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Michetti C, Falace A, Benfenati F, Fassio A. Synaptic genes and neurodevelopmental disorders: From molecular mechanisms to developmental strategies of behavioral testing. Neurobiol Dis 2022; 173:105856. [PMID: 36070836 DOI: 10.1016/j.nbd.2022.105856] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022] Open
Abstract
Synaptopathies are a class of neurodevelopmental disorders caused by modification in genes coding for synaptic proteins. These proteins oversee the process of neurotransmission, mainly controlling the fusion and recycling of synaptic vesicles at the presynaptic terminal, the expression and localization of receptors at the postsynapse and the coupling between the pre- and the postsynaptic compartments. Murine models, with homozygous or heterozygous deletion for several synaptic genes or knock-in for specific pathogenic mutations, have been developed. They have proved to be extremely informative for understanding synaptic physiology, as well as for clarifying the patho-mechanisms leading to developmental delay, epilepsy and motor, cognitive and social impairments that are the most common clinical manifestations of neurodevelopmental disorders. However, the onset of these disorders emerges during infancy and adolescence while the behavioral phenotyping is often conducted in adult mice, missing important information about the impact of synaptic development and maturation on the manifestation of the behavioral phenotype. Here, we review the main achievements obtained by behavioral testing in murine models of synaptopathies and propose a battery of behavioral tests to improve classification, diagnosis and efficacy of potential therapeutic treatments. Our aim is to underlie the importance of studying behavioral development and better focusing on disease onset and phenotypes.
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Affiliation(s)
- Caterina Michetti
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy.
| | - Antonio Falace
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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Harrar D, Mondok L, Adams S, Farias-Moeller R. Zebras Seize the Day. Crit Care Clin 2022; 38:349-373. [DOI: 10.1016/j.ccc.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The epileptic encephalopathy jungle - from Dr West to the concepts of aetiology-related and developmental encephalopathies. Curr Opin Neurol 2019; 31:216-222. [PMID: 29356691 DOI: 10.1097/wco.0000000000000535] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW We aim to further disentangle the jungle of terminology of epileptic encephalopathy and provide some insights into the current understanding about the aetiology and pathophysiology of this process. We cover also the key features of epilepsy syndromes of infancy and childhood which are considered at high risk of developing an epileptic encephalopathy. RECENT FINDINGS The concept of 'epileptic encephalopathy' has progressively been elaborated by the International League Against Epilepsy according to growing clinical and laboratory evidence. It defines a process of neurological impairment caused by the epileptic activity itself and, therefore, potentially reversible with successful treatment, although to a variable extent. Epileptic activity interfering with neurogenesis, synaptogenesis, and normal network organization as well as triggering neuroinflammation are among the possible pathophysiological mechanisms leading to the neurological compromise. This differs from the newly introduced concept of 'developmental encephalopathy' which applies to where the epilepsy and developmental delay are both because of the underlying aetiology and aggressive antiepileptic treatment may not be helpful. SUMMARY The understanding and use of correct terminology is crucial in clinical practice enabling appropriate expectations of antiepileptic treatment. Further research is needed to elucidate underlying pathophysiological mechanisms, define clear outcome predictors, and find new treatment targets.
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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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5
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A novel homozygous nonsense mutation in CCDC88A gene cause PEHO-like syndrome in consanguineous Saudi family. Neurol Sci 2018; 40:299-303. [DOI: 10.1007/s10072-018-3626-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 10/26/2018] [Indexed: 12/15/2022]
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Abstract
Medicinal cannabis, and cannabidiol in particular, has garnered much attention in the media and medical community as a possible therapeutic for multiple conditions including epilepsy. Although the use of cannabis has been reported for centuries, evidence in its usefulness in the treatment of epilepsy has been mainly anecdotal. This review discusses emerging research on cannabidiol in the treatment of severe pediatric epilepsies, including Dravet syndrome and Lennox Gastaut syndrome. We discuss the data from both open-label and Phase III trials and report a consistently significant reduction in seizures but also concomitant drug interactions and adverse effects. Future directions of research are considered to determine the full therapeutic potential of this old, but new, class of compounds.
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Affiliation(s)
- Samantha J Hagopian
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Eric D Marsh
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Departments of Neurology & Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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7
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Marini C, Hardies K, Pisano T, May P, Weckhuysen S, Cellini E, Suls A, Mei D, Balling R, Jonghe PD, Helbig I, Garozzo D, Guerrini R. Recessive mutations in SLC35A3 cause early onset epileptic encephalopathy with skeletal defects. Am J Med Genet A 2017; 173:1119-1123. [PMID: 28328131 DOI: 10.1002/ajmg.a.38112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/28/2016] [Accepted: 12/09/2016] [Indexed: 11/08/2022]
Abstract
We describe the clinical and whole genome sequencing (WGS) study of a non-consanguineous Italian family in which two siblings, a boy and a girl, manifesting a severe epileptic encephalopathy (EE) with skeletal abnormalities, carried novel SLC35A3 compound heterozygous mutations. Both siblings exhibited infantile spasms, associated with focal, and tonic vibratory seizures from early infancy. EEG recordings showed a suppression-burst (SB) pattern and multifocal paroxysmal activity in both. In addition both had quadriplegia, acquired microcephaly, and severe intellectual disability. General examination showed distal arthrogryposis predominant in the hands in both siblings and severe left dorso-lumbar convex scoliosis in one. WGS of the siblings-parents quartet identified novel compound heterozygous mutations in SLC35A3 in both children. SLC35A3 encodes the major Golgi uridine diphosphate N-acetylglucosamine transporter. With this study, we add SLC35A3 to the gene list of epilepsies. Neurological symptoms and skeletal abnormalities might result from impaired glycosylation of proteins involved in normal development and function of the central nervous system and skeletal apparatus.
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Affiliation(s)
- Carla Marini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Katia Hardies
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Tiziana Pisano
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Luxembourg, Luxembourg.,Institute for Systems Biology (ISB), Seattle, Washington
| | - Sarah Weckhuysen
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Elena Cellini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Arvid Suls
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Davide Mei
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Luxembourg, Luxembourg
| | - Peter D Jonghe
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany.,Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Domenico Garozzo
- CNR, Institute of Chemistry and Technology of Polymers, Section of Catania, Catania, Italy
| | | | - Renzo Guerrini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy.,University of Florence, Florence, Italy
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Dejanovic B, Djémié T, Grünewald N, Suls A, Kress V, Hetsch F, Craiu D, Zemel M, Gormley P, Lal D, Myers CT, Mefford HC, Palotie A, Helbig I, Meier JC, De Jonghe P, Weckhuysen S, Schwarz G. Simultaneous impairment of neuronal and metabolic function of mutated gephyrin in a patient with epileptic encephalopathy. EMBO Mol Med 2016; 7:1580-94. [PMID: 26613940 PMCID: PMC4693503 DOI: 10.15252/emmm.201505323] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition plays an important role in neurological disorders. Gephyrin is a central player at inhibitory postsynapses, directly binds and organizes GABAA and glycine receptors (GABAARs and GlyRs), and is thereby indispensable for normal inhibitory neurotransmission. Additionally, gephyrin catalyzes the synthesis of the molybdenum cofactor (MoCo) in peripheral tissue. We identified a de novo missense mutation (G375D) in the gephyrin gene (GPHN) in a patient with epileptic encephalopathy resembling Dravet syndrome. Although stably expressed and correctly folded, gephyrin‐G375D was non‐synaptically localized in neurons and acted dominant‐negatively on the clustering of wild‐type gephyrin leading to a marked decrease in GABAAR surface expression and GABAergic signaling. We identified a decreased binding affinity between gephyrin‐G375D and the receptors, suggesting that Gly375 is essential for gephyrin–receptor complex formation. Surprisingly, gephyrin‐G375D was also unable to synthesize MoCo and activate MoCo‐dependent enzymes. Thus, we describe a missense mutation that affects both functions of gephyrin and suggest that the identified defect at GABAergic synapses is the mechanism underlying the patient's severe phenotype.
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Affiliation(s)
- Borislav Dejanovic
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Tania Djémié
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Nora Grünewald
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Arvid Suls
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium GENOMED, Center for Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Vanessa Kress
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Dana Craiu
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Matthew Zemel
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Padhraig Gormley
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis Lal
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | | | - Candace T Myers
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Aarno Palotie
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Program in Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein Christian Albrechts University, Kiel, Germany Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Peter De Jonghe
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Sarah Weckhuysen
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Inserm U 1127 CNRS UMR 7225 Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Institut du Cerveau et de la Moelle épinière, ICM, Paris, France Centre de reference épilepsies rares, Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière, F-75013, Paris, France
| | - Guenter Schwarz
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany
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9
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Nahorski MS, Asai M, Wakeling E, Parker A, Asai N, Canham N, Holder SE, Chen YC, Dyer J, Brady AF, Takahashi M, Woods CG. CCDC88A mutations cause PEHO-like syndrome in humans and mouse. Brain 2016; 139:1036-44. [PMID: 26917597 PMCID: PMC4806221 DOI: 10.1093/brain/aww014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/23/2015] [Indexed: 11/14/2022] Open
Abstract
Progressive encephalopathy with oedema, hypsarrhythmia and optic atrophy (PEHO) syndrome is a rare Mendelian phenotype comprising severe retardation, early onset epileptic seizures, optic nerve/cerebellar atrophy, pedal oedema, and early death. Atypical cases are often known as PEHO-like, and there is an overlap with 'early infantile epileptic encephalopathy'. PEHO is considered to be recessive, but surprisingly since initial description in 1991, no causative recessive gene(s) have been described. Hence, we report a multiplex consanguineous family with the PEHO phenotype where affected individuals had a homozygous frame-shift deletion in CCDC88A (c.2313delT, p.Leu772*ter). Analysis of cDNA extracted from patient lymphocytes unexpectedly failed to show non-sense mediated decay, and we demonstrate that the mutation produces a truncated protein lacking the crucial C-terminal half of CCDC88A (girdin). To further investigate the possible role of CCDC88A in human neurodevelopment we re-examined the behaviour and neuroanatomy of Ccdc88a knockout pups. These mice had mesial-temporal lobe epilepsy, microcephaly and corpus callosum deficiency, and by postnatal Day 21, microcephaly; the mice died at an early age. As the mouse knockout phenotype mimics the human PEHO phenotype this suggests that loss of CCDC88A is a cause of the PEHO phenotype, and that CCDC88A is essential for multiple aspects of normal human neurodevelopment.
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Affiliation(s)
- Michael S Nahorski
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Masato Asai
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - Emma Wakeling
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Alasdair Parker
- Department of Paediatric Neuroscience, Addenbrooke's Hospital, Hills Rd, Cambridge, CB2 0QQ, UK
| | - Naoya Asai
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - Natalie Canham
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Susan E Holder
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Ya-Chun Chen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Joshua Dyer
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Angela F Brady
- North West Thames Regional Genetics Service, Level 8V, London North West Healthcare NHS Trust, Watford Road, Harrow, HA1 3UJ, UK
| | - Masahide Takahashi
- Department of Pathology, Centre for Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466N, Japan
| | - C Geoffrey Woods
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
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Kim JA, Yoon JR, Lee EJ, Lee JS, Kim JT, Kim HD, Kang HC. Efficacy of the classic ketogenic and the modified Atkins diets in refractory childhood epilepsy. Epilepsia 2015; 57:51-8. [PMID: 26662710 DOI: 10.1111/epi.13256] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We aimed to compare the efficacy, safety, and tolerability of a modified Atkins diet (MAD) with the classic ketogenic diet (KD) for the treatment of intractable childhood epilepsy. METHODS From March 2011 to March 2014, 104 patients aged 1-18 years who had refractory epilepsy were randomly assigned to each diet group (ClinicalTrials.gov, number NCT2100501). A seizure diary record was used to compare seizure frequencies with the baseline prediet seizure frequency at the third and sixth months after diet therapy initiation. RESULTS Fifty-one patients were assigned to the KD and 53 patients to the MAD. The KD group had a lower mean percentage of baseline seizures compared with the MAD group at 3 months (38.6% for KD, 47.9% for MAD) and 6 months (33.8% for KD, 44.6% for MAD), but the differences were not statistically significant (95% confidence interval [CI] 24.1-50.8, p = 0.291 for 3 months; 95% CI 17.8-46.1, p = 0.255 for 6 months). Instead, for patients aged 1-2 years, seizure outcomes were consistently much more favorable in patients consuming the KD compared with those consuming the MAD. The rate of seizure freedom at 3 months after diet therapy initiation was significantly higher (53% for KD, 20% for MAD, p = 0.047) in these patients. The MAD had advantages with respect to better tolerability and fewer serious side effects. SIGNIFICANCE The MAD might be considered as the primary choice for the treatment of intractable epilepsy in children, but the classic KD is more suitable as the first line of diet therapy in patients <2 years of age.
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Affiliation(s)
- Jeong A Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jung-Rim Yoon
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Joo Lee
- Division of Dietetics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Joon Soo Lee
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jeong Tae Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Heung Dong Kim
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Hoon-Chul Kang
- Division of Pediatric Neurology, Department of Pediatrics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
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11
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Paolicchi JM, Ross G, Lee D, Drummond R, Isojarvi J. Clobazam and Aggression-Related Adverse Events in Pediatric Patients With Lennox-Gastaut Syndrome. Pediatr Neurol 2015; 53:338-42. [PMID: 26245776 DOI: 10.1016/j.pediatrneurol.2015.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Lennox-Gastaut syndrome is an intractable epileptic encephalopathy marked by frequent drop seizures. Most patients develop moderate intellectual disability and behavioral problems, including hyperactivity, aggressiveness, insecurity, and autistic features. Treatment with benzodiazepines, including clobazam, may increase aggression/behavioral problems in patients with Lennox-Gastaut syndrome. Post hoc analyses of data from the OV-1012 trial assessed the potential for behavioral effects with clobazam treatment in pediatric (2 to 18 years) patients with Lennox-Gastaut syndrome. METHODS OV-1012 was a phase 3, randomized, double-blind, parallel-group trial comprising a 4-week baseline period, 3-week titration period, and a 12-week maintenance period. Data from 194 patients were analyzed for a history of aggression/behavioral problems, occurrence of aggression-related adverse events, and by assessment of potential drug-related effects on four behavior domains of the Child Behavior Checklist. RESULTS Twenty-nine aggression-related adverse events were reported for 27 (13.9%) patients. Similar percentages of clobazam-treated patients with and without a history of aggressive behavior experienced an aggression-related adverse event (16.7% versus 15.5%, respectively). In the medium- and high-dosage clobazam groups, onset of aggression-related adverse effects occurred within the 3-week titration period with 63.2% resolving by the end of the study. Aggression-related adverse event onset and resolution were similar for the low-dosage clobazam and placebo groups. Analysis of baseline to postbaseline T scores for the behavior domains of the Child Behavior Checklist indicated no significant differences between clobazam and placebo. CONCLUSIONS Post hoc analyses indicate that the overall rate of aggression with clobazam treatment was low and dosage dependent. Clobazam treatment was effective in reducing drop seizures regardless of aggression experience.
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Affiliation(s)
| | - Gail Ross
- Weill Cornell Medical College, New York, New York
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12
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Early-onset epileptic encephalopathy caused by gain-of-function mutations in the voltage sensor of Kv7.2 and Kv7.3 potassium channel subunits. J Neurosci 2015; 35:3782-93. [PMID: 25740509 DOI: 10.1523/jneurosci.4423-14.2015] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mutations in Kv7.2 (KCNQ2) and Kv7.3 (KCNQ3) genes, encoding for voltage-gated K(+) channel subunits underlying the neuronal M-current, have been associated with a wide spectrum of early-onset epileptic disorders ranging from benign familial neonatal seizures to severe epileptic encephalopathies. The aim of the present work has been to investigate the molecular mechanisms of channel dysfunction caused by voltage-sensing domain mutations in Kv7.2 (R144Q, R201C, and R201H) or Kv7.3 (R230C) recently found in patients with epileptic encephalopathies and/or intellectual disability. Electrophysiological studies in mammalian cells transfected with human Kv7.2 and/or Kv7.3 cDNAs revealed that each of these four mutations stabilized the activated state of the channel, thereby producing gain-of-function effects, which are opposite to the loss-of-function effects produced by previously found mutations. Multistate structural modeling revealed that the R201 residue in Kv7.2, corresponding to R230 in Kv7.3, stabilized the resting and nearby voltage-sensing domain states by forming an intricate network of electrostatic interactions with neighboring negatively charged residues, a result also confirmed by disulfide trapping experiments. Using a realistic model of a feedforward inhibitory microcircuit in the hippocampal CA1 region, an increased excitability of pyramidal neurons was found upon incorporation of the experimentally defined parameters for mutant M-current, suggesting that changes in network interactions rather than in intrinsic cell properties may be responsible for the neuronal hyperexcitability by these gain-of-function mutations. Together, the present results suggest that gain-of-function mutations in Kv7.2/3 currents may cause human epilepsy with a severe clinical course, thus revealing a previously unexplored level of complexity in disease pathogenetic mechanisms.
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Pisano T, Numis AL, Heavin SB, Weckhuysen S, Angriman M, Suls A, Podesta B, Thibert RL, Shapiro KA, Guerrini R, Scheffer IE, Marini C, Cilio MR. Early and effective treatment ofKCNQ2encephalopathy. Epilepsia 2015; 56:685-91. [DOI: 10.1111/epi.12984] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Tiziana Pisano
- Neurology Unit and Laboratories; A. Meyer Children's Hospital; Florence Italy
| | - Adam L. Numis
- Department of Neurology; University of California, San Francisco; San Francisco California U.S.A
| | - Sinéad B. Heavin
- Departments of Medicine and Paediatrics; Florey Institute; Austin Health and Royal Children's Hospital; University of Melbourne; Melbourne Victoria Australia
| | - Sarah Weckhuysen
- Neurogenetics Group; Department of Molecular Genetics; VIB; Antwerp Belgium
- Laboratory of Neurogenetics; Institute Born-Bunge; University of Antwerp; Antwerp Belgium
| | | | - Arvid Suls
- Neurogenetics Group; Department of Molecular Genetics; VIB; Antwerp Belgium
- Laboratory of Neurogenetics; Institute Born-Bunge; University of Antwerp; Antwerp Belgium
| | - Barbara Podesta
- Child Neurology and Psychiatry Unit; S. Croce and S. Carlo Hospital; Cuneo Italy
| | - Ronald L. Thibert
- Pediatric Epilepsy Program; Massachusetts General Hospital; Harvard Medical School; Boston Massachusetts U.S.A
| | - Kevin A. Shapiro
- Department of Neurology; University of California, San Francisco; San Francisco California U.S.A
| | - Renzo Guerrini
- Neurology Unit and Laboratories; A. Meyer Children's Hospital; Florence Italy
- University of Florence; Florence Italy
| | - Ingrid E. Scheffer
- Departments of Medicine and Paediatrics; Florey Institute; Austin Health and Royal Children's Hospital; University of Melbourne; Melbourne Victoria Australia
| | - Carla Marini
- Neurology Unit and Laboratories; A. Meyer Children's Hospital; Florence Italy
| | - Maria Roberta Cilio
- Department of Neurology; University of California, San Francisco; San Francisco California U.S.A
- Department of Pediatrics; University of California San Francisco; San Francisco California U.S.A
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14
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Vaher U, Nõukas M, Nikopensius T, Kals M, Annilo T, Nelis M, Ounap K, Reimand T, Talvik I, Ilves P, Piirsoo A, Seppet E, Metspalu A, Talvik T. De novo SCN8A mutation identified by whole-exome sequencing in a boy with neonatal epileptic encephalopathy, multiple congenital anomalies, and movement disorders. J Child Neurol 2014; 29:NP202-6. [PMID: 24352161 DOI: 10.1177/0883073813511300] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epileptic encephalopathies represent a clinically and genetically heterogeneous group of disorders, majority of which are of unknown etiology. We used whole-exome sequencing of a parent-offspring trio to identify the cause of early infantile epileptic encephalopathy in a boy with neonatal seizures, movement disorders, and multiple congenital anomalies who died at the age of 17 months because of respiratory illness and identified a de novo heterozygous missense mutation (c.3979A>G; p.Ile1327Val) in SCN8A (voltage-gated sodium-channel type VIII alpha subunit) gene. The variant was confirmed in the proband with Sanger sequencing. Because the clinical phenotype associated with SCN8A mutations has previously been identified only in a few patients with or without epileptic seizures, these data together with our results suggest that mutations in SCN8A can lead to early infantile epileptic encephalopathy with a broad phenotypic spectrum. Additional investigations will be worthwhile to determine the prevalence and contribution of SCN8A mutations to epileptic encephalopathies.
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Affiliation(s)
- Ulvi Vaher
- Children's Clinic, Tartu University Hospital, Tartu, Estonia
| | - Margit Nõukas
- Estonian Genome Center, University of Tartu, Tartu, Estonia Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Tiit Nikopensius
- Estonian Genome Center, University of Tartu, Tartu, Estonia Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Mart Kals
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - Tarmo Annilo
- Estonian Genome Center, University of Tartu, Tartu, Estonia Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Mari Nelis
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - Katrin Ounap
- Children's Clinic, Tartu University Hospital, Tartu, Estonia Department of Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
| | - Tiia Reimand
- Children's Clinic, Tartu University Hospital, Tartu, Estonia Department of Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia Institute of Biomedicine and Translational Medicine, Department of Biomedicine, University of Tartu, Tartu, Estonia
| | - Inga Talvik
- Children's Clinic, Tartu University Hospital, Tartu, Estonia Department of Pediatrics, University of Tartu, Tartu, Estonia
| | - Pilvi Ilves
- Radiology Clinic, Tartu University Hospital, Tartu, Estonia
| | - Andres Piirsoo
- Institute of Biomedicine and Translational Medicine, Department of Biomedicine, University of Tartu, Tartu, Estonia
| | - Enn Seppet
- Institute of Biomedicine, Department of Pathophysiology, University of Tartu, Tartu, Estonia
| | - Andres Metspalu
- Estonian Genome Center, University of Tartu, Tartu, Estonia Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Tiina Talvik
- Children's Clinic, Tartu University Hospital, Tartu, Estonia Department of Pediatrics, University of Tartu, Tartu, Estonia
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15
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Striano P, de Jonghe P, Zara F. Genetic epileptic encephalopathies: is all written into the DNA? Epilepsia 2014; 54 Suppl 8:22-6. [PMID: 24571113 DOI: 10.1111/epi.12419] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epileptic encephalopathy is a condition in which epileptic activity, clinical or subclinical, is thought to be responsible for any disturbance of cognition, behavior, or motor control. However, experimental evidence supporting this clinical observation are still poor and the causal relationship between pharmacoresistant seizures and cognitive outcome is controversial. In the past two decades, genetic studies shed new light onto complex mechanisms underlying different severe epileptic conditions associated with intellectual disability and behavioral abnormalities, thereby providing important clues on the relationship between seizures and cognitive outcome. Dravet syndrome is a childhood disorder associated with loss-of-function mutations in SCN1A and is characterized by frequent seizures and severe cognitive impairment, thus well illustrating the concept of epileptic encephalopathy. However, it is difficult to determine the causative role of the underlying sodium channel dysfunction and that of the consequent seizures in influencing cognitive outcome in these children. It is also difficult to demonstrate whether a recognizable profile of cognitive impairment or a definite behavioral phenotype exists. Data from the laboratory and the clinics may provide greater insight into the degree to which epileptic activity may contribute to cognitive impairment in individual syndromes.
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Affiliation(s)
- Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, Institute "G. Gaslini", University of Genova, Genoa, Italy
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16
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Romaniello R, Zucca C, Tenderini E, Arrigoni F, Ragona F, Zorzi G, Bassi MT, Borgatti R. A novel mutation in STXBP1 gene in a child with epileptic encephalopathy and an atypical electroclinical pattern. J Child Neurol 2014; 29:249-53. [PMID: 24170257 DOI: 10.1177/0883073813506936] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mutations in STXBP1 gene, encoding the syntaxin binding protein 1, have been recently described in Ohtahara syndrome, or early infantile epileptic encephalopathy with suppression-burst pattern, and in other early-onset epileptic encephalopathies. A 3-year-old boy affected by epileptic encephalopathy started at 8 months of age is described. Focal epilepsy was characterized by drug resistance seizures with multifocal interictal and ictal electroencephalographic (EEG) features and variable EEG focus. Direct sequencing of the STXBP1 gene showed a novel de novo mutation (c.751G>A), leading to a p.Ala251Thr substitution. Based on reported data, treatment with vigabatrin was attempted and patient became immediately seizure free for 4 months. The present case further expands the clinical spectrum of "STXBP1-related encephalopathy" suggesting molecular analysis of STXBP1 in early onset epileptic encephalopathies of unknown etiology (with onset within the first year of life). In addition, the case provides valuable suggestions on seizures treatment in STXBP1 mutated subjects.
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Affiliation(s)
- Romina Romaniello
- 1Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
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17
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Suls A, Jaehn JA, Kecskés A, Weber Y, Weckhuysen S, Craiu DC, Siekierska A, Djémié T, Afrikanova T, Gormley P, von Spiczak S, Kluger G, Iliescu CM, Talvik T, Talvik I, Meral C, Caglayan HS, Giraldez BG, Serratosa J, Lemke JR, Hoffman-Zacharska D, Szczepanik E, Barisic N, Komarek V, Hjalgrim H, Møller RS, Linnankivi T, Dimova P, Striano P, Zara F, Marini C, Guerrini R, Depienne C, Baulac S, Kuhlenbäumer G, Crawford AD, Lehesjoki AE, de Witte PAM, Palotie A, Lerche H, Esguerra CV, De Jonghe P, Helbig I. De novo loss-of-function mutations in CHD2 cause a fever-sensitive myoclonic epileptic encephalopathy sharing features with Dravet syndrome. Am J Hum Genet 2013; 93:967-75. [PMID: 24207121 DOI: 10.1016/j.ajhg.2013.09.017] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 05/28/2013] [Accepted: 09/30/2013] [Indexed: 11/18/2022] Open
Abstract
Dravet syndrome is a severe epilepsy syndrome characterized by infantile onset of therapy-resistant, fever-sensitive seizures followed by cognitive decline. Mutations in SCN1A explain about 75% of cases with Dravet syndrome; 90% of these mutations arise de novo. We studied a cohort of nine Dravet-syndrome-affected individuals without an SCN1A mutation (these included some atypical cases with onset at up to 2 years of age) by using whole-exome sequencing in proband-parent trios. In two individuals, we identified a de novo loss-of-function mutation in CHD2 (encoding chromodomain helicase DNA binding protein 2). A third CHD2 mutation was identified in an epileptic proband of a second (stage 2) cohort. All three individuals with a CHD2 mutation had intellectual disability and fever-sensitive generalized seizures, as well as prominent myoclonic seizures starting in the second year of life or later. To explore the functional relevance of CHD2 haploinsufficiency in an in vivo model system, we knocked down chd2 in zebrafish by using targeted morpholino antisense oligomers. chd2-knockdown larvae exhibited altered locomotor activity, and the epileptic nature of this seizure-like behavior was confirmed by field-potential recordings that revealed epileptiform discharges similar to seizures in affected persons. Both altered locomotor activity and epileptiform discharges were absent in appropriate control larvae. Our study provides evidence that de novo loss-of-function mutations in CHD2 are a cause of epileptic encephalopathy with generalized seizures.
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Affiliation(s)
- Arvid Suls
- Neurogenetics group, Department of Molecular Genetics, VIB, 2610 Antwerp, Belgium; Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, 2610 Antwerp, Belgium
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