is predominantly expressed in inhibitory neurons. In contrast, SCN2/3/8A are profoundly expressed in excitatory neurons with SCN2/3A starting prenatally, followed by SCN1/8A neonatally. In contrast to previous observations from low resolution RNA screens, we observe that all four genes are expressed in both excitatory and inhibitory neurons, however, exhibit differential expression strength. These findings provide molecular evidence, at single-cell resolution, to support the hypothesis that the excitatory/inhibitory (E/I) neuronal expression ratios of sodium channels are important regulatory mechanisms underlying brain homeostasis and neurological diseases. Modulating the E/I expression balance within cell types of sodium channels could serve as a potential strategy to develop targeted treatment for NaV-associated neuronal developmental disorders.
Collapse
Affiliation(s)
- Juanjiangmeng Du
- Cologne Center for Genomics, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Sean Simmons
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Analytic and Translational Genetics Unit, Massachusetts General Hospital, Cambridge, MA, USA
| | - Andreas Brunklaus
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK.
| | - Xian Adiconis
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Cynthia C Hession
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Zhanyan Fu
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Yinqing Li
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Reut Shema
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark; Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Boaz Barak
- McGovern Institute for Brain Research and Department of Brain & Cognitive Sciences, MIT, Cambridge, MA, USA
| | - Guoping Feng
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; McGovern Institute for Brain Research and Department of Brain & Cognitive Sciences, MIT, Cambridge, MA, USA
| | - Miriam Meisler
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Stephan Sanders
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Arthur J Campbell
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Steven McCarroll
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Joshua Z Levin
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, University Hospital Cologne, Cologne, Germany; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Analytic and Translational Genetics Unit, Massachusetts General Hospital, Cambridge, MA, USA; Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA; Genomic Medicine Institute, Lerner Research Institute Cleveland Clinic, Cleveland, OH, USA.
| |
Collapse
|
24
|
Ricobaraza A, Mora-Jimenez L, Puerta E, Sanchez-Carpintero R, Mingorance A, Artieda J, Nicolas MJ, Besne G, Bunuales M, Gonzalez-Aparicio M, Sola-Sevilla N, Valencia M, Hernandez-Alcoceba R. Epilepsy and neuropsychiatric comorbidities in mice carrying a recurrent Dravet syndrome SCN1A missense mutation. Sci Rep 2019; 9:14172. [PMID: 31578435 PMCID: PMC6775062 DOI: 10.1038/s41598-019-50627-w] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/11/2019] [Indexed: 11/30/2022] Open
Abstract
Dravet Syndrome (DS) is an encephalopathy with epilepsy associated with multiple neuropsychiatric comorbidities. In up to 90% of cases, it is caused by functional happloinsufficiency of the SCN1A gene, which encodes the alpha subunit of a voltage-dependent sodium channel (Nav1.1). Preclinical development of new targeted therapies requires accessible animal models which recapitulate the disease at the genetic and clinical levels. Here we describe that a C57BL/6 J knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V) presents a full spectrum of DS manifestations. This includes 70% mortality rate during the first 8 weeks of age, reduced threshold for heat-induced seizures (4.7 °C lower compared with control littermates), cognitive impairment, motor disturbances, anxiety, hyperactive behavior and defects in the interaction with the environment. In contrast, sociability was relatively preserved. Electrophysiological studies showed spontaneous interictal epileptiform discharges, which increased in a temperature-dependent manner. Seizures were multifocal, with different origins within and across individuals. They showed intra/inter-hemispheric propagation and often resulted in generalized tonic-clonic seizures. 18F-labelled flourodeoxyglucose positron emission tomography (FDG-PET) revealed a global increase in glucose uptake in the brain of Scn1aWT/A1783V mice. We conclude that the Scn1aWT/A1783V model is a robust research platform for the evaluation of new therapies against DS.
Collapse
Affiliation(s)
- Ana Ricobaraza
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain.
| | - Lucia Mora-Jimenez
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Elena Puerta
- University of Navarra, Department of Pharmacology and Toxicology, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | | | - Julio Artieda
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Neurophysiology Service, Clinica Universidad de Navarra, University of Navarra, Pamplona, Spain
| | - Maria Jesus Nicolas
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Guillermo Besne
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Maria Bunuales
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Noemi Sola-Sevilla
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Miguel Valencia
- University of Navarra, Neuroscience Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- University of Navarra, Gene Therapy Program CIMA, IdiSNA, Navarra institute for health research, Pamplona, Spain
| |
Collapse
|
25
|
Wong JC, Thelin JT, Escayg A. Donepezil increases resistance to induced seizures in a mouse model of Dravet syndrome. Ann Clin Transl Neurol 2019; 6:1566-1571. [PMID: 31402621 PMCID: PMC6689688 DOI: 10.1002/acn3.50848] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 01/11/2023] Open
Abstract
De novo loss-of-function mutations in SCN1A are the main cause of Dravet syndrome, a catastrophic encephalopathy characterized by recurrent early-life febrile seizures, a number of other afebrile seizure types that are often refractory to treatment, and behavioral abnormalities including social deficits, motor dysfunction, and cognitive impairment. We previously demonstrated that the reversible acetylcholinesterase inhibitor, Huperzine A, increases seizure resistance in Scn1a mutants. In the present study, we evaluated the therapeutic potential of donepezil, a reversible acetylcholinesterase inhibitor approved by the Food and Drug Administration, in a mouse model of Dravet syndrome (Scn1a+/- ). We found that donepezil conferred robust protection against induced seizures in Scn1a+/- mutants.
Collapse
Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, GA, 30322
| | | | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, 30322
| |
Collapse
|
26
|
Kuo FS, Cleary CM, LoTurco JJ, Chen X, Mulkey DK. Disordered breathing in a mouse model of Dravet syndrome. eLife 2019; 8:e43387. [PMID: 31025941 PMCID: PMC6506208 DOI: 10.7554/elife.43387] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Dravet syndrome (DS) is a form of epilepsy with a high incidence of sudden unexpected death in epilepsy (SUDEP). Respiratory failure is a leading cause of SUDEP, and DS patients' frequently exhibit disordered breathing. Despite this, mechanisms underlying respiratory dysfunction in DS are unknown. We found that mice expressing a DS-associated Scn1a missense mutation (A1783V) conditionally in inhibitory neurons (Slc32a1cre/+::Scn1aA1783V fl/+; defined as Scn1aΔE26) exhibit spontaneous seizures, die prematurely and present a respiratory phenotype including hypoventilation, apnea, and a diminished ventilatory response to CO2. At the cellular level in the retrotrapezoid nucleus (RTN), we found inhibitory neurons expressing the Scn1a A1783V variant are less excitable, whereas glutamatergic chemosensitive RTN neurons, which are a key source of the CO2/H+-dependent drive to breathe, are hyper-excitable in slices from Scn1aΔE26 mice. These results show loss of Scn1a function can disrupt respiratory control at the cellular and whole animal levels.
Collapse
Affiliation(s)
- Fu-Shan Kuo
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Colin M Cleary
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Joseph J LoTurco
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Xinnian Chen
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| | - Daniel K Mulkey
- Department of Physiology and NeurobiologyUniversity of ConnecticutStorrsUnited States
| |
Collapse
|
27
|
Dhifallah S, Lancaster E, Merrill S, Leroudier N, Mantegazza M, Cestèle S. Gain of Function for the SCN1A/hNa v1.1-L1670W Mutation Responsible for Familial Hemiplegic Migraine. Front Mol Neurosci 2018; 11:232. [PMID: 30038559 PMCID: PMC6046441 DOI: 10.3389/fnmol.2018.00232] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/12/2018] [Indexed: 12/21/2022] Open
Abstract
The SCN1A gene encodes for the voltage-dependent Nav1.1 Na+ channel, an isoform mainly expressed in GABAergic neurons that is the target of hundreds of epileptogenic mutations. More recently, it has been shown that the SCN1A gene is also the target of mutations responsible for familial hemiplegic migraine (FHM-3), a rare autosomal dominant subtype of migraine with aura. Studies of these mutations indicate that they induce gain of function of the channel. Surprisingly, the mutation L1649Q responsible for pure FHM-3 showed a complete loss of function, but, when partially rescued it induced an overall gain of function because of modification of the gating properties of the mutant channel. Here, we report the characterization of the L1670W SCN1A mutation that has been previously identified in a Chinese family with pure FHM-3, and that we have identified also in a Caucasian American family with pure FHM-3. Notably, one patient in our family had severe neurological deterioration after brain radiation for cancer treatment. Functional analysis of L1670W reveals that the mutation is responsible for folding/trafficking defects and, when they are rescued by incubation at lower temperature or by expression in neurons, modifications of the gating properties lead to an overall gain of function. Therefore, L1670W is the second mutation responsible for FHM-3 with this pathophysiological mechanism, showing that it may be a recurrent mechanism for Nav1.1 hemiplegic migraine mutations.
Collapse
Affiliation(s)
- Sandra Dhifallah
- Université Côte d'Azur, CNRS UMR 7275, INSERM, IPMC, Valbonne, France
| | - Eric Lancaster
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Shana Merrill
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | | | | | - Sandrine Cestèle
- Université Côte d'Azur, CNRS UMR 7275, INSERM, IPMC, Valbonne, France
| |
Collapse
|
28
|
Johan Arief MF, Choo BKM, Yap JL, Kumari Y, Shaikh MF. A Systematic Review on Non-mammalian Models in Epilepsy Research. Front Pharmacol 2018; 9:655. [PMID: 29997502 PMCID: PMC6030834 DOI: 10.3389/fphar.2018.00655] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/31/2018] [Indexed: 02/03/2023] Open
Abstract
Epilepsy is a common neurological disorder characterized by seizures which result in distinctive neurobiological and behavioral impairments. Not much is known about the causes of epilepsy, making it difficult to devise an effective cure for epilepsy. Moreover, clinical studies involving epileptogenesis and ictogenesis cannot be conducted in humans due to ethical reasons. As a result, animal models play a crucial role in the replication of epileptic seizures. In recent years, non-mammalian models have been given a primary focus in epilepsy research due to their advantages. This systematic review aims to summarize the importance of non-mammalian models in epilepsy research, such as in the screening of anti-convulsive compounds. The reason for this review is to integrate currently available information on the use and importance of non-mammalian models in epilepsy testing to aid in the planning of future studies as well as to provide an overview of the current state of this field. A PRISMA model was utilized and PubMed, Springer, ScienceDirect and SCOPUS were searched for articles published between January 2007 and November 2017. Fifty-one articles were finalized based on the inclusion/exclusion criteria and were discussed in this review. The results of this review demonstrated the current use of non-mammalian models in epilepsy research and reaffirmed their potential to supplement the typical rodent models of epilepsy in future research into both epileptogenesis and the treatment of epilepsy. This review also revealed a preference for zebrafish and fruit flies in lieu of other non-mammalian models, which is a shortcoming that should be corrected in future studies due to the great potential of these underutilized animal models.
Collapse
Affiliation(s)
- Muhammad Faiz Johan Arief
- MBBS Young Scholars Program, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia.,Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Brandon Kar Meng Choo
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Jia Ling Yap
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia.,School of Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Yatinesh Kumari
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Mohd Farooq Shaikh
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| |
Collapse
|
29
|
Abstract
Fever-associated seizures or epilepsy (FASE) is primarily characterised by the occurrence of a seizure or epilepsy usually accompanied by a fever. It is common in infants and children, and generally includes febrile seizures (FS), febrile seizures plus (FS+), Dravet syndrome (DS) and genetic epilepsy with febrile seizures plus (GEFSP). The aetiology of FASE is unclear. Genetic factors may play crucial roles in FASE. Mutations in certain genes may cause a wide spectrum of phenotypical overlap ranging from isolated FS, FS+ and GEFSP to DS. Synapse-associated proteins, postsynaptic GABAA receptor, and sodium channels play important roles in synaptic transmission. Mutations in these genes may involve in the pathogenesis of FASE. Elevated temperature promotes synaptic vesicle (SV) recycling and enlarges SV size, which may enhance synaptic transmission and contribute to FASE occurring. This review provides an overview of the loci, genes, underlying pathogenesis and the fever-inducing effect of FASE. It may provide a more comprehensive understanding of pathogenesis and contribute to the clinical diagnosis of FASE.
Collapse
|
30
|
Mahdieh N, Mikaeeli S, Badv RS, Shirazi AG, Maleki M, Rabbani B. Pathogenic significance of SCN1A splicing variants causing Dravet syndrome: Improving diagnosis with targeted sequencing for variants by in silico analysis. Clin Neurol Neurosurg 2018; 166:80-90. [PMID: 29408779 DOI: 10.1016/j.clineuro.2018.01.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/21/2018] [Accepted: 01/27/2018] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Genetic heterogeneity of epileptic encephalopathy (IEE) mandates the use of gene-panels for diagnosis. PATIENTS AND METHODS A 36-gene-panel next-generation sequencing was applied for IEE in two Iranian families. A literature search was performed using keywords to identify reported splicing mutations in SCN1A and perform genotype-phenotype correlation. RESULTS An update of splicing mutations revealed 147 variants with 65.75% of them de novo mutations. Most of the familial variants were of parental origin. The structure of the protein was often affected in the linker and transmembrane segments. 92% of intronic variants were pathogenic. A de novo heterozygous mutation was found in the first patient, but not in her sibling and parents. In the second family, a novel de novo heterozygous mutation was found at position c.1210insT leading to a truncated protein. CONCLUSION Gene-panel sequencing is helpful for reducing the time and cost, guiding early treatment, and estimating the recurrence risks. The importance of characterization of intronic variants was noticed; though bioinformatics analysis of novel intronic variants should be of concern for rapid reporting the pathogenic effect of variants.
Collapse
Affiliation(s)
- Nejat Mahdieh
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Sepideh Mikaeeli
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Azadeh Gharehzadeh Shirazi
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Majid Maleki
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
31
|
Wong JC, Makinson CD, Lamar T, Cheng Q, Wingard JC, Terwilliger EF, Escayg A. Selective targeting of Scn8a prevents seizure development in a mouse model of mesial temporal lobe epilepsy. Sci Rep 2018; 8:126. [PMID: 29317669 PMCID: PMC5760706 DOI: 10.1038/s41598-017-17786-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/30/2017] [Indexed: 11/08/2022] Open
Abstract
We previously found that genetic mutants with reduced expression or activity of Scn8a are resistant to induced seizures and that co-segregation of a mutant Scn8a allele can increase survival and seizure resistance of Scn1a mutant mice. In contrast, Scn8a expression is increased in the hippocampus following status epilepticus and amygdala kindling. These findings point to Scn8a as a promising therapeutic target for epilepsy and raise the possibility that aberrant overexpression of Scn8a in limbic structures may contribute to some epilepsies, including temporal lobe epilepsy. Using a small-hairpin-interfering RNA directed against the Scn8a gene, we selectively reduced Scn8a expression in the hippocampus of the intrahippocampal kainic acid (KA) mouse model of mesial temporal lobe epilepsy. We found that Scn8a knockdown prevented the development of spontaneous seizures in 9/10 mice, ameliorated KA-induced hyperactivity, and reduced reactive gliosis. These results support the potential of selectively targeting Scn8a for the treatment of refractory epilepsy.
Collapse
Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University, Atlanta, Georgia, 30322, USA
| | | | - Tyra Lamar
- Department of Human Genetics, Emory University, Atlanta, Georgia, 30322, USA
| | - Qi Cheng
- Department of Human Genetics, Emory University, Atlanta, Georgia, 30322, USA
| | - Jeffrey C Wingard
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Ernest F Terwilliger
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, Georgia, 30322, USA.
| |
Collapse
|
32
|
Panneman DM, Smeitink JA, Rodenburg RJ. Mining for mitochondrial mechanisms: Linking known syndromes to mitochondrial function. Clin Genet 2017; 93:943-951. [PMID: 28686290 DOI: 10.1111/cge.13094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/28/2022]
Abstract
Mitochondrial disorders (MDs) are caused by defects in 1 or multiple complexes of the oxidative phosphorylation (OXPHOS) machinery. MDs are associated with a broad range of clinical signs and symptoms, and have considerable clinical overlap with other neuromuscular syndromes. This overlap might be due to involvement of mitochondrial pathways in some of these non-mitochondrial syndromes. Here, we give an overview of around 25 non-mitochondrial syndromes, diagnosed in patients who were initially suspected to have a MD on the basis of clinical and biochemical parameters. In addition, we highlight the mitochondrial connections of 6 of these non-mitochondrial syndromes (eg, Rett syndrome and Dravet syndrome) diagnosed in multiple patients. Further research to unravel the interplay between these genes and mitochondria may help to increase knowledge on these syndromes. Additionally, it may open new avenues for research on pathways interacting with mitochondrial function in order to find new targets for therapeutics to treat MDs. The data presented in this review underline the importance of careful assessment of clinical, genetic, and biochemical data in all patients suspected of a neuromuscular syndrome, and highlights the importance of the role of clinical geneticists, physicians, and clinical biochemists in recognizing the possible mitochondrial connection of non-mitochondrial syndromes.
Collapse
Affiliation(s)
- D M Panneman
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - J A Smeitink
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - R J Rodenburg
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands
| |
Collapse
|
33
|
Mantegazza M, Cestèle S. Pathophysiological mechanisms of migraine and epilepsy: Similarities and differences. Neurosci Lett 2017; 667:92-102. [PMID: 29129678 DOI: 10.1016/j.neulet.2017.11.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/08/2017] [Accepted: 11/08/2017] [Indexed: 01/03/2023]
Abstract
Migraine and epilepsy are episodic disorders with distinct features, but they have some clinical and pathophysiological overlaps. We review here clinical overlaps between seizures and migraine attacks, activities of neuronal networks observed during seizures and migraine attacks, and molecular and cellular mechanisms of migraine identified in genetic forms, focusing on genetic variants identified in hemiplegic migraine and their functional effects. Epilepsy and migraine can be generated by dysfunctions of the same neuronal networks, but these dysfunctions can be disease-specific, even if pathogenic mutations target the same protein. Studies of rare monogenic forms have allowed the identification of some molecular/cellular dysfunctions that provide a window on pathological mechanisms: we have begun to disclose the tip of the iceberg.
Collapse
Affiliation(s)
- Massimo Mantegazza
- Université Côte d'Azur (UCA), 660 route des Lucioles, 06560 Valbonne, Sophia Antipolis, France; Institute of Molecular and Cellular Pharmacology (IPMC), CNRS UMR7275, 660 Route des Lucioles, 06560 Valbonne, Sophia Antipolis, France.
| | - Sandrine Cestèle
- Université Côte d'Azur (UCA), 660 route des Lucioles, 06560 Valbonne, Sophia Antipolis, France; Institute of Molecular and Cellular Pharmacology (IPMC), CNRS UMR7275, 660 Route des Lucioles, 06560 Valbonne, Sophia Antipolis, France
| |
Collapse
|
34
|
Lyu G, Han YL. [Research advances in hereditary epilepsy and precision drug therapy]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:1118-1123. [PMID: 29046212 PMCID: PMC7389281 DOI: 10.7499/j.issn.1008-8830.2017.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 05/27/2017] [Indexed: 06/07/2023]
Abstract
Epilepsy is a common nervous system disease. It has been found that the pathogenesis of epilepsy is associated mutations in various genes, including genes encoding voltage-dependent ion channel, genes encoding ligand-gated ion channel, and solute carrier family genes. Different types of epilepsy caused by different mutations have different responses to drugs, and therefore, diagnosis and medication guidance based on genes are new thoughts for developing therapies. With the application of next-generation sequencing technology, more and more genes will be determined, which helps to further study the pathogenic mechanism of mutant genes and provides a basis for precision drug therapy for epilepsy.
Collapse
Affiliation(s)
- Ge Lyu
- Department of Pediatrics, First Affiliated Hospital of Guangxi Medical University, Nanning 530000, China.
| | | |
Collapse
|
35
|
Testing Genes Implicated in the Novel Case of Familial Hemiplegic Migraine. BIONANOSCIENCE 2017. [DOI: 10.1007/s12668-016-0314-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
36
|
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.
Collapse
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
| |
Collapse
|
37
|
Somatosensory reflex seizures in a child with epilepsy related to novel SCN1A mutation. Childs Nerv Syst 2017; 33:677-680. [PMID: 27889818 DOI: 10.1007/s00381-016-3297-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 11/11/2016] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Mutations in SCN1A have been reported in patients with different types of epilepsy, including generalized epilepsy with febrile seizures plus, severe myoclonic epilepsy in infancy, malignant migrating partial seizures in infancy, and other infantile epileptic encephalopathies. CASE REPORT We report a case of a 10-month-old girl presented with reflex epileptic seizures provoked by somatosensory stimuli with a novel de novo mutation of SCN1A gene. She was observed to have seizures with eye deviation, unresponsiveness provoked by somatosensory stimuli of the face. Video-electroencephalography (EEG) revealed generalized spike-and-wave patterns. She experienced one or two focal clonic seizures per month over the 6 months while taking valproate and carbamazepine. At 22 months old, she was hospitalized with an episode of generalized tonic clonic febrile status epilepticus lasting for 45 min. Interictal sleep video-EEG showed sharp-and-slow wave discharges in the left occipital lobe with normal background activity. We found a de novo heterozygote mutation in SCN1A gene, c.1337A>C (p. Q422P). CONCLUSION To our knowledge, this mutation has not been previously described in the SCN1A gene and this is the first report of epilepsy related to SCN1A mutation as a presenting with reflex epilepsy of somatosensory stimuli. This case report contributes to an expanding clinical spectrum of patients with SCN1A mutations.
Collapse
|
38
|
Zhang D, Liu X, Deng X. Genetic basis of pediatric epilepsy syndromes. Exp Ther Med 2017; 13:2129-2133. [PMID: 28565819 PMCID: PMC5443213 DOI: 10.3892/etm.2017.4267] [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: 06/13/2016] [Accepted: 03/21/2017] [Indexed: 01/26/2023] Open
Abstract
Childhood epilepsy affects ~0.5-1% in the general population worldwide. Early-onset epileptic encephalopathies are considered to be severe neurological disorders, which lead to impaired motor, cognitive, and sensory development due to recurrence of seizures. Many of the observed epilepsy phenotypes are associated with specific chromosomal imbalances and thus display gene dosage effects, and also specific mutations of a variety of genes ranging from ion channels to transcription factors. High throughput sequencing technologies and whole exome sequencing have led to the recognition of several new candidate genes with a possible role in the pathogenesis of epileptic encephalopathies. The mutations causing channelopathies can be either a gain or a loss of ion channel function and contribute to the pathogenesis of epilepsy syndrome. Nearly 300 mutations of SCN1A gene coding for the Nav1.1 channel protein have been identified that contribute to the pathology of epilepsy. Besides Na, potassium and calcium channels are also implicated in epileptic encephalopathies. Therapeutic management of epileptic encephalopathies has been challenging as the majority of the medications are not efficient and often have many undesirable side effects. A better understanding of the molecular nature of epilepsy in an individual is important to design a personalized medication, considering the number of possible genetic mutations that can contribute to epileptic encephalopathies.
Collapse
Affiliation(s)
- Dongli Zhang
- Department of Neurology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Xiaoming Liu
- Department of Neurology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Xingqiang Deng
- Department of Neurology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| |
Collapse
|
39
|
Angelopoulou C, Veletza S, Heliopoulos I, Vadikolias K, Tripsianis G, Stathi C, Piperidou C. Association of SCN1A gene polymorphism with antiepileptic drug responsiveness in the population of Thrace, Greece. Arch Med Sci 2017; 13:138-147. [PMID: 28144265 PMCID: PMC5206360 DOI: 10.5114/aoms.2016.59737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/13/2015] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION The aim was to examine the influence of the SCN1A gene polymorphism IVS5-91 rs3812718 G>A on the response to antiepileptic drugs (AEDs) in monotherapy or polytherapy. MATERIAL AND METHODS Two hundred epilepsy patients and 200 healthy subjects were genotyped for SCN1A IVS5-91 rs3812718 G>A polymorphism using TaqMan assay. Patients were divided into drug-responsive and drug-resistant patients. The drug-responsive group was further studied, comparing monotherapy in maximum and minimum doses and monotherapy-responsive and -resistant groups. RESULTS There were no statistically significant differences in the allelic frequencies and genotype distributions between patients and controls (p = 0.178). The distribution of SCN1A IVS5-91 rs3812718 G>A genotypes was similar between drug-responsive and drug-resistant patients (p = 0.463). The differences in genotype distributions (A/A or A/G vs. G/G) between monotherapy-responsive and -resistant groups were statistically significant (p = 0.021). Within the monotherapy-responsive group, patients with the A/A or A/G genotype needed higher dose AEDs than patients with the G/G genotype (p = 0.032). The relative risk for generalized epilepsy due to A-containing genotypes was of marginal statistical significance when compared with the G/G genotype (p = 0.05). CONCLUSIONS Overall, our findings demonstrate an association of SCN1A IVS5-91 rs3812718 G>A polymorphism with AED responsiveness in monotherapy without evidence of an effect on drug-resistant epilepsy.
Collapse
Affiliation(s)
| | - Stavroula Veletza
- Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece
| | - Ioannis Heliopoulos
- Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece
| | | | - Grigorios Tripsianis
- Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece
| | - Chrysa Stathi
- Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece
| | | |
Collapse
|
40
|
Wong JC, Dutton SBB, Collins SD, Schachter S, Escayg A. Huperzine A Provides Robust and Sustained Protection against Induced Seizures in Scn1a Mutant Mice. Front Pharmacol 2016; 7:357. [PMID: 27799911 PMCID: PMC5065986 DOI: 10.3389/fphar.2016.00357] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 09/20/2016] [Indexed: 01/21/2023] Open
Abstract
De novo loss-of-function mutations in the voltage-gated sodium channel (VGSC) SCN1A (encoding Nav1.1) are the main cause of Dravet syndrome (DS), a catastrophic early-life encephalopathy associated with prolonged and recurrent early-life febrile seizures (FSs), refractory afebrile epilepsy, cognitive and behavioral deficits, and a 15–20% mortality rate. SCN1A mutations also lead to genetic epilepsy with febrile seizures plus (GEFS+), which is an inherited disorder characterized by early-life FSs and the development of a range of adult epilepsy subtypes. Current antiepileptic drugs often fail to protect against the severe seizures and behavioral and cognitive deficits found in patients with SCN1A mutations. To address the need for more efficacious treatments for SCN1A-derived epilepsies, we evaluated the therapeutic potential of Huperzine A, a naturally occurring reversible acetylcholinesterase inhibitor. In CF1 mice, Hup A (0.56 or 1 mg/kg) was found to confer protection against 6 Hz-, pentylenetetrazole (PTZ)-, and maximal electroshock (MES)-induced seizures. Robust protection against 6 Hz-, MES-, and hyperthermia-induced seizures was also achieved following Hup A administration in mouse models of DS (Scn1a+/−) and GEFS+ (Scn1aRH/+). Furthermore, Hup A-mediated seizure protection was sustained during 3 weeks of daily injections in Scn1aRH/+ mutants. Finally, we determined that muscarinic and GABAA receptors play a role in Hup A-mediated seizure protection. These findings indicate that Hup A might provide a novel therapeutic strategy for increasing seizure resistance in DS and GEFS+, and more broadly, in other forms of refractory epilepsy.
Collapse
Affiliation(s)
- Jennifer C Wong
- Department of Human Genetics, Emory University Atlanta, GA, USA
| | - Stacey B B Dutton
- Department of Human Genetics, Emory UniversityAtlanta, GA, USA; Department of Biology, Agnes Scott CollegeAtlanta, GA, USA
| | | | - Steven Schachter
- Department of Neurology, Harvard Medical School, Beth Israel Deaconess Medical Center, and Massachusetts General Hospital Boston, MA, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University Atlanta, GA, USA
| |
Collapse
|
41
|
Abo El Fotoh WMM, Abd El Naby SAA, Habib MSED, ALrefai AA, Kasemy ZA. The potential implication of SCN1A and CYP3A5 genetic variants on antiepileptic drug resistance among Egyptian epileptic children. Seizure 2016; 41:75-80. [PMID: 27498208 DOI: 10.1016/j.seizure.2016.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/09/2016] [Accepted: 07/14/2016] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Despite the advances in the pharmacological treatment of epilepsy, pharmacoresistance still remains challenging. Understanding of the pharmacogenetic causes is critical to predict drug response hence providing a basis for personalized medications. Genetic alteration in activity of drug target and drug metabolizing proteins could explain the development of pharmacoresistant epilepsy. So the aim of this study was to explore whether SCN1A c.3184 A/G (rs2298771) and CYP3A5*3 (rs776746) polymorphisms could serve as genetic based biomarkers to predict pharmacoresistance among Egyptian epileptic children. METHODS Genotyping of SCN1A c.3184 A/G and CYP3A5*3 polymorphisms using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed in 65 healthy control subjects and 130 patients with epilepsy, of whom 50 were drug resistant and 80 were drug responsive. RESULTS There was a significant higher frequency of the AG genotype (p=0.001) and G allele (p=0.006) of SCN1A polymorphism in epileptic patients than in controls. Also their frequency was significantly higher in drug resistant patients in comparison with drug responders (p=0.005 and 0.054 respectively). No significant association between CYP3A5*3 polymorphism and drug-resistance was found. CONCLUSIONS Overall, results confirmed the claimed role of SCN1A c.3184 A/G polymorphism in epilepsy and moreover in development of pharmacoresistance among Egyptian epileptic children. CYP3A5*3 variants have no contributing effect on pharmacoresistance among Egyptian epileptic children.
Collapse
Affiliation(s)
| | | | | | - Abeer Ahmed ALrefai
- Lecturer of Medical Biochemistry, Faculty of Medicine, Menoufia University, Egypt.
| | - Zeinab A Kasemy
- Lecturer of Public Health and Community Medicine, Faculty of Medicine, Menoufia University, Egypt.
| |
Collapse
|
42
|
Ben-Johny M, Dick IE, Sang L, Limpitikul WB, Kang PW, Niu J, Banerjee R, Yang W, Babich JS, Issa JB, Lee SR, Namkung H, Li J, Zhang M, Yang PS, Bazzazi H, Adams PJ, Joshi-Mukherjee R, Yue DN, Yue DT. Towards a Unified Theory of Calmodulin Regulation (Calmodulation) of Voltage-Gated Calcium and Sodium Channels. Curr Mol Pharmacol 2016; 8:188-205. [PMID: 25966688 DOI: 10.2174/1874467208666150507110359] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 01/29/2015] [Accepted: 04/20/2015] [Indexed: 12/13/2022]
Abstract
Voltage-gated Na and Ca(2+) channels represent two major ion channel families that enable myriad biological functions including the generation of action potentials and the coupling of electrical and chemical signaling in cells. Calmodulin regulation (calmodulation) of these ion channels comprises a vital feedback mechanism with distinct physiological implications. Though long-sought, a shared understanding of the channel families remained elusive for two decades as the functional manifestations and the structural underpinnings of this modulation often appeared to diverge. Here, we review recent advancements in the understanding of calmodulation of Ca(2+) and Na channels that suggest a remarkable similarity in their regulatory scheme. This interrelation between the two channel families now paves the way towards a unified mechanistic framework to understand vital calmodulin-dependent feedback and offers shared principles to approach related channelopathic diseases. An exciting era of synergistic study now looms.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - David T Yue
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, MD 21205, USA.
| |
Collapse
|
43
|
Ghovanloo MR, Aimar K, Ghadiry-Tavi R, Yu A, Ruben PC. Physiology and Pathophysiology of Sodium Channel Inactivation. CURRENT TOPICS IN MEMBRANES 2016; 78:479-509. [PMID: 27586293 DOI: 10.1016/bs.ctm.2016.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Voltage-gated sodium channels are present in different tissues within the human body, predominantly nerve, muscle, and heart. The sodium channel is composed of four similar domains, each containing six transmembrane segments. Each domain can be functionally organized into a voltage-sensing region and a pore region. The sodium channel may exist in resting, activated, fast inactivated, or slow inactivated states. Upon depolarization, when the channel opens, the fast inactivation gate is in its open state. Within the time frame of milliseconds, this gate closes and blocks the channel pore from conducting any more sodium ions. Repetitive or continuous stimulations of sodium channels result in a rate-dependent decrease of sodium current. This process may continue until the channel fully shuts down. This collapse is known as slow inactivation. This chapter reviews what is known to date regarding, sodium channel inactivation with a focus on various mutations within each NaV subtype and with clinical implications.
Collapse
Affiliation(s)
- M-R Ghovanloo
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - K Aimar
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - R Ghadiry-Tavi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - A Yu
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - P C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| |
Collapse
|
44
|
SCN1A gene sequencing in 46 Turkish epilepsy patients disclosed 12 novel mutations. Seizure 2016; 39:34-43. [DOI: 10.1016/j.seizure.2016.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 12/26/2022] Open
|
45
|
Dulla CG, Coulter DA, Ziburkus J. From Molecular Circuit Dysfunction to Disease: Case Studies in Epilepsy, Traumatic Brain Injury, and Alzheimer's Disease. Neuroscientist 2016; 22:295-312. [PMID: 25948650 PMCID: PMC4641826 DOI: 10.1177/1073858415585108] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Complex circuitry with feed-forward and feed-back systems regulate neuronal activity throughout the brain. Cell biological, electrical, and neurotransmitter systems enable neural networks to process and drive the entire spectrum of cognitive, behavioral, and motor functions. Simultaneous orchestration of distinct cells and interconnected neural circuits relies on hundreds, if not thousands, of unique molecular interactions. Even single molecule dysfunctions can be disrupting to neural circuit activity, leading to neurological pathology. Here, we sample our current understanding of how molecular aberrations lead to disruptions in networks using three neurological pathologies as exemplars: epilepsy, traumatic brain injury (TBI), and Alzheimer's disease (AD). Epilepsy provides a window into how total destabilization of network balance can occur. TBI is an abrupt physical disruption that manifests in both acute and chronic neurological deficits. Last, in AD progressive cell loss leads to devastating cognitive consequences. Interestingly, all three of these neurological diseases are interrelated. The goal of this review, therefore, is to identify molecular changes that may lead to network dysfunction, elaborate on how altered network activity and circuit structure can contribute to neurological disease, and suggest common threads that may lie at the heart of molecular circuit dysfunction.
Collapse
Affiliation(s)
- Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Douglas A Coulter
- Department of Pediatrics and Neuroscience, University of Pennsylvania Perleman School of Medicine, Philadelphia, PA, USA Division of Neurology and the Research Institute of Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jokubas Ziburkus
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| |
Collapse
|
46
|
Lal D, Reinthaler EM, Dejanovic B, May P, Thiele H, Lehesjoki AE, Schwarz G, Riesch E, Ikram MA, van Duijn CM, Uitterlinden AG, Hofman A, Steinböck H, Gruber-Sedlmayr U, Neophytou B, Zara F, Hahn A, Gormley P, Becker F, Weber YG, Cilio MR, Kunz WS, Krause R, Zimprich F, Lemke JR, Nürnberg P, Sander T, Lerche H, Neubauer BA. Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes. PLoS One 2016; 11:e0150426. [PMID: 26990884 PMCID: PMC4798642 DOI: 10.1371/journal.pone.0150426] [Citation(s) in RCA: 14] [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: 06/16/2015] [Accepted: 02/12/2016] [Indexed: 11/23/2022] Open
Abstract
Objective The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants are more likely to be classified as pathogenic if they have already been identified previously in a patient with epilepsy. Here, we critically re-evaluate the pathogenicity of this class of variants in a cohort of patients with common epilepsy syndromes and subsequently ask whether a significant fraction of benign variants have been misclassified as pathogenic. Methods We screened a discovery cohort of 448 patients with a broad range of common genetic epilepsies and 734 controls for previously reported SCN1A mutations that were assumed to be disease causing. We re-evaluated the evidence for pathogenicity of the identified variants using in silico predictions, segregation, original reports, available functional data and assessment of allele frequencies in healthy individuals as well as in a follow up cohort of 777 patients. Results and Interpretation We identified 8 known missense mutations, previously reported as pathogenic, in a total of 17 unrelated epilepsy patients (17/448; 3.80%). Our re-evaluation indicates that 7 out of these 8 variants (p.R27T; p.R28C; p.R542Q; p.R604H; p.T1250M; p.E1308D; p.R1928G; NP_001159435.1) are not pathogenic. Only the p.T1174S mutation may be considered as a genetic risk factor for epilepsy of small effect size based on the enrichment in patients (P = 6.60 x 10−4; OR = 0.32, fishers exact test), previous functional studies but incomplete penetrance. Thus, incorporation of previous studies in genetic counseling of SCN1A sequencing results is challenging and may produce incorrect conclusions.
Collapse
Affiliation(s)
- Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Eva M. Reinthaler
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Anna-Elina Lehesjoki
- Folkhälsan Institute of Genetics, Helsinki, Finland
- Neuroscience Center, University of Helsinki, Helsinki, Finland
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | - Erik Riesch
- CeGaT GmbH—Centre for Genomics and Transcriptomics, Tübingen, Germany
| | - M. Arfan Ikram
- Departments of Epidemiology, Neurology, Radiology, Erasmus Medical Center, Rotterdam, Netherlands
| | - Cornelia M. van Duijn
- Departments of Epidemiology, Neurology, Radiology, Erasmus Medical Center, Rotterdam, Netherlands
| | | | - Albert Hofman
- Department of Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | | | | | - Birgit Neophytou
- St. Anna Children’s Hospital, Department of Neuropediatrics, Vienna, Austria
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, Institute G. Gaslini, Genova, Italy
| | - Andreas Hahn
- Department of Neuropediatrics, University Medical Center Giessen and Marburg, Giessen, Germany
| | | | | | - Padhraig Gormley
- Psychiatric and Neurodevelopmental Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Felicitas Becker
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Yvonne G. Weber
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Maria Roberta Cilio
- Departments of Neurology and Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Wolfram S. Kunz
- Department of Epileptology, University of Bonn, Bonn, Germany
| | - Roland Krause
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Johannes R. Lemke
- Institute of Human Genetics, University of Leipzig, Leipzig, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Thomas Sander
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Bernd A. Neubauer
- Department of Neuropediatrics, University Medical Center Giessen and Marburg, Giessen, Germany
| |
Collapse
|
47
|
Gürsoy S, Erçal D. Diagnostic Approach to Genetic Causes of Early-Onset Epileptic Encephalopathy. J Child Neurol 2016; 31:523-32. [PMID: 26271793 DOI: 10.1177/0883073815599262] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 07/13/2015] [Indexed: 01/08/2023]
Abstract
Epileptic encephalopathies are characterized by recurrent clinical seizures and prominent interictal epileptiform discharges seen during the early infantile period. Although epileptic encephalopathies are mostly associated with structural brain defects and inherited metabolic disorders, pathogenic gene mutations may also be involved in the development of epileptic encephalopathies even when no clear genetic inheritance patterns or consanguinity exist. The most common epileptic encephalopathies are Ohtahara syndrome, early myoclonic encephalopathy, epilepsy of infancy with migrating focal seizures, West syndrome and Dravet syndrome, which are usually unresponsive to traditional antiepileptic medication. Many of the diagnoses describe the phenotype of these electroclinical syndromes, but not the underlying causes. To date, approximately 265 genes have been defined in epilepsy and several genes including STXBP1, ARX, SLC25A22, KCNQ2, CDKL5, SCN1A, and PCDH19 have been found to be associated with early-onset epileptic encephalopathies. In this review, we aimed to present a diagnostic approach to primary genetic causes of early-onset epileptic encephalopathies.
Collapse
Affiliation(s)
- Semra Gürsoy
- Faculty of Medicine, Department of Pediatric Genetics, Dokuz Eylül University, İzmir, Turkey
| | - Derya Erçal
- Faculty of Medicine, Department of Pediatric Genetics, Dokuz Eylül University, İzmir, Turkey
| |
Collapse
|
48
|
Saras A, Tanouye MA. Mutations of the Calcium Channel Gene cacophony Suppress Seizures in Drosophila. PLoS Genet 2016; 12:e1005784. [PMID: 26771829 PMCID: PMC4714812 DOI: 10.1371/journal.pgen.1005784] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 12/12/2015] [Indexed: 11/30/2022] Open
Abstract
Bang sensitive (BS) Drosophila mutants display characteristic seizure-like phenotypes resembling, in some aspects, those of human seizure disorders such as epilepsy. The BS mutant parabss1, caused by a gain-of-function mutation of the voltage-gated Na+ channel gene, is extremely seizure-sensitive with phenotypes that have proven difficult to ameliorate by anti-epileptic drug feeding or by seizure-suppressor mutation. It has been presented as a model for intractable human epilepsy. Here we show that cacophony (cacTS2), a mutation of the Drosophila presynaptic Ca++ channel α1 subunit gene, is a particularly potent seizure-suppressor mutation, reverting seizure-like phenotypes for parabss1 and other BS mutants. Seizure-like phenotypes for parabss1 may be suppressed by as much as 90% in double mutant combinations with cacTS2. Unexpectedly, we find that parabss1 also reciprocally suppresses cacTS2 seizure-like phenotypes. The cacTS2 mutant displays these seizure-like behaviors and spontaneous high-frequency action potential firing transiently after exposure to high temperature. We find that this seizure-like behavior in cacTS2 is ameliorated by 85% in double mutant combinations with parabss1. Seizure disorders, such as epilepsy, are a serious health concern because of the large number of patients affected and a limited availability of treatment options. About 10% of the population will have at least one seizure during their lifetime, and 1% will experience persistent, recurrent epileptic seizures. Moreover, for about one-third of patients, epilepsy is intractable with seizures that are not controlled with any available drugs. Genetic seizure suppressors are modifier mutations that are capable of reverting seizure susceptibility to wild type levels when combined with seizure-prone mutants in double mutant individuals. Suppressors are valuable in providing an experimental approach that can provide insight into mechanisms underlying seizure susceptibility. Also, they identify novel gene products that may be targets for therapeutic drug development. In the present study we show that a severe seizure phenotype of the Drosophila paralyticbss1(parabss1) mutant is 90% suppressed by the N-type calcium channel mutation cacophonyTS2(cacTS2). The effect of suppression is not restricted to parabss1, but cacTS2 can also revert seizure-like phenotypes of other Drosophila mutants like easily-shocked (eas) and slamdance (sda). Thus, cacTS2 acts as a highly potent, general seizure suppressor mutation. A surprising finding in this study is co-suppression: parabss1 also suppresses a seizure phenotype in cacTS2 mutants induced by elevated temperature. A current view of complex diseases such as epilepsy, is that multiple genes and environmental factors can each contribute small, additive effects that can summate to produce a disease state when some threshold value is exceeded. Our findings indicate that different pathogenic ion channel mutations can sometimes form therapeutic combinations with effects that mask one another.
Collapse
Affiliation(s)
- Arunesh Saras
- Department of Environmental Science, Policy and Management, Division of Organismal Biology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
| | - Mark A. Tanouye
- Department of Environmental Science, Policy and Management, Division of Organismal Biology, University of California Berkeley, Berkeley, California, United States of America
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
| |
Collapse
|
49
|
Onwuli DO, Beltran-Alvarez P. An update on transcriptional and post-translational regulation of brain voltage-gated sodium channels. Amino Acids 2015; 48:641-651. [PMID: 26503606 PMCID: PMC4752963 DOI: 10.1007/s00726-015-2122-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 11/29/2022]
Abstract
Voltage-gated sodium channels are essential proteins in brain physiology, as they generate the sodium currents that initiate neuronal action potentials. Voltage-gated sodium channels expression, localisation and function are regulated by a range of transcriptional and post-translational mechanisms. Here, we review our understanding of regulation of brain voltage-gated sodium channels, in particular SCN1A (NaV1.1), SCN2A (NaV1.2), SCN3A (NaV1.3) and SCN8A (NaV1.6), by transcription factors, by alternative splicing, and by post-translational modifications. Our focus is strongly centred on recent research lines, and newly generated knowledge.
Collapse
Affiliation(s)
- Donatus O Onwuli
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK
| | - Pedro Beltran-Alvarez
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK.
| |
Collapse
|
50
|
Makinson CD, Dutt K, Lin F, Papale LA, Shankar A, Barela AJ, Liu R, Goldin AL, Escayg A. An Scn1a epilepsy mutation in Scn8a alters seizure susceptibility and behavior. Exp Neurol 2015; 275 Pt 1:46-58. [PMID: 26410685 DOI: 10.1016/j.expneurol.2015.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 09/03/2015] [Accepted: 09/12/2015] [Indexed: 11/26/2022]
Abstract
Understanding the role of SCN8A in epilepsy and behavior is critical in light of recently identified human SCN8A epilepsy mutations. We have previously demonstrated that Scn8a(med) and Scn8a(med-jo) mice carrying mutations in the Scn8a gene display increased resistance to flurothyl and kainic acid-induced seizures; however, they also exhibit spontaneous absence seizures. To further investigate the relationship between altered SCN8A function and epilepsy, we introduced the SCN1A-R1648H mutation, identified in a family with generalized epilepsy with febrile seizures plus (GEFS+), into the corresponding position (R1627H) of the mouse Scn8a gene. Heterozygous R1627H mice exhibited increased resistance to some forms of pharmacologically and electrically induced seizures and the mutant Scn8a allele ameliorated the phenotype of Scn1a-R1648H mutants. Hippocampal slices from heterozygous R1627H mice displayed decreased bursting behavior compared to wild-type littermates. Paradoxically, at the homozygous level, R1627H mice did not display increased seizure resistance and were susceptible to audiogenic seizures. We furthermore observed increased hippocampal pyramidal cell excitability in heterozygous and homozygous Scn8a-R1627H mutants, and decreased interneuron excitability in heterozygous Scn8a-R1627H mutants. These results expand the phenotypes associated with disruption of the Scn8a gene and demonstrate that an Scn8a mutation can both confer seizure protection and increase seizure susceptibility.
Collapse
Affiliation(s)
| | - Karoni Dutt
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, CA 92697, USA
| | - Frank Lin
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Ligia A Papale
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA
| | - Anupama Shankar
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA
| | - Arthur J Barela
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, CA 92697, USA
| | - Robert Liu
- Department of Biology, Emory University, Atlanta, GA 30022, USA
| | - Alan L Goldin
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, CA 92697, USA.
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA.
| |
Collapse
|