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Devinsky O, Elder C, Sivathamboo S, Scheffer IE, Koepp MJ. Idiopathic Generalized Epilepsy: Misunderstandings, Challenges, and Opportunities. Neurology 2024; 102:e208076. [PMID: 38165295 PMCID: PMC11097769 DOI: 10.1212/wnl.0000000000208076] [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: 06/12/2023] [Accepted: 10/19/2023] [Indexed: 01/03/2024] Open
Abstract
The idiopathic generalized epilepsies (IGE) make up a fifth of all epilepsies, but <1% of epilepsy research. This skew reflects misperceptions: diagnosis is straightforward, pathophysiology is understood, seizures are easily controlled, epilepsy is outgrown, morbidity and mortality are low, and surgical interventions are impossible. Emerging evidence reveals that patients with IGE may go undiagnosed or misdiagnosed with focal epilepsy if EEG or semiology have asymmetric or focal features. Genetic, electrophysiologic, and neuroimaging studies provide insights into pathophysiology, including overlaps and differences from focal epilepsies. IGE can begin in adulthood and patients have chronic and drug-resistant seizures. Neuromodulatory interventions for drug-resistant IGE are emerging. Rates of psychiatric and other comorbidities, including sudden unexpected death in epilepsy, parallel those in focal epilepsy. IGE is an understudied spectrum for which our diagnostic sensitivity and specificity, scientific understanding, and therapies remain inadequate.
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Affiliation(s)
- Orrin Devinsky
- From the Comprehensive Epilepsy Center (O.D., C.E.), New York University School of Medicine, New York, Department of Neuroscience (S.S.), Central Clinical School, Monash University, Melbourne, Department of Neurology (S.S.), Alfred Health, Melbourne; Departments of Medicine and Neurology, The Royal Melbourne Hospital (S.S.), Epilepsy Research Centre, Department of Medicine, Austin Health (I.E.S.), Murdoch Children's Research Institute (I.E.S.), and Department of Pediatrics (I.E.S.), Royal Children's Hospital, The University of Melbourne; The Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne, Victoria, Australia; and Department of Clinical and Experimental Epilepsy (M.J.K.), University College London Institute of Neurology, United Kingdom
| | - Christopher Elder
- From the Comprehensive Epilepsy Center (O.D., C.E.), New York University School of Medicine, New York, Department of Neuroscience (S.S.), Central Clinical School, Monash University, Melbourne, Department of Neurology (S.S.), Alfred Health, Melbourne; Departments of Medicine and Neurology, The Royal Melbourne Hospital (S.S.), Epilepsy Research Centre, Department of Medicine, Austin Health (I.E.S.), Murdoch Children's Research Institute (I.E.S.), and Department of Pediatrics (I.E.S.), Royal Children's Hospital, The University of Melbourne; The Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne, Victoria, Australia; and Department of Clinical and Experimental Epilepsy (M.J.K.), University College London Institute of Neurology, United Kingdom
| | - Shobi Sivathamboo
- From the Comprehensive Epilepsy Center (O.D., C.E.), New York University School of Medicine, New York, Department of Neuroscience (S.S.), Central Clinical School, Monash University, Melbourne, Department of Neurology (S.S.), Alfred Health, Melbourne; Departments of Medicine and Neurology, The Royal Melbourne Hospital (S.S.), Epilepsy Research Centre, Department of Medicine, Austin Health (I.E.S.), Murdoch Children's Research Institute (I.E.S.), and Department of Pediatrics (I.E.S.), Royal Children's Hospital, The University of Melbourne; The Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne, Victoria, Australia; and Department of Clinical and Experimental Epilepsy (M.J.K.), University College London Institute of Neurology, United Kingdom
| | - Ingrid E Scheffer
- From the Comprehensive Epilepsy Center (O.D., C.E.), New York University School of Medicine, New York, Department of Neuroscience (S.S.), Central Clinical School, Monash University, Melbourne, Department of Neurology (S.S.), Alfred Health, Melbourne; Departments of Medicine and Neurology, The Royal Melbourne Hospital (S.S.), Epilepsy Research Centre, Department of Medicine, Austin Health (I.E.S.), Murdoch Children's Research Institute (I.E.S.), and Department of Pediatrics (I.E.S.), Royal Children's Hospital, The University of Melbourne; The Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne, Victoria, Australia; and Department of Clinical and Experimental Epilepsy (M.J.K.), University College London Institute of Neurology, United Kingdom
| | - Matthias J Koepp
- From the Comprehensive Epilepsy Center (O.D., C.E.), New York University School of Medicine, New York, Department of Neuroscience (S.S.), Central Clinical School, Monash University, Melbourne, Department of Neurology (S.S.), Alfred Health, Melbourne; Departments of Medicine and Neurology, The Royal Melbourne Hospital (S.S.), Epilepsy Research Centre, Department of Medicine, Austin Health (I.E.S.), Murdoch Children's Research Institute (I.E.S.), and Department of Pediatrics (I.E.S.), Royal Children's Hospital, The University of Melbourne; The Florey Institute of Neuroscience and Mental Health (I.E.S.), Melbourne, Victoria, Australia; and Department of Clinical and Experimental Epilepsy (M.J.K.), University College London Institute of Neurology, United Kingdom
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Wu X, Zhong S, Cai Y, Yang Y, Lian Y, Ding J, Wang X. Heterozygous RELN missense variants associated with genetic generalized epilepsy. Seizure 2023; 111:122-129. [PMID: 37625192 DOI: 10.1016/j.seizure.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
PURPOSE The RELN gene encodes the secreted glycoprotein Reelin and has important functions in both developing and adult brains. In this study, we aimed to explore the association between the RELN and genetic generalized epilepsy (GGE). METHODS We performed whole-exome sequencing on a cohort of 92 patients with GGE. Based on amino acid sequence alignments, allele frequency, pedigree validation and computational modeling, the RELN variants were identified and clinical features of cases were summarized. Cell-based Reelin secretion assays were examined by Western blotting. Alterations of mutant Reelin transport through the secretion pathway were detected by immunofluorescence staining. RESULTS Three novel pathogenic RELN variants (3.26%; c.2260C>T/p.R754W, c.2914C>G/p.P972A and c.3029G>A/p.R1010H) were identified. All probands showed adolescence-onset generalized seizures characterized by generalized epileptiform discharges with normal EEG backgrounds, no or mild cognitive impairment, and responded well to anti-seizure medications. All these variants were located in the central regions from 1B to 2A consecutive repeats, and protein modeling demonstrated structural alterations in Reelin. Moreover, we found that these heterozygous missense variants significantly decreased the secretion of mutant proteins in HEK-293T cells, and this impairment was due to the altered transport of mutant Reelin in the secretion pathway. CONCLUSION These results suggest that RELN is potentially associated with GGE. The phenotype of GGE caused by RELN variants is relatively mild, and the pathogenic mechanism may involve a loss-of-function.
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Affiliation(s)
- Xiaoling Wu
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Shaoping Zhong
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yang Cai
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yuling Yang
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Yangye Lian
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Jing Ding
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Xin Wang
- Department of Neurology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
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Casillas-Espinosa PM, Lin R, Li R, Nandakumar NM, Dawson G, Braine EL, Martin B, Powell KL, O'Brien TJ. Effects of the T-type calcium channel Ca V3.2 R1584P mutation on absence seizure susceptibility in GAERS and NEC congenic rats models. Neurobiol Dis 2023:106217. [PMID: 37391087 DOI: 10.1016/j.nbd.2023.106217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 06/13/2023] [Accepted: 06/27/2023] [Indexed: 07/02/2023] Open
Abstract
RATIONALE Low-voltage-activated or T-type Ca2+ channels play a key role in the generation of seizures in absence epilepsy. We have described a homozygous, gain of function substitution mutation (R1584P) in the CaV3.2 T-type Ca2+ channel gene (Cacna1h) in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS). The non-epileptic control (NEC) rats, derived from the same original Wistar strains as GAERS but selectively in-breed not to express seizures, are null for the R1584P mutation. To study the effects of this mutation in rats who otherwise have a GAERS or NEC genetic background, we bred congenic GAERS-Cacna1hNEC (GAERS null for R1584P mutation) and congenic NEC-Cacna1hGAERS (NEC homozygous for R1584P mutation) and evaluated the seizure and behavioral phenotype of these strains in comparison to the original GAERS and NEC strains. METHODS To evaluate seizure expression in the congenic strains, EEG electrodes were implanted in NEC, GAERS, GAERS-Cacna1hNEC without the R1584P mutation, and NEC-Cacna1hGAERS with the R1584P mutation rats. In the first study, continuous EEG recordings were acquired from week 4 (when seizures begin to develop in GAERS) to week 14 of age (when GAERS display hundreds of seizures per day). In the second study, the seizure and behavioral phenotype of GAERS and NEC-Cacna1hGAERS strains were evaluated during young age (6 weeks of age) and adulthood (16 weeks of age) of GAERS, NEC, GAERS-Cacna1hNEC and NEC-Cacna1hGAERS. The Open field test (OFT) and sucrose preference test (SPT) were performed to evaluate anxiety-like and depressive-like behavior, respectively. This was followed by EEG recordings at 18 weeks of age to quantify the seizures, and spike-wave discharge (SWD) cycle frequency. At the end of the study, the whole thalamus was collected for T-type calcium channel mRNA expression analysis. RESULTS GAERS had a significantly shorter latency to first seizures and an increased number of seizures per day compared to GAERS-Cacna1hNEC. On the other hand, the presence of the R1584P mutation in the NEC-Cacna1hGAERS was not enough to generate spontaneous seizures in their seizure-resistant background. 6 and 16-week-old GAERS and GAERS-Cacna1hNEC rats showed anxiety-like behavior in the OFT, in contrast to NEC and NEC-Cacna1hGAERS. Results from the SPT showed that the GAERS developed depressive-like in the SPT compared to GAERS-Cacna1hNEC, NEC, and NEC-Cacna1hGAERS. Analysis of the EEG at 18 weeks of age showed that the GAERS had an increased number of seizures per day, increased total seizure duration and a higher cycle frequency of SWD relative to GAERS-Cacna1hNEC. However, the average seizure duration was not significantly different between strains. Quantitative real-time PCR showed that the T-type Ca2+ channel isoform CaV3.2 channel expression was significantly increased in GAERS compared to NEC, GAERS-Cacna1hNEC and NEC-Cacna1hGAERS. The presence of the R1584P mutation increased the total ratio of CaV3.2 + 25/-25 splice variants in GAERS and NEC-Cacna1hGAERS compared to NEC and GAERS-Cacna1hNEC. DISCUSSION The data from this study demonstrate that the R1584P mutation in isolation on a seizure-resistant NEC genetic background was insufficient to generate absence seizures, and that a GAERS genetic background can cause seizures even without the mutation. However, the study provides evidence that the R1584P mutation acts as a modulator of seizures development and expression, and depressive-like behavior in the SPT, but not the anxiety phenotype of the GAERS model of absence epilepsy.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria, 3004, Victoria, Australia.
| | - Runxuan Lin
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Rui Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Nanditha M Nandakumar
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Georgia Dawson
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Emma L Braine
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia
| | - Benoît Martin
- Univ Rennes, INSERM, LTSI - UMR 1099, F-35000 Rennes, France
| | - Kim L Powell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Victoria, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia; Department of Neurology, The Alfred Hospital, Commercial Road, Melbourne, Victoria, 3004, Victoria, Australia.
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Wang X, Rao X, Zhang J, Gan J. Genetic mechanisms in generalized epilepsies. ACTA EPILEPTOLOGICA 2023. [DOI: 10.1186/s42494-023-00118-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
Abstract
AbstractThe genetic generalized epilepsies (GGEs) have been proved to generate from genetic impact by twin studies and family studies. The genetic mechanisms of generalized epilepsies are always updating over time. Although the genetics of GGE is complex, there are always new susceptibility genes coming up as well as copy number variations which can lead to important breakthroughs in exploring the problem. At the same time, the development of ClinGen fades out some of the candidate genes. This means we have to figure out what accounts for a reliable gene for GGE, in another word, which gene has sufficient evidence for GGE. This will improve our understanding of the genetic mechanisms of GGE. In this review, important up-to-date genetic mechanisms of GGE were discussed.
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Chen S, Neale BM, Berkovic SF. Shared and distinct ultra-rare genetic risk for diverse epilepsies: A whole-exome sequencing study of 54,423 individuals across multiple genetic ancestries. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.02.22.23286310. [PMID: 36865150 PMCID: PMC9980234 DOI: 10.1101/2023.02.22.23286310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Identifying genetic risk factors for highly heterogeneous disorders like epilepsy remains challenging. Here, we present the largest whole-exome sequencing study of epilepsy to date to investigate rare variants that confer risk for a spectrum of epilepsy syndromes. With an unprecedented sample size of >54,000 human exomes, composed of 20,979 deep-phenotyped patients with epilepsy and 33,444 controls, we replicate previous gene findings at exome-wide significance; using a hypothesis-free approach, we identify potential novel associations. Most discoveries are specific to a particular subtype of epilepsy, highlighting distinct genetic contributions to different epilepsies. Combining evidence from rare single nucleotide/short indel-, copy number-, and common variants, we find convergence of different genetic risk factors at the level of individual genes. Further comparing to other exome-sequencing studies, we implicate shared rare variant risk between epilepsy and other neurodevelopmental disorders. Our study also demonstrates the value of collaborative sequencing and deep-phenotyping efforts, which will continue to unravel the complex genetic architecture underlying the heterogeneity of epilepsy.
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Affiliation(s)
- Siwei Chen
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Benjamin M Neale
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Samuel F Berkovic
- Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg 3084, Australia
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Sun S, Wang H. Clocking Epilepsies: A Chronomodulated Strategy-Based Therapy for Rhythmic Seizures. Int J Mol Sci 2023; 24:ijms24044223. [PMID: 36835631 PMCID: PMC9962262 DOI: 10.3390/ijms24044223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/08/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Epilepsy is a neurological disorder characterized by hypersynchronous recurrent neuronal activities and seizures, as well as loss of muscular control and sometimes awareness. Clinically, seizures have been reported to display daily variations. Conversely, circadian misalignment and circadian clock gene variants contribute to epileptic pathogenesis. Elucidation of the genetic bases of epilepsy is of great importance because the genetic variability of the patients affects the efficacies of antiepileptic drugs (AEDs). For this narrative review, we compiled 661 epilepsy-related genes from the PHGKB and OMIM databases and classified them into 3 groups: driver genes, passenger genes, and undetermined genes. We discuss the potential roles of some epilepsy driver genes based on GO and KEGG analyses, the circadian rhythmicity of human and animal epilepsies, and the mutual effects between epilepsy and sleep. We review the advantages and challenges of rodents and zebrafish as animal models for epileptic studies. Finally, we posit chronomodulated strategy-based chronotherapy for rhythmic epilepsies, integrating several lines of investigation for unraveling circadian mechanisms underpinning epileptogenesis, chronopharmacokinetic and chronopharmacodynamic examinations of AEDs, as well as mathematical/computational modeling to help develop time-of-day-specific AED dosing schedules for rhythmic epilepsy patients.
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Affiliation(s)
- Sha Sun
- Center for Circadian Clocks, Soochow University, Suzhou 215123, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou 215123, China
| | - Han Wang
- Center for Circadian Clocks, Soochow University, Suzhou 215123, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, Suzhou 215123, China
- Correspondence: or ; Tel.: +86-186-0512-8971
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Saleem T, Maqbool H, Sheikh N, Tayyeb A, Mukhtar M, Ashfaq A. GABRG2 C588T Polymorphism Is Associated with Idiopathic Generalized Epilepsy but Not with Antiepileptic Drug Resistance in Pakistani Cohort. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3460792. [PMID: 36425336 PMCID: PMC9681559 DOI: 10.1155/2022/3460792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 10/19/2022] [Accepted: 10/29/2022] [Indexed: 08/30/2023]
Abstract
Idiopathic generalized epilepsy (IGE) is the most prevalent type of epilepsy with genetic origin. Mutations in ion channel genes have been identified as a common cause of IGE. Several studies have reported various epilepsy risk variants of GABRG2 (gamma-aminobutyric acid type A receptor subunit gamma2 subunit) gene in different ethnic groups, but the results are inconsistent. The purpose of this case-control research is to determine if GABRG2 polymorphisms contribute to IGE susceptibility and antiepileptic drug resistance in Pakistani population. For this purpose, we genotyped exon2, exon5 (C540T and C588T), exon7 (T813C), exon8 (K289M), and exon9 of GABRG2 gene by restriction fragment length polymorphism and Sanger's sequencing in 87 drug-responsive idiopathic generalized epilepsy patients, 55 drug-resistant epilepsy patients, and 83 healthy controls. Restriction fragment length polymorphism (RFLP) and sequencing results indicated only C588T polymorphism in the studied subjects. The comparison of genotypic and allelic frequencies showed significant differences between IGE patients and control groups (P = 0.008 and odds ratio = 4.2) and nonsignificant association of C588T polymorphism in antiseizure medication-resistant patients (P = 0.9). Our findings showed that C588T polymorphism of GABRG2 is a risk variant for IGE in Pakistani population. Further studies are required to validate the results.
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Affiliation(s)
- Tayyaba Saleem
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Hafsa Maqbool
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Nadeem Sheikh
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Asima Tayyeb
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Maryam Mukhtar
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Aqsa Ashfaq
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
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Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives. Biomedicines 2022; 10:biomedicines10112934. [PMID: 36428502 PMCID: PMC9687921 DOI: 10.3390/biomedicines10112934] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.
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Krey I, Platzer K, Esterhuizen A, Berkovic SF, Helbig I, Hildebrand MS, Lerche H, Lowenstein D, Møller RS, Poduri A, Sadleir L, Sisodiya SM, Weckhuysen S, Wilmshurst JM, Weber Y, Lemke JR. Current practice in diagnostic genetic testing of the epilepsies. Epileptic Disord 2022; 24:765-786. [PMID: 35830287 PMCID: PMC10752379 DOI: 10.1684/epd.2022.1448] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/10/2022] [Indexed: 01/19/2023]
Abstract
Epilepsy genetics is a rapidly developing field, in which novel disease-associated genes, novel mechanisms associated with epilepsy, and precision medicine approaches are continuously being identified. In the past decade, advances in genomic knowledge and analysis platforms have begun to make clinical genetic testing accessible for, in principle, people of all ages with epilepsy. For this reason, the Genetics Commission of the International League Against Epilepsy (ILAE) presents this update on clinical genetic testing practice, including current techniques, indications, yield of genetic testing, recommendations for pre- and post-test counseling, and follow-up after genetic testing is completed. We acknowledge that the resources vary across different settings but highlight that genetic diagnostic testing for epilepsy should be prioritized when the likelihood of an informative finding is high. Results of genetic testing, in particular the identification of causative genetic variants, are likely to improve individual care. We emphasize the importance of genetic testing for individuals with epilepsy as we enter the era of precision therapy.
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Affiliation(s)
- Ilona Krey
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Alina Esterhuizen
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
| | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia
| | - Ingo Helbig
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian-Albrechts-University, Building C, Arnold-Heller-Straße 3, 24105 Kiel, Germany
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
- The Epilepsy NeuroGenetics Initiative (ENGIN), Children’s Hospital of Philadelphia, Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA
- Department of Biomedical and Health Informatics (DBHi), Children’s Hospital of Philadelphia, Philadelphia, PA, 19104 USA
- Department of Neurology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, 19104 USA
| | - Michael S. Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg and Murdoch Children’s Research Institute, Royal Children’s Hospital, Victoria, Australia
| | - Holger Lerche
- Department of Epileptology and Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Daniel Lowenstein
- Department of Neurology, University of California, San Francisco, USA
| | - Rikke S. Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Lynette Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Sanjay M. Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology London, UK and Chalfont Centre for Epilepsy, Buckinghamshire, UK
| | - Sarah Weckhuysen
- Center for Molecular Neurology, VIB-University of Antwerp, VIB, Antwerp, Belgium; Department of Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Jo M. Wilmshurst
- Department of Paediatric Neurology, Paediatric and Child Health, Red Cross War Memorial Children’s Hospital, Neuroscience Institute, University of Cape Town, South Africa
| | - Yvonne Weber
- Department of Epileptology and Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
- Department of Epileptology and Neurology, University of Aachen, Germany
| | - Johannes R. Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
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Hirsch E, French J, Scheffer IE, Bogacz A, Alsaadi T, Sperling MR, Abdulla F, Zuberi SM, Trinka E, Specchio N, Somerville E, Samia P, Riney K, Nabbout R, Jain S, Wilmshurst JM, Auvin S, Wiebe S, Perucca E, Moshé SL, Tinuper P, Wirrell EC. ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia 2022; 63:1475-1499. [PMID: 35503716 DOI: 10.1111/epi.17236] [Citation(s) in RCA: 127] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 12/13/2022]
Abstract
In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the "genetic generalized epilepsies" (GGEs), which contained the "idiopathic generalized epilepsies" (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE's Task Force on Nosology and Definitions (2017-2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic-clonic and myoclonic-tonic-clonic seizures, with 2.5-5.5 Hz generalized spike-wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.
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Affiliation(s)
- Edouard Hirsch
- Francis Rohmer Neurology Epilepsy Units, National Institute of Health and Medical Research 1258, Federation of Translational Medicine of Strasbourg, Strasbourg University, Strasbourg, France
| | - Jacqueline French
- New York University Grossman School of Medicine and NYU Langone Health, New York, New York, USA
| | - Ingrid E Scheffer
- Austin Health and Royal Children's Hospital, Florey Institute, Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Alicia Bogacz
- Institute of Neurology, Clinical Hospital, Faculty of Medicine, University of the Republic, Montevideo, Uruguay
| | - Taoufik Alsaadi
- Department of Neurology, American Center for Psychiatry and Neurology, Abu Dhabi, United Arab Emirates
| | - Michael R Sperling
- Department of Neurology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Fatema Abdulla
- Salmaniya Medical Complex-Government Hospital, Manama, Bahrain
| | - Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children and Institute of Health & Wellbeing, University of Glasgow, member of EpiCARE, Glasgow, UK
| | - Eugen Trinka
- Department of Neurology and Neuroscience Institute, Christian Doppler University Hospital, Paracelsus Medical University, Center for Cognitive Neuroscience, member of EpiCARE, Salzburg, Austria.,Department of Public Health, Health Services Research, and Health Technology Assessment, University for Health Sciences, Medical Informatics, and Technology, Hall in Tirol, Austria
| | - Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, Scientific Institute for Research and Health Care, member of EpiCARE, Rome, Italy
| | - Ernest Somerville
- Prince of Wales Hospital, University of New South Wales, Sydney, New South Wales, Australia
| | - Pauline Samia
- Department of Pediatrics and Child Health, Aga Khan University, East Africa, Nairobi, Kenya
| | - Kate Riney
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Necker-Enfants Malades Hospital, Public Hospital Network of Paris, member of EpiCARE, Imagine Institute, National Institute of Health and Medical Research, Mixed Unit of Research 1163, University of Paris, Paris, France
| | | | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Stephane Auvin
- Pediatric Neurology, Public Hospital Network of Paris, Robert Debré Hospital, NeuroDiderot, National Institute of Health and Medical Research, Department Medico-Universitaire, Innovation Robert-Debré, University of Paris, Paris, France.,University Institute of France, Paris, France
| | - Samuel Wiebe
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Emilio Perucca
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, and Departments of Neuroscience and Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA
| | - Paolo Tinuper
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Institute of Neurological Sciences, Scientific Institute for Research and Health Care, member of EpiCARE, Bologna, Italy
| | - Elaine C Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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11
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Abstract
PURPOSE OF REVIEW This article reviews the clinical features, typical EEG findings, treatment, prognosis, and underlying molecular etiologies of the more common genetic epilepsy syndromes. Genetic generalized epilepsy, self-limited focal epilepsy of childhood, self-limited neonatal and infantile epilepsy, select developmental and epileptic encephalopathies, progressive myoclonus epilepsies, sleep-related hypermotor epilepsy, photosensitive occipital lobe epilepsy, and focal epilepsy with auditory features are discussed. Also reviewed are two familial epilepsy syndromes: genetic epilepsy with febrile seizures plus and familial focal epilepsy with variable foci. RECENT FINDINGS Recent years have seen considerable advances in our understanding of the genetic factors underlying genetic epilepsy syndromes. New therapies are emerging for some of these conditions; in some cases, these precision medicine approaches may dramatically improve the prognosis. SUMMARY Many recognizable genetic epilepsy syndromes exist, the identification of which is a crucial skill for neurologists, particularly those who work with children. Proper diagnosis of the electroclinical syndrome allows for appropriate treatment choices and counseling regarding prognosis and possible comorbidities.
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12
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Koko M, Motelow JE, Stanley KE, Bobbili DR, Dhindsa RS, May P. Association of ultra-rare coding variants with genetic generalized epilepsy: A case-control whole exome sequencing study. Epilepsia 2022; 63:723-735. [PMID: 35032048 PMCID: PMC8891088 DOI: 10.1111/epi.17166] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/29/2021] [Accepted: 12/29/2021] [Indexed: 01/18/2023]
Abstract
OBJECTIVE We aimed to identify genes associated with genetic generalized epilepsy (GGE) by combining large cohorts enriched with individuals with a positive family history. Secondarily, we set out to compare the association of genes independently with familial and sporadic GGE. METHODS We performed a case-control whole exome sequencing study in unrelated individuals of European descent diagnosed with GGE (previously recruited and sequenced through multiple international collaborations) and ancestry-matched controls. The association of ultra-rare variants (URVs; in 18 834 protein-coding genes) with epilepsy was examined in 1928 individuals with GGE (vs. 8578 controls), then separately in 945 individuals with familial GGE (vs. 8626 controls), and finally in 1005 individuals with sporadic GGE (vs. 8621 controls). We additionally examined the association of URVs with familial and sporadic GGE in two gene sets important for inhibitory signaling (19 genes encoding γ-aminobutyric acid type A [GABAA ] receptors, 113 genes representing the GABAergic pathway). RESULTS GABRG2 was associated with GGE (p = 1.8 × 10-5 ), approaching study-wide significance in familial GGE (p = 3.0 × 10-6 ), whereas no gene approached a significant association with sporadic GGE. Deleterious URVs in the most intolerant subgenic regions in genes encoding GABAA receptors were associated with familial GGE (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 1.9-7.8, false discovery rate [FDR]-adjusted p = .0024), whereas their association with sporadic GGE had marginally lower odds (OR = 3.1, 95% CI = 1.3-6.7, FDR-adjusted p = .022). URVs in GABAergic pathway genes were associated with familial GGE (OR = 1.8, 95% CI = 1.3-2.5, FDR-adjusted p = .0024) but not with sporadic GGE (OR = 1.3, 95% CI = .9-1.9, FDR-adjusted p = .19). SIGNIFICANCE URVs in GABRG2 are likely an important risk factor for familial GGE. The association of gene sets of GABAergic signaling with familial GGE is more prominent than with sporadic GGE.
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Affiliation(s)
- Mahmoud Koko
- Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Joshua E. Motelow
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Kate E. Stanley
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Dheeraj R. Bobbili
- Luxembourg Centre for Systems Biomedicine, University Luxembourg, 4367 Belvaux, Luxembourg
| | - Ryan S. Dhindsa
- Institute for Genomic Medicine, Columbia University, 10032 New York, USA
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, University Luxembourg, 4367 Belvaux, Luxembourg
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13
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Gozzelino L, Kochlamazashvili G, Baldassari S, Mackintosh AI, Licchetta L, Iovino E, Liu YC, Bennett CA, Bennett MF, Damiano JA, Zsurka G, Marconi C, Giangregorio T, Magini P, Kuijpers M, Maritzen T, Norata GD, Baulac S, Canafoglia L, Seri M, Tinuper P, Scheffer IE, Bahlo M, Berkovic SF, Hildebrand MS, Kunz WS, Giordano L, Bisulli F, Martini M, Haucke V, Hirsch E, Pippucci T. OUP accepted manuscript. Brain 2022; 145:2313-2331. [PMID: 35786744 PMCID: PMC9337808 DOI: 10.1093/brain/awac082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 01/13/2022] [Accepted: 02/12/2022] [Indexed: 11/20/2022] Open
Abstract
Epilepsy is one of the most frequent neurological diseases, with focal epilepsy accounting for the largest number of cases. The genetic alterations involved in focal epilepsy are far from being fully elucidated. Here, we show that defective lipid signalling caused by heterozygous ultra-rare variants in PIK3C2B, encoding for the class II phosphatidylinositol 3-kinase PI3K-C2β, underlie focal epilepsy in humans. We demonstrate that patients’ variants act as loss-of-function alleles, leading to impaired synthesis of the rare signalling lipid phosphatidylinositol 3,4-bisphosphate, resulting in mTORC1 hyperactivation. In vivo, mutant Pik3c2b alleles caused dose-dependent neuronal hyperexcitability and increased seizure susceptibility, indicating haploinsufficiency as a key driver of disease. Moreover, acute mTORC1 inhibition in mutant mice prevented experimentally induced seizures, providing a potential therapeutic option for a selective group of patients with focal epilepsy. Our findings reveal an unexpected role for class II PI3K-mediated lipid signalling in regulating mTORC1-dependent neuronal excitability in mice and humans.
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Affiliation(s)
| | | | | | - Albert Ian Mackintosh
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Laura Licchetta
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies—EpiCARE), Bologna, Italy
| | - Emanuela Iovino
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
| | - Yu Chi Liu
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VictoriaAustralia
| | - Caitlin A Bennett
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Mark F Bennett
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VictoriaAustralia
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Gábor Zsurka
- Department of Experimental Epileptology and Cognition Research and Department of Epileptology, University Bonn Medical Center, Venusberg Campus 1, D-53105 Bonn, Germany
| | - Caterina Marconi
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
| | - Tania Giangregorio
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
| | - Pamela Magini
- U.O. Genetica Medica, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Marijn Kuijpers
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Tanja Maritzen
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Strasse 10, 13125 Berlin, Germany
- Department of Nanophysiology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Giuseppe Danilo Norata
- Department of Excellence in Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan and Center for the Study of Atherosclerosis, SISA Bassini Hospital Cinisello B, Italy
| | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau—Paris Brain Institute—ICM, Inserm, CNRS, F-75013 Paris, France
| | - Laura Canafoglia
- Unit of Integrated Diagnostics for Epilepsy, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marco Seri
- Department of Medical and Surgical Sciences (DIMEC), University of Bologna, Bologna, Italy
- U.O. Genetica Medica, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Paolo Tinuper
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies—EpiCARE), Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Melbourne, Victoria, Australia
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Melanie Bahlo
- Spedali Civili, Neuropsychiatric Department, Brescia, Italy
- Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Melbourne, Victoria, Australia
| | - Wolfram S Kunz
- Department of Experimental Epileptology and Cognition Research and Department of Epileptology, University Bonn Medical Center, Venusberg Campus 1, D-53105 Bonn, Germany
| | - Lucio Giordano
- Spedali Civili, Neuropsychiatric Department, Brescia, Italy
| | - Francesca Bisulli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies—EpiCARE), Bologna, Italy
- Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | | | - Volker Haucke
- Volker Haucke Robert-Roessle-Strasse 10, 13125 Berlin, Germany E-mail:
| | - Emilio Hirsch
- Correspondence may also be addressed to: Emilio Hirsch via Nizza 52, 10126 Torino (TO), Italy E-mail:
| | - Tommaso Pippucci
- Correspondence to: Tommaso Pippucci Via Giuseppe Massarenti 9, 40138 Bologna (BO), Italy E-mail:
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14
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Murphy M, McSweeney N, Cavalleri G, Greally M, Benson K, Costello D. KBG syndrome mimicking genetic generalized epilepsy. Epilepsy Behav Rep 2022; 19:100545. [PMID: 35573061 PMCID: PMC9092988 DOI: 10.1016/j.ebr.2022.100545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 10/28/2022] Open
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15
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New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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16
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Wolking S, Moreau C, McCormack M, Krause R, Krenn M, Berkovic S, Cavalleri GL, Delanty N, Depondt C, Johnson MR, Koeleman BPC, Kunz WS, Lerche H, Marson AG, O’Brien TJ, Petrovski S, Sander JW, Sills GJ, Striano P, Zara F, Zimprich F, Sisodiya SM, Girard SL, Cossette P. Assessing the role of rare genetic variants in drug-resistant, non-lesional focal epilepsy. Ann Clin Transl Neurol 2021; 8:1376-1387. [PMID: 34018700 PMCID: PMC8283173 DOI: 10.1002/acn3.51374] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/08/2021] [Accepted: 04/14/2021] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE Resistance to antiseizure medications (ASMs) is one of the major concerns in the treatment of epilepsy. Despite the increasing number of ASMs available, the proportion of individuals with drug-resistant epilepsy remains unchanged. In this study, we aimed to investigate the role of rare genetic variants in ASM resistance. METHODS We performed exome sequencing of 1,128 individuals with non-familial non-acquired focal epilepsy (NAFE) (762 non-responders, 366 responders) and were provided with 1,734 healthy controls. We undertook replication in a cohort of 350 individuals with NAFE (165 non-responders, 185 responders). We performed gene-based and gene-set-based kernel association tests to investigate potential enrichment of rare variants in relation to drug response status and to risk for NAFE. RESULTS We found no gene or gene set that reached genome-wide significance. Yet, we identified several prospective candidate genes - among them DEPDC5, which showed a potential association with resistance to ASMs. We found some evidence for an enrichment of truncating variants in dominant familial NAFE genes in our cohort of non-familial NAFE and in association with drug-resistant NAFE. INTERPRETATION Our study identifies potential candidate genes for ASM resistance. Our results corroborate the role of rare variants for non-familial NAFE and imply their involvement in drug-resistant epilepsy. Future large-scale genetic research studies are needed to substantiate these findings.
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Affiliation(s)
- Stefan Wolking
- Université de MontréalMontrealCanada
- Neurology and EpileptologyHertie Institute for Clinical Brain ResearchUniversity of TübingenTübingenGermany
- Department of Epileptology and NeurologyUniversity of AachenAachenGermany
| | - Claudia Moreau
- Centre Intersectoriel en Santé DurableUniversité du Québec à ChicoutimiSaguenayCanada
| | - Mark McCormack
- Molecular and Cellular TherapeuticsRoyal College of Surgeons in IrelandDublinIreland
| | - Roland Krause
- Luxembourg Centre for Systems BiomedicineUniversity of LuxembourgEsch‐sur‐AlzetteLuxembourg
| | - Martin Krenn
- Department of NeurologyMedical University of ViennaViennaAustria
| | | | - Samuel Berkovic
- Department of MedicineEpilepsy Research Centre, Austin HealthUniversity of MelbourneMelbourneAustralia
- Department of NeurologyAustin HealthHeidelbergAustralia
| | - Gianpiero L. Cavalleri
- Department of Molecular and Cellular TherapeuticsRoyal College of Surgeons in IrelandDublinIreland
- FutureNeuro Research CentreScience Foundation IrelandDublinIreland
- Division of Brain SciencesImperial College Faculty of MedicineLondonUK
| | - Norman Delanty
- Department of Molecular and Cellular TherapeuticsRoyal College of Surgeons in IrelandDublinIreland
- FutureNeuro Research CentreScience Foundation IrelandDublinIreland
- Division of NeurologyBeaumont HospitalDublinIreland
| | - Chantal Depondt
- Department of NeurologyHôpital ErasmeUniversité Libre de BruxellesBrusselsBelgium
| | | | | | - Wolfram S. Kunz
- Institute of Experimental Epileptology and Cognition Research and Department of EpileptologyUniversity of BonnBonnGermany
| | - Holger Lerche
- Neurology and EpileptologyHertie Institute for Clinical Brain ResearchUniversity of TübingenTübingenGermany
| | - Anthony G. Marson
- Department of Molecular and Clinical PharmacologyInstitute of Translational MedicineUniversity of LiverpoolLiverpoolUK
- The Walton Centre NHS Foundation TrustLiverpoolUK
- Liverpool Health PartnersLiverpoolUK
| | - Terence J. O’Brien
- Departments of Medicine and NeurologyRoyal Melbourne HospitalUniversity of MelbourneParkvilleAustralia
- Departments of Neuroscience and NeurologyThe Central Clinical SchoolMonash University and The Alfred HospitalMelbourneAustralia
| | - Slave Petrovski
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&DAstraZenecaCambridgeUK
| | - Josemir W. Sander
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyChalfont‐St‐PeterUK
- Stichting Epilepsie Instellingen Nederland (SEIN)HeemstedeNetherlands
| | | | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases UnitIRCCS "G. Gaslini" InstituteGenovaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversity of GenoaGenovaItaly
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversity of GenoaGenovaItaly
- Laboratory of Neurogenetics and NeuroscienceIRCCS "G. Gaslini" InstituteGenovaItaly
| | - Fritz Zimprich
- Department of NeurologyMedical University of ViennaViennaAustria
| | - Sanjay M. Sisodiya
- Department of Clinical and Experimental EpilepsyUCL Queen Square Institute of NeurologyLondonUK
- Chalfont Centre for EpilepsyChalfont‐St‐PeterUK
| | - Simon L. Girard
- Centre Intersectoriel en Santé DurableUniversité du Québec à ChicoutimiSaguenayCanada
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17
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Chen WL, Mefford HC. Diagnostic Considerations in the Epilepsies-Testing Strategies, Test Type Advantages, and Limitations. Neurotherapeutics 2021; 18:1468-1477. [PMID: 34532824 PMCID: PMC8608977 DOI: 10.1007/s13311-021-01121-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2021] [Indexed: 02/04/2023] Open
Abstract
The role of genetics in epilepsy has been recognized for a long time. Over the past decade, genome-wide technologies have identified numerous genes and variants associated with epilepsy. In the clinical setting, a myriad of genetic testing options are available, and a subset of specific genetic diagnoses have management implications. Furthermore, genetic testing can be a dynamic process. As a result, fundamental knowledge about genetics and genomics has become essential for all specialists. Here, we review current knowledge of the genetic contribution to various types of epilepsy, provide an overview of types of genetic variants, and discuss genetic testing options and their diagnostic yield. We also consider advantages and limitations of testing approaches.
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Affiliation(s)
- Wei-Liang Chen
- Department of Pediatrics, Division of Genetic Medicine, University of Washington and Seattle Children's Hospital, Seattle, WA, 98105, USA
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington and Seattle Children's Hospital, Seattle, WA, 98105, USA.
- Current Location: Center for Pediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
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18
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Khoshkhoo S, Lal D, Walsh CA. Application of single cell genomics to focal epilepsies: A call to action. Brain Pathol 2021; 31:e12958. [PMID: 34196990 PMCID: PMC8412079 DOI: 10.1111/bpa.12958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/24/2022] Open
Abstract
Focal epilepsies are the largest epilepsy subtype and associated with significant morbidity. Somatic variation is a newly recognized genetic mechanism underlying a subset of focal epilepsies, but little is known about the processes through which somatic mosaicism causes seizures, the cell types carrying the pathogenic variants, or their developmental origin. Meanwhile, the inception of single cell biology has completely revolutionized the study of neurological diseases and has the potential to answer some of these key questions. Focusing on single cell genomics, transcriptomics, and epigenomics in focal epilepsy research, circumvents the averaging artifact associated with studying bulk brain tissue and offers the kind of granularity that is needed for investigating the consequences of somatic mosaicism. Here we have provided a brief overview of some of the most developed single cell techniques and the major considerations around applying them to focal epilepsy research.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Dennis Lal
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.,Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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Stier C, Elshahabi A, Li Hegner Y, Kotikalapudi R, Marquetand J, Braun C, Lerche H, Focke NK. Heritability of Magnetoencephalography Phenotypes Among Patients With Genetic Generalized Epilepsy and Their Siblings. Neurology 2021; 97:e166-e177. [PMID: 34045271 PMCID: PMC8279565 DOI: 10.1212/wnl.0000000000012144] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 04/07/2021] [Indexed: 11/15/2022] Open
Abstract
Objective To assess whether neuronal signals in patients with genetic generalized epilepsy (GGE) are heritable, we examined magnetoencephalography resting-state recordings in patients and their healthy siblings. Methods In a prospective, cross-sectional design, we investigated source-reconstructed power and functional connectivity in patients, siblings, and controls. We analyzed 5 minutes of cleaned and awake data without epileptiform discharges in 6 frequency bands (1–40 Hz). We further calculated intraclass correlations to estimate heritability for the imaging patterns within families. Results Compared with controls (n = 45), patients with GGE (n = 25) showed widespread increased functional connectivity (θ to γ frequency bands) and power (δ to γ frequency bands) across the spectrum. Siblings (n = 18) fell between the levels of patients and controls. Heritability of the imaging metrics was observed in regions where patients strongly differed from controls, mainly in β frequencies, but also for δ and θ power. Network connectivity in GGE was heritable in frontal, central, and inferior parietal brain areas and power in central, temporo-parietal, and subcortical structures. Presence of generalized spike-wave activity during recordings and medication were associated with the network patterns, whereas other clinical factors such as age at onset, disease duration, or seizure control were not. Conclusion Metrics of brain oscillations are well suited to characterize GGE and likely relate to genetic factors rather than the active disease or treatment. High power and connectivity levels co-segregated in patients with GGE and healthy siblings, predominantly in the β band, representing an endophenotype of GGE.
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Affiliation(s)
- Christina Stier
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Adham Elshahabi
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Yiwen Li Hegner
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Raviteja Kotikalapudi
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Justus Marquetand
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Christoph Braun
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Holger Lerche
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy
| | - Niels K Focke
- From the Clinic of Clinical Neurophysiology (C.S., R.K., N.K.F.), University Medical Center Göttingen; Department of Neurology and Epileptology, Hertie Institute of Clinical Brain Research (C.S., A.E., Y.L.H., R.K., J.M., H.L., N.K.F., C.B.), and MEG Center (C.B.), University of Tübingen, Germany; Department of Neurology (A.E.), University Hospital Zurich; Institute of Psychology (R.K.), University of Bern, Switzerland; and CIMeC (C.B.), Center for Mind/Brain Sciences, University of Trento, Italy.
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Zheng Z, Yan Y, Guo Q, Wang L, Han X, Liu S. Genetic Interaction of H19 and TGFBR1 Polymorphisms with Risk of Epilepsy in a Chinese Population. Pharmgenomics Pers Med 2021; 14:77-86. [PMID: 33488113 PMCID: PMC7814234 DOI: 10.2147/pgpm.s279664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/12/2020] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Long non-coding RNA H19 was highly expressed in the latent period of epilepsy, contributing to apoptosis of hippocampal neurons by targeting let-7b. Transforming growth factor beta receptor 1 (TGFBR1), a target of let-7b, is located on the susceptibility locus for epilepsy. In this context, we investigated the association between tagSNPs in long non-coding RNA H19 and transforming growth factor beta receptor 1 (TGFBR1) rs6478974 and the risk of epilepsy. PATIENTS AND METHODS The present study consisted of 302 patients with epilepsy and 612 age- and gender-matched controls. The polymorphisms were analyzed using a TaqMan allelic genotyping assay. H19 and TGFBR1 mRNA levels were determined using quantitative real-time polymerase chain reaction. RESULTS The TGFBR1 AT and TT genotypes emerged as a protective factor for the risk of epilepsy (AT vs AA: adjusted OR = 0.59, 95% CI: 0.39-0.89, P = 0.01; TT vs AA: adjusted OR = 0.53, 95% CI: 0.35-0.80, P = 0.002, respectively). The protective effect was also observed in recessive genetic model (adjusted OR = 0.56, 95% CI: 0.38-0.82, P = 0.003). Individuals carrying the rs6478974 TT genotype had lower levels of TGFBR1 mRNA. Moreover, the TCTAT and TCCAA haplotypes emerged as a risk factor for epilepsy and the rs3741219-rs2839698-rs6478974 was associated with an interactive effect on the risk of epilepsy. CONCLUSION The current study provides evidence of the rs6478974 TT genotype decreasing the susceptibility to epilepsy by reducing the levels of TGFBR1 mRNA.
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Affiliation(s)
- Zhaoshi Zheng
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
| | - Yayun Yan
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
| | - Qi Guo
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
| | - Libo Wang
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
| | - Xuemei Han
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
| | - Songyan Liu
- No. 1 Department of Neurology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, People's Republic of China
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Myers KA, Bennett MF, Grinton BE, Dabscheck G, Chan EK, Bello-Espinosa LE, Sadleir LG, D'Alfonso S, Schneider AL, Damiano JA, Hildebrand MS, Bahlo M, Berkovic SF, Buchhalter J, Scheffer IE. Contribution of rare genetic variants to drug response in absence epilepsy. Epilepsy Res 2021; 170:106537. [PMID: 33421703 DOI: 10.1016/j.eplepsyres.2020.106537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 01/02/2023]
Abstract
OBJECTIVE We investigated the possible significance of rare genetic variants to response to valproic acid (VPA) and ethosuximide (ETX) in patients with absence epilepsy. Our primary hypothesis was that rare CACNA1H variants are more frequent in ETX-non-responsive patients compared to ETX-responsive. Our secondary hypothesis was that rare variants in GABA-receptor genes are more frequent in VPA-non-responsive patients compared to VPA-responsive. METHODS We recruited patients with absence epilepsy treated with both VPA and ETX, and performed whole exome sequencing in order to investigate the potential role of rare variants in CACNA1H, other voltage-gated calcium channel (VGCC) genes, or GABA-receptor genes in predicting response to ETX or VPA. RESULTS Sixty-two patients were included; 12 were ETX-responsive, 14 VPA-responsive, and 36 did not have a clear positive response to either medication. We did not find significant enrichment inCACNA1H rare variants in ETX-responsive patients (odds ratio 3.43; 0.43-27.65; p = 0.20), nor was there enrichment for other VGCC genes. No significant enrichment of GABA-receptor gene rare variants was seen for VPA-non-responsive patients versus VPA-responsive. We found enrichment of rare GABA-receptor variants in our absence cohort compared to controls (odds ratio 3.82; 1.68-8.69). There was no difference in frequency of CACNA1H rs61734410 and CACNA1I rs3747178 polymorphisms between ETX-responsive and ETX-non-responsive groups; these polymorphisms have previously been reported to predict lack of response to ETX in absence epilepsy. SIGNIFICANCE We conclude that if CACNA1H rare variants predict lack of response to ETX, a larger sample is necessary to test this with sufficient power. Increased GABA-receptor gene rare variant frequency in absence epilepsy patients who fail initial anti-seizure therapy suggests subtle GABA receptor dysfunction may contribute to the underlying pathophysiology.
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Affiliation(s)
- Kenneth A Myers
- Department of Pediatrics, Division of Child Neurology, Montreal Children's Hospital, McGill University Health Centre, 1001 Décarie Blvd, Montreal, PQ, H4A 3J1, Canada; Department of Neurology & Neurosurgery, Montreal Children's Hospital, McGill University Health Centre, 1001 Décarie Blvd, Montreal, PQ, H4A 3J1, Canada; Research Institute of the McGill University Health Center, 1001 Décarie Blvd, Montreal, PQ, H4A 3J1, Canada; Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia.
| | - Mark F Bennett
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia; Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, 1G, Royal Parade, Parkville, VIC, 3052, Australia; Department of Medical Biology, The University of Melbourne, 1G, Royal Parade, Parkville, VIC, 3052, Australia
| | - Bronwyn E Grinton
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia
| | - Gabriel Dabscheck
- Department of Neurology, Royal Children's Hospital, The University of Melbourne, 50 Flemington Rd, Parkville, VIC, 3052, Australia
| | - Eunice K Chan
- Department of Neurology, Royal Children's Hospital, The University of Melbourne, 50 Flemington Rd, Parkville, VIC, 3052, Australia
| | - Luis E Bello-Espinosa
- Division of Pediatric Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, 28 Oki Dr NW, Calgary, AB, T3B 6A8, Canada
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, 23 Mein Street, Newtown, Wellington, 6021, New Zealand
| | - Sabrina D'Alfonso
- Division of Pediatric Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, 28 Oki Dr NW, Calgary, AB, T3B 6A8, Canada
| | - Amy L Schneider
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, 50 Flemington Rd, Parkville, VIC, 3052, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, 1G, Royal Parade, Parkville, VIC, 3052, Australia; Department of Medical Biology, The University of Melbourne, 1G, Royal Parade, Parkville, VIC, 3052, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia
| | - Jeffrey Buchhalter
- Division of Pediatric Neurology, Department of Pediatrics, Alberta Children's Hospital, Cumming School of Medicine, University of Calgary, 28 Oki Dr NW, Calgary, AB, T3B 6A8, Canada
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, 245 Burgundy St, Heidelberg, VIC, 3084, Australia; Department of Neurology, Royal Children's Hospital, The University of Melbourne, 50 Flemington Rd, Parkville, VIC, 3052, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, 50 Flemington Rd, Parkville, VIC, 3052, Australia; Florey Institute of Neuroscience and Mental Health, 30 Royal Parade, Parkville, VIC, 3052, Australia
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Zaki MA, ElSherif LN, Shamloul RM. Assessment of the response to antiepileptic drugs in epileptic patients with structural lesion(s) on neuroimaging. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2020. [DOI: 10.1186/s41983-020-00243-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Focal epilepsy is the most common form of epilepsy in adults. Advances in brain imaging allowed better identification of different structural lesions underlying focal epilepsy. However, the response to antiepileptic drugs in lesional epilepsy is heterogeneous and difficult to anticipate. This study aimed to evaluate the response to antiepileptic drugs (AED) in patients with lesional epilepsy and to identify the predictors for poor seizure control.
Methods
One hundred and sixty-five patients with lesional epilepsy were included; the clinical diagnosis of epilepsy and seizure classification was based on the revised criteria of the International League Against Epilepsy (ILAE). Patients were subjected to full clinical assessment, MRI brain imaging epilepsy protocol, and EEG monitoring. All subjects were followed in the epilepsy clinic for at least 6 months.
Results
75.8% of patients with lesional epilepsy showed poor response to antiepileptic medications. Cerebromalatic lesions related to brain trauma was the most frequently encountered (21.8%). Malformations of cortical development were significantly associated with poor response to AED (p = 0.040). Polytherapy and the combined use of 1st- and 2nd-generation AED were higher in the poor response group. Logistic regression analysis revealed that younger age at seizure onset and abnormal EEG findings was 0.965 times and 2.5 times more associated with poor seizure control, respectively.
Conclusion
This study revealed that patients with lesional epilepsy who develop seizures in their early life, who suffer from malformations of cortical development, or who show abnormal EEG findings are more suspected to show poor response to AED.
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Ellis CA, Ottman R, Epstein MP, Berkovic SF. Generalized, focal, and combined epilepsies in families: New evidence for distinct genetic factors. Epilepsia 2020; 61:2667-2674. [PMID: 33098311 DOI: 10.1111/epi.16732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To determine the roles of shared and distinct genetic influences on generalized and focal epilepsy operating in individuals who manifest features of both types (combined epilepsies), and in families manifesting both generalized and focal epilepsies in separate individuals (mixed families). METHODS We analyzed the deeply phenotyped Epi4K cohort of multiplex families (≥3 affected individuals per family) using methods that quantify the aggregation of phenotypes within families and the relatedness of individuals with different phenotypes within family pedigrees. RESULTS The cohort included 281 families containing 1021 individuals with generalized (n = 484), focal (304), combined (51), or unclassified (182) epilepsies. The odds of combined epilepsy was higher in relatives of participants with combined epilepsy than in relatives of those with other epilepsy types (odds ratio [OR] 5.2, 95% confidence interval [CI] 1.7-16.1, P = .004). Individuals with combined epilepsy co-occurred in families more often than expected by chance (P = .03). Within mixed families, individuals with each type of epilepsy were more closely related to relatives with the same type than to relatives with other types (P < .001). SIGNIFICANCE These findings suggest that distinct genetic influences underlie the recently recognized entity of combined epilepsies, just as generalized epilepsies and focal epilepsies each have distinct genetic influences. Mixed families may in part reflect chance co-occurrence of these distinct genetic influences. These conclusions have important implications for molecular genetic studies aimed at identifying genetic determinants of the epilepsies.
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Affiliation(s)
- Colin A Ellis
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Ruth Ottman
- Departments of Epidemiology and Neurology, and the G. H. Sergievsky Center, Columbia University, New York, NY, USA.,Division of Translational Epidemiology, New York State Psychiatric Institute, New York, NY, USA
| | - Michael P Epstein
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia.,Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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Abstract
PURPOSE OF REVIEW Seizures can arise in neocortical, thalamocortical, limbic or brainstem networks. Here, we review recent genetic mechanisms implicated in focal and genetic generalized epilepsies (GGEs). RECENT FINDINGS Pathogenic variation in GAP activity toward RAGs 1 (GATOR1) complex genes (i.e., DEPDC5, NPRL2 and NPRL3) mainly result in focal epilepsies. They are associated with high rates of sudden unexpected death in epilepsy and malformations of cortical development (MCD), where "two-hits" in GATOR1-related pathways are also found in MCDs. Large-scale sequencing studies continue to reveal new genetic risk (germline or somatic) variants, and new genes relevant to epileptic encephalopathies (EEs). Genes previously associated with EEs, including GABAA receptor genes, are now known to play a role in both common focal and GGEs in individuals without intellectual disabilities. These findings suggest that there may be a common pathophysiological mechanism in GGEs and focal epilepsies. Finally, polygenic risk scores, based on common genetic variation, offer promise in helping to differentiate between GGEs and common forms of focal epilepsies. Genetic abnormalities are a significant cause of common sporadic epilepsies, epilepsies associated with inflammatory markers, and focal epilepsies with or without MCD. Future studies using genome sequencing may provide more answers to the remaining unresolved epilepsy cases.
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Abstract
Epilepsy encompasses a group of heterogeneous brain diseases that affect more than 50 million people worldwide. Epilepsy may have discernible structural, infectious, metabolic, and immune etiologies; however, in most people with epilepsy, no obvious cause is identifiable. Based initially on family studies and later on advances in gene sequencing technologies and computational approaches, as well as the establishment of large collaborative initiatives, we now know that genetics plays a much greater role in epilepsy than was previously appreciated. Here, we review the progress in the field of epilepsy genetics and highlight molecular discoveries in the most important epilepsy groups, including those that have been long considered to have a nongenetic cause. We discuss where the field of epilepsy genetics is moving as it enters a new era in which the genetic architecture of common epilepsies is starting to be unraveled.
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Affiliation(s)
- Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria 3000, Australia.,Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria 3050, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria 3000, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria 3084, Australia;
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Krzemiński D, Masuda N, Hamandi K, Singh KD, Routley B, Zhang J. Energy landscape of resting magnetoencephalography reveals fronto-parietal network impairments in epilepsy. Netw Neurosci 2020; 4:374-396. [PMID: 32537532 PMCID: PMC7286306 DOI: 10.1162/netn_a_00125] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/07/2020] [Indexed: 12/13/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME) is a form of idiopathic generalized epilepsy. It is yet unclear to what extent JME leads to abnormal network activation patterns. Here, we characterized statistical regularities in magnetoencephalograph (MEG) resting-state networks and their differences between JME patients and controls by combining a pairwise maximum entropy model (pMEM) and novel energy landscape analyses for MEG. First, we fitted the pMEM to the MEG oscillatory power in the front-oparietal network (FPN) and other resting-state networks, which provided a good estimation of the occurrence probability of network states. Then, we used energy values derived from the pMEM to depict an energy landscape, with a higher energy state corresponding to a lower occurrence probability. JME patients showed fewer local energy minima than controls and had elevated energy values for the FPN within the theta, beta, and gamma bands. Furthermore, simulations of the fitted pMEM showed that the proportion of time the FPN was occupied within the basins of energy minima was shortened in JME patients. These network alterations were highlighted by significant classification of individual participants employing energy values as multivariate features. Our findings suggested that JME patients had altered multistability in selective functional networks and frequency bands in the fronto-parietal cortices.
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Affiliation(s)
- Dominik Krzemiński
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom
| | - Naoki Masuda
- Department of Engineering Mathematics, University of Bristol, United Kingdom
| | - Khalid Hamandi
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom
| | - Krish D Singh
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom
| | - Bethany Routley
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom
| | - Jiaxiang Zhang
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, United Kingdom
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Tan L, Chen Y, Wu W, Liu C, Fu Y, He J, Zhang M, Wang G, Wang K, Long H, Xiao W, Xiao B, Long L. Impaired Cognitive Abilities in Siblings of Patients with Temporal Lobe Epilepsy. Neuropsychiatr Dis Treat 2020; 16:3071-3079. [PMID: 33363375 PMCID: PMC7752648 DOI: 10.2147/ndt.s258074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Patients with temporal lobe epilepsy (TLE) are at high risk of cognitive impairment. In addition to persistent seizures and antiepileptic drugs (AEDs), genetic factors also play an important role in the progression of cognitive deficits in TLE patients. Defining a cognitive endophenotype for TLE can provide information on the risk of cognitive impairment in patients. This study investigated the cognitive endophenotype of TLE by comparing neuropsychological function between patients with TLE, their unaffected siblings, and healthy control subjects. PATIENTS AND METHODS A total of 46 patients with TLE, 26 siblings, and 33 control subjects were recruited. Cognitive function (ie, general cognition, short- and long-term memory, attention, visuospatial and executive functions, and working memory) was assessed with a battery of neuropsychological tests. Differences between groups were evaluated by analysis of covariance, with age and years of education as covariates. The Kruskal-Wallis test was used to evaluate data that did not satisfy the homogeneity of variance assumption. Pairwise comparisons were adjusted by Bonferroni correction, with a significance threshold of P<0.05. RESULTS Patients with TLE showed deficits in the information test (P<0.001), arithmetic test (P=0.003), digit symbol substitution test (P=0.001), block design test (BDT; P=0.005), and backward digit span test (P=0.001) and took a longer time to complete the Hayling test Part A (P=0.011) compared to controls. Left TLE patients tended to have worse executive function test scores than right TLE patients. The siblings of TLE patients showed deficits in the BDT (P=0.006, Bonferroni-corrected) relative to controls. CONCLUSION Patients with TLE exhibit cognitive impairment. Executive function is worse in patients with left TLE than in those with right TLE. Siblings show impaired visuospatial function relative to controls. Thus, cognitive deficits in TLE patients have a genetic component and are independent of seizures or AED use.
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Affiliation(s)
- Langzi Tan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Yayu Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Wenyue Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Chaorong Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Yujiao Fu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Jialinzi He
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Min Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Ge Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Kangrun Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Hongyu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Wenbiao Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
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Quantitative analysis of phenotypic elements augments traditional electroclinical classification of common familial epilepsies. Epilepsia 2019; 60:2194-2203. [PMID: 31625138 PMCID: PMC7145322 DOI: 10.1111/epi.16354] [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: 01/23/2019] [Revised: 08/16/2019] [Accepted: 09/04/2019] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Classification of epilepsy into types and subtypes is important for both clinical care and research into underlying disease mechanisms. A quantitative, data-driven approach may augment traditional electroclinical classification and shed new light on existing classification frameworks. METHODS We used latent class analysis, a statistical method that assigns subjects into groups called latent classes based on phenotypic elements, to classify individuals with common familial epilepsies from the Epi4K Multiplex Families study. Phenotypic elements included seizure types, seizure symptoms, and other elements of the medical history. We compared class assignments to traditional electroclinical classifications and assessed familial aggregation of latent classes. RESULTS A total of 1120 subjects with epilepsy were assigned to five latent classes. Classes 1 and 2 contained subjects with generalized epilepsy, largely reflecting the distinction between absence epilepsies and younger onset (class 1) versus myoclonic epilepsies and older onset (class 2). Classes 3 and 4 contained subjects with focal epilepsies, and in contrast to classes 1 and 2, these did not adhere as closely to clinically defined focal epilepsy subtypes. Class 5 contained nearly all subjects with febrile seizures plus or unknown epilepsy type, as well as a few subjects with generalized epilepsy and a few with focal epilepsy. Family concordance of latent classes was similar to or greater than concordance of clinically defined epilepsy types. SIGNIFICANCE Quantitative classification of epilepsy has the potential to augment traditional electroclinical classification by (1) combining some syndromes into a single class, (2) splitting some syndromes into different classes, (3) helping to classify subjects who could not be classified clinically, and (4) defining the boundaries of clinically defined classifications. This approach can guide future research, including molecular genetic studies, by identifying homogeneous sets of individuals that may share underlying disease mechanisms.
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Krenn M, Ernst M, Tomschik M, Treven M, Wagner M, Westphal DS, Meitinger T, Pataraia E, Zimprich F, Aull-Watschinger S. Phenotypic variability of GABRA1-related epilepsy in monozygotic twins. Ann Clin Transl Neurol 2019; 6:2317-2322. [PMID: 31568673 PMCID: PMC6856628 DOI: 10.1002/acn3.50895] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 01/01/2023] Open
Abstract
Variants in GABRA1 have been associated with different epilepsies ranging from mild generalized forms to epileptic encephalopathies. Despite the broad clinical spectrum, phenotypes were found to be largely concordant within families. Contrary to this observation, we report monozygotic twin sisters with generalized epilepsy due to the c.541C>T; p.(Pro181Ser) de novo variant in GABRA1. One experienced juvenile absence seizures promptly responding to first-line medication, whereas the second developed severe treatment-refractory epilepsy with febrile, absence, atonic, and tonic-clonic seizures indicating marked intrafamilial variability in GABRA1-related epilepsy. Moreover, we provide a molecular characterization of the novel variant based on recently published structural data.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria.,Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Margot Ernst
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Matthias Tomschik
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Marco Treven
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Neurogenomics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dominik S Westphal
- Institute of Human Genetics, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technical University Munich, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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30
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Ellis CA, Petrovski S, Berkovic SF. Epilepsy genetics: clinical impacts and biological insights. Lancet Neurol 2019; 19:93-100. [PMID: 31494011 DOI: 10.1016/s1474-4422(19)30269-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/18/2019] [Accepted: 06/11/2019] [Indexed: 01/23/2023]
Abstract
Genomics now has an increasingly important role in neurology clinics. Regarding the epilepsies, innovations centred around technology, analytics, and collaboration have led to remarkable progress in gene discovery and have revealed the diverse array of genetic mechanisms and neurobiological pathways that contribute to these disorders. The new genomic era can present a challenge to clinicians, who now find themselves asked to interpret and apply genetic data to their daily management of patients with epilepsy. Navigation of this new era will require genetic literacy and familiarity with research advances in epilepsy genetics. Genetic epilepsy diagnoses now directly affect clinical care, and their importance will only increase as new targeted treatments continue to emerge. At the same time, new genetic insights challenge us to move from a deterministic view of genetic changes to a more nuanced appreciation of genetic risk within complex neurobiological systems that give rise to epilepsy.
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Affiliation(s)
- Colin A Ellis
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA; Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia
| | - Slavé Petrovski
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia; Centre for Genomics Research, Discovery Sciences, Research and Development Biopharmaceuticals, AstraZeneca, Cambridge, UK
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia.
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31
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An overview of structurally diversified anticonvulsant agents. ACTA PHARMACEUTICA (ZAGREB, CROATIA) 2019; 69:321-344. [PMID: 31259739 DOI: 10.2478/acph-2019-0023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/15/2018] [Indexed: 01/19/2023]
Abstract
There are several limited approaches to treat epilepsy in hospitals, for example, using medicines, surgery, electrical stimulation and dietary interventions. Despite the availability of all these new and old approaches, seizure is particularly difficult to manage. The quest for new antiepileptic molecules with more specificity and less CNS toxicity continues for medicinal chemists until a new and ideal drug arrives. This review covers new antiseizure molecules of different chemical classes, the exact mode of action of which is still unidentified. Newer agents include sulfonamides, thiadiazoles, semi- and thiosemicarbazones, pyrrolidine-2,5-diones, imidazoles, benzothiazoles and amino acid deriva tives. These new chemical entities can be useful for the design and development of forthcoming antiseizure agents.
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32
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Caciagli L, Wandschneider B, Xiao F, Vollmar C, Centeno M, Vos SB, Trimmel K, Sidhu MK, Thompson PJ, Winston GP, Duncan JS, Koepp MJ. Abnormal hippocampal structure and function in juvenile myoclonic epilepsy and unaffected siblings. Brain 2019; 142:2670-2687. [PMID: 31365054 PMCID: PMC6776114 DOI: 10.1093/brain/awz215] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 04/09/2019] [Accepted: 05/27/2019] [Indexed: 02/05/2023] Open
Abstract
Juvenile myoclonic epilepsy is the most common genetic generalized epilepsy syndrome, characterized by a complex polygenetic aetiology. Structural and functional MRI studies demonstrated mesial or lateral frontal cortical derangements and impaired fronto-cortico-subcortical connectivity in patients and their unaffected siblings. The presence of hippocampal abnormalities and associated memory deficits is controversial, and functional MRI studies in juvenile myoclonic epilepsy have not tested hippocampal activation. In this observational study, we implemented multi-modal MRI and neuropsychological data to investigate hippocampal structure and function in 37 patients with juvenile myoclonic epilepsy, 16 unaffected siblings and 20 healthy controls, comparable for age, gender, handedness and hemispheric dominance as assessed with language laterality indices. Automated hippocampal volumetry was complemented by validated qualitative and quantitative morphological criteria to detect hippocampal malrotation, assumed to represent a neurodevelopmental marker. Neuropsychological measures of verbal and visuo-spatial learning and an event-related verbal and visual memory functional MRI paradigm addressed mesiotemporal function. We detected a reduction of mean left hippocampal volume in patients and their siblings compared with controls (P < 0.01). Unilateral or bilateral hippocampal malrotation was identified in 51% of patients and 50% of siblings, against 15% of controls (P < 0.05). For bilateral hippocampi, quantitative markers of verticalization had significantly larger values in patients and siblings compared with controls (P < 0.05). In the patient subgroup, there was no relationship between structural measures and age at disease onset or degree of seizure control. No overt impairment of verbal and visual memory was identified with neuropsychological tests. Functional mapping highlighted atypical patterns of hippocampal activation, pointing to abnormal recruitment during verbal encoding in patients and their siblings [P < 0.05, familywise error (FWE)-corrected]. Subgroup analyses indicated distinct profiles of hypoactivation along the hippocampal long axis in juvenile myoclonic epilepsy patients with and without malrotation; patients with malrotation also exhibited reduced frontal recruitment for verbal memory, and more pronounced left posterior hippocampal involvement for visual memory. Linear models across the entire study cohort indicated significant associations between morphological markers of hippocampal positioning and hippocampal activation for verbal items (all P < 0.05, FWE-corrected). We demonstrate abnormalities of hippocampal volume, shape and positioning in patients with juvenile myoclonic epilepsy and their siblings, which are associated with reorganization of function and imply an underlying neurodevelopmental mechanism with expression during the prenatal stage. Co-segregation of abnormal hippocampal morphology in patients and their siblings is suggestive of a genetic imaging phenotype, independent of disease activity, and can be construed as a novel endophenotype of juvenile myoclonic epilepsy.
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Affiliation(s)
- Lorenzo Caciagli
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Britta Wandschneider
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Fenglai Xiao
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Christian Vollmar
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
- Department of Neurology, Ludwig-Maximilians-Universität, Marchioninistrasse 15, Munich, Germany
| | - Maria Centeno
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Sjoerd B Vos
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK
- Centre for Medical Image Computing, University College London, London, UK
| | - Karin Trimmel
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Meneka K Sidhu
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Pamela J Thompson
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
- Department of Medicine, Division of Neurology, Queen’s University, Kingston, Ontario, Canada
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, UK
- MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK
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Helbig I, Riggs ER, Barry CA, Klein KM, Dyment D, Thaxton C, Sadikovic B, Sands TT, Wagnon JL, Liaquat K, Cilio MR, Mirzaa G, Park K, Axeen E, Butler E, Bardakjian TM, Striano P, Poduri A, Siegert RK, Grant AR, Helbig KL, Mefford HC. The ClinGen Epilepsy Gene Curation Expert Panel-Bridging the divide between clinical domain knowledge and formal gene curation criteria. Hum Mutat 2019; 39:1476-1484. [PMID: 30311377 DOI: 10.1002/humu.23632] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/01/2018] [Accepted: 08/28/2018] [Indexed: 01/03/2023]
Abstract
The field of epilepsy genetics is advancing rapidly and epilepsy is emerging as a frequent indication for diagnostic genetic testing. Within the larger ClinGen framework, the ClinGen Epilepsy Gene Curation Expert Panel is tasked with connecting two increasingly separate fields: the domain of traditional clinical epileptology, with its own established language and classification criteria, and the rapidly evolving area of diagnostic genetic testing that adheres to formal criteria for gene and variant curation. We identify critical components unique to the epilepsy gene curation effort, including: (a) precise phenotype definitions within existing disease and phenotype ontologies; (b) consideration of when epilepsy should be curated as a distinct disease entity; (c) strategies for gene selection; and (d) emerging rules for evaluating functional models for seizure disorders. Given that de novo variants play a prominent role in many of the epilepsies, sufficient genetic evidence is often awarded early in the curation process. Therefore, the emphasis of gene curation is frequently shifted toward an iterative precuration process to better capture phenotypic associations. We demonstrate that within the spectrum of neurodevelopmental disorders, gene curation for epilepsy-associated genes is feasible and suggest epilepsy-specific conventions, laying the groundwork for a curation process of all major epilepsy-associated genes.
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Affiliation(s)
- Ingo Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Neuropediatrics, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Erin Rooney Riggs
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Carrie-Anne Barry
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Karl Martin Klein
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe University, Frankfurt am Main, Frankfurt, Germany.,Department of Neurology, Epilepsy Center Hessen, Philipps University, Marburg, Marburg, Germany
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University Molecular Genetic Laboratory, London Health Sciences, London, Ontario, Canada
| | - Tristan T Sands
- Division of Child Neurology, Columbia University Medical Center, New York, New York, USA
| | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Khalida Liaquat
- Quest Diagnostics, Athena Diagnostics, Marlborough, Massachusetts, USA
| | - Maria Roberta Cilio
- Departments of Pediatrics and Neurology, University of California, San Francisco, California, USA
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Kristen Park
- Department of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Erika Axeen
- Department of Neurology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Tanya M Bardakjian
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rebecca K Siegert
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Andrew R Grant
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Katherine L Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Heather C Mefford
- Division of Genetic Medicine, University of Washington, Seattle, Washington, USA
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34
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Feng YCA, Howrigan DP, Abbott LE, Tashman K, Cerrato F, Singh T, Heyne H, Byrnes A, Churchhouse C, Watts N, Solomonson M, Lal D, Heinzen EL, Dhindsa RS, Stanley KE, Cavalleri GL, Hakonarson H, Helbig I, Krause R, May P, Weckhuysen S, Petrovski S, Kamalakaran S, Sisodiya SM, Cossette P, Cotsapas C, De Jonghe P, Dixon-Salazar T, Guerrini R, Kwan P, Marson AG, Stewart R, Depondt C, Dlugos DJ, Scheffer IE, Striano P, Freyer C, McKenna K, Regan BM, Bellows ST, Leu C, Bennett CA, Johns EM, Macdonald A, Shilling H, Burgess R, Weckhuysen D, Bahlo M, O’Brien TJ, Todaro M, Stamberger H, Andrade DM, Sadoway TR, Mo K, Krestel H, Gallati S, Papacostas SS, Kousiappa I, Tanteles GA, Štěrbová K, Vlčková M, Sedláčková L, Laššuthová P, Klein KM, Rosenow F, Reif PS, Knake S, Kunz WS, Zsurka G, Elger CE, Bauer J, Rademacher M, Pendziwiat M, Muhle H, Rademacher A, van Baalen A, von Spiczak S, Stephani U, Afawi Z, Korczyn AD, Kanaan M, Canavati C, Kurlemann G, Müller-Schlüter K, Kluger G, Häusler M, Blatt I, Lemke JR, Krey I, Weber YG, Wolking S, Becker F, Hengsbach C, Rau S, Maisch AF, Steinhoff BJ, Schulze-Bonhage A, Schubert-Bast S, Schreiber H, Borggräfe I, Schankin CJ, Mayer T, Korinthenberg R, Brockmann K, Kurlemann G, Dennig D, Madeleyn R, Kälviäinen R, Auvinen P, Saarela A, Linnankivi T, Lehesjoki AE, Rees MI, Chung SK, Pickrell WO, Powell R, Schneider N, Balestrini S, Zagaglia S, Braatz V, Johnson MR, Auce P, Sills GJ, Baum LW, Sham PC, Cherny SS, Lui CH, Barišić N, Delanty N, Doherty CP, Shukralla A, McCormack M, El-Naggar H, Canafoglia L, Franceschetti S, Castellotti B, Granata T, Zara F, Iacomino M, Madia F, Vari MS, Mancardi MM, Salpietro V, Bisulli F, Tinuper P, Licchetta L, Pippucci T, Stipa C, Minardi R, Gambardella A, Labate A, Annesi G, Manna L, Gagliardi M, Parrini E, Mei D, Vetro A, Bianchini C, Montomoli M, Doccini V, Marini C, Suzuki T, Inoue Y, Yamakawa K, Tumiene B, Sadleir LG, King C, Mountier E, Caglayan SH, Arslan M, Yapıcı Z, Yis U, Topaloglu P, Kara B, Turkdogan D, Gundogdu-Eken A, Bebek N, Uğur-İşeri S, Baykan B, Salman B, Haryanyan G, Yücesan E, Kesim Y, Özkara Ç, Poduri A, Shiedley BR, Shain C, Buono RJ, Ferraro TN, Sperling MR, Lo W, Privitera M, French JA, Schachter S, Kuzniecky RI, Devinsky O, Hegde M, Khankhanian P, Helbig KL, Ellis CA, Spalletta G, Piras F, Piras F, Gili T, Ciullo V, Reif A, McQuillin A, Bass N, McIntosh A, Blackwood D, Johnstone M, Palotie A, Pato MT, Pato CN, Bromet EJ, Carvalho CB, Achtyes ED, Azevedo MH, Kotov R, Lehrer DS, Malaspina D, Marder SR, Medeiros H, Morley CP, Perkins DO, Sobell JL, Buckley PF, Macciardi F, Rapaport MH, Knowles JA, Fanous AH, McCarroll SA, Gupta N, Gabriel SB, Daly MJ, Lander ES, Lowenstein DH, Goldstein DB, Lerche H, Berkovic SF, Neale BM. Ultra-Rare Genetic Variation in the Epilepsies: A Whole-Exome Sequencing Study of 17,606 Individuals. Am J Hum Genet 2019; 105:267-282. [PMID: 31327507 PMCID: PMC6698801 DOI: 10.1016/j.ajhg.2019.05.020] [Citation(s) in RCA: 168] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/29/2019] [Indexed: 12/20/2022] Open
Abstract
Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABAA receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.
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Bird LJ, Jackson GD, Wilson SJ. Music training is neuroprotective for verbal cognition in focal epilepsy. Brain 2019; 142:1973-1987. [PMID: 31074775 DOI: 10.1093/brain/awz124] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 02/18/2019] [Accepted: 03/07/2019] [Indexed: 12/21/2022] Open
Abstract
Focal epilepsy is a unilateral brain network disorder, providing an ideal neuropathological model with which to study the effects of focal neural disruption on a range of cognitive processes. While language and memory functions have been extensively investigated in focal epilepsy, music cognition has received less attention, particularly in patients with music training or expertise. This represents a critical gap in the literature. A better understanding of the effects of epilepsy on music cognition may provide greater insight into the mechanisms behind disease- and training-related neuroplasticity, which may have implications for clinical practice. In this cross-sectional study, we comprehensively profiled music and non-music cognition in 107 participants; musicians with focal epilepsy (n = 35), non-musicians with focal epilepsy (n = 39), and healthy control musicians and non-musicians (n = 33). Parametric group comparisons revealed a specific impairment in verbal cognition in non-musicians with epilepsy but not musicians with epilepsy, compared to healthy musicians and non-musicians (P = 0.029). This suggests a possible neuroprotective effect of music training against the cognitive sequelae of focal epilepsy, and implicates potential training-related cognitive transfer that may be underpinned by enhancement of auditory processes primarily supported by temporo-frontal networks. Furthermore, our results showed that musicians with an earlier age of onset of music training performed better on a composite score of melodic learning and memory compared to non-musicians (P = 0.037), while late-onset musicians did not differ from non-musicians. For most composite scores of music cognition, although no significant group differences were observed, a similar trend was apparent. We discuss these key findings in the context of a proposed model of three interacting dimensions (disease status, music expertise, and cognitive domain), and their implications for clinical practice, music education, and music neuroscience research.
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Affiliation(s)
- Laura J Bird
- Melbourne School of Psychological Sciences, The University of Melbourne, Grattan Street, Parkville, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria, Australia
| | - Graeme D Jackson
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria, Australia.,Department of Medicine, The University of Melbourne, Grattan Street, Parkville, Victoria, Australia
| | - Sarah J Wilson
- Melbourne School of Psychological Sciences, The University of Melbourne, Grattan Street, Parkville, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria, Australia
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36
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Al-Eitan LN, Al-Dalalah IM, Mustafa MM, Alghamdi MA, Elshammari AK, Khreisat WH, Aljamal HA. Effects of MTHFR and ABCC2 gene polymorphisms on antiepileptic drug responsiveness in Jordanian epileptic patients. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2019; 12:87-95. [PMID: 31354331 PMCID: PMC6572658 DOI: 10.2147/pgpm.s211490] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/27/2019] [Indexed: 01/09/2023]
Abstract
Background Epilepsy is one of the most common neurological diseases with unclear etiology where its genetic background and treatment regime still need further exploration. Objectives This study designed to evaluate the pharmacogenomics of MTHFR and ABCC2 genes, and their association with epilepsy susceptibility among Jordanian population. Methods A case-control study was conducted on Jordanian cohort of 296 epileptic patients and 299 healthy individuals. Custom platform array was used to genotype the genetic polymorphisms within MTHFR (rs1801133) and ABCC2 (rs717620, rs3740066, rs2273697) genes. Results This study revealed a significant genetic association of MTHFR rs1801133 polymorphism with susceptibility to generalized in general and generalized tonic-clonic epilepsy (GTCE)(p=0.018 and 0.01, respectively). Regarding ABCC2 gene, rs717620 was of linkage with generalized and GTCE subtypes (p=0.045 and 0.048, respectively), while rs717620 was associated with poor responder patients (p=0.036) with no linkage of the ABCC2 haplotypes. Conclusions MTHFR and ABCC2 polymorphisms showed an association with either epilepsy types in general or subtypes and treatment response among Jordanian population. This study also suggested that these gene polymorphisms have an important role in epilepsy development and drug effectiveness and could be of a great impact in the era of epilepsy diagnosis and treatment.
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Affiliation(s)
- Laith N Al-Eitan
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan.,Department of Biotechnology and Genetic Engineering, Jordan University of Science and Technology, Irbid, Jordan
| | - Islam M Al-Dalalah
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohamed M Mustafa
- Department of Neuroscience, Jordan University of Science and Technology, Irbid, Jordan
| | | | - Afrah K Elshammari
- Queen Rania Hospital for Children, King Hussein Medical Center, Royal Medical Services, Amman, Jordan
| | - Wael H Khreisat
- Queen Rania Hospital for Children, King Hussein Medical Center, Royal Medical Services, Amman, Jordan
| | - Hanan A Aljamal
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan
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Ellis CA, Churilov L, Epstein MP, Xie SX, Bellows ST, Ottman R, Berkovic SF. Epilepsy in families: Age at onset is a familial trait, independent of syndrome. Ann Neurol 2019; 86:91-98. [PMID: 31050039 DOI: 10.1002/ana.25499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 04/04/2019] [Accepted: 04/28/2019] [Indexed: 12/20/2022]
Abstract
OBJECTIVE We tested 2 hypotheses regarding age at onset within familial epilepsies: (1) family members with epilepsy tend to have similar ages at onset, independent of epilepsy syndrome; and (2) age at onset is younger in successive generations after controlling for sampling bias. METHODS We analyzed clinical data collected by the Epi4K Consortium (303 multiplex families, 1,120 individuals). To test hypothesis 1, we used both linear mixed models commonly used for heritability analysis and Cox regression models with frailty terms to assess clustering of onset within families after controlling for other predictors. To test hypothesis 2, we used mixed effects models, pairwise analyses, and survival analysis to address sampling-related bias that may mimic anticipation. RESULTS Regarding hypothesis 1, age at seizure onset was significantly heritable (intraclass correlation coefficient = 0.17, p < 0.001) after adjusting for epilepsy type, sex, site, history of febrile seizure, and age at last observation. This finding remained significant after adjusting for epilepsy syndromes, and was robust across statistical methods in all families and in generalized families. Regarding hypothesis 2, the mean age at onset decreased in successive generations (p < 0.001). After adjusting for age at last observation, this effect was not significant in mixed effects models (p = 0.14), but remained significant in pairwise (p = 0.0003) and survival analyses (p = 0.02). INTERPRETATION Age at seizure onset is an independent familial trait, and may have genetic determinants distinct from the determinants of particular epilepsy syndromes. Younger onsets in successive generations can be explained in part by sampling bias, but the presence of genetic anticipation cannot be excluded. ANN NEUROL 2019.
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Affiliation(s)
- Colin A Ellis
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, Victoria, Australia.,Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Leonid Churilov
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | | | - Sharon X Xie
- Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, PA
| | - Susannah T Bellows
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, Victoria, Australia
| | - Ruth Ottman
- Departments of Epidemiology and Neurology, and the G. H. Sergievsky Center, Columbia University; and Division of Translational Epidemiology, New York State Psychiatric Institute, New York, NY
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, Victoria, Australia
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Abstract
Idiopathic generalized epilepsies (IGE) are characterized by normal background EEG activity and generalized interictal spike-and-wave discharges in the absence of any evidence of brain lesion. Absence epilepsies are the prototypes of IGEs. In childhood and juvenile absence epilepsies, by definition, all patients manifest absence seizures associated with an EEG pattern of generalized spike-wave (GSW) discharges. In juvenile myoclonic epilepsy, myoclonic jerks, usually affecting shoulders and arms bilaterally and appearing upon awakening, are the most characteristic clinical feature. Myoclonic jerks are accompanied on the EEG by generalized spike/polyspike-and-wave (GSW, GPWS) complexes at 3.5-6Hz. Idiopathic generalized epilepsy with generalized tonic-clonic seizures only is a broad and nonspecific category including all patients with generalized tonic-clonic seizures and an interictal EEG pattern of GSW discharges. Despite the strong heritability and the recent advances in genetic technology, the genetic basis of IGEs remains largely elusive and only in a small minority of patients with classic IGE phenotypes is a monogenic cause identified. Early myoclonic encephalopathy (EME), early infantile encephalopathy with suppression bursts, West syndrome, and Lennox-Gastaut syndrome, once classified among the generalized epilepsies, are now considered to be epileptic encephalopathies. Among them, only Lennox-Gastaut syndrome is characterized by prominent generalized clinical and EEG features.
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Affiliation(s)
- Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy.
| | - Carla Marini
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Carmen Barba
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy
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Abstract
This article is based on a lecture delivered at the 2017 American Epilepsy Society Annual Meeting and provides an overview of the growing evidence supporting the strong genetic contribution to focal epilepsies. This also discusses how advances in the molecular genetics of focal epilepsies are rapidly translating to routine clinical care.
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Myers KA, Johnstone DL, Dyment DA. Epilepsy genetics: Current knowledge, applications, and future directions. Clin Genet 2018; 95:95-111. [PMID: 29992546 DOI: 10.1111/cge.13414] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 07/03/2018] [Accepted: 07/06/2018] [Indexed: 12/12/2022]
Abstract
The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate next-generation sequencing-based test(s), and the interpretation of sequencing results require a care provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will also probably include other-omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease.
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Affiliation(s)
- K A Myers
- Department of Pediatrics, University of McGill, Montreal, Canada.,Research Institute of the McGill University Health Centre, Montreal, Canada
| | - D L Johnstone
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - D A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada.,Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Canada
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Rare coding variants in genes encoding GABA A receptors in genetic generalised epilepsies: an exome-based case-control study. Lancet Neurol 2018; 17:699-708. [PMID: 30033060 DOI: 10.1016/s1474-4422(18)30215-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 05/17/2018] [Accepted: 05/29/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Genetic generalised epilepsy is the most common type of inherited epilepsy. Despite a high concordance rate of 80% in monozygotic twins, the genetic background is still poorly understood. We aimed to investigate the burden of rare genetic variants in genetic generalised epilepsy. METHODS For this exome-based case-control study, we used three different genetic generalised epilepsy case cohorts and three independent control cohorts, all of European descent. Cases included in the study were clinically evaluated for genetic generalised epilepsy. Whole-exome sequencing was done for the discovery case cohort, a validation case cohort, and two independent control cohorts. The replication case cohort underwent targeted next-generation sequencing of the 19 known genes encoding subunits of GABAA receptors and was compared to the respective GABAA receptor variants of a third independent control cohort. Functional investigations were done with automated two-microelectrode voltage clamping in Xenopus laevis oocytes. FINDINGS Statistical comparison of 152 familial index cases with genetic generalised epilepsy in the discovery cohort to 549 ethnically matched controls suggested an enrichment of rare missense (Nonsyn) variants in the ensemble of 19 genes encoding GABAA receptors in cases (odds ratio [OR] 2·40 [95% CI 1·41-4·10]; pNonsyn=0·0014, adjusted pNonsyn=0·019). Enrichment for these genes was validated in a whole-exome sequencing cohort of 357 sporadic and familial genetic generalised epilepsy cases and 1485 independent controls (OR 1·46 [95% CI 1·05-2·03]; pNonsyn=0·0081, adjusted pNonsyn=0·016). Comparison of genes encoding GABAA receptors in the independent replication cohort of 583 familial and sporadic genetic generalised epilepsy index cases, based on candidate-gene panel sequencing, with a third independent control cohort of 635 controls confirmed the overall enrichment of rare missense variants for 15 GABAA receptor genes in cases compared with controls (OR 1·46 [95% CI 1·02-2·08]; pNonsyn=0·013, adjusted pNonsyn=0·027). Functional studies for two selected genes (GABRB2 and GABRA5) showed significant loss-of-function effects with reduced current amplitudes in four of seven tested variants compared with wild-type receptors. INTERPRETATION Functionally relevant variants in genes encoding GABAA receptor subunits constitute a significant risk factor for genetic generalised epilepsy. Examination of the role of specific gene groups and pathways can disentangle the complex genetic architecture of genetic generalised epilepsy. FUNDING EuroEPINOMICS (European Science Foundation through national funding organisations), Epicure and EpiPGX (Sixth Framework Programme and Seventh Framework Programme of the European Commission), Research Unit FOR2715 (German Research Foundation and Luxembourg National Research Fund).
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Expanding role of GABA A receptors in generalised epilepsies. Lancet Neurol 2018; 17:657-658. [PMID: 30033051 DOI: 10.1016/s1474-4422(18)30252-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 01/24/2023]
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Lee CG, Lee J, Lee M. Multi-gene panel testing in Korean patients with common genetic generalized epilepsy syndromes. PLoS One 2018; 13:e0199321. [PMID: 29924869 PMCID: PMC6010271 DOI: 10.1371/journal.pone.0199321] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 06/05/2018] [Indexed: 11/18/2022] Open
Abstract
Genetic heterogeneity of common genetic generalized epilepsy syndromes is frequently considered. The present study conducted a focused analysis of potential candidate or susceptibility genes for common genetic generalized epilepsy syndromes using multi-gene panel testing with next-generation sequencing. This study included patients with juvenile myoclonic epilepsy, juvenile absence epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We identified pathogenic variants according to the American College of Medical Genetics and Genomics guidelines and identified susceptibility variants using case-control association analyses and family analyses for familial cases. A total of 57 patients were enrolled, including 51 sporadic cases and 6 familial cases. Twenty-two pathogenic and likely pathogenic variants of 16 different genes were identified. CACNA1H was the most frequently observed single gene. Variants of voltage-gated Ca2+ channel genes, including CACNA1A, CACNA1G, and CACNA1H were observed in 32% of variants (n = 7/22). Analyses to identify susceptibility variants using case-control association analysis indicated that KCNMA1 c.400G>C was associated with common genetic generalized epilepsy syndromes. Only 1 family (family A) exhibited a candidate pathogenic variant p.(Arg788His) on CACNA1H, as determined via family analyses. This study identified candidate genetic variants in about a quarter of patients (n = 16/57) and an average of 2.8 variants was identified in each patient. The results reinforced the polygenic disorder with very high locus and allelic heterogeneity of common GGE syndromes. Further, voltage-gated Ca2+ channels are suggested as important contributors to common genetic generalized epilepsy syndromes. This study extends our comprehensive understanding of common genetic generalized epilepsy syndromes.
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Affiliation(s)
- Cha Gon Lee
- Department of Pediatrics, Nowon Eulji Medical Center, Eulji University, Seoul, Republic of Korea
| | - Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- * E-mail:
| | - Munhyang Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Pawluski JL, Kuchenbuch M, Hadjadj S, Dieuset G, Costet N, Vercueil L, Biraben A, Martin B. Long-term negative impact of an inappropriate first antiepileptic medication on the efficacy of a second antiepileptic medication in mice. Epilepsia 2018; 59:e109-e113. [PMID: 29901235 DOI: 10.1111/epi.14454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2018] [Indexed: 11/29/2022]
Abstract
Childhood absence epilepsy (CAE) is one of the most frequent epilepsies in infancy. The first-line recommended therapy for CAE is based on the prescription of the narrow-spectrum ethosuximide and the broad-spectrum valproic acid, which have similar efficacy in the first 12 months. Nevertheless, some antiepileptic drugs (AEDs) may worsen seizure duration and type in this syndrome. In line with this, we have encountered a case of identical twins with CAE and early exposure to different antiseizure drugs leading to divergent outcomes. From this, we hypothesized that the first AED to treat CAE may determine the long-term prognosis, especially in the developing brain, and that some situations leading to drug resistance may be explained by use of an inappropriate first AED. Therefore, we investigated this hypothesis by using a genetic mouse model of absence epilepsy (BS/Orl). Mice received a first appropriate or inappropriate AED followed by the same appropriate AED. Our data demonstrate that an inappropriate first AED has a negative impact on the long-term efficacy of a second appropriate AED. This work supports the necessity to effectively diagnose epileptic syndromes prior to medication use, particularly in children, in order to prevent the deleterious effects of an inappropriate initial AED.
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Affiliation(s)
- Jodi L Pawluski
- Univ Rennes, Inserm, EHESP, Irset (Research Institute for Environmental and Occupational Health), UMR_S 1085, Rennes, France
| | | | - Sarah Hadjadj
- Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, Rennes, France
| | - Gabriel Dieuset
- Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, Rennes, France
| | - Nathalie Costet
- Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, Rennes, France
| | - Laurent Vercueil
- Inserm, GIN, University of Grenoble Alpes, Grenoble, France.,EFSN, CHU Grenoble Alpes, Grenoble, France
| | - Arnaud Biraben
- Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, Rennes, France
| | - Benoît Martin
- Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, Rennes, France
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45
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Mullen SA, Berkovic SF. Genetic generalized epilepsies. Epilepsia 2018; 59:1148-1153. [DOI: 10.1111/epi.14042] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Saul A. Mullen
- Epilepsy Research Centre; Department of Medicine; Austin Health; University of Melbourne; Heidelberg Vic. Australia
- Florey Institute of Neuroscience and Mental Health; Heidelberg Vic. Australia
| | - Samuel F. Berkovic
- Epilepsy Research Centre; Department of Medicine; Austin Health; University of Melbourne; Heidelberg Vic. Australia
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Monlong J, Girard SL, Meloche C, Cadieux-Dion M, Andrade DM, Lafreniere RG, Gravel M, Spiegelman D, Dionne-Laporte A, Boelman C, Hamdan FF, Michaud JL, Rouleau G, Minassian BA, Bourque G, Cossette P. Global characterization of copy number variants in epilepsy patients from whole genome sequencing. PLoS Genet 2018; 14:e1007285. [PMID: 29649218 PMCID: PMC5978987 DOI: 10.1371/journal.pgen.1007285] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/24/2018] [Accepted: 03/04/2018] [Indexed: 12/17/2022] Open
Abstract
Epilepsy will affect nearly 3% of people at some point during their lifetime. Previous copy number variants (CNVs) studies of epilepsy have used array-based technology and were restricted to the detection of large or exonic events. In contrast, whole-genome sequencing (WGS) has the potential to more comprehensively profile CNVs but existing analytic methods suffer from limited accuracy. We show that this is in part due to the non-uniformity of read coverage, even after intra-sample normalization. To improve on this, we developed PopSV, an algorithm that uses multiple samples to control for technical variation and enables the robust detection of CNVs. Using WGS and PopSV, we performed a comprehensive characterization of CNVs in 198 individuals affected with epilepsy and 301 controls. For both large and small variants, we found an enrichment of rare exonic events in epilepsy patients, especially in genes with predicted loss-of-function intolerance. Notably, this genome-wide survey also revealed an enrichment of rare non-coding CNVs near previously known epilepsy genes. This enrichment was strongest for non-coding CNVs located within 100 Kbp of an epilepsy gene and in regions associated with changes in the gene expression, such as expression QTLs or DNase I hypersensitive sites. Finally, we report on 21 potentially damaging events that could be associated with known or new candidate epilepsy genes. Our results suggest that comprehensive sequence-based profiling of CNVs could help explain a larger fraction of epilepsy cases.
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Affiliation(s)
- Jean Monlong
- Department of Human Genetics, McGill University, Montréal, Canada
- Canadian Center for Computational Genomics, Montréal, Canada
| | - Simon L. Girard
- Department of Human Genetics, McGill University, Montréal, Canada
- Département des sciences fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
| | - Caroline Meloche
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
| | - Maxime Cadieux-Dion
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
- Center for Pediatric Genomic Medicine, Children’s Mercy Hospital, Kansas City, Missouri, United States of America
| | - Danielle M. Andrade
- Epilepsy Genetics Program, Division of Neurology, Toronto Western Hospital, University of Toronto, Toronto, Canada
| | - Ron G. Lafreniere
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
| | - Micheline Gravel
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
| | - Dan Spiegelman
- Montreal Neurological Institute, McGill University, Montréal, Canada
| | | | - Cyrus Boelman
- Division of Neurology, BC Children’s Hospital, Vancouver, Canada
| | | | | | - Guy Rouleau
- Montreal Neurological Institute, McGill University, Montréal, Canada
| | | | - Guillaume Bourque
- Department of Human Genetics, McGill University, Montréal, Canada
- Canadian Center for Computational Genomics, Montréal, Canada
- McGill University and Génome Québec Innovation Center, Montréal, Canada
- * E-mail: (GB); (PC)
| | - Patrick Cossette
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Canada
- * E-mail: (GB); (PC)
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Lesca G. Aspetti genetici delle epilessie. Neurologia 2018. [DOI: 10.1016/s1634-7072(18)41286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Churbanov A, Abrahamyan L. Preventing Common Hereditary Disorders through Time-Separated Twinning. BIONANOSCIENCE 2018. [DOI: 10.1007/s12668-017-0488-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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49
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Koeleman BP. What do genetic studies tell us about the heritable basis of common epilepsy? Polygenic or complex epilepsy? Neurosci Lett 2018; 667:10-16. [DOI: 10.1016/j.neulet.2017.03.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 12/23/2022]
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50
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