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Veltra D, Theodorou V, Katsalouli M, Vorgia P, Niotakis G, Tsaprouni T, Pons R, Kosma K, Kampouraki A, Tsoutsou I, Makrythanasis P, Kekou K, Traeger-Synodinos J, Sofocleous C. SCN1A Channels a Wide Range of Epileptic Phenotypes: Report of Novel and Known Variants with Variable Presentations. Int J Mol Sci 2024; 25:5644. [PMID: 38891831 PMCID: PMC11171476 DOI: 10.3390/ijms25115644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/15/2024] [Accepted: 05/18/2024] [Indexed: 06/21/2024] Open
Abstract
SCN1A, the gene encoding for the Nav1.1 channel, exhibits dominant interneuron-specific expression, whereby variants disrupting the channel's function affect the initiation and propagation of action potentials and neuronal excitability causing various types of epilepsy. Dravet syndrome (DS), the first described clinical presentation of SCN1A channelopathy, is characterized by severe myoclonic epilepsy in infancy (SMEI). Variants' characteristics and other genetic or epigenetic factors lead to extreme clinical heterogeneity, ranging from non-epileptic conditions to developmental and epileptic encephalopathy (DEE). This current study reports on findings from 343 patients referred by physicians in hospitals and tertiary care centers in Greece between 2017 and 2023. Positive family history for specific neurologic disorders was disclosed in 89 cases and the one common clinical feature was the onset of seizures, at a mean age of 17 months (range from birth to 15 years old). Most patients were specifically referred for SCN1A investigation (Sanger Sequencing and MLPA) and only five for next generation sequencing. Twenty-six SCN1A variants were detected, including nine novel causative variants (c.4567A>Τ, c.5564C>A, c.2176+2T>C, c.3646G>C, c.4331C>A, c.1130_1131delGAinsAC, c.1574_1580delCTGAGGA, c.4620A>G and c.5462A>C), and are herein presented, along with subsequent genotype-phenotype associations. The identification of novel variants complements SCN1A databases extending our expertise on genetic counseling and patient and family management including gene-based personalized interventions.
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Affiliation(s)
- Danai Veltra
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
- Research University Institute for the Study and Prevention of Genetic and Malignant Disease of Childhood, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece
| | - Virginia Theodorou
- Pediatric Neurology Department, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (V.T.); (M.K.)
| | - Marina Katsalouli
- Pediatric Neurology Department, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (V.T.); (M.K.)
| | - Pelagia Vorgia
- Agrifood and Life Sciences Institute, Hellenic Mediterranean University, 71410 Heraklion, Greece;
| | - Georgios Niotakis
- Pediatric Neurology Department, Venizelion Hospital, 71409 Heraklion, Greece;
| | | | - Roser Pons
- First Department of Pediatrics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece;
| | - Konstantina Kosma
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
| | - Afroditi Kampouraki
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
| | - Irene Tsoutsou
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
| | - Periklis Makrythanasis
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
- Department of Genetic Medicine and Development, Medical School, University of Geneva, 1211 Geneva, Switzerland
- Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece
| | - Kyriaki Kekou
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
| | - Joanne Traeger-Synodinos
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
| | - Christalena Sofocleous
- Laboratory of Medical Genetics, Medical School, National and Kapodistrian University of Athens, St. Sophia’s Children’s Hospital, 11527 Athens, Greece; (D.V.); (K.K.); (A.K.); (I.T.); (P.M.); (K.K.); (J.T.-S.)
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Pellinen J, Foster EC, Wilmshurst JM, Zuberi SM, French J. Improving epilepsy diagnosis across the lifespan: approaches and innovations. Lancet Neurol 2024; 23:511-521. [PMID: 38631767 DOI: 10.1016/s1474-4422(24)00079-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/11/2024] [Accepted: 02/16/2024] [Indexed: 04/19/2024]
Abstract
Epilepsy diagnosis is often delayed or inaccurate, exposing people to ongoing seizures and their substantial consequences until effective treatment is initiated. Important factors contributing to this problem include delayed recognition of seizure symptoms by patients and eyewitnesses; cultural, geographical, and financial barriers to seeking health care; and missed or delayed diagnosis by health-care providers. Epilepsy diagnosis involves several steps. The first step is recognition of epileptic seizures; next is classification of epilepsy type and whether an epilepsy syndrome is present; finally, the underlying epilepsy-associated comorbidities and potential causes must be identified, which differ across the lifespan. Clinical history, elicited from patients and eyewitnesses, is a fundamental component of the diagnostic pathway. Recent technological advances, including smartphone videography and genetic testing, are increasingly used in routine practice. Innovations in technology, such as artificial intelligence, could provide new possibilities for directly and indirectly detecting epilepsy and might make valuable contributions to diagnostic algorithms in the future.
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Affiliation(s)
- Jacob Pellinen
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO, USA.
| | - Emma C Foster
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Jo M Wilmshurst
- Red Cross War Memorial Children's Hospital and University of Cape Town Neuroscience Institute, Cape Town, South Africa
| | - Sameer M Zuberi
- Royal Hospital for Children and University of Glasgow School of Health & Wellbeing, Glasgow, UK
| | - Jacqueline French
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA
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3
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Sullivan J, Benítez A, Roth J, Andrews JS, Shah D, Butcher E, Jones A, Cross JH. A systematic literature review on the global epidemiology of Dravet syndrome and Lennox-Gastaut syndrome: Prevalence, incidence, diagnosis, and mortality. Epilepsia 2024; 65:1240-1263. [PMID: 38252068 DOI: 10.1111/epi.17866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/14/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024]
Abstract
Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare developmental and epileptic encephalopathies associated with seizure and nonseizure symptoms. A comprehensive understanding of how many individuals are affected globally, the diagnostic journey they face, and the extent of mortality associated with these conditions is lacking. Here, we summarize and evaluate published data on the epidemiology of DS and LGS in terms of prevalence, incidence, diagnosis, genetic mutations, and mortality and sudden unexpected death in epilepsy (SUDEP) rates. The full study protocol is registered on PROSPERO (CRD42022316930). After screening 2172 deduplicated records, 91 unique records were included; 67 provided data on DS only, 17 provided data on LGS only, and seven provided data on both. Case definitions varied considerably across studies, particularly for LGS. Incidence and prevalence estimates per 100 000 individuals were generally higher for LGS than for DS (LGS: incidence proportion = 14.5-28, prevalence = 5.8-60.8; DS: incidence proportion = 2.2-6.5, prevalence = 1.2-6.5). Diagnostic delay was frequently reported for LGS, with a wider age range at diagnosis reported than for DS (DS, 1.6-9.2 years; LGS, 2-15 years). Genetic screening data were reported by 63 studies; all screened for SCN1A variants, and only one study specifically focused on individuals with LGS. Individuals with DS had a higher mortality estimate per 1000 person-years than individuals with LGS (DS, 15.84; LGS, 6.12) and a lower median age at death. SUDEP was the most frequently reported cause of death for individuals with DS. Only four studies reported mortality information for LGS, none of which included SUDEP. This systematic review highlights the paucity of epidemiological data available for DS and especially LGS, demonstrating the need for further research and adoption of standardized diagnostic criteria.
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Affiliation(s)
- Joseph Sullivan
- Department of Neurology, University of California, San Francisco, San Francisco, California, USA
| | - Arturo Benítez
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | - Jeannine Roth
- Takeda Pharmaceuticals International, Zurich, Switzerland
| | - J Scott Andrews
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | - Drishti Shah
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | | | | | - J Helen Cross
- University College London, National Institute for Health and Care Research Biomedical Research Centre, London, UK
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4
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Gallagher D, Pérez-Palma E, Bruenger T, Ghanty I, Brilstra E, Ceulemans B, Chemaly N, de Lange I, Depienne C, Guerrini R, Mei D, Møller RS, Nabbout R, Regan BM, Schneider AL, Scheffer IE, Schoonjans AS, Symonds JD, Weckhuysen S, Zuberi SM, Lal D, Brunklaus A. Genotype-phenotype associations in 1018 individuals with SCN1A-related epilepsies. Epilepsia 2024; 65:1046-1059. [PMID: 38410936 DOI: 10.1111/epi.17882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE SCN1A variants are associated with epilepsy syndromes ranging from mild genetic epilepsy with febrile seizures plus (GEFS+) to severe Dravet syndrome (DS). Many variants are de novo, making early phenotype prediction difficult, and genotype-phenotype associations remain poorly understood. METHODS We assessed data from a retrospective cohort of 1018 individuals with SCN1A-related epilepsies. We explored relationships between variant characteristics (position, in silico prediction scores: Combined Annotation Dependent Depletion (CADD), Rare Exome Variant Ensemble Learner (REVEL), SCN1A genetic score), seizure characteristics, and epilepsy phenotype. RESULTS DS had earlier seizure onset than other GEFS+ phenotypes (5.3 vs. 12.0 months, p < .001). In silico variant scores were higher in DS versus GEFS+ (p < .001). Patients with missense variants in functionally important regions (conserved N-terminus, S4-S6) exhibited earlier seizure onset (6.0 vs. 7.0 months, p = .003) and were more likely to have DS (280/340); those with missense variants in nonconserved regions had later onset (10.0 vs. 7.0 months, p = .036) and were more likely to have GEFS+ (15/29, χ2 = 19.16, p < .001). A minority of protein-truncating variants were associated with GEFS+ (10/393) and more likely to be located in the proximal first and last exon coding regions than elsewhere in the gene (9.7% vs. 1.0%, p < .001). Carriers of the same missense variant exhibited less variability in age at seizure onset compared with carriers of different missense variants for both DS (1.9 vs. 2.9 months, p = .001) and GEFS+ (8.0 vs. 11.0 months, p = .043). Status epilepticus as presenting seizure type is a highly specific (95.2%) but nonsensitive (32.7%) feature of DS. SIGNIFICANCE Understanding genotype-phenotype associations in SCN1A-related epilepsies is critical for early diagnosis and management. We demonstrate an earlier disease onset in patients with missense variants in important functional regions, the occurrence of GEFS+ truncating variants, and the value of in silico prediction scores. Status epilepticus as initial seizure type is a highly specific, but not sensitive, early feature of DS.
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Affiliation(s)
- Declan Gallagher
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago, Chile
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Tobias Bruenger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Ismael Ghanty
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eva Brilstra
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Berten Ceulemans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Nicole Chemaly
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Iris de Lange
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Davide Mei
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Rikke S Møller
- Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Brigid M Regan
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Amy L Schneider
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia
| | - An-Sofie Schoonjans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB Center for Molecular Neurology, Antwerp, Belgium
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium
- Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Stanley Center for Psychiatric Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Neurology, McGovern Medical School, UTHealth Houston, Houston, Texas, USA
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
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Boßelmann CM, Ivaniuk A, St John M, Taylor SC, Krishnaswamy G, Milinovich A, Leu C, Gupta A, Pestana-Knight EM, Najm I, Lal D. Healthcare utilization and clinical characteristics of genetic epilepsy in electronic health records. Brain Commun 2024; 6:fcae090. [PMID: 38524155 PMCID: PMC10959483 DOI: 10.1093/braincomms/fcae090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 02/05/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024] Open
Abstract
Understanding the clinical characteristics and medical treatment of individuals affected by genetic epilepsies is instrumental in guiding selection for genetic testing, defining the phenotype range of these rare disorders, optimizing patient care pathways and pinpointing unaddressed medical need by quantifying healthcare resource utilization. To date, a matched longitudinal cohort study encompassing the entire spectrum of clinical characteristics and medical treatment from childhood through adolescence has not been performed. We identified individuals with genetic and non-genetic epilepsies and onset at ages 0-5 years by linkage across the Cleveland Clinic Health System. We used natural language processing to extract medical terms and procedures from longitudinal electronic health records and tested for cross-sectional and temporal associations with genetic epilepsy. We implemented a two-stage design: in the discovery cohort, individuals were stratified as being 'likely genetic' or 'non-genetic' by a natural language processing algorithm, and controls did not receive genetic testing. The validation cohort consisted of cases with genetic epilepsy confirmed by manual chart review and an independent set of controls who received negative genetic testing. The discovery and validation cohorts consisted of 503 and 344 individuals with genetic epilepsy and matched controls, respectively. The median age at the first encounter was 0.1 years and 7.9 years at the last encounter, and the mean duration of follow-up was 8.2 years. We extracted 188,295 Unified Medical Language System annotations for statistical analysis across 9659 encounters. Individuals with genetic epilepsy received an earlier epilepsy diagnosis and had more frequent and complex encounters with the healthcare system. Notably, the highest enrichment of encounters compared with the non-genetic groups was found during the transition from paediatric to adult care. Our computational approach could validate established comorbidities of genetic epilepsies, such as behavioural abnormality and intellectual disability. We also revealed novel associations for genitourinary abnormalities (odds ratio 1.91, 95% confidence interval: 1.66-2.20, P = 6.16 × 10-19) linked to a spectrum of underrecognized epilepsy-associated genetic disorders. This case-control study leveraged real-world data to identify novel features associated with the likelihood of a genetic aetiology and quantified the healthcare utilization of genetic epilepsies compared with matched controls. Our results strongly recommend early genetic testing to stratify individuals into specialized care paths, thus improving the clinical management of people with genetic epilepsies.
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Affiliation(s)
- Christian M Boßelmann
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Alina Ivaniuk
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Mark St John
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Sara C Taylor
- Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | | | - Alex Milinovich
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Costin Leu
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Center for Neurogenetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ajay Gupta
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | | | - Imad Najm
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Neurology, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Center for Neurogenetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T., Cambridge, MA 02142, USA
- Cologne Center for Genomics (CCG), University of Cologne, 50931 Cologne, Germany
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6
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Saez-Matia A, Ibarluzea MG, M-Alicante S, Muguruza-Montero A, Nuñez E, Ramis R, Ballesteros OR, Lasa-Goicuria D, Fons C, Gallego M, Casis O, Leonardo A, Bergara A, Villarroel A. MLe-KCNQ2: An Artificial Intelligence Model for the Prognosis of Missense KCNQ2 Gene Variants. Int J Mol Sci 2024; 25:2910. [PMID: 38474157 DOI: 10.3390/ijms25052910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
Despite the increasing availability of genomic data and enhanced data analysis procedures, predicting the severity of associated diseases remains elusive in the absence of clinical descriptors. To address this challenge, we have focused on the KV7.2 voltage-gated potassium channel gene (KCNQ2), known for its link to developmental delays and various epilepsies, including self-limited benign familial neonatal epilepsy and epileptic encephalopathy. Genome-wide tools often exhibit a tendency to overestimate deleterious mutations, frequently overlooking tolerated variants, and lack the capacity to discriminate variant severity. This study introduces a novel approach by evaluating multiple machine learning (ML) protocols and descriptors. The combination of genomic information with a novel Variant Frequency Index (VFI) builds a robust foundation for constructing reliable gene-specific ML models. The ensemble model, MLe-KCNQ2, formed through logistic regression, support vector machine, random forest and gradient boosting algorithms, achieves specificity and sensitivity values surpassing 0.95 (AUC-ROC > 0.98). The ensemble MLe-KCNQ2 model also categorizes pathogenic mutations as benign or severe, with an area under the receiver operating characteristic curve (AUC-ROC) above 0.67. This study not only presents a transferable methodology for accurately classifying KCNQ2 missense variants, but also provides valuable insights for clinical counseling and aids in the determination of variant severity. The research context emphasizes the necessity of precise variant classification, especially for genes like KCNQ2, contributing to the broader understanding of gene-specific challenges in the field of genomic research. The MLe-KCNQ2 model stands as a promising tool for enhancing clinical decision making and prognosis in the realm of KCNQ2-related pathologies.
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Affiliation(s)
| | - Markel G Ibarluzea
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
- Donostia International Physics Center, 20018 Donostia, Spain
| | - Sara M-Alicante
- Instituto Biofisika, CSIC-UPV/EHU, 48940 Leioa, Spain
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
| | | | - Eider Nuñez
- Instituto Biofisika, CSIC-UPV/EHU, 48940 Leioa, Spain
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
| | - Rafael Ramis
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
- Donostia International Physics Center, 20018 Donostia, Spain
| | - Oscar R Ballesteros
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
- Centro de Física de Materiales CFM, CSIC-UPV/EHU, 20018 Donostia, Spain
| | | | - Carmen Fons
- Pediatric Neurology Department, Sant Joan de Déu Hospital, Institut de Recerca Sant Joan de Déu, Barcelona University, 08950 Barcelona, Spain
| | - Mónica Gallego
- Departamento de Fisiología, Universidad del País Vasco, UPV/EHU, 01006 Vitoria-Gasteiz, Spain
| | - Oscar Casis
- Departamento de Fisiología, Universidad del País Vasco, UPV/EHU, 01006 Vitoria-Gasteiz, Spain
| | - Aritz Leonardo
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
- Donostia International Physics Center, 20018 Donostia, Spain
| | - Aitor Bergara
- Physics Department, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain
- Donostia International Physics Center, 20018 Donostia, Spain
- Centro de Física de Materiales CFM, CSIC-UPV/EHU, 20018 Donostia, Spain
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7
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Perry MS, Scheffer IE, Sullivan J, Brunklaus A, Boronat S, Wheless JW, Laux L, Patel AD, Roberts CM, Dlugos D, Holder D, Knupp KG, Lallas M, Phillips S, Segal E, Smeyers P, Lal D, Wirrell E, Zuberi S, Brünger T, Wojnaroski M, Maru B, O'Donnell P, Morton M, James E, Vila MC, Huang N, Gofshteyn JS, Rico S. Severe communication delays are independent of seizure burden and persist despite contemporary treatments in SCN1A+ Dravet syndrome: Insights from the ENVISION natural history study. Epilepsia 2024; 65:322-337. [PMID: 38049202 DOI: 10.1111/epi.17850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
OBJECTIVE Dravet syndrome (DS) is a developmental and epileptic encephalopathy characterized by high seizure burden, treatment-resistant epilepsy, and developmental stagnation. Family members rate communication deficits among the most impactful disease manifestations. We evaluated seizure burden and language/communication development in children with DS. METHODS ENVISION was a prospective, observational study evaluating children with DS associated with SCN1A pathogenic variants (SCN1A+ DS) enrolled at age ≤5 years. Seizure burden and antiseizure medications were assessed every 3 months and communication and language every 6 months with the Bayley Scales of Infant and Toddler Development 3rd edition and the parent-reported Vineland Adaptive Behavior Scales 3rd edition. We report data from the first year of observation, including analyses stratified by age at Baseline: 0:6-2:0 years:months (Y:M; youngest), 2:1-3:6 Y:M (middle), and 3:7-5:0 Y:M (oldest). RESULTS Between December 2020 and March 2023, 58 children with DS enrolled at 16 sites internationally. Median follow-up was 17.5 months (range = .0-24.0), with 54 of 58 (93.1%) followed for at least 6 months and 51 of 58 (87.9%) for 12 months. Monthly countable seizure frequency (MCSF) increased with age (median [minimum-maximum] = 1.0 in the youngest [1.0-70.0] and middle [1.0-242.0] age groups and 4.5 [.0-2647.0] in the oldest age group), and remained high, despite use of currently approved antiseizure medications. Language/communication delays were observed early, and developmental stagnation occurred after age 2 years with both instruments. In predictive modeling, chronologic age was the only significant covariate of seizure frequency (effect size = .52, p = .024). MCSF, number of antiseizure medications, age at first seizure, and convulsive status epilepticus were not predictors of language/communication raw scores. SIGNIFICANCE In infants and young children with SCN1A+ DS, language/communication delay and stagnation were independent of seizure burden. Our findings emphasize that the optimal therapeutic window to prevent language/communication delay is before 3 years of age.
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Affiliation(s)
- M Scott Perry
- Cook Children's Medical Center, Fort Worth, Texas, USA
| | - Ingrid E Scheffer
- University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Joseph Sullivan
- University of California, San Francisco, San Francisco, California, USA
| | | | | | | | - Linda Laux
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Anup D Patel
- Nationwide Children's Hospital, Columbus, Ohio, USA
| | | | - Dennis Dlugos
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Deborah Holder
- Cedars-Sinai Medical Center, Los Angeles, California, USA
| | | | - Matt Lallas
- Nicklaus Children's Hospital, Miami, Florida, USA
| | | | - Eric Segal
- Northeast Regional Epilepsy Group & Hackensack University Medical Center, Hackensack Meridian School of Medicine, Hackensack, New Jersey, USA
| | | | | | | | - Sameer Zuberi
- School of Health & Wellbeing, University of Glasgow, Glasgow, UK
| | | | | | | | | | - Magda Morton
- Encoded Therapeutics, South San Francisco, California, USA
| | - Emma James
- Encoded Therapeutics, South San Francisco, California, USA
| | | | - Norman Huang
- Encoded Therapeutics, South San Francisco, California, USA
| | | | - Salvador Rico
- Encoded Therapeutics, South San Francisco, California, USA
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8
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Feng T, Makiello P, Dunwoody B, Steckler F, Symonds JD, Zuberi SM, Dorris L, Brunklaus A. Long-term predictors of developmental outcome and disease burden in SCN1A-positive Dravet syndrome. Brain Commun 2024; 6:fcae004. [PMID: 38229878 PMCID: PMC10789590 DOI: 10.1093/braincomms/fcae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 11/25/2023] [Accepted: 01/05/2024] [Indexed: 01/18/2024] Open
Abstract
Dravet syndrome is a severe infantile onset developmental and epileptic encephalopathy associated with mutations in the sodium channel alpha 1 subunit gene SCN1A. Prospective data on long-term developmental and clinical outcomes are limited; this study seeks to evaluate the clinical course of Dravet syndrome over a 10-year period and identify predictors of developmental outcome. SCN1A mutation-positive Dravet syndrome patients were prospectively followed up in the UK from 2010 to 2020. Caregivers completed structured questionnaires on clinical features and disease burden; the Epilepsy & Learning Disability Quality of Life Questionnaire, the Adaptive Behavioural Assessment System-3 and the Sleep Disturbance Scale for Children. Sixty-eight of 113 caregivers (60%) returned posted questionnaires. Developmental outcome worsened at follow-up (4.45 [SD 0.65], profound cognitive impairment) compared to baseline (2.9 [SD 1.1], moderate cognitive impairment, P < 0.001), whereas epilepsy severity appeared less severe at 10-year follow-up (P = 0.042). Comorbidities were more apparent at 10-year outcome including an increase in autistic features (77% [48/62] versus 30% [17/57], χ2 = 19.9, P < 0.001), behavioural problems (81% [46/57] versus 38% [23/60], χ2 = 14.1, P < 0.001) and motor/mobility problems (80% [51/64] versus 41% [24/59], χ2 = 16.9, P < 0.001). Subgroup analysis demonstrated a more significant rise in comorbidities in younger compared to older patients. Predictors of worse long-term developmental outcome included poorer baseline language ability (P < 0.001), more severe baseline epilepsy severity (P = 0.003) and a worse SCN1A genetic score (P = 0.027). Sudden unexpected death in epilepsy had not been discussed with a medical professional in 35% (24/68) of participants. Over 90% of caregivers reported a negative impact on their own health and career opportunities. Our study identifies important predictors and potential biomarkers of developmental outcome in Dravet syndrome and emphasizes the significant caregiver burden of illness. The negative impact of epilepsy severity at baseline on long-term developmental outcomes highlights the importance of implementing early and focused therapies whilst the potential impact of newer anti-seizure medications requires further study.
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Affiliation(s)
- Tony Feng
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Phoebe Makiello
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Benjamin Dunwoody
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Felix Steckler
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Liam Dorris
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
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9
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De Wachter M, Schoonjans AS, Weckhuysen S, Van Schil K, Löfgren A, Meuwissen M, Jansen A, Ceulemans B. From diagnosis to treatment in genetic epilepsies: Implementation of precision medicine in real-world clinical practice. Eur J Paediatr Neurol 2024; 48:46-60. [PMID: 38039826 DOI: 10.1016/j.ejpn.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 07/20/2023] [Accepted: 11/11/2023] [Indexed: 12/03/2023]
Abstract
The implementation of whole exome sequencing (WES) has had a major impact on the diagnostic yield of genetic testing in individuals with epilepsy. The identification of a genetic etiology paves the way to precision medicine: an individualized treatment approach, based on the disease pathophysiology. The aim of this retrospective cohort study was to: (1) determine the diagnostic yield of WES in a heterogeneous cohort of individuals with epilepsy referred for genetic testing in a real-world clinical setting, (2) investigate the influence of epilepsy characteristics on the diagnostic yield, (3) determine the theoretical yield of treatment changes based on genetic diagnosis and (4) explore the barriers to implementation of precision medicine. WES was performed in 247 individuals with epilepsy, aged between 7 months and 68 years. In 34/247 (14 %) a (likely) pathogenic variant was identified. In 7/34 (21 %) of these individuals the variant was found using a HPO-based filtering. Diagnostic yield was highest for individuals with an early onset of epilepsy (39 %) or in those with a developmental and epileptic encephalopathy (34 %). Precision medicine was a theoretical possibility in 20/34 (59 %) of the individuals with a (likely) pathogenic variant but implemented in only 11/34 (32 %). The major barrier to implementation of precision treatment was the limited availability or reimbursement of a given drug. These results confirm the potential impact of genetic analysis on treatment choices, but also highlight the hurdles to the implementation of precision medicine. To optimize precision medicine in real-world practice, additional endeavors are needed: unifying definitions of precision medicine, establishment of publicly accessible databases that include data on the functional effect of gene variants, increasing availability and reimbursement of precision therapeutics, and broadening access to innovative clinical trials.
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Affiliation(s)
- Matthias De Wachter
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium.
| | - An-Sofie Schoonjans
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Sarah Weckhuysen
- Department of Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium; Applied&Translational Neurogenomics Group, VIB-CMN, VIB, UAntwerpen, Universiteitsplein 1, 2610, Wilrijk, Belgium; Translational Neurosciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Kristof Van Schil
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Ann Löfgren
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Marije Meuwissen
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Anna Jansen
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium; Translational Neurosciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Berten Ceulemans
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
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10
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Fan HC, Yang MT, Lin LC, Chiang KL, Chen CM. Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy. Int J Mol Sci 2023; 25:31. [PMID: 38203200 PMCID: PMC10779156 DOI: 10.3390/ijms25010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.
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Affiliation(s)
- Hueng-Chuen Fan
- Department of Pediatrics, Tungs’ Taichung Metroharbor Hospital, Wuchi, Taichung 435, Taiwan;
- Department of Rehabilitation, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 356, Taiwan
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
| | - Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan;
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan
| | - Lung-Chang Lin
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Kuo-Liang Chiang
- Department of Pediatric Neurology, Kuang-Tien General Hospital, Taichung 433, Taiwan;
- Department of Nutrition, Hungkuang University, Taichung 433, Taiwan
| | - Chuan-Mu Chen
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- The iEGG and Animal Biotechnology Center, and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan
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11
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Chiron C, Chemaly N, Chancharme L, Nabbout R. Initiating stiripentol before 2 years of age in patients with Dravet syndrome is safe and beneficial against status epilepticus. Dev Med Child Neurol 2023; 65:1607-1616. [PMID: 37198755 DOI: 10.1111/dmcn.15638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 05/19/2023]
Abstract
AIM To evaluate the safety and efficacy of stiripentol initiated before 2 years of age in patients with Dravet syndrome. METHOD This was a 30-year, real-world retrospective study. We extracted the data of the 131 patients (59 females, 72 males) who initiated stiripentol before 2 years of age between 1991 and 2021 from the four longitudinal databases of Dravet syndrome available in France. RESULTS Stiripentol was added to valproate and clobazam (93%) at 13 months and a median dose of 50 mg/kg/day. With short-term therapy (<6 months on stiripentol, median 4 months, median age 16 months), the frequency of tonic-clonic seizures (TCS) lasting longer than 5 minutes decreased (p < 0.01) and status epilepticus (>30 minutes) disappeared in 55% of patients. With long-term therapy (last visit on stiripentol <7 years of age, median stiripentol 28 months, median age 41 months), the frequency of long-lasting TCS continued to decline (p = 0.03). Emergency hospitalizations dropped from 91% to 43% and 12% with short- and long-term therapies respectively (p < 0.001). Three patients died, all from sudden unexpected death in epilepsy. Three patients discontinued stiripentol for adverse events; 55% reported at least one adverse event, mostly loss of appetite/weight (21%) and somnolence (11%). Stiripentol was used earlier, at lower doses, and was better tolerated by patients in the newest database than in the oldest (p < 0.01). INTERPRETATION Initiating stiripentol in infants with Dravet syndrome is safe and beneficial, significantly reducing long-lasting seizures including status epilepticus, hospitalizations, and mortality in the critical first years of life.
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Affiliation(s)
- Catherine Chiron
- Pediatric Neurology and French Reference Center for Rare Epilepsies (CRéER), APHP, Necker-Enfants Malades Hospital, Paris, France
- INSERM U1141 and Institut Neurospin, Paris, France
| | - Nicole Chemaly
- Pediatric Neurology and French Reference Center for Rare Epilepsies (CRéER), APHP, Necker-Enfants Malades Hospital, Paris, France
| | | | - Rima Nabbout
- Pediatric Neurology and French Reference Center for Rare Epilepsies (CRéER), APHP, Necker-Enfants Malades Hospital, Paris, France
- INSERM U1163, Institut Imagine, chaire GEEN-DS, Université Paris cité, Paris, France
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12
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Stefanski A, Pérez-Palma E, Brünger T, Montanucci L, Gati C, Klöckner C, Johannesen KM, Goodspeed K, Macnee M, Deng AT, Aledo-Serrano Á, Borovikov A, Kava M, Bouman AM, Hajianpour MJ, Pal DK, Engelen M, Hagebeuk EEO, Shinawi M, Heidlebaugh AR, Oetjens K, Hoffman TL, Striano P, Freed AS, Futtrup L, Balslev T, Abulí A, Danvoye L, Lederer D, Balci T, Nouri MN, Butler E, Drewes S, van Engelen K, Howell KB, Khoury J, May P, Trinidad M, Froelich S, Lemke JR, Tiller J, Freed AN, Kang JQ, Wuster A, Møller RS, Lal D. SLC6A1 variant pathogenicity, molecular function and phenotype: a genetic and clinical analysis. Brain 2023; 146:5198-5208. [PMID: 37647852 PMCID: PMC10689929 DOI: 10.1093/brain/awad292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/05/2023] [Accepted: 07/08/2023] [Indexed: 09/01/2023] Open
Abstract
Genetic variants in the SLC6A1 gene can cause a broad phenotypic disease spectrum by altering the protein function. Thus, systematically curated clinically relevant genotype-phenotype associations are needed to understand the disease mechanism and improve therapeutic decision-making. We aggregated genetic and clinical data from 172 individuals with likely pathogenic/pathogenic (lp/p) SLC6A1 variants and functional data for 184 variants (14.1% lp/p). Clinical and functional data were available for a subset of 126 individuals. We explored the potential associations of variant positions on the GAT1 3D structure with variant pathogenicity, altered molecular function and phenotype severity using bioinformatic approaches. The GAT1 transmembrane domains 1, 6 and extracellular loop 4 (EL4) were enriched for patient over population variants. Across functionally tested missense variants (n = 156), the spatial proximity from the ligand was associated with loss-of-function in the GAT1 transporter activity. For variants with complete loss of in vitro GABA uptake, we found a 4.6-fold enrichment in patients having severe disease versus non-severe disease (P = 2.9 × 10-3, 95% confidence interval: 1.5-15.3). In summary, we delineated associations between the 3D structure and variant pathogenicity, variant function and phenotype in SLC6A1-related disorders. This knowledge supports biology-informed variant interpretation and research on GAT1 function. All our data can be interactively explored in the SLC6A1 portal (https://slc6a1-portal.broadinstitute.org/).
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Affiliation(s)
- Arthur Stefanski
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago de Chile 7610658, Chile
| | - Tobias Brünger
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, Cologne 50931, Germany
| | - Ludovica Montanucci
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Cornelius Gati
- Department of Biological Sciences, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Chiara Klöckner
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Katrine M Johannesen
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund 4293, Denmark
- Department of Genetics, University Hospital of Copenhagen, Rigshispitalet, Copenhagen 2100, Denmark
| | - Kimberly Goodspeed
- Children’s Health, Medical Center, Dallas, TX 75235, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marie Macnee
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, Cologne 50931, Germany
| | - Alexander T Deng
- Clinical Genetics, Guys and St Thomas NHS Trust, London SE19RT, UK
| | - Ángel Aledo-Serrano
- Epilepsy Program, Neurology Department, Hospital Ruber Internacional, Madrid 28034, Spain
| | - Artem Borovikov
- Research and Counseling Department, Research Centre for Medical Genetics, Moscow 115478, Russia
| | - Maina Kava
- Department of Neurology and Metabolic Medicine, Perth Children’s Hospital, Perth 6009, Australia
- School of Paediatrics and Child Health, UWA Medical School, University of Western Australia, Perth 6009, Australia
| | - Arjan M Bouman
- Department of Clinical Genetics, Erasmus MC, University Medical Center, Rotterdam 3015GD, The Netherlands
| | - M J Hajianpour
- Department of Pediatrics, Division of Medical Genetics and Genomics, Albany Medical College, Albany Med Health System, Albany, NY 12208, USA
| | - Deb K Pal
- Department of Basic and Clinical Neurosciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College, London SE58AF, UK
- Department of Basic and Clinical Neurosciences, King’s College Hospital, London SE59RS, UK
| | - Marc Engelen
- Department of Pediatric Neurology, Amsterdam Public Health, Amsterdam University Medical Center, Amsterdam 1081HV, The Netherlands
| | - Eveline E O Hagebeuk
- Department of Pediatric Neurology, Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede and Zwolle 2103SW, The Netherlands
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, St.Louis Children’s Hospital, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | - Kathryn Oetjens
- Autism and Developmental Medicine Institute, Geisinger, Danville, PA 17837, USA
| | - Trevor L Hoffman
- Department of Regional Genetics, Anaheim, Southern California Kaiser Permanente Medical Group, CA 92806, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa 16147, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa 16132, Italy
| | - Amanda S Freed
- Department of Clinical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA 91101, USA
| | - Line Futtrup
- Department of Paediatrics, Regional Hospital of Central Jutland, Viborg 8800, Denmark
| | - Thomas Balslev
- Department of Paediatrics, Regional Hospital of Central Jutland, Viborg 8800, Denmark
- Centre for Educational Development, Aarhus University, Aarhus 8200, Denmark
| | - Anna Abulí
- Department of Clinical and Molecular Genetics and Medicine Genetics Group, VHIR, University Hospital Vall d’Hebron, Barcelona 08035, Spain
| | - Leslie Danvoye
- Department of Neurology, Université catholique de Louvain, Cliniques universitaires Saint-Luc, Brussels 1200, Belgium
| | - Damien Lederer
- Centre for Human Genetics, Institute for Pathology and Genetics, Gosselies 6041, Belgium
| | - Tugce Balci
- Department of Pediatrics, Division of Medical Genetics, Western University, London, ON N6A3K7, Canada
- Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre and Children's Health Research Institute, London, ON N6A5A5, Canada
| | - Maryam Nabavi Nouri
- Department of Paediatrics, Division of Pediatric Neurology, London Health Sciences Centre, London, ON N6A5W9, Canada
| | | | - Sarah Drewes
- Department of Medical Genetics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Kalene van Engelen
- Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre, London, ON N6A5W9, Canada
| | - Katherine B Howell
- Department of Neurology, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia
| | - Jean Khoury
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette 4362, Luxembourg
| | - Marena Trinidad
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Steven Froelich
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig 04103, Germany
| | | | | | - Jing-Qiong Kang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurology, Vanderbilt Brain Institute, Nashville, TN 37235, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Kennedy Center of Human Development, Nashville, TN 37203, USA
| | - Arthur Wuster
- Translational Genomics, BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund 4293, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense 5000, Denmark
| | - Dennis Lal
- Genomic Medicine Institute and Epilepsy Center, Cleveland Clinic, Cleveland, OH 44195, USA
- Stanley Center of Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
- Department of Neurology, University of Texas Health Sciences Center at Houston, Houston, TX 77030, USA
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13
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Zeng B, Zhang H, Lu Q, Fu Q, Yan Y, Lu W, Ma P, Feng C, Qin J, Luo L, Yang B, Zou Y, Liu Y. Identification of five novel SCN1A variants. Front Behav Neurosci 2023; 17:1272748. [PMID: 38025388 PMCID: PMC10663289 DOI: 10.3389/fnbeh.2023.1272748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Background Epilepsy is characterized by recurrent unprovoked seizures. Mutations in the voltage-gated sodium channel alpha subunit 1 (SCN1A) gene are the main monogenic cause of epilepsy. Type and location of variants make a huge difference in the severity of SCN1A disorder, ranging from the mild phenotype (genetic epilepsy with febrile seizures plus, GEFS+) to the severe phenotype (developmental and epileptic encephalopathies, DEEs). Dravet Syndrome (DS) is an infantile-onset DEE, characterized by drug-resistant epilepsy and temperature sensitivity or febrile seizures. Genetic test results reveal SCN1A variants are positive in 80% DS patients and DS is mainly caused by de novo variants. Methods Trio-whole exome sequencing (WES) was used to detect variants which were associated with clinical phenotype of five probands with epilepsy or twitching. Then, Sanger sequencing was performed to validate the five novel SCN1A variants and segregation analysis. After analyzing the location of five SCN1A variants, the pathogenic potential was assessed. Results In this study, we identified five novel SCN1A variants (c.4224G > C, c.3744_3752del, c.209del, c.5727_5734delTTTAAAACinsCTTAAAAAG and c.5776delT) as the causative variants. In the five novel SCN1A variants, four were de novo and the remaining one was inherited. All novel variants would be classified as "pathogenic" or "likely pathogenic." Conclusion The five novel SCN1A variants will enrich the SCN1A mutations database and provide the corresponding reference data for the further genetic counseling.
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Affiliation(s)
- Baitao Zeng
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Haoyi Zhang
- School of Public Health, Nanchang University, Nanchang, China
| | - Qing Lu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Qingzi Fu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yang Yan
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Wan Lu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Pengpeng Ma
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Chuanxin Feng
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Jiawei Qin
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Laipeng Luo
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Bicheng Yang
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yongyi Zou
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yanqiu Liu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
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14
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Lenge M, Balestrini S, Mei D, Macconi L, Caligiuri ME, Cuccarini V, Aquino D, Mazzi F, d’Incerti L, Darra F, Bernardina BD, Guerrini R. Morphometry and network-based atrophy patterns in SCN1A-related Dravet syndrome. Cereb Cortex 2023; 33:9532-9541. [PMID: 37344172 PMCID: PMC10431750 DOI: 10.1093/cercor/bhad224] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 06/23/2023] Open
Abstract
Mutations of the voltage-gated sodium channel SCN1A gene (MIM#182389) are among the most clinically relevant epilepsy-related genetic mutations and present variable phenotypes, from the milder genetic epilepsy with febrile seizures plus to Dravet syndrome, a severe developmental and epileptic encephalopathy. Qualitative neuroimaging studies have identified malformations of cortical development in some patients and mild atrophic changes, partially confirmed by quantitative studies. Precise correlations between MRI findings and clinical variables have not been addressed. We used morphometric methods and network-based models to detect abnormal brain structural patterns in 34 patients with SCN1A-related epilepsy, including 22 with Dravet syndrome. By measuring the morphometric characteristics of the cortical mantle and volume of subcortical structures, we found bilateral atrophic changes in the hippocampus, amygdala, and the temporo-limbic cortex (P-value < 0.05). By correlating atrophic patterns with brain connectivity profiles, we found the region of the hippocampal formation as the epicenter of the structural changes. We also observed that Dravet syndrome was associated with more severe atrophy patterns with respect to the genetic epilepsy with febrile seizures plus phenotype (r = -0.0613, P-value = 0.03), thus suggesting that both the underlying mutation and seizure severity contribute to determine atrophic changes.
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Affiliation(s)
- Matteo Lenge
- Neuroscience Department, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
| | - Simona Balestrini
- Neuroscience Department, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
| | - Davide Mei
- Neuroscience Department, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
| | - Letizia Macconi
- Neuroradiology Unit, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
| | - Maria Eugenia Caligiuri
- Neuroscience Research Center, Department of Medical and Surgical Sciences, Magna Grecia University, 88100, Catanzaro, Italy
| | - Valeria Cuccarini
- Neuroradiology Unit, Fondazione IRCCS Neurologico Carlo Besta, 20100, Milan, Italy
| | - Domenico Aquino
- Neuroradiology Unit, Fondazione IRCCS Neurologico Carlo Besta, 20100, Milan, Italy
| | - Federica Mazzi
- Neuroradiology Unit, Fondazione IRCCS Neurologico Carlo Besta, 20100, Milan, Italy
| | - Ludovico d’Incerti
- Neuroradiology Unit, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
| | - Francesca Darra
- Child Neuropsychiatry Unit, Department of Engineering for Innovation Medicine University of Verona, 37100, Verona, Italy
| | - Bernardo Dalla Bernardina
- Child Neuropsychiatry Unit, Department of Engineering for Innovation Medicine University of Verona, 37100, Verona, Italy
- Pediatric Epilepsy Research Center (CREP), Azienda Ospedaliera Universitaria Integrata, 37100, Verona, Italy
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children’s Hospital IRCCS, 50139, Florence, Italy
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15
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Pickrell WO, Fry AE. Epilepsy genetics: a practical guide for adult neurologists. Pract Neurol 2023; 23:111-119. [PMID: 36639246 DOI: 10.1136/pn-2022-003623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2022] [Indexed: 01/15/2023]
Abstract
An understanding of epilepsy genetics is important for adult neurologists, as making a genetic diagnosis gives clinical benefit. In this review, we describe the key features of different groups of genetic epilepsies. We describe the common available genetic tests for epilepsy, and how to interpret them.
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Affiliation(s)
- William Owen Pickrell
- Department of Neurology, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Andrew E Fry
- All Wales Medical Genomics Service, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
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16
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Gao C, Pielas M, Jiao F, Mei D, Wang X, Kotulska K, Jozwiak S. Epilepsy in Dravet Syndrome—Current and Future Therapeutic Opportunities. J Clin Med 2023; 12:jcm12072532. [PMID: 37048615 PMCID: PMC10094968 DOI: 10.3390/jcm12072532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023] Open
Abstract
Dravet Syndrome (DS) is a developmental epileptic encephalopathy characterized by drug-resistant seizures and other clinical features, including intellectual disability and behavioral, sleep, and gait problems. The pathogenesis is strongly connected to voltage-gated sodium channel dysfunction. The current consensus of seizure management in DS consists of a combination of conventional and recently approved drugs such as stiripentol, cannabidiol, and fenfluramine. Despite promising results in randomized clinical trials and extension studies, the prognosis of the developmental outcomes of patients with DS remains unfavorable. The article summarizes recent changes in the therapeutic approach to DS and discusses ongoing clinical research directions. Serotonergic agents under investigation show promising results and may replace less DS-specific medicines. The use of antisense nucleotides and gene therapy is focused not only on symptom relief but primarily addresses the underlying cause of the syndrome. Novel compounds, after expected safe and successful implementation in clinical practice, will open a new era for patients with DS. The main goal of causative treatment is to modify the natural course of the disease and provide the best neurodevelopmental outcome with minimum neurological deficit.
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17
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Chang YT, Hong SY, Lin WD, Lin CH, Lin SS, Tsai FJ, Chou IC. Genetic Testing in Children with Developmental and Epileptic Encephalopathies: A Review of Advances in Epilepsy Genomics. CHILDREN 2023; 10:children10030556. [PMID: 36980114 PMCID: PMC10047509 DOI: 10.3390/children10030556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023]
Abstract
Advances in disease-related gene discovery have led to tremendous innovations in the field of epilepsy genetics. Identification of genetic mutations that cause epileptic encephalopathies has opened new avenues for the development of targeted therapies. Clinical testing using extensive gene panels, exomes, and genomes is currently accessible and has resulted in higher rates of diagnosis and better comprehension of the disease mechanisms underlying the condition. Children with developmental disabilities have a higher risk of developing epilepsy. As our understanding of the mechanisms underlying encephalopathies and epilepsies improves, there may be greater potential to develop innovative therapies tailored to an individual’s genotype. This article provides an overview of the significant progress in epilepsy genomics in recent years, with a focus on developmental and epileptic encephalopathies in children. The aim of this review is to enhance comprehension of the clinical utilization of genetic testing in this particular patient population. The development of effective and precise therapeutic strategies for epileptic encephalopathies may be facilitated by a comprehensive understanding of their molecular pathogenesis.
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Affiliation(s)
- Yu-Tzu Chang
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
| | - Syuan-Yu Hong
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Medicine, School of Medicine, China Medical University, Taichung 40447, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40447, Taiwan
| | - Wei-De Lin
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
| | - Chien-Heng Lin
- Division of Pediatric Pulmonology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medial University, Taichung 40447, Taiwan
| | - Sheng-Shing Lin
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
| | - Fuu-Jen Tsai
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
- Division of Genetics and Metabolism, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Medical Genetics, China Medical University Hospital, Taichung 40447, Taiwan
- School of Chinese Medicine, China Medical University, Taichung 40447, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung 40447, Taiwan
| | - I-Ching Chou
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Graduate Institute of Integrated Medicine, China Medical University, Taichung 40447, Taiwan
- Correspondence: ; Tel.: +886-4-22052121
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18
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Costain G, Andrade DM. Third-generation computational approaches for genetic variant interpretation. Brain 2023; 146:411-412. [PMID: 36691296 DOI: 10.1093/brain/awad011] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 01/25/2023] Open
Abstract
This scientific commentary refers to ‘Delineation of functionally essential protein regions for 242 neurodevelopmental genes’ by Iqbal et al. (https://doi.org/10.1093/brain/awac381).
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Affiliation(s)
- Gregory Costain
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, and Program in Genetics & Genome Biology, SickKids Research Institute, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada.,Departments of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Danielle M Andrade
- Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, Krembil Brain Institute, Toronto, ON, Canada.,Division of Neurology, Department of Medicine, University of Toronto, Toronto, ON, Canada
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19
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Blank LJ, Jette N. Epilepsy research in 2022: clinical advances. Lancet Neurol 2023; 22:15-17. [PMID: 36517157 DOI: 10.1016/s1474-4422(22)00486-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022]
Affiliation(s)
- Leah J Blank
- Department of Neurology, Icahn School of Medicine, New York, NY, USA
| | - Nathalie Jette
- Department of Neurology, Icahn School of Medicine, New York, NY, USA.
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20
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Data-driven historical characterization of epilepsy-associated genes. Eur J Paediatr Neurol 2023; 42:82-87. [PMID: 36586220 DOI: 10.1016/j.ejpn.2022.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/11/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Many epilepsy-associated genes have been identified over the last three decades, revealing a remarkable molecular heterogeneity with the shared outcome of recurrent seizures. Information about the genetic landscape of epilepsies is scattered throughout the literature and answering the simple question of how many genes are associated with epilepsy is not straightforward. Here, we present a computationally driven analytical review of epilepsy-associated genes using the complete scientific literature in PubMed. Based on our search criteria, we identified a total of 738 epilepsy-associated genes. We further classified these genes into two Tiers. A broad gene list of 738 epilepsy-associated genes (Tier 2) and a narrow gene list composed of 143 epilepsy-associated genes (Tier 1). Our search criteria do not reflect the degree of association. The average yearly number of identified epilepsy-associated genes between 1992 and 2021 was 4.8. However, most of these genes were only identified in the last decade (2010-2019). Ion channels represent the largest class of epilepsy-associated genes. For many of these, both gain- and loss-of-function effects have been associated with epilepsy in recent years. We identify 28 genes frequently reported with heterogenous variant effects which should be considered for variant interpretation. Overall, our study provides an updated and manually curated list of epilepsy-related genes together with additional annotations and classifications reflecting the current genetic landscape of epilepsy.
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21
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Zimmern V, Korff C. Updates on the diagnostic evaluation, genotype-phenotype correlation, and treatments of genetic epilepsies. Curr Opin Pediatr 2022; 34:538-543. [PMID: 36081356 PMCID: PMC9640276 DOI: 10.1097/mop.0000000000001170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW This article reviews the latest publications in genetic epilepsies, with an eye on publications that have had a translational impact. This review is both timely and relevant as translational discoveries in genetic epilepsies are becoming so frequent that it is difficult for the general pediatrician and even the general child neurologist to keep up. RECENT FINDINGS We divide these publications from 2021 and 2022 into three categories: diagnostic testing, genotype-phenotype correlation, and therapies. We also summarize ongoing and upcoming clinical trials. SUMMARY Two meta-analyses and systematic reviews suggest that exome and genome sequencing offer higher diagnostic yield than gene panels. Genotype-phenotype correlation studies continue to increase our knowledge of the clinical evolution of genetic epilepsy syndromes, particularly with regards to sudden death, auditory dysfunction, neonatal presentation, and magnetoencephalographic manifestations. Pyridoxine supplementation may be helpful in seizure management for various genetic epilepsies. There has been interest in using the neurosteroid ganaxolone for various genetic epilepsy syndromes, with clear efficacy in certain trials. Triheptanoin for epilepsy secondary to glucose transporter 1 ( GLUT1 ) deficiency syndrome is not clearly effective but further studies will be needed.
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Affiliation(s)
- Vincent Zimmern
- Division of Child Neurology, University of Texas Southwestern, Dallas, Texas, USA
| | - Christian Korff
- Pediatric Neurology Unit, University Hospitals, Geneva, Switzerland
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22
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Brunklaus A, Brünger T, Feng T, Fons C, Lehikoinen A, Panagiotakaki E, Vintan MA, Symonds J, Andrew J, Arzimanoglou A, Delima S, Gallois J, Hanrahan D, Lesca G, MacLeod S, Marjanovic D, McTague A, Nuñez-Enamorado N, Perez-Palma E, Scott Perry M, Pysden K, Russ-Hall SJ, Scheffer IE, Sully K, Syrbe S, Vaher U, Velayutham M, Vogt J, Weiss S, Wirrell E, Zuberi SM, Lal D, Møller RS, Mantegazza M, Cestèle S. The gain of function SCN1A disorder spectrum: novel epilepsy phenotypes and therapeutic implications. Brain 2022; 145:3816-3831. [PMID: 35696452 PMCID: PMC9679167 DOI: 10.1093/brain/awac210] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/14/2022] [Accepted: 05/26/2022] [Indexed: 11/29/2022] Open
Abstract
Brain voltage-gated sodium channel NaV1.1 (SCN1A) loss-of-function variants cause the severe epilepsy Dravet syndrome, as well as milder phenotypes associated with genetic epilepsy with febrile seizures plus. Gain of function SCN1A variants are associated with familial hemiplegic migraine type 3. Novel SCN1A-related phenotypes have been described including early infantile developmental and epileptic encephalopathy with movement disorder, and more recently neonatal presentations with arthrogryposis. Here we describe the clinical, genetic and functional evaluation of affected individuals. Thirty-five patients were ascertained via an international collaborative network using a structured clinical questionnaire and from the literature. We performed whole-cell voltage-clamp electrophysiological recordings comparing sodium channels containing wild-type versus variant NaV1.1 subunits. Findings were related to Dravet syndrome and familial hemiplegic migraine type 3 variants. We identified three distinct clinical presentations differing by age at onset and presence of arthrogryposis and/or movement disorder. The most severely affected infants (n = 13) presented with congenital arthrogryposis, neonatal onset epilepsy in the first 3 days of life, tonic seizures and apnoeas, accompanied by a significant movement disorder and profound intellectual disability. Twenty-one patients presented later, between 2 weeks and 3 months of age, with a severe early infantile developmental and epileptic encephalopathy and a movement disorder. One patient presented after 3 months with developmental and epileptic encephalopathy only. Associated SCN1A variants cluster in regions of channel inactivation associated with gain of function, different to Dravet syndrome variants (odds ratio = 17.8; confidence interval = 5.4-69.3; P = 1.3 × 10-7). Functional studies of both epilepsy and familial hemiplegic migraine type 3 variants reveal alterations of gating properties in keeping with neuronal hyperexcitability. While epilepsy variants result in a moderate increase in action current amplitude consistent with mild gain of function, familial hemiplegic migraine type 3 variants induce a larger effect on gating properties, in particular the increase of persistent current, resulting in a large increase of action current amplitude, consistent with stronger gain of function. Clinically, 13 out of 16 (81%) gain of function variants were associated with a reduction in seizures in response to sodium channel blocker treatment (carbamazepine, oxcarbazepine, phenytoin, lamotrigine or lacosamide) without evidence of symptom exacerbation. Our study expands the spectrum of gain of function SCN1A-related epilepsy phenotypes, defines key clinical features, provides novel insights into the underlying disease mechanisms between SCN1A-related epilepsy and familial hemiplegic migraine type 3, and identifies sodium channel blockers as potentially efficacious therapies. Gain of function disease should be considered in early onset epilepsies with a pathogenic SCN1A variant and non-Dravet syndrome phenotype.
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Affiliation(s)
- Andreas Brunklaus
- Correspondence to: Professor Andreas Brunklaus, MD Institute of Health and Wellbeing University of Glasgow Paediatric Neurosciences Research Group Office Block, Ground Floor, Zone 2 Royal Hospital for Children 1345 Govan Road, Glasgow G51 4TF, UK E-mail:
| | - Tobias Brünger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Tony Feng
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK
| | - Carmen Fons
- Pediatric Neurology Department, CIBERER-ISCIII, Sant Joan de Déu Universitary Hospital, Institut de Recerca Sant Joan de Déu, Member of the ERN EpiCARE, Barcelona, Spain
| | - Anni Lehikoinen
- Pediatric Neurology Department, Kuopio University Hospital, Member of the ERN EpiCARE, Kuopio, Finland
| | - Eleni Panagiotakaki
- Department of Paediatric Clinical Epileptology, sleep disorders and functional neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL) and Inserm U1028/CNRS UMR5292, Lyon, France
| | - Mihaela-Adela Vintan
- ‘Iuliu Hatieganu’ University of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology and Pediatric Neurology, Victor Babes, 43, 400012 Cluj-Napoca, Romania
| | - Joseph Symonds
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK
| | - James Andrew
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK
| | - Alexis Arzimanoglou
- Pediatric Neurology Department, CIBERER-ISCIII, Sant Joan de Déu Universitary Hospital, Institut de Recerca Sant Joan de Déu, Member of the ERN EpiCARE, Barcelona, Spain
- Department of Paediatric Clinical Epileptology, sleep disorders and functional neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL) and Inserm U1028/CNRS UMR5292, Lyon, France
| | - Sarah Delima
- Indiana University School of Medicine, IU Health Riley Hospital for Children, Department of Neurology, Division of Pediatric Neurology, Indianapolis, IN, USA
| | - Julie Gallois
- Louisiana State University Health Sciences Center School of Medicine, New Orleans, LA, USA
| | - Donncha Hanrahan
- Department of Paediatric Neurology, Royal Belfast Hospital for Sick Children, Belfast, UK
| | - Gaetan Lesca
- Department of Medical Genetics, Lyon University Hospital, Member of the ERN EpiCARE, Université Claude Bernard Lyon 1, Lyon, France
| | - Stewart MacLeod
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK
| | - Dragan Marjanovic
- The Danish Epilepsy Centre, Member of the ERN EpiCARE, Dianalund, Denmark
| | - Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital for Children, Member of the ERN EpiCARE, London, UK
| | | | - Eduardo Perez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago, Chile
| | - M Scott Perry
- Jane and John Justin Neurosciences Center, Cook Children’s Medical Center, Ft Worth, TX, USA
| | - Karen Pysden
- Paediatric Neurology Department, Leeds Teaching Hospitals, Leeds General Infirmary, Leeds, UK
| | - Sophie J Russ-Hall
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Australia
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
- Murdoch Children’s Research Institute and Department of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, Australia
| | - Krystal Sully
- Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Hospital, Houston, TX, USA
| | - Steffen Syrbe
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ulvi Vaher
- Children’s Clinic of Tartu University Hospital, Faculty of Medicine of Tartu University, Member of the ERN EpiCARE, Tartu, Estonia
| | | | - Julie Vogt
- West Midlands Regional Genetics Service, Birmingham Women’s and Children’s Hospital, Birmingham, UK
| | - Shelly Weiss
- Division of Neurology, SickKids, University of Toronto, Toronto, Canada
| | - Elaine Wirrell
- Divisions of Epilepsy and Child and Adolescent Neurology, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Sameer M Zuberi
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
- Stanley Center for Psychiatric Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Rikke S Møller
- Correspondence may also be addressed to: Professor Rikke Steensbjerre Møller, PhD E-mail: ; Professor Massimo Mantegazza, PhD E-mail: ; Professor Sandrine Cestèle, PhD E-mail:
| | - Massimo Mantegazza
- Correspondence may also be addressed to: Professor Rikke Steensbjerre Møller, PhD E-mail: ; Professor Massimo Mantegazza, PhD E-mail: ; Professor Sandrine Cestèle, PhD E-mail:
| | - Sandrine Cestèle
- Correspondence may also be addressed to: Professor Rikke Steensbjerre Møller, PhD E-mail: ; Professor Massimo Mantegazza, PhD E-mail: ; Professor Sandrine Cestèle, PhD E-mail:
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23
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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.
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24
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Andrade DM. Time Is Brain: The Importance of an Accurate SCN1A Prediction Score in the Era of Precision Medicine. Epilepsy Curr 2022; 22:231-233. [PMID: 36187151 PMCID: PMC9483759 DOI: 10.1177/15357597221096017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Development and Validation of a Prediction Model for Early Diagnosis of
SCN1A-Related Epilepsies Brunklaus A, Pérez-Palma E, Ghanty I, et al. Neurology.
2022;98(11):e1163-e1174. doi:10.1212/WNL.0000000000200028. Background and objectives: Pathogenic variants in the neuronal sodium channel α1-subunit gene (SCN1A) are the
most frequent monogenic cause of epilepsy. Phenotypes comprise a wide clinical
spectrum including the severe childhood epilepsy, Dravet syndrome, characterized by
drug-resistant seizures, intellectual disability and high mortality, and the milder
genetic epilepsy with febrile seizures plus (GEFS+), characterized by normal
cognition. Early recognition of a child’s risk for developing Dravet syndrome versus
GEFS+ is key for implementing disease-modifying therapies when available before
cognitive impairment emerges. Our objective was to develop and validate a prediction
model using clinical and genetic biomarkers for early diagnosis of SCN1A-related
epilepsies. Methods: Retrospective multicenter cohort study comprising data from SCN1A-positive Dravet
syndrome and GEFS+ patients consecutively referred for genetic testing (March
2001-June 2020) including age of seizure onset and a newly-developed SCN1A genetic
score. A training cohort was used to develop multiple prediction models that were
validated using two independent blinded cohorts. Primary outcome was the
discriminative accuracy of the model predicting Dravet syndrome versus other GEFS+
phenotypes. Results: 1018 participants were included. The frequency of Dravet syndrome was 616/743 (83%)
in the training cohort, 147/203 (72%) in validation cohort 1 and 60/72 (83%) in
validation cohort 2. A high SCN1A genetic score 133.4 (SD, 78.5) versus 52.0 (SD,
57.5; p < 0.001) and young age of onset 6.0 (SD, 3.0) months versus 14.8 (SD,
11.8; p < 0.001) months, were each associated with Dravet syndrome versus GEFS+.
A combined “SCN1A genetic score and seizure onset” model separated Dravet syndrome
from GEFS+ more effectively (area under the curve [AUC], 0.89 [95% CI, 0.86-0.92])
and outperformed all other models (AUC, 0.79-0.85; p < 0.001). Model performance
was replicated in both validation cohorts 1 (AUC, 0.94 [95% CI, 0.91-0.97]) and 2
(AUC, 0.92 [95% CI, 0.82-1.00]). Discussion: The prediction model allows objective estimation at disease onset whether a child
will develop Dravet syndrome versus GEFS+, assisting clinicians with prognostic
counseling and decisions on early institution of precision therapies (http://scn1a-prediction-model.broadinstitute.org/). Classification of evidence: This study provides Class II evidence that a combined “SCN1A genetic score and
seizure onset” model distinguishes Dravet syndrome from other GEFS+ phenotypes.
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Affiliation(s)
- Danielle M. Andrade
- Adult Genetic Epilepsy Program, Division of Neurology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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25
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Wirrell EC, Hood V, Knupp KG, Meskis MA, Nabbout R, Scheffer I, Wilmshurst J, Sullivan J. The International Consensus on Diagnosis and Management of Dravet Syndrome. Epilepsia 2022; 63:1761-1777. [PMID: 35490361 PMCID: PMC9543220 DOI: 10.1111/epi.17274] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022]
Abstract
Objective This study was undertaken to gain consensus from experienced physicians and caregivers regarding optimal diagnosis and management of Dravet syndrome (DS), in the context of recently approved, DS‐specific therapies and emerging disease‐modifying treatments. Methods A core working group was convened consisting of six physicians with recognized expertise in DS and two representatives of the Dravet Syndrome Foundation. This core group summarized the current literature (focused on clinical presentation, comorbidities, maintenance and rescue therapies, and evolving disease‐modifying therapies) and nominated the 31‐member expert panel (ensuring international representation), which participated in two rounds of a Delphi process to gain consensus on diagnosis and management of DS. Results There was strong consensus that infants 2–15 months old, presenting with either a first prolonged hemiclonic seizure or first convulsive status epilepticus with fever or following vaccination, in the absence of another cause, should undergo genetic testing for DS. Panelists agreed on evolution of specific comorbidities with time, but less agreement was achieved on optimal management. There was also agreement on appropriate first‐ to third‐line maintenance therapies, which included the newly approved agents. Whereas there was agreement for recommendation of disease‐modifying therapies, if they are proven safe and efficacious for seizures and/or reduction of comorbidities, there was less consensus for when these should be started, with caregivers being more conservative than physicians. Significance This International DS Consensus, informed by both experienced global caregiver and physician voices, provides a strong overview of the impact of DS, therapeutic goals and optimal management strategies incorporating the recent therapeutic advances in DS, and evolving disease‐modifying therapies.
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Affiliation(s)
- Elaine C Wirrell
- Divisions of Child and Adolescent Medicine and Epilepsy Department of Neurology Mayo Clinic Rochester MN USA
| | | | - Kelly G Knupp
- Departments of Pediatrics and Neurology University of Colorado Anschutz Campus Aurora CO USA
| | | | - Rima Nabbout
- Reference Centre for Rare Epilepsies Department of Pediatric Neurology Necker–Enfants Malades Hospital, APHP, Member of European Reference Network EpiCARE, Institut Imagine, INSERM, UMR 1163 Université de Paris Paris France
| | - Ingrid Scheffer
- University of Melbourne Austin Health and Royal Children’s Hospital Florey Institute of Neuroscience and Mental Health Murdoch Children’s Research Institute Melbourne Australia
| | - Jo Wilmshurst
- Department of Paediatric Neurology Red Cross War Memorial Children’s Hospital Neuroscience Institute University of Cape Town South Africa
| | - Joseph Sullivan
- Departments of Neurology and Pediatrics Benioff Children’s Hospital University of California San Francisco CA USA
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