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Ng ACH, Chahine M, Scantlebury MH, Appendino JP. Channelopathies in epilepsy: an overview of clinical presentations, pathogenic mechanisms, and therapeutic insights. J Neurol 2024:10.1007/s00415-024-12352-x. [PMID: 38607431 DOI: 10.1007/s00415-024-12352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024]
Abstract
Pathogenic variants in genes encoding ion channels are causal for various pediatric and adult neurological conditions. In particular, several epilepsy syndromes have been identified to be caused by specific channelopathies. These encompass a spectrum from self-limited epilepsies to developmental and epileptic encephalopathies spanning genetic and acquired causes. Several of these channelopathies have exquisite responses to specific antiseizure medications (ASMs), while others ASMs may prove ineffective or even worsen seizures. Some channelopathies demonstrate phenotypic pleiotropy and can cause other neurological conditions outside of epilepsy. This review aims to provide a comprehensive exploration of the pathophysiology of seizure generation, ion channels implicated in epilepsy, and several genetic epilepsies due to ion channel dysfunction. We outline the clinical presentation, pathogenesis, and the current state of basic science and clinical research for these channelopathies. In addition, we briefly look at potential precision therapy approaches emerging for these disorders.
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Affiliation(s)
- Andy Cheuk-Him Ng
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Division of Neurology, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta and Stollery Children's Hospital, Edmonton, AB, Canada
| | - Mohamed Chahine
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
- CERVO, Brain Research Centre, Quebec City, Canada
| | - Morris H Scantlebury
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Calgary, Canada
| | - Juan P Appendino
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada.
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Yoganathan S, Whitney R, Thomas M, Danda S, Chettali AM, Prasad AN, Farhan SMK, AlSowat D, Abukhaled M, Aldhalaan H, Gowda VK, Kinhal UV, Bylappa AY, Konanki R, Lingappa L, Parchuri BM, Appendino JP, Scantlebury MH, Cunningham J, Hadjinicolaou A, El Achkar CM, Kamate M, Menon RN, Jose M, Riordan G, Kannan L, Jain V, Manokaran RK, Chau V, Donner EJ, Costain G, Minassian BA, Jain P. KCTD7-related progressive myoclonic epilepsy: Report of 42 cases and review of literature. Epilepsia 2024; 65:709-724. [PMID: 38231304 DOI: 10.1111/epi.17880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/18/2024]
Abstract
OBJECTIVE KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort. METHODS Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized. RESULTS Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years). SIGNIFICANCE This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.
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Affiliation(s)
- Sangeetha Yoganathan
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Robyn Whitney
- Comprehensive Pediatric Epilepsy Program, Division of Neurology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Maya Thomas
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sumita Danda
- Department of Medical Genetics, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Asuri N Prasad
- Division of Pediatric Neurology and Clinical Neurosciences, Department of Pediatrics, Children's Hospital, London Health Sciences Centre, London, Ontario, Canada
| | - Sali M K Farhan
- Department of Neurology and Neurosurgery, and Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Daad AlSowat
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Musaad Abukhaled
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hesham Aldhalaan
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Uddhava V Kinhal
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Arun Y Bylappa
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Ramesh Konanki
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Lokesh Lingappa
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | | | - Juan P Appendino
- Pediatric Neurology Service, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Morris H Scantlebury
- Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jessie Cunningham
- Hospital Library and Archives, Learning Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Aristides Hadjinicolaou
- Division of Neurology, Department of Pediatrics, CHU (Centre Hospitalier Universitaire) Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Christelle Moufawad El Achkar
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mahesh Kamate
- Department of Pediatric Neurology, Jawaharlal Nehru Medical College, KLE (Karnataka Lingayat Education) Academy of Higher Education and Research, KLE's Dr Prabhakar Kore (PK) Hospital, Belagavi, Karnataka, India
| | - Ramshekhar N Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Manna Jose
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Gillian Riordan
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | | | - Vivek Jain
- Department of Pediatric Neurology, Neoclinic Children's Hospital, Jaipur, Rajasthan, India
| | - Ranjith Kumar Manokaran
- Division of Pediatric neurology, Department of Neurology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Vann Chau
- Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Donner
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, and Program in Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Puneet Jain
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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Huntsman RJ, Elliott J, Lewis E, Moore-Hepburn C, Alcorn J, Mansell H, Appendino JP, Bélanger RE, Corley S, Crooks B, Denny AM, Finkelstein Y, Finley A, Fung R, Gilpin A, Litalien C, Jacobs J, Oberlander TF, Palm A, Palm J, Polewicz M, Quinn D, Rassekh SR, Repetski A, Rieder MJ, Robson-McKay A, Seifert B, Shackelford A, Siden H, Szafron M, ‘t Jong G, Vaillancourt R, Kelly LE. Removing barriers to accessing medical cannabis for paediatric patients. Paediatr Child Health 2024; 29:12-16. [PMID: 38332979 PMCID: PMC10848115 DOI: 10.1093/pch/pxac129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 12/05/2022] [Indexed: 02/10/2024] Open
Abstract
Medical cannabis (MC) may offer therapeutic benefits for children with complex neurological conditions and chronic diseases. In Canada, parents, and caregivers frequently report encountering barriers when accessing MC for their children. These include negative preconceived notions about risks and benefits, challenges connecting with a knowledgeable healthcare provider (HCP), the high cost of MC products, and navigating MC product shortages. In this manuscript, we explore several of these barriers and provide recommendations to decision-makers to enable a family-centered and evidence-based approach to MC medicine and research for children.
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Affiliation(s)
- Richard J Huntsman
- Division of Pediatric Neurology, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jesse Elliott
- Independent Researcher, Canadian Collaborative for Childhood Cannabinoid Therapeutics, Winnipeg, Manitoba, Canada
| | - Evan Lewis
- Neurology Center of Toronto and Division of Pediatric Neurology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | | | - Jane Alcorn
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Holly Mansell
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Juan P Appendino
- Division of Pediatric Neurology, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Richard E Bélanger
- Départment de Pédiatrie, Faculté de medicine, Université de Laval, Québec, Québec, Canada
| | - Scott Corley
- Cannabinoid Research Initiative of Saskatchewan, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Bruce Crooks
- Division of Paediatric Hematology/Oncology, Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - AnneMarie M Denny
- Division of Pediatric Neurology, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yaron Finkelstein
- Divisions of Emergency Medicine and Clinical Pharmacology and Toxicology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Allen Finley
- Departments of Anesthesia and Psychology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ryan Fung
- Department of Pediatric Pharmacy, Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada
| | - Andrea Gilpin
- The Rosalind and Morris Goodman Family Pediatrics Formulation Centre of the CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Catherine Litalien
- Département de Pédiatrie, Faculté de Médecine, Université de Montréal, and The Rosalind and Morris Goodman Family Pediatric Formulation Centre of the CHU Sainte Justine, Montréal, Québec, Canada
| | - Julia Jacobs
- Division of Pediatric Neurology, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Timothy F Oberlander
- Department of Pediatrics and School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ashley Palm
- Parent Advocate, Canadian Collaborative for Childhood Cannabinoid Therapeutics, Winnipeg, Manitoba, Canada
| | - Jacob Palm
- Parent Advocate, Canadian Collaborative for Childhood Cannabinoid Therapeutics, Winnipeg, Manitoba, Canada
| | - Monika Polewicz
- Division of Pediatric Research, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Declan Quinn
- Division of Pediatric Psychiatry, Department of Psychiatry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - S Rod Rassekh
- Division of Pediatric Hematology/Oncology/BMT, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander Repetski
- Parent Advocate, Canadian Collaborative for Childhood Cannabinoid Therapeutics, Winnipeg, Manitoba, Canada
| | - Michael J Rieder
- Division of Pediatric Pharmacology, Department of Pediatrics, University of Western Ontario, London, Ontario, Canada
| | - Amy Robson-McKay
- Division of Pediatric Psychiatry, Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Blair Seifert
- Department of Pediatric Pharmacy, Saskatchewan Health Authority, Saskatoon, Saskatchewan, Canada
| | | | - Hal Siden
- Division of Palliative Care, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael Szafron
- School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Geert ‘t Jong
- Departments of Pediatrics and Pharmacology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Régis Vaillancourt
- Department of Pediatric Pharmacy, Children’s Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Lauren E Kelly
- George and Fay Yee Centre for Health Care Innovation and Children’s Hospital Research Institute of Manitoba, Department of Pediatrics & Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
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Sjonnesen K, Hader W, Xu Q, Jacobs-Levan J, Federico P, Langdon KD, Appendino JP. Chronic Herpes Simplex Virus Encephalitis with Unexpected Neuropathological Findings. Can J Neurol Sci 2023:1-5. [PMID: 37935452 DOI: 10.1017/cjn.2023.311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
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Borlot F, Kozlik S, Alfaro L, Payne ET, Ho AW, Appendino JP, Scantlebury MH, Jacobs J. Proposed Pathway for the Utilization of Pediatric Ambulatory EEG. J Clin Neurophysiol 2023; 40:443-449. [PMID: 37399043 DOI: 10.1097/wnp.0000000000000906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The clinical utility of pediatric ambulatory-EEG (A-EEG) has been studied for decades, but limited information exists regarding which variables influence its utility. The authors aimed to evaluate clinical/EEG variables that may influence A-EEG yields and to develop a pathway for A-EEG utilization in children. METHODS Single-center retrospective review of A-EEGs performed from July 2019 to January 2021 in a tertiary referral center. The primary outcome was whether the A-EEG test successfully answered the referring physician's clinical question or influenced therapy. When it did, the A-EEG test was deemed useful. Clinical and EEG variables were assessed for their ability to predict utility. Further, the literature review generated 10 relevant prior studies whose details were used to generate a pathway for A-EEG utilization in children. RESULTS One hundred forty-two A-EEG studies were included (mean age 8.8 years, 48% male patients, mean A-EEG duration 33.5 hours). Overall, A-EEG was considered useful in 106 children (75%) but heavily influenced by A-EEG indication. Specifically, it was deemed useful for 94% of patients evaluated for electrical status epilepticus in slow-wave sleep, 92% of those evaluated for interictal/ictal burden, and 63% of those undergoing spell classification. The test indication (P < 0.001), a diagnosis of epilepsy (P = 0.02), and an abnormal routine EEG (P = 0.04) were associated with A-EEG test utility, although the multivariate analysis confirmed the test indication as the only independent outcome predictor of A-EEG. CONCLUSIONS Pediatric A-EEG is extremely useful for evaluating electrical status epilepticus in slow-wave sleep and interictal/ictal burden and is often helpful for spell classification. Among all clinical and EEG variables analyzed, the test indication was the only independent outcome predictor of obtaining a helpful A-EEG.
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Affiliation(s)
- Felippe Borlot
- Alberta Children's Hospital Research Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, AB, Canada
| | | | | | - Eric T Payne
- Alberta Children's Hospital Research Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, AB, Canada
- Alberta Children's Hospital, Calgary, AB, Canada
- Section of Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; and
| | - Alice W Ho
- Alberta Children's Hospital, Calgary, AB, Canada
- Section of Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; and
| | - Juan P Appendino
- Alberta Children's Hospital, Calgary, AB, Canada
- Section of Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; and
| | - Morris H Scantlebury
- Alberta Children's Hospital Research Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, AB, Canada
- Alberta Children's Hospital, Calgary, AB, Canada
- Section of Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; and
| | - Julia Jacobs
- Alberta Children's Hospital Research Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, AB, Canada
- Alberta Children's Hospital, Calgary, AB, Canada
- Section of Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; and
- Department of Neuropediatrics and Muscle Disorders, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Pijpers JA, Au PYB, Weeke LC, Vein AA, Smit LS, Vilan A, Jacobs E, de Vries LS, Steggerda SJ, Cilio MR, Carapancea E, Cornet MC, Appendino JP, Peeters-Scholte CMPCD. Early recognition of characteristic conventional and amplitude-integrated EEG patterns of seizures in SCN2A and KCNQ3-related epilepsy in neonates. Seizure 2023; 110:212-219. [PMID: 37429183 DOI: 10.1016/j.seizure.2023.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/30/2023] [Accepted: 06/19/2023] [Indexed: 07/12/2023] Open
Abstract
PURPOSE Early recognition of seizures in neonates secondary to pathogenic variants in potassium or sodium channel coding genes is crucial, as these seizures are often resistant to commonly used anti-seizure medications but respond well to sodium channel blockers. Recently, a characteristic ictal amplitude-integrated electroencephalogram (aEEG) pattern was described in neonates with KCNQ2-related epilepsy. We report a similar aEEG pattern in seizures caused by SCN2A- and KCNQ3-pathogenic variants, as well as conventional EEG (cEEG) descriptions. METHODS International multicentre descriptive study, reporting clinical characteristics, aEEG and cEEG findings of 13 neonates with seizures due to pathogenic SCN2A- and KCNQ3-variants. As a comparison group, aEEGs and cEEGs of neonates with seizures due to hypoxic-ischemic encephalopathy (n = 117) and other confirmed genetic causes affecting channel function (n = 55) were reviewed. RESULTS In 12 out of 13 patients, the aEEG showed a characteristic sequence of brief onset with a decrease, followed by a quick rise, and then postictal amplitude attenuation. This pattern correlated with bilateral EEG onset attenuation, followed by rhythmic discharges ending in several seconds of post-ictal amplitude suppression. Apart from patients with KCNQ2-related epilepsy, none of the patients in the comparison groups had a similar aEEG or cEEG pattern. DISCUSSION Seizures in SCN2A- and KCNQ3-related epilepsy in neonates can usually be recognized by a characteristic ictal aEEG pattern, previously reported only in KCNQ2-related epilepsy, extending this unique feature to other channelopathies. Awareness of this pattern facilitates the prompt initiation of precision treatment with sodium channel blockers even before genetic results are available.
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Affiliation(s)
- Judith A Pijpers
- Departments of Neurology and Clinical Neurophysiology, Leiden University Medical Center, PO Box 9600, Leiden 2300 RC, the Netherlands.
| | - Ping Yee Billie Au
- Departments of Medical Genetics, Cumming School of Medicine, University of Calgary, Canada
| | - Lauren C Weeke
- Departments of Neonatology, Erasmus Medical Center, the Netherlands
| | - Alla A Vein
- Departments of Neurology and Clinical Neurophysiology, Leiden University Medical Center, PO Box 9600, Leiden 2300 RC, the Netherlands
| | - Liesbeth S Smit
- Departments of Neonatology, Erasmus Medical Center, the Netherlands; Departments of Neurology, Erasmus Medical Center, the Netherlands
| | - Ana Vilan
- Department of Neonatology, Centro Hospitalar Universitário São João, Faculty of Medicine, University of Porto, Portugal
| | - Elke Jacobs
- Departments of Neurology, Erasmus Medical Center, the Netherlands
| | - Linda S de Vries
- Departments of Neonatology, Leiden University Medical Center, the Netherlands
| | - Sylke J Steggerda
- Departments of Neonatology, Leiden University Medical Center, the Netherlands
| | - Maria Roberta Cilio
- Division of Pediatric Neurology, Department of Pediatrics, Catholic University of Louvain, Brussels, Belgium
| | - Evelina Carapancea
- Division of Pediatric Neurology, Department of Pediatrics, Catholic University of Louvain, Brussels, Belgium
| | - Marie-Coralie Cornet
- Division of Neonatology, Department of Pediatrics, Benioff Children's Hospital, University of California, San Francisco, CA, USA
| | - Juan P Appendino
- Departments of Pediatric Neurology, Cumming School of Medicine, University of Calgary, Canada
| | - Cacha M P C D Peeters-Scholte
- Departments of Neurology and Clinical Neurophysiology, Leiden University Medical Center, PO Box 9600, Leiden 2300 RC, the Netherlands
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Zhan X, Drummond-Main C, Greening D, Yao J, Chen SWR, Appendino JP, Au PYB, Turner RW. Cannabidiol counters the effects of a dominant-negative pathogenic Kv7.2 variant. iScience 2022; 25:105092. [PMID: 36157585 PMCID: PMC9490039 DOI: 10.1016/j.isci.2022.105092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/17/2022] [Accepted: 09/02/2022] [Indexed: 11/04/2022] Open
Abstract
Epilepsy and neurodevelopmental disorders can arise from pathogenic variants of KCNQ (Kv7) channels. A patient with developmental and epileptic encephalopathy exhibited an in-frame deletion of histidine 260 on Kv7.2. Coexpression of Kv7.2 mutant (mut) subunits with Kv7.3 invoked a decrease in current density, a depolarizing shift in voltage for activation, and a decrease in membrane conductance. Biotinylation revealed an increased level of surface Kv7.2mut compared to Kv7.3 with no change in total membrane protein expression. Super-resolution and FRET imaging confirmed heteromeric channel formation and a higher expression density of Kv7.2mut. Cannabidiol (1 μM) offset the effects of Kv7.2mut by inducing a hyperpolarizing shift in voltage for activation independent of CB1 or CB2 receptors. These data reveal that the ability for cannabidiol to reduce the effects of a pathogenic Kv7.2 variant supports its use as a potential therapeutic to reduce seizure activity. A patient with epileptic encephalopathy exhibits a Kv7.2 deletion at H260 (Kv7.2mut) Kv7.2mut shows increased expression at the membrane compared to Kv7.3 Kv7.2mut acts in a dominant-negative manner to reduce Kv7 conductance Cannabidiol acts on Kv7.x activation voltage to offset the effects of Kv7.2mut
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Affiliation(s)
- Xiaoqin Zhan
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Chris Drummond-Main
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Dylan Greening
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinjing Yao
- Libin Cardiovascular Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - S W R Chen
- Libin Cardiovascular Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - J P Appendino
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Pediatric Department, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - P Y Billie Au
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Department of Medical Genetics, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ray W Turner
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Cherian C, Appendino JP, Ashtiani S, Federico P, Molnar CP, Kerr M, Khan A, Au PYB, Klein KM. The phenotypic spectrum of KCNT1: a new family with variable epilepsy syndromes including mild focal epilepsy. J Neurol 2021; 269:2162-2171. [PMID: 34537872 DOI: 10.1007/s00415-021-10808-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVE Pathogenic variants in KCNT1 have been associated with severe forms of epilepsy, typically sleep-related hypermotor epilepsy or epilepsy of infancy with migrating focal seizures. To show that pathogenic variants in KCNT1 can be associated with mild extra-frontal epilepsy, we report a KCNT1 family with a wide spectrum of phenotypes ranging from developmental and epileptic encephalopathy to mild focal epilepsy without cognitive regression and not consistent with sleep-related hypermotor epilepsy. METHODS A large Canadian family of Caucasian descent including 9 affected family members was recruited. Family members were phenotyped by direct interview and review of existing medical records. Clinical epilepsy gene panel analysis and exome sequencing were performed. RESULTS Phenotypic information was available for five family members of which two had developmental and epileptic encephalopathy and three had normal development and focal epilepsy with presumed extra-frontal onset. All three had predominantly nocturnal seizures that did not show hyperkinetic features. All three reported clusters of seizures at night with a feeling of being unable to breathe associated with gasping for air, choking and/or repetitive swallowing possibly suggesting insular or opercular involvement. Genetic analysis identified a heterozygous KCNT1 c.2882G > A, p.Arg961His variant that was predicted to be deleterious. DISCUSSION This family demonstrates that the phenotypic spectrum associated with KCNT1 pathogenic variants is broader than previously assumed. Our findings indicate that variants in KCNT1 can be associated with mild focal epilepsy and should not be excluded during variant interpretation in such patients based solely on gene-disease validity.
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Affiliation(s)
- Christina Cherian
- Department of Clinical Neurosciences, Cumming School of Medicine, Foothills Medical Centre, University of Calgary, 1403 29 Street NW, Calgary, AB, T2N 2T9, Canada
| | - Juan P Appendino
- Division of Clinical Neuroscience, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada
| | - Setareh Ashtiani
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Paolo Federico
- Department of Clinical Neurosciences, Cumming School of Medicine, Foothills Medical Centre, University of Calgary, 1403 29 Street NW, Calgary, AB, T2N 2T9, Canada.,Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Seaman Family MR Research Centre, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christine P Molnar
- Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marina Kerr
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Aneal Khan
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Ping Yee Billie Au
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Karl Martin Klein
- Department of Clinical Neurosciences, Cumming School of Medicine, Foothills Medical Centre, University of Calgary, 1403 29 Street NW, Calgary, AB, T2N 2T9, Canada. .,Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada. .,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada. .,Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Center of Neurology and Neurosurgery, University Hospital, Goethe-University, Frankfurt, Germany. .,Center for Personalized Translational Epilepsy Research (CePTER), Goethe University, Frankfurt, Germany.
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9
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Maghera J, Li J, Lamothe SM, Braun M, Appendino JP, Au PYB, Kurata HT. Familial neonatal seizures caused by the Kv7.3 selectivity filter mutation T313I. Epilepsia Open 2020; 5:562-573. [PMID: 33336127 PMCID: PMC7733659 DOI: 10.1002/epi4.12438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 08/14/2020] [Accepted: 09/09/2020] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE A spectrum of seizure disorders is linked to mutations in Kv7.2 and Kv7.3 channels. Linking functional effects of identified mutations to their clinical presentation requires ongoing characterization of newly identified variants. In this study, we identified and functionally characterized a previously unreported mutation in the selectivity filter of Kv7.3. METHODS Next-generation sequencing was used to identify the Kv7.3[T313I] mutation in a family affected by neonatal seizures. Electrophysiological approaches were used to characterize the functional effects of this mutation on ion channels expressed in Xenopus laevis oocytes. RESULTS Substitution of residue 313 from threonine to isoleucine (Kv7.3[T313I]) likely disrupts a critical intersubunit hydrogen bond. Characterization of the mutation in homomeric Kv7.3 channels demonstrated a total loss of channel function. Assembly in heteromeric channels (with Kv7.2) leads to modest suppression of total current when expressed in Xenopus laevis oocytes. Using a Kv7 activator with distinct effects on homomeric Kv7.2 vs heteromeric Kv7.2/Kv7.3 channels, we demonstrated that assembly of Kv7.2 and Kv7.3[T313I] generates functional channels. SIGNIFICANCE Biophysical and clinical effects of the T313I mutation are consistent with Kv7.3 mutations previously identified in cases of pharmacoresponsive self-limiting neonatal epilepsy. These findings expand our description of functionally characterized Kv7 channel variants and report new methods to distinguish molecular mechanisms of channel mutations.
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Affiliation(s)
- Jasmine Maghera
- Department of PharmacologyAlberta Diabetes InstituteUniversity of AlbertaEdmontonABCanada
| | - Jingru Li
- Department of PharmacologyAlberta Diabetes InstituteUniversity of AlbertaEdmontonABCanada
| | - Shawn M. Lamothe
- Department of PharmacologyAlberta Diabetes InstituteUniversity of AlbertaEdmontonABCanada
| | - Marvin Braun
- Division of Child NeurologyDepartment of PediatricsWeill Cornell MedicineNew YorkNYUSA
| | - Juan P. Appendino
- Section of NeurologyDepartment of PediatricsCumming School of MedicineUniversity of Calgary, and Alberta Children’s HospitalCalgaryABCanada
| | - P. Y. Billie Au
- Department of Medical GeneticsCumming School of MedicineAlberta Children’s Hospital Research InstituteUniversity of CalgaryCalgaryABCanada
| | - Harley T. Kurata
- Department of PharmacologyAlberta Diabetes InstituteUniversity of AlbertaEdmontonABCanada
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10
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Wiwchar LD, Hader W, Pauranik A, Joseph JT, Appendino JP. Focal seizures associated with the chapeau de gendarme sign or ictal pouting of insular origin. Epilepsy Behav Rep 2019; 12:100347. [PMID: 31828237 PMCID: PMC6888707 DOI: 10.1016/j.ebr.2019.100347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/10/2019] [Accepted: 11/11/2019] [Indexed: 12/02/2022] Open
Abstract
We report a teenager with childhood onset focal seizures associated with the chapeau de gendarme sign or ictal pouting of anterior insular lobe origin. The chapeau de gendarme sign has been associated with frontal lobe seizures in patients with focal epilepsy. However, in this case, stereo-electroencephalography (SEEG) localized seizures to the anterior insular cortex prior to her typical clinical manifestations. Surgical resection of the insular and frontal-lobe network resulted in seizure freedom. We propose that the anterior insular cortex should be a site of investigation during pre-surgical phase 2 evaluation in patients exhibiting the chapeau de gendarme sign during focal seizures. Chapeau de gendarme seizures or ictal pouting could have insular lobe involvement at electrical seizure onset. Phase 2 investigation should include insular monitoring when assessing for this kind of seizures. Pediatric population could also have chapeau de gendarme or ictal pouting seizures. Ripples were associated with epileptogenicity in insular cortex requiring resection.
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Affiliation(s)
- Logan D Wiwchar
- Cumming School of Medicine, University of Calgary, 3330 Hospital Dr NW, Calgary, AB T2N 4N1, Canada
| | - Walter Hader
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, 3330 Hospital Dr NW, Calgary, AB T2N 4N1, Canada
| | - Anvita Pauranik
- Division of Pediatric Neuroradiology, Department of Radiology, Alberta Children's Hospital, 28 Oki Drive NW, Calgary, AB T3B 6A8, Canada
| | - Jeffrey T Joseph
- Dept. of Pathology and Laboratory Medicine. University of Calgary. McCaig 7539 Alberta Public Laboratories, Foothills Medical Centre, 1403 - 29 St. NW, Calgary, Alberta T2N2T9, Canada
| | - Juan P Appendino
- Section of Paediatric Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, 28 Oki Drive NW, Calgary, AB T3B 6A8, Canada
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11
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Punetha J, Karaca E, Gezdirici A, Lamont RE, Pehlivan D, Marafi D, Appendino JP, Hunter JV, Akdemir ZC, Fatih JM, Jhangiani SN, Gibbs RA, Innes AM, Posey JE, Lupski JR. Biallelic CACNA2D2 variants in epileptic encephalopathy and cerebellar atrophy. Ann Clin Transl Neurol 2019; 6:1395-1406. [PMID: 31402629 PMCID: PMC6689679 DOI: 10.1002/acn3.50824] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To characterize the molecular and clinical phenotypic basis of developmental and epileptic encephalopathies caused by rare biallelic variants in CACNA2D2. METHODS Two affected individuals from a family with clinical features of early onset epileptic encephalopathy were recruited for exome sequencing at the Centers for Mendelian Genomics to identify their molecular diagnosis. GeneMatcher facilitated identification of a second family with a shared candidate disease gene identified through clinical gene panel-based testing. RESULTS Rare biallelic CACNA2D2 variants have been previously reported in three families with developmental and epileptic encephalopathy, and one family with congenital ataxia. We identified three individuals in two unrelated families with novel homozygous rare variants in CACNA2D2 with clinical features of developmental and epileptic encephalopathy and cerebellar atrophy. Family 1 includes two affected siblings with a likely damaging homozygous rare missense variant c.1778G>C; p.(Arg593Pro) in CACNA2D2. Family 2 includes a proband with a homozygous rare nonsense variant c.485_486del; p.(Tyr162Ter) in CACNA2D2. We compared clinical and molecular findings from all nine individuals reported to date and note that cerebellar atrophy is shared among all. INTERPRETATION Our study supports the candidacy of CACNA2D2 as a disease gene associated with a phenotypic spectrum of neurological disease that include features of developmental and epileptic encephalopathy, ataxia, and cerebellar atrophy. Age at presentation may affect apparent penetrance of neurogenetic trait manifestations and of a particular clinical neurological endophenotype, for example, seizures or ataxia.
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Affiliation(s)
- Jaya Punetha
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ender Karaca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alper Gezdirici
- Department of Medical Genetics, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Ryan E Lamont
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Juan P Appendino
- Clinical Neuroscience, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jill V Hunter
- Department of Radiology, Texas Children's Hospital, Houston, Texas
| | - Zeynep C Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Jawid M Fatih
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | | | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - A Micheil Innes
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas.,Texas Children's Hospital, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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