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Huguenard JR. Adult Gene Therapy for Epilepsy in a Model of Angelman Syndrome: Hope or Hype? Epilepsy Curr 2023; 23:312-314. [PMID: 37901779 PMCID: PMC10601042 DOI: 10.1177/15357597231191885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023] Open
Abstract
Antisense Oligonucleotide Therapy Rescues Disturbed Brain Rhythms and Sleep in Juvenile and Adult Mouse Models of Angelman Syndrome Lee D, Chen W, Kaku HN, Zhuo X, Chao ES, Soriano A, Kuncheria A, Flores S, Kim JH, Rivera A, Rigo F, Jafar-Nejad P, Beaudet AL, Caudill MS, Xue M. Elife . 20233;12:e81892. doi:10.7554/eLife.81892 UBE3A encodes ubiquitin protein ligase E3A, and in neurons its expression from the paternal allele is repressed by the UBE3A antisense transcript (UBE3A-ATS). This leaves neurons susceptible to loss-of-function of maternal UBE3A. Indeed, Angelman syndrome, a severe neurodevelopmental disorder, is caused by maternal UBE3A deficiency. A promising therapeutic approach to treating Angelman syndrome is to reactivate the intact paternal UBE3A by suppressing UBE3A-ATS. Prior studies show that many neurological phenotypes of maternal Ube3a knockout mice can only be rescued by reinstating Ube3a expression in early development, indicating a restricted therapeutic window for Angelman syndrome. Here, we report that reducing Ube3a-ATS by antisense oligonucleotides in juvenile or adult maternal Ube3a knockout mice rescues the abnormal electroencephalogram (EEG) rhythms and sleep disturbance, two prominent clinical features of Angelman syndrome. Importantly, the degree of phenotypic improvement correlates with the increase of Ube3a protein levels. These results indicate that the therapeutic window of genetic therapies for Angelman syndrome is broader than previously thought, and EEG power spectrum and sleep architecture should be used to evaluate the clinical efficacy of therapies.
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Affiliation(s)
- John R Huguenard
- Neurology and Neurological Sciences, Stanford University School of Medicine
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Abstract
INTRODUCTION Angelman syndrome (AS) is a neurodevelopmental disorder characterized by intellectual disability, limited expressive language, epilepsy, and motor impairment. Angelman syndrome is caused by haploinsufficiency of the UBE3A gene on the maternal copy of chromosome 15. There have been ongoing advances in the understanding of neurological, behavioral, and sleep-based problems and associated treatments for patients with AS. These results along with gene-based therapies entering into clinical development prompted this review. AREAS COVERED The authors summarize the research basis describing phenomenology of epilepsy and behavioral concerns such as hyperactivity behavior, aggression, self-injury, repetitive behavior, and sleep disorder. The evidence for recent treatment advances in these target symptom domains of concern is reviewed, and the potential for emerging gene therapy treatments is considered. EXPERT OPINION The prospect for emerging gene therapies means that increasing efforts should be directed toward the early identification of AS implemented equitably. Recent studies emphasize the important role of behavioral therapy in addressing mental health concerns such as aggression and disordered sleep.
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Affiliation(s)
- Christopher J Keary
- Department is department of psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Lurie Center for Autism, Lexington, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
- Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, MA, USA
| | - Christopher J McDougle
- Department is department of psychiatry, Massachusetts General Hospital, Boston, MA, USA
- Lurie Center for Autism, Lexington, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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Ascoli M, Elia M, Gasparini S, Bonanni P, Mastroianni G, Cianci V, Neri S, Pascarella A, Santangelo D, Aguglia U, Ferlazzo E. Therapeutic approach to neurological manifestations of Angelman syndrome. Expert Rev Clin Pharmacol 2022; 15:843-850. [PMID: 35917229 DOI: 10.1080/17512433.2022.2109463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Angelman syndrome (AS) is a neurogenetic disorder due to deficient expression of the maternal copy of the UBE3A gene, which encodes ubiquitin ligase E3A protein. Severe developmental delay, seizures and other neurological disorders characterizes AS. AREAS COVERED In this review, we focus on a comprehensive therapeutic approach to the most disabling neurological manifestations of AS: epilepsy, sleep disturbances, behavioral and movement disorders. Articles were identified through PubMed and Google Scholar up to October 2021. EXPERT OPINION Evidence for the treatment of neurological manifestations in AS mainly derives from poor quality studies (case reports, small case series, expert opinions). Seizures can be polymorphic and includes atypical absences, myoclonic, generalized tonic-clonic, unilateral clonic, or atonic attacks. Sodium valproate, levetiracetam and benzodiazepines are the most commonly used anti-seizure medications. Melatonin or mirtazapine seem to improve sleep quality. Antipsychotics, antidepressants and anxiolytics have been proposed for treatment of behavioral manifestations, but no evidence-based studies are available. Non-pharmacological approach may also be useful. Mild dystonia is common but usually does not significantly impact patients' motor performances. Well-conducted clinical trials aimed to evaluate treatment of neurological complications of AS are warranted. Gene and molecular precision therapies represent a fascinating area of research in the future.
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Affiliation(s)
- Michele Ascoli
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | | | - Sara Gasparini
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Paolo Bonanni
- Epilepsy and Neurophysiology Unit, IRCCS Medea, Conegliano, Treviso, Italy
| | - Giovanni Mastroianni
- Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Vittoria Cianci
- Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Sabrina Neri
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Angelo Pascarella
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Domenico Santangelo
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Umberto Aguglia
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
| | - Edoardo Ferlazzo
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
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Neklyudova A, Smirnov K, Rebreikina A, Martynova O, Sysoeva O. Electrophysiological and Behavioral Evidence for Hyper- and Hyposensitivity in Rare Genetic Syndromes Associated with Autism. Genes (Basel) 2022; 13:671. [PMID: 35456477 PMCID: PMC9027402 DOI: 10.3390/genes13040671] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/29/2022] [Accepted: 04/05/2022] [Indexed: 01/27/2023] Open
Abstract
Our study reviewed abnormalities in spontaneous, as well as event-related, brain activity in syndromes with a known genetic underpinning that are associated with autistic symptomatology. Based on behavioral and neurophysiological evidence, we tentatively subdivided the syndromes on primarily hyper-sensitive (Fragile X, Angelman) and hypo-sensitive (Phelan–McDermid, Rett, Tuberous Sclerosis, Neurofibromatosis 1), pointing to the way of segregation of heterogeneous idiopathic ASD, that includes both hyper-sensitive and hypo-sensitive individuals. This segmentation links abnormalities in different genes, such as FMR1, UBE3A, GABRB3, GABRA5, GABRG3, SHANK3, MECP2, TSC1, TSC2, and NF1, that are causative to the above-mentioned syndromes and associated with synaptic transmission and cell growth, as well as with translational and transcriptional regulation and with sensory sensitivity. Excitation/inhibition imbalance related to GABAergic signaling, and the interplay of tonic and phasic inhibition in different brain regions might underlie this relationship. However, more research is needed. As most genetic syndromes are very rare, future investigations in this field will benefit from multi-site collaboration with a common protocol for electrophysiological and event-related potential (EEG/ERP) research that should include an investigation into all modalities and stages of sensory processing, as well as potential biomarkers of GABAergic signaling (such as 40-Hz ASSR).
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Fernández-Torre JL, Kaplan PW. Atypical or Typical Triphasic Waves-Is There a Difference? A Review. J Clin Neurophysiol 2021; 38:384-398. [PMID: 34155183 DOI: 10.1097/wnp.0000000000000731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY The entity of triphasic waves (TWs) and TW encephalopathy has derived from the subjective art of EEG interpretation. Indeed, there are few if any guidelines regarding many different aspects of TWs. The authors seek to shed light on the nature and the diagnostic characteristics of various types of TWs, differentiating "typical" from "atypical" forms. The authors conclude that morphologies in the form of bursts of well-formed, smoothly contoured, negative-positive-negative, bilateral, symmetrical and synchronous, regular, reactive, periodic or rhythmic, 1.5 to 2.0 Hz, fronto-central, triphasic complexes with fronto-occipital lag meet the criteria for typical TWs and are highly suggestive of toxic-metabolic encephalopathies. These are most frequently hepatic, uremic, or sepsis-associated encephalopathies with multi-organ failure. In such cases, atypical TWs (frontopolar or parieto-occipital maximum, negative-positive or negative-positive-negative, asymmetric and asynchronous, unreactive, irregular, multifocal, continuous with spatiotemporal evolution, sharper and without fronto-occipital/occipito-frontal lag, or triphasic delta waves) are rarely seen. Atypical TWs are encountered in Angelman syndrome, toxic encephalopathies, hyperthyroidism/hypothyroidism, Hashimoto encephalopathy, nonconvulsive status epilepticus, dementia, sepsis-associated encephalopathy, cerebrovascular disorders, and certain boundary syndromes. Investigations describing TWs with uncommon etiologies revealed few with typical TWs, suggesting that the term "TWs" has been overused in the past. Triphasic waves arise from the interaction of multiple factors including toxic, metabolic, infectious, and structural disorders that affect circuits between thalamus and cortex. The patient's metabolic status, presence of potentially neurotoxic drugs, cerebral atrophy, white matter disease, dementia, or seizures help differentiate typical from typical TWs. Future studies will determine whether this dichotomy is heuristically and clinically helpful.
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Affiliation(s)
- José L Fernández-Torre
- Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain
- Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
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Abstract
SUMMARY Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus.
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Affiliation(s)
- José L Fernández-Torre
- Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain
- Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and
| | - Peter W Kaplan
- Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A
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Egawa K, Saitoh S, Asahina N, Shiraishi H. Variance in the pathophysiological impact of the hemizygosity of gamma-aminobutyric acid type A receptor subunit genes between Prader-Willi syndrome and Angelman syndrome. Brain Dev 2021; 43:521-527. [PMID: 33419637 DOI: 10.1016/j.braindev.2020.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/29/2020] [Accepted: 12/20/2020] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are neurodevelopmental disorders caused by loss of function of maternally expressed UBE3A and paternally expressed contiguous genes on chromosome 15q11-13, respectively. A majority of these syndromes suffer from a large deletion of the relevant chromosome (AS Del or PWS Del), which includes biallelically expressed gamma-aminobutyric acid type A receptor subunit (GABAaR) genes, while remaining individuals present without the deletion (AS non-Del or PWS non-Del). We previously reported that AS Del, but not AS non-Del individuals, show aberrantly desynchronized somatosensory-evoked magnetic fields (SEFs) and speculated that it might reflect GABAergic dysfunction due to the hemizygosity of GABAaR genes. To verify its pathophysiological impact on PWS and AS, we analyzed the SEFs of PWS individuals. METHOD SEFs were recorded from eight PWS Del and two PWS non-Del individuals. The latency and strength of the first peak (N1m) were compared with those of AS Del/non-Del individuals and controls, most of which were obtained earlier. RESULTS In contrast to AS, both PWS Del and PWS non-Del showed normal SEF waveforms. Desynchronized response with delayed N1m peak latency was exclusively indicated in AS Del. N1m strength was statistically higher in AS Del and AS non-Del, but not in PWS Del and PWS non-Del. CONCLUSIONS Our results indicate that the pathophysiological impact of the hemizygosity of GABAaR genes is lower in PWS than AS. UBE3A deficiency and the hemizygosity of GABAaR genes could synergistically deteriorate neuronal function, resulting in aberrant SEFs in AS Del.
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Affiliation(s)
- Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Naoko Asahina
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan.
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Born HA, Martinez LA, Levine AT, Harris SE, Mehra S, Lee WL, Dindot SV, Nash KR, Silverman JL, Segal DJ, Weeber EJ, Anderson AE. Early Developmental EEG and Seizure Phenotypes in a Full Gene Deletion of Ubiquitin Protein Ligase E3A Rat Model of Angelman Syndrome. eNeuro 2021; 8:ENEURO. [PMID: 33531368 DOI: 10.1523/ENEURO.0345-20.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/27/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Angelman syndrome (AS) is a neurodevelopmental disorder with unique behavioral phenotypes, seizures, and distinctive electroencephalographic (EEG) patterns. Recent studies identified motor, social communication, and learning and memory deficits in a CRISPR engineered rat model with a complete maternal deletion of the Ube3a gene. It is unknown whether this model recapitulates other aspects of the clinical disorder. We report here the effect of Ube3a maternal deletion in the rat on epileptiform activity, seizure threshold, and quantitative EEG. Using video-synchronized EEG (vEEG) monitoring, we assessed spectral power and epileptiform activity early postnatally through adulthood. While EEG power was similar to wild-type (WT) at 1.5 weeks postnatally, at all other ages analyzed, our findings were similar to the AS phenotype in mice and humans with significantly increased δ power. Analysis of epileptiform activity in juvenile and adult rats showed increased time spent in epileptiform activity in AS compared with WT rats. We evaluated seizure threshold using pentylenetetrazol (PTZ), audiogenic stimulus, and hyperthermia to provoke febrile seizures (FSs). Behavioral seizure scoring following PTZ induction revealed no difference in seizure threshold in AS rats, however behavioral recovery from the PTZ-induced seizure was longer in the adult group with significantly increased hippocampal epileptiform activity during this phase. When exposed to hyperthermia, AS rat pups showed a significantly lower temperature threshold to first seizure than WT. Our findings highlight an age-dependence for the EEG and epileptiform phenotypes in a preclinical model of AS, and support the use of quantitative EEG and increased δ power as a potential biomarker of AS.
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Copping NA, Silverman JL. Abnormal electrophysiological phenotypes and sleep deficits in a mouse model of Angelman Syndrome. Mol Autism 2021; 12:9. [PMID: 33549123 PMCID: PMC7866697 DOI: 10.1186/s13229-021-00416-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/18/2021] [Indexed: 01/17/2023] Open
Abstract
Background Angelman Syndrome (AS) is a rare genetic disorder characterized by impaired communication, motor and balance deficits, intellectual disabilities, recurring seizures and abnormal sleep patterns. The genetic cause of AS is neuronal-specific loss of expression of UBE3A (ubiquitin-protein ligase E6-AP), an imprinted gene. Seizure and sleep disorders are highly prevalent (> 80%) in the AS population. The present experiments were designed to identify translational, neurophysiological outcome measures in a model of AS. Methods We used the exon-2 deletion mouse (Ube3a-del) on a C57BL/6J background to assess seizure, sleep and electrophysiological phenotypes. Seizure susceptibility has been reported in Ube3a-del mice with a variety of seizure induction methods. Here, we provoked seizures by a single high-dose injection of 80 mg/kg pentylenetetrazole. Novel experiments included the utilization of wireless telemetry devices to acquire global electroencephalogram (EEG) and neurophysiological data on electrographic seizures, power spectra, light–dark cycles, sleep stages and sleep spindles in Ube3a-del and WT mice. Results Ube3a-del mice exhibited reduced seizure threshold compared to WT. EEG illustrated that Ube3a-del mice had increased epileptiform spiking activity and delta power, which corroborates findings from other laboratories and recapitulates clinical reports in AS. This is the first report to use a cortical surface-based recording by a wireless telemetry device over tethered/fixed head-mount depth recordings. Less time in both paradoxical and slow-wave sleep, longer latencies to paradoxical sleep stages and total less sleep time in Ube3a-del mice were observed compared to WT. For the first time, we detected fewer sleep spindles in the AS mouse model. Limitations This study was limited to the exon 2 deletion mouse model, and future work will investigate the rat model of AS, containing a complete Ube3a deletion and pair EEG with behavior. Conclusions Our data enhance rigor and translatability as our study provides important corroboration of previous reports on epileptiform and elevated delta power. For the first time we report neurophysiological phenotypes collected via translational methodology. Furthermore, this is the first report of reduced sleep spindles, a critical marker of memory consolidation during sleep, in an AS model. Our results are useful outcomes for therapeutic testing.
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Affiliation(s)
- N A Copping
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Room 1001B, Research II Building 96, 4625 2nd Avenue, Sacramento, CA, 95817, USA
| | - J L Silverman
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Room 1001B, Research II Building 96, 4625 2nd Avenue, Sacramento, CA, 95817, USA.
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den Besten I, de Jong RF, Geerts‐Haages A, Bruggenwirth HT, Koopmans M, Brooks A, Elgersma Y, Festen DAM, Valstar MJ. Clinical aspects of a large group of adults with Angelman syndrome. Am J Med Genet A 2021; 185:168-181. [PMID: 33108066 PMCID: PMC7756639 DOI: 10.1002/ajmg.a.61940] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/28/2020] [Accepted: 10/03/2020] [Indexed: 11/06/2022]
Abstract
Descriptions of the clinical features of Angelman syndrome (AS) have mainly been focused on children. Here, we describe the evolution of the clinical phenotypes of AS in adulthood, using clinical data from 95 individuals (mean age 31.6 years, median 29.0 years, range 18-83 years), with genetically confirmed AS. Data was collected through physical examination and inspection of medical records, combined with questionnaires and interviews. Adults with AS experience substantial debilitating health problems. Constipation, reflux, visual problems, scoliosis, behavioral and sleeping problems occurred frequently and require appropriate attention. Epilepsy was reported in 57% of adults, negatively affecting the level of functioning. Non-convulsive status epilepticus was not observed in the adults, however some individuals developed prolonged episodes of rhythmic shaking while awake. A decline in mobility was noted in the majority of adults. A minority of adults with AS showed microcephaly. Taken together, this first phenotypic study of adults with AS to include in person interviews with care-givers and physical examination of patients, including the eldest adult reported to date, provides important insight in the development of the syndrome into adulthood. This knowledge is required to improve care for adult individuals with AS and to evaluate future therapies for this group.
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Affiliation(s)
- Inge den Besten
- Intellectual Disability Medicine, Department of General PracticeErasmus MCRotterdamThe Netherlands
| | - Rianne F. de Jong
- Intellectual Disability Medicine, Department of General PracticeErasmus MCRotterdamThe Netherlands
| | - Amber Geerts‐Haages
- Intellectual Disability Medicine, Department of General PracticeErasmus MCRotterdamThe Netherlands
| | - Hennie T. Bruggenwirth
- Department of Clinical GeneticsErasmus University Medical CenterRotterdamThe Netherlands
| | - Marije Koopmans
- Department of Medical GeneticsUtrecht University Medical CenterUtrechtThe Netherlands
| | | | - Alice Brooks
- Department of Clinical GeneticsErasmus University Medical CenterRotterdamThe Netherlands
| | - Ype Elgersma
- Department of NeuroscienceErasmus MC University Medical CenterRotterdamThe Netherlands
| | - Dederieke A. M. Festen
- Intellectual Disability Medicine, Department of General PracticeErasmus MCRotterdamThe Netherlands
| | - Marlies J. Valstar
- Intellectual Disability Medicine, Department of General PracticeErasmus MCRotterdamThe Netherlands
- ASVZ, Medical DepartmentCare and Service Centre for People with Intellectual DisabilitiesSliedrechtThe Netherlands
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Egawa K, Saitoh S, Asahina N, Shiraishi H. Short-latency somatosensory-evoked potentials demonstrate cortical dysfunction in patients with Angelman syndrome. eNeurologicalSci 2020; 22:100298. [PMID: 33313428 PMCID: PMC7721653 DOI: 10.1016/j.ensci.2020.100298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/18/2020] [Accepted: 11/25/2020] [Indexed: 11/06/2022] Open
Abstract
Background Angelman syndrome (AS) is neurodevelopmental disorder, causal gene of which is maternally expressed UBE3A. A majority of patients results from the large deletion of relevant chromosome which includes GABAA receptor subunit genes (GABARs) as well as UBE3A (AS Del). We previously reported aberrantly desynchronized primary somatosensory response in AS Del by using magnetoencephalography. The purpose of this study is to estimate cortical and subcortical involvement in the deficit of primary somatosensory processing in AS. Methods We analyzed short-latency somatosensory-evoked potentials (SSEPs) in 8 patients with AS Del. SSEPs were recorded on a 4-channel system comprising of two cortical electrodes which were placed on the frontal and centro-parietal areas. The peak and onset latency of each component were measured to compare latency and interval times. Results The first-cortical peak latency (N20, P20), and N13-N20 peak interval times were significantly prolonged in AS Del compared to healthy controls. In contrast, there was no difference in latencies between subcortical components up to N20 onset or for N11-N20 onset interval times. Conclusion Highly desynchronized first-cortical SSEP components and normal latencies of subcortical components indicated cortical dysfunction rather than impairment of afferent pathways in AS Del patients, which might be attributed to GABAergic dysfunction due to loss of UBE3A function and heterozygosity of GABARs Somatosensory-evoked potentials (SEPs) were evaluated in Angelman syndrome (AS). All subjects had a 15q11-13 deletion, which includes the GABAA receptor subunit genes. The duration of the first-cortical SEP components was significantly prolonged. Latencies between subcortical components were comparable to controls. Desynchronized cortical response suggests GABAergic dysfunction in AS with deletion.
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Affiliation(s)
- Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Shinji Saitoh
- Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho -ku, Nagoya 467-8601, Japan
| | - Naoko Asahina
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan
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Buonfiglio D, Hummer DL, Armstrong A, Christopher Ehlen J, DeBruyne JP. Angelman syndrome and melatonin: What can they teach us about sleep regulation. J Pineal Res 2020; 69:e12697. [PMID: 32976638 PMCID: PMC7577950 DOI: 10.1111/jpi.12697] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 01/20/2023]
Abstract
In 1965, Dr Harry Angelman reported a neurodevelopmental disorder affecting three unrelated children who had similar symptoms: brachycephaly, mental retardation, ataxia, seizures, protruding tongues, and remarkable paroxysms of laughter. Over the past 50 years, the disorder became Angelman's namesake and symptomology was expanded to include hyper-activity, stereotypies, and severe sleep disturbances. The sleep disorders in many Angelman syndrome (AS) patients are broadly characterized by difficulty falling and staying asleep at night. Some of these patients sleep less than 4 hours a night and, in most cases, do not make up this lost sleep during the day-leading to the speculation that AS patients may "need" less sleep. Most AS patients also have severely reduced levels of melatonin, a hormone produced by the pineal gland exclusively at night. This nightly pattern of melatonin production is thought to help synchronize internal circadian rhythms and promote nighttime sleep in humans and other diurnal species. It has been proposed that reduced melatonin levels contribute to the sleep problems in AS patients. Indeed, emerging evidence suggests melatonin replacement therapy can improve sleep in many AS patients. However, AS mice show sleep problems that are arguably similar to those in humans despite being on genetic backgrounds that do not make melatonin. This suggests the hypothesis that the change in nighttime melatonin may be a secondary factor rather than the root cause of the sleeping disorder. The goals of this review article are to revisit the sleep and melatonin findings in both AS patients and animal models of AS and discuss what AS may tell us about the underlying mechanisms of, and interplay between, melatonin and sleep.
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Affiliation(s)
- Daniella Buonfiglio
- Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Daniel L Hummer
- Department of Psychology, Morehouse College, Atlanta, GA, USA
| | - Ariel Armstrong
- Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
| | | | - Jason P DeBruyne
- Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA, USA
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13
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Saravanapandian V, Frohlich J, Hipp JF, Hyde C, Scheffler AW, Golshani P, Cook EH, Reiter LT, Senturk D, Jeste SS. Properties of beta oscillations in Dup15q syndrome. J Neurodev Disord 2020; 12:22. [PMID: 32791992 PMCID: PMC7425173 DOI: 10.1186/s11689-020-09326-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 07/30/2020] [Indexed: 11/21/2022] Open
Abstract
Background Duplications of 15q11.2-q13.1 (Dup15q syndrome) are highly penetrant for autism, intellectual disability, hypotonia, and epilepsy. The 15q region harbors genes critical for brain development, particularly UBE3A and a cluster of gamma-aminobutyric acid type A receptor (GABAAR) genes. We recently described an electrophysiological biomarker of the syndrome, characterized by excessive beta oscillations (12–30 Hz), resembling electroencephalogram (EEG) changes induced by allosteric modulation of GABAARs. In this follow-up study, we tested a larger cohort of children with Dup15q syndrome to comprehensively examine properties of this EEG biomarker that would inform its use in future clinical trials, specifically, its (1) relation to basic clinical features, such as age, duplication type, and epilepsy; (2) relation to behavioral characteristics, such as cognition and adaptive function; (3) stability over time; and (4) reproducibility of the signal in clinical EEG recordings. Methods We computed EEG power and beta peak frequency (BPF) in a cohort of children with Dup15q syndrome (N = 41, age range 9–189 months). To relate EEG parameters to clinical (study 1) and behavioral features (study 2), we examined age, duplication type, epilepsy, cognition, and daily living skills (DLS) as predictors of beta power and BPF. To evaluate stability over time (study 3), we derived the intraclass correlation coefficients (ICC) from beta power and BPF computed from children with multiple EEG recordings (N = 10, age range 18–161 months). To evaluate reproducibility in a clinical setting (study 4), we derived ICCs from beta power computed from children (N = 8, age range 19–96 months), who had undergone both research EEG and clinical EEG. Results The most promising relationships between EEG and clinical traits were found using BPF. BPF was predicted both by epilepsy status (R2 = 0.11, p = 0.038) and the DLS component of the Vineland Adaptive Behavior Scale (R2 = 0.17, p = 0.01). Beta power and peak frequency showed high stability across repeated visits (beta power ICC = 0.93, BPF ICC = 0.92). A reproducibility analysis revealed that beta power estimates are comparable between research and clinical EEG (ICC = 0.94). Conclusions In this era of precision health, with pharmacological and neuromodulatory therapies being developed and tested for specific genetic etiologies of neurodevelopmental disorders, quantification and examination of mechanistic biomarkers can greatly improve clinical trials. To this end, the robust beta oscillations evident in Dup15q syndrome are clinically reproducible and stable over time. With future preclinical and computational studies that will help disentangle the underlying mechanism, it is possible that this biomarker could serve as a robust measure of drug target engagement or a proximal outcome measure in future disease modifying intervention trials.
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Affiliation(s)
- Vidya Saravanapandian
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA.,Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland.,Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, CA, 90095, USA
| | - Joerg F Hipp
- Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland
| | - Carly Hyde
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA
| | - Aaron W Scheffler
- Department of Biostatistics, University of California Los Angeles School of Public Health, Room 21-254C CHS, Los Angeles, CA, 90095, USA
| | - Peyman Golshani
- Department of Neurology and Semel Institute for Neuroscience, David Geffen School of Medicine, 710 Westwood Plaza, Los Angeles, CA, 90095, USA.,West Los Angeles VA Medical Center, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA
| | - Edwin H Cook
- Department of Psychiatry, University of Illinois at Chicago, 1747 W Roosevelt Road, Chicago, IL, 60608, USA
| | - Lawrence T Reiter
- Department of Neurology, Pediatrics and Anatomy & Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link, Memphis, TN, 415, USA
| | - Damla Senturk
- Department of Biostatistics, University of California Los Angeles School of Public Health, Room 21-254C CHS, Los Angeles, CA, 90095, USA
| | - Shafali S Jeste
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California Los Angeles, Los Angeles, CA, 90024, USA
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14
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Pereira JA, Ravichandran CT, Mullett J, McDougle CJ, Keary CJ. Characterization of sleep habits and medication outcomes for sleep disturbance in children and adults with Angelman syndrome. Am J Med Genet A 2020; 182:1913-1922. [PMID: 32506735 DOI: 10.1002/ajmg.a.61642] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 03/30/2020] [Accepted: 05/02/2020] [Indexed: 12/16/2022]
Abstract
The objectives of this study were to characterize the sleep habits of 50 clinically referred individuals with Angelman syndrome (AS) and to retrospectively compare the effectiveness/tolerability of the three most commonly prescribed sleep medications in the sample. An experienced physician assigned a Clinical Global Impressions-Severity scale (CGI-S) score for each subject's AS-specific symptoms. Caregivers completed the Child Sleep Habits Questionnaire (CSHQ; screen for sleep problems in school-aged [4-10 years] children), a screening assessment for sleep problems. Caregivers provided information about medication trials targeting disturbed sleep, with the physician assigning a CGI-Improvement scale (CGI-I) score for each trial. Linear regression showed significant negative association between age and CSHQ score. In their lifetime, 72% of participants had taken a medication for sleep, most commonly melatonin, clonidine and trazodone. The majority continued these for 6 months or longer. With these medications, many demonstrated significant improvement in sleep disturbances, with no difference in odds of improvement between medications. Disturbed sleep was common in this cohort and significantly worse in younger-aged participants. The majority received at least one medication trial for disturbed sleep and each of the most commonly prescribed medication was effective for a substantial percentage of participants. Most participants remained on medication for at least 6 months, suggesting favorable tolerability.
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Affiliation(s)
| | - Caitlin T Ravichandran
- Harvard Medical School, Boston, Massachusetts, USA.,Lurie Center for Autism, Massachusetts General Hospital, Lexington, Massachusetts, USA.,McLean Hospital, Belmont, Massachusetts, USA
| | - Jennifer Mullett
- Lurie Center for Autism, Massachusetts General Hospital, Lexington, Massachusetts, USA
| | - Christopher J McDougle
- Harvard Medical School, Boston, Massachusetts, USA.,Lurie Center for Autism, Massachusetts General Hospital, Lexington, Massachusetts, USA.,Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, Massachusetts, USA
| | - Christopher J Keary
- Harvard Medical School, Boston, Massachusetts, USA.,Lurie Center for Autism, Massachusetts General Hospital, Lexington, Massachusetts, USA.,Angelman Syndrome Program, Massachusetts General Hospital for Children, Boston, Massachusetts, USA
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15
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Wang TS, Tsai WH, Tsai LP, Wong SB. Clinical characteristics and epilepsy in genomic imprinting disorders: Angelman syndrome and Prader-Willi syndrome. Tzu Chi Med J 2020; 32:137-144. [PMID: 32269945 PMCID: PMC7137370 DOI: 10.4103/tcmj.tcmj_103_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/03/2019] [Accepted: 09/03/2019] [Indexed: 11/17/2022] Open
Abstract
Angelman syndrome (AS) and Prader–Willi syndrome (PWS) are considered sister imprinting disorders. Although both AS and PWS congenital neurodevelopmental disorders have chromosome 15q11.3-q13 dysfunction, their molecular mechanisms differ owing to genomic imprinting, which results in different parent-of-the-origin gene expressions. Recently, several randomized controlled trials have been proceeded to treat specific symptoms of AS and PWS. Due to the advance of clinical management, early diagnosis for patients with AS and PWS is important. PWS is induced by multiple paternal gene dysfunctions, including those in MKRN3, MAGEL2, NDN, SNURF-SNPRPN, NPAP1, and a cluster of small nucleolar RNA genes. PWS patients exhibit characteristic facial features, endocrinological, and behavioral phenotypes, including short and obese figures, hyperphagia, growth hormone deficiency, hypogonadism, autism, or obsessive– compulsive-like behaviors. In addition, hypotonia, poor feeding, failure to thrive, and typical facial features are major factors for early diagnosis of PWS. For PWS patients, epilepsy is not common and easy to treat. Conversely, AS is a single-gene disorder induced by ubiquitin-protein ligase E3A dysfunction, which only expresses from a maternal allele. AS patients develop epilepsy in their early lives and their seizures are difficult to control. The distinctive gait pattern, excessive laughter, and characteristic electroencephalography features, which contain anterior-dominated, high-voltage triphasic delta waves intermixed with epileptic spikes, result in early suspicion of AS. Often, polytherapy, including the combination of valproate, levetiracetam, lamotrigine, and benzodiazepines, is required for controlling seizures of AS patients. Notably, carbamazepine, oxcarbazepine, and vigabatrin should be avoided, since these may induce nonconvulsive status epilepticus. AS and PWS presented with distinct clinical manifestations according to specific molecular defects due to genomic imprinting. Early diagnosis and teamwork intervention, including geneticists, neurologists, rehabilitation physicians, and pulmonologists, are important. Epilepsy is common in patients with AS, and after proper treatment, seizures could be effectively controlled in late childhood or early adulthood for both AS and PWS patients.
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Affiliation(s)
- Tzong-Shi Wang
- Department of Psychiatry, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan
| | - Wen-Hsin Tsai
- Department of Pediatrics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Li-Ping Tsai
- Department of Pediatrics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Shi-Bing Wong
- Department of Pediatrics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
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16
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Frohlich J, Reiter LT, Saravanapandian V, DiStefano C, Huberty S, Hyde C, Chamberlain S, Bearden CE, Golshani P, Irimia A, Olsen RW, Hipp JF, Jeste SS. Mechanisms underlying the EEG biomarker in Dup15q syndrome. Mol Autism 2019; 10:29. [PMID: 31312421 PMCID: PMC6609401 DOI: 10.1186/s13229-019-0280-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/11/2019] [Indexed: 12/11/2022] Open
Abstract
Background Duplications of 15q11.2-q13.1 (Dup15q syndrome), including the paternally imprinted gene UBE3A and three nonimprinted gamma-aminobutyric acid type-A (GABAA) receptor genes, are highly penetrant for neurodevelopmental disorders such as autism spectrum disorder (ASD). To guide targeted treatments of Dup15q syndrome and other forms of ASD, biomarkers are needed that reflect molecular mechanisms of pathology. We recently described a beta EEG phenotype of Dup15q syndrome, but it remains unknown which specific genes drive this phenotype. Methods To test the hypothesis that UBE3A overexpression is not necessary for the beta EEG phenotype, we compared EEG from a reference cohort of children with Dup15q syndrome (n = 27) to (1) the pharmacological effects of the GABAA modulator midazolam (n = 12) on EEG from healthy adults, (2) EEG from typically developing (TD) children (n = 14), and (3) EEG from two children with duplications of paternal 15q (i.e., the UBE3A-silenced allele). Results Peak beta power was significantly increased in the reference cohort relative to TD controls. Midazolam administration recapitulated the beta EEG phenotype in healthy adults with a similar peak frequency in central channels (f = 23.0 Hz) as Dup15q syndrome (f = 23.1 Hz). Both paternal Dup15q syndrome cases displayed beta power comparable to the reference cohort. Conclusions Our results suggest a critical role for GABAergic transmission in the Dup15q syndrome beta EEG phenotype, which cannot be explained by UBE3A dysfunction alone. If this mechanism is confirmed, the phenotype may be used as a marker of GABAergic pathology in clinical trials for Dup15q syndrome.
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Affiliation(s)
- Joel Frohlich
- Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
- Department of Psychology, University of California Los Angeles, 3423 Franz Hall, Los Angeles, CA 90095 USA
| | - Lawrence T. Reiter
- Departments of Neurology, Pediatrics and Anatomy & Neurobiology, The University of Tennessee Health Science Center, 855 Monroe Ave., Link, Memphis, TN 415 USA
| | - Vidya Saravanapandian
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
| | - Charlotte DiStefano
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
| | - Scott Huberty
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
- McGill University, MUHC Research Institute, 5252, boul. de Maisonneuve Ouest, 3E.19, Montreal, QC H4A 3S5 Canada
| | - Carly Hyde
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
| | - Stormy Chamberlain
- Genetics and Genome Sciences, UConn Health, 400 Farmington Avenue, Farmington, CT 06030-6403 USA
| | - Carrie E. Bearden
- Department of Psychiatry and Biobehavioral Sciences and Department of Psychology, University of California Los Angeles, Suite A7-460, 760 Westwood Plaza, Los Angeles, CA 90095 USA
| | - Peyman Golshani
- Department of Neurology and Psychiatry, David Geffen School of Medicine, 710 Westwood Plaza, Los Angeles, CA 90095 USA
| | - Andrei Irimia
- Leonard Davis School of Gerontology, University of Southern California, 3715 McClintock Ave., Suite 228C, California, Los Angeles 90089 USA
| | - Richard W. Olsen
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, California, Los Angeles 90095 USA
| | - Joerg F. Hipp
- Roche Pharma Research and Early Development, Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center Basel, Basel, Switzerland
| | - Shafali S. Jeste
- Center for Autism Research and Treatment, University of California Los Angeles, Semel Institute for Neuroscience, Los Angeles, CA 90024 USA
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17
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Frohlich J, Miller MT, Bird LM, Garces P, Purtell H, Hoener MC, Philpot BD, Sidorov MS, Tan WH, Hernandez MC, Rotenberg A, Jeste SS, Krishnan M, Khwaja O, Hipp JF. Electrophysiological Phenotype in Angelman Syndrome Differs Between Genotypes. Biol Psychiatry 2019; 85:752-759. [PMID: 30826071 PMCID: PMC6482952 DOI: 10.1016/j.biopsych.2019.01.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/11/2018] [Accepted: 01/04/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by either disruptions of the gene UBE3A or deletion of chromosome 15 at 15q11-q13, which encompasses UBE3A and several other genes, including GABRB3, GABRA5, GABRG3, encoding gamma-aminobutyric acid type A receptor subunits (β3, α5, γ3). Individuals with deletions are generally more impaired than those with other genotypes, but the underlying pathophysiology remains largely unknown. Here, we used electroencephalography (EEG) to test the hypothesis that genes other than UBE3A located on 15q11-q13 cause differences in pathophysiology between AS genotypes. METHODS We compared spectral power of clinical EEG recordings from children (1-18 years of age) with a deletion genotype (n = 37) or a nondeletion genotype (n = 21) and typically developing children without Angelman syndrome (n = 48). RESULTS We found elevated theta power (peak frequency: 5.3 Hz) and diminished beta power (peak frequency: 23 Hz) in the deletion genotype compared with the nondeletion genotype as well as excess broadband EEG power (1-32 Hz) peaking in the delta frequency range (peak frequency: 2.8 Hz), shared by both genotypes but stronger for the deletion genotype at younger ages. CONCLUSIONS Our results provide strong evidence for the contribution of non-UBE3A neuronal pathophysiology in deletion AS and suggest that hemizygosity of the GABRB3-GABRA5-GABRG3 gene cluster causes abnormal theta and beta EEG oscillations that may underlie the more severe clinical phenotype. Our work improves the understanding of AS pathophysiology and has direct implications for the development of AS treatments and biomarkers.
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Affiliation(s)
- Joel Frohlich
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland; Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California, Los Angeles, Los Angeles.
| | - Meghan T Miller
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Lynne M Bird
- Department of Pediatrics, University of California, San Diego, Massachusetts; Division of Genetics/Dysmorphology, Rady Children's Hospital San Diego, San Diego, Massachusetts
| | - Pilar Garces
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Hannah Purtell
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marius C Hoener
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Benjamin D Philpot
- Neuroscience Center, Carolina Institute for Developmental Disabilities, Chapel Hill, North Carolina; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael S Sidorov
- Neuroscience Center, Carolina Institute for Developmental Disabilities, Chapel Hill, North Carolina; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Wen-Hann Tan
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maria-Clemencia Hernandez
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Alexander Rotenberg
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shafali S Jeste
- Center for Autism Research and Treatment, Semel Institute for Neuroscience, University of California, Los Angeles, Los Angeles
| | - Michelle Krishnan
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Omar Khwaja
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland
| | - Joerg F Hipp
- Neuroscience, Ophthalmology and Rare Diseases, Roche Innovation Center, Roche Pharma Research and Early Development, Basel, Switzerland.
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Abstract
The relationship between generalized and lateralized rhythmic delta activity (RDA) and seizures is more ambiguous than the relationship between periodic discharges and seizures. Although frontally predominant generalized RDA is not associated with seizures, occipitally predominant RDA may be associated with the absence of seizures. Lateralized RDA seems to be more strongly associated with the presence of seizure activity. Appropriate recognition of generalized RDA and lateralized rhythmic delta activity may be confounded by benign etiologies of RDA, such as phi rhythm, slow alpha variant, subclinical rhythmic electrographic discharges of adults, or hyperventilation-induced high-amplitude rhythmic slowing. Angelman syndrome and NMDA-receptor antibody encephalitis can also produce morphologically distinct patterns of RDA.
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19
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Prasad A, Grocott O, Parkin K, Larson A, Thibert RL. Angelman syndrome in adolescence and adulthood: A retrospective chart review of 53 cases. Am J Med Genet A 2018; 176:1327-1334. [PMID: 29696750 DOI: 10.1002/ajmg.a.38694] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 02/25/2018] [Accepted: 03/05/2018] [Indexed: 02/04/2023]
Abstract
Angelman syndrome is a neurogenetic disorder with varying clinical presentations and symptoms as the individual ages. The goal of this study was to characterize changes over time in the natural history of this syndrome in a large population. We reviewed the medical records of the 53 patients who were born prior to 2000 and seen at the Angelman Syndrome Clinic at Massachusetts General Hospital to assess neurological, sleep, behavioral, gastrointestinal, orthopedic, and ophthalmologic functioning. The average age of this cohort was 24 years. Active seizures were present in 35%, nonepileptic myoclonus in 42%, and clinically significant tremors in 55%. Anxiety was present in 57%, increasing to 71% in those ages 26-43 years. In terms of sleep, 56% reported 8 hr of sleep or more, although 43% reported frequent nocturnal awakenings. Gastrointestinal issues remain problematic with 81% having constipation and 53% gastroesophageal reflux. The majority lived in a parent's home and remained independently mobile, though scoliosis was reportedly present in 30%, and 20% had reported low bone density/osteoporosis. The results of this study suggest that the prevalence of active seizures may decrease in adulthood but that the prevalence of movement disorders such as tremor and nonepileptic myoclonus may increase. Anxiety increases significantly as individuals age while defiant behaviors appear to decrease. Sleep dysfunction typically improves as compared to childhood but remains a significant issue for many adults. Other areas that require monitoring into adulthood include gastrointestinal dysfunction, and orthopedic/mobility issues, such as reported scoliosis and bone density, and ophthalmologic disorders.
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Affiliation(s)
- Ankita Prasad
- Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts
| | - Olivia Grocott
- Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts
| | - Kimberly Parkin
- Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts
| | - Anna Larson
- Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts
| | - Ronald L Thibert
- Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts
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20
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Tomei KL, Mau CY, Ghali M, Pak J, Goldstein IM. Vagal nerve stimulation for medically refractory epilepsy in Angelman syndrome: a series of three cases. Childs Nerv Syst 2018; 34:395-400. [PMID: 29350262 DOI: 10.1007/s00381-018-3723-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/04/2018] [Indexed: 11/24/2022]
Abstract
BACKGROUND We describe three children with Angelman syndrome and medically refractory epilepsy. METHODS Case series of three pediatric patients with Angelman syndrome and medically refractory epilepsy. All three patients failed medical treatment and were recommended for vagal nerve stimulator (VNS) implantation. RESULTS Following VNS implantation, all three patients experienced reduction in seizure frequency greater than that afforded by medication alone. CONCLUSION We present vagal nerve stimulator implantation as a viable treatment option for medically refractory epilepsy associated with Angelman syndrome.
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Affiliation(s)
- Krystal L Tomei
- University Hospitals Case Medical Center, Rainbow Babies and Children's Hospital, Cleveland, OH, USA
| | - Christine Y Mau
- Department of Neurological Surgery, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Michael Ghali
- Department of General Surgery, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Jayoung Pak
- Department of Neurology, Rutgers New Jersey Medical School Newark, Newark, NJ, USA
| | - Ira M Goldstein
- Department of Neurological Surgery, Rutgers New Jersey Medical School, 90 Bergen Street, Suite 8100, Newark, NJ, 07101-1709, USA.
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21
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Born HA, Dao AT, Levine AT, Lee WL, Mehta NM, Mehra S, Weeber EJ, Anderson AE. Strain-dependence of the Angelman Syndrome phenotypes in Ube3a maternal deficiency mice. Sci Rep 2017; 7:8451. [PMID: 28814801 DOI: 10.1038/s41598-017-08825-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/17/2017] [Indexed: 11/09/2022] Open
Abstract
Angelman syndrome (AS) is a genetic neurodevelopmental disorder, most commonly caused by deletion or mutation of the maternal allele of the UBE3A gene, with behavioral phenotypes and seizures as key features. Currently no treatment is available, and therapeutics are often ineffective in controlling AS-associated seizures. Previous publications using the Ube3a maternal deletion model have shown behavioral and seizure susceptibility phenotypes, however findings have been variable and merit characterization of electroencephalographic (EEG) activity. In this study, we extend previous studies comparing the effect of genetic background on the AS phenotype by investigating the behavioral profile, EEG activity, and seizure threshold. AS C57BL/6J mice displayed robust behavioral impairments, spontaneous EEG polyspikes, and increased cortical and hippocampal power primarily driven by delta and theta frequencies. AS 129 mice performed poorly on wire hang and contextual fear conditioning and exhibited a lower seizure threshold and altered spectral power. AS F1 hybrid mice (C57BL/6J × 129) showed milder behavioral impairments, infrequent EEG polyspikes, and fewer spectral power alterations. These findings indicate the effect of common genetic backgrounds on the Ube3a maternal deletion behavioral, EEG, and seizure threshold phenotypes. Our results will inform future studies on the optimal strain for evaluating therapeutics with different AS-like phenotypes.
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22
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Sidorov MS, Deck GM, Dolatshahi M, Thibert RL, Bird LM, Chu CJ, Philpot BD. Delta rhythmicity is a reliable EEG biomarker in Angelman syndrome: a parallel mouse and human analysis. J Neurodev Disord 2017; 9:17. [PMID: 28503211 PMCID: PMC5422949 DOI: 10.1186/s11689-017-9195-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/21/2017] [Indexed: 01/11/2023] Open
Abstract
Background Clinicians have qualitatively described rhythmic delta activity as a prominent EEG abnormality in individuals with Angelman syndrome, but this phenotype has yet to be rigorously quantified in the clinical population or validated in a preclinical model. Here, we sought to quantitatively measure delta rhythmicity and evaluate its fidelity as a biomarker. Methods We quantified delta oscillations in mouse and human using parallel spectral analysis methods and measured regional, state-specific, and developmental changes in delta rhythms in a patient population. Results Delta power was broadly increased and more dynamic in both the Angelman syndrome mouse model, relative to wild-type littermates, and in children with Angelman syndrome, relative to age-matched neurotypical controls. Enhanced delta oscillations in children with Angelman syndrome were present during wakefulness and sleep, were generalized across the neocortex, and were more pronounced at earlier ages. Conclusions Delta rhythmicity phenotypes can serve as reliable biomarkers for Angelman syndrome in both preclinical and clinical settings. Electronic supplementary material The online version of this article (doi:10.1186/s11689-017-9195-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael S Sidorov
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599 USA.,Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599 USA.,Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Gina M Deck
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114 USA.,Harvard Medical School, Boston, MA 02215 USA.,Present Address: The Neurology Foundation, Rhode Island Hospital and Warren Alpert School of Medicine at Brown University, Providence, RI 02903 USA
| | - Marjan Dolatshahi
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114 USA.,Harvard Medical School, Boston, MA 02215 USA
| | - Ronald L Thibert
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Lynne M Bird
- Department of Pediatrics, University of California, San Diego, CA USA.,Division of Dysmorphology/Genetics, Rady Children's Hospital, San Diego, CA USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114 USA.,Harvard Medical School, Boston, MA 02215 USA
| | - Benjamin D Philpot
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599 USA.,Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599 USA.,Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599 USA
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Grocott OR, Herrington KS, Pfeifer HH, Thiele EA, Thibert RL. Low glycemic index treatment for seizure control in Angelman syndrome: A case series from the Center for Dietary Therapy of Epilepsy at the Massachusetts General Hospital. Epilepsy Behav 2017; 68:45-50. [PMID: 28109989 DOI: 10.1016/j.yebeh.2016.12.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 12/15/2016] [Accepted: 12/17/2016] [Indexed: 11/20/2022]
Abstract
The low glycemic index treatment, a dietary therapy that focuses on glycemic index and reduced carbohydrate intake, has been successful in reducing seizure frequency in the general epilepsy population. Epilepsy is a common feature of Angelman syndrome and seizures are often refractory to multiple medications, especially in those with maternal deletions. Dietary therapy has become a more frequently used option for treating epilepsy, often in combination with other antiepileptic drugs, due to its efficacy and favorable side effect profile. This study aimed to assess the effectiveness of the low glycemic index treatment for seizure control in Angelman syndrome. Through a retrospective medical record review of 23 subjects who utilized the low glycemic index treatment at the Clinic and Center for Dietary Therapy of Epilepsy at the Massachusetts General Hospital, we found that the high level of seizure control and favorable side effect profile make the low glycemic index treatment a viable treatment for seizures in Angelman syndrome. The majority of subjects in our cohort experienced some level of seizure reduction after initiating the diet, 5 (22%) maintained complete seizure freedom, 10 (43%) maintained seizure freedom except in the setting of illness or non-convulsive status epilepticus, 7 (30%) had a decrease in seizure frequency, and only 1 (4%) did not have enough information to determine seizure control post-initiation. The low glycemic index treatment monotherapy was successful for some subjects in our cohort but most subjects used an antiepileptic drug concurrently. Some subjects were able to maintain the same level of seizure control on a liberalized version of the low glycemic index treatment which included a larger amount of low glycemic carbohydrates. No correlation between the level of carbohydrate restriction and level of seizure control was found. Few subjects experienced side effects and those that did found them to be mild and easily treated. The efficacy of the low glycemic index treatment and its favorable side effect profile make it an excellent alternative or supplement to antiepileptic drug therapy for the treatment of seizures in Angelman syndrome.
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Ciarlone SL, Wang X, Rogawski MA, Weeber EJ. Effects of the synthetic neurosteroid ganaxolone on seizure activity and behavioral deficits in an Angelman syndrome mouse model. Neuropharmacology 2016; 116:142-150. [PMID: 27986596 DOI: 10.1016/j.neuropharm.2016.12.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/02/2016] [Accepted: 12/12/2016] [Indexed: 11/25/2022]
Abstract
Angelman syndrome (AS) is a rare neurogenetic disorder characterized by severe developmental delay, motor impairments, and epilepsy. GABAergic dysfunction is believed to contribute to many of the phenotypic deficits seen in AS. We hypothesized that restoration of inhibitory tone mediated by extrasynaptic GABAA receptors could provide therapeutic benefit. Here, we report that ganaxolone, a synthetic neurosteroid that acts as a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors, was anxiolytic, anticonvulsant, and improved motor deficits in the Ube3a-deficient mouse model of AS when administered by implanted mini-pump for 3 days or 4 weeks. Treatment for 4 weeks also led to recovery of spatial working memory and hippocampal synaptic plasticity deficits. This study demonstrates that ganaxolone ameliorates many of the behavioral abnormalities in the adult AS mouse, and tolerance did not occur to the therapeutic effects of the drug. The results support clinical studies to investigate ganaxolone as a symptomatic treatment for AS.
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Affiliation(s)
- Stephanie L Ciarlone
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Xinming Wang
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA
| | - Michael A Rogawski
- Departments of Neurology and Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Edwin J Weeber
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA.
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25
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Fitzgerald M, Turner SM. Angelman syndrome in an infant boy. JAAPA 2016; 29:35-37. [DOI: 10.1097/01.jaa.0000488694.88670.e1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Battaglia A, Bernardini L, Torrente I, Novelli A, Scarselli G. Spectrum of epilepsy and electroencephalogram patterns in idic (15) syndrome. Am J Med Genet A 2016; 170:2531-9. [PMID: 27513709 DOI: 10.1002/ajmg.a.37844] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/29/2016] [Indexed: 12/22/2022]
Abstract
Previous reports summarized the seizure types occurring in patients with idic(15) syndrome. To better define this issue, we retrospectively analyzed the evolution of electroencephalogram findings and seizures in 35 patients with confirmed idic(15). Epilepsy occurred in 28 patients (80%), with a median age of onset of 3 years 3 months. The initial seizures were infantile spasms associated with a hypsarrhythmic electroencephalogram (nine patients), focal/generalized tonic (seven patients), or atypical absences (eight patients). High doses of oral steroids were given in all nine children with infantile spasms, with remission of seizures and resolution of electroencephalogram abnormalities. Among them, three were seizure free at the time of evaluation, but six later developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. The eight patients with atypical absences developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. Epilepsy was well controlled in 32% of the patients; satisfactorily controlled (seizures reduced >75%) in 21.4%; partially controlled (seizures reduced <50%) in 10.7%; and uncontrolled in 32%. One patient was not taking any anti-epileptic drugs by his parents' choice. Fourteen percent were on monotherapy; whereas the other 82% were on polytherapy. Seizures stopped at a median age of 5 years 5 months. The interictal electroencephalogram showed slow/sharp waves, and/or biphasic spikes-polyspikes, spike/wave complexes, and an excess of fast activity mainly over the fronto-temporal areas. Epilepsy is a major clinical challenge in patients with idic(15), associated with a poor prognosis in 55%. Frontal lobe seizures are a novel finding. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Agatino Battaglia
- Stella Maris Clinical Research Institute for Child and Adolescent Neurology and Psychiatry, Calambrone, Pisa, Italy.
| | - Laura Bernardini
- Mendel Laboratory IRCCS "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, Rome, Italy
| | - Isabella Torrente
- Mendel Laboratory IRCCS "Casa Sollievo della Sofferenza" Hospital, San Giovanni Rotondo, Rome, Italy.,Department of Experimental Medicine, Sapienza University, Rome, Italy
| | | | - Gloria Scarselli
- Stella Maris Clinical Research Institute for Child and Adolescent Neurology and Psychiatry, Calambrone, Pisa, Italy
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Abstract
The aim was to explore the comorbidity between Angelman syndrome and autism spectrum disorders (ASDs). Identification of autism in children with Angelman syndrome presents a diagnostic challenge. In the present study, 16 children with Angelman syndrome, all with a 15q11-13 deletion, were examined for ASDs. Thirteen children with Angelman syndrome received an ADOS-G algorithm classification of ASD; the remaining three were outside the autistic spectrum. Ten fulfilled the criteria for autism, and three for PDD-NOS. The 10 children with Angelman syndrome and comorbid autism were compared with eight children with only autism regarding their social and communicative skills. The results indicated that Angelman syndrome is better understood in terms of developmental delay, and autism in terms of developmental deviance. It is concluded that autism might have been overdiagnosed due to the extremely low mental age of the children with Angelman syndrome.
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Affiliation(s)
- Anegen Trillingsgaard
- Psychiatric Hospital for Children and Adolescents, University Hospital, Aarhus, Denmark.
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Samanta D, Willis E. Electroencephalographic findings in KBG syndrome: a child with novel mutation in ANKRD11 gene. Acta Neurol Belg 2015; 115:779-82. [PMID: 25543316 DOI: 10.1007/s13760-014-0413-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/13/2014] [Indexed: 11/25/2022]
Affiliation(s)
- Debopam Samanta
- Division of Child Neurology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR, 72205, USA.
| | - Erin Willis
- Division of Child Neurology, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR, 72205, USA
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Nicita F, Garone G, Papetti L, Consoli F, Magliozzi M, De Luca A, Spalice A. Myoclonic status and central fever in Angelman syndrome due to paternal uniparental disomy. J Neurogenet 2015; 29:178-82. [PMID: 26559560 DOI: 10.3109/01677063.2015.1091452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Myoclonic status in nonprogressive encephalopathy (MSNE) is an early-onset, drug-resistant epileptic syndrome characterized by occurrence of continuous diffuse epileptiform abnormalities, associated with positive and/or negative phenomena and accompanied by transient and recurring motor, cognitive, and behavioral impairment. MSNE has been reported in Angelman syndrome (AS) secondary to 15q11-13 deletions or UBE3A mutations but not to paternal uniparental disomy (UPD). We describe the case of a male patient with AS caused by UPD who developed a myoclonic status (MS) associated with long-lasting fever of central origin, both promptly regressed with introduction of levetiracetam. Only three descriptions of thermal dysregulation in AS exist, and none of the previously reported cases were associated with MS or with UPD. Association of MS and central fever expands the spectrum of epileptic and non-epileptic features in UPD-related AS and provides a further evidence of hypothalamus involvement in the pathogenesis of this neurodevelopmental disorder.
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Affiliation(s)
- Francesco Nicita
- a Department of Pediatrics and Child Neuropsychiatry, Division of Child Neurology , Policlinico Hospital, Sapienza University , Roma , Italy
| | - Giacomo Garone
- a Department of Pediatrics and Child Neuropsychiatry, Division of Child Neurology , Policlinico Hospital, Sapienza University , Roma , Italy
| | - Laura Papetti
- a Department of Pediatrics and Child Neuropsychiatry, Division of Child Neurology , Policlinico Hospital, Sapienza University , Roma , Italy
| | - Federica Consoli
- b IRCCS - Casa Sollievo della Sofferenza Hospital, Mendel Institute , Roma , Italy
| | - Monia Magliozzi
- b IRCCS - Casa Sollievo della Sofferenza Hospital, Mendel Institute , Roma , Italy
| | - Alessandro De Luca
- b IRCCS - Casa Sollievo della Sofferenza Hospital, Mendel Institute , Roma , Italy
| | - Alberto Spalice
- a Department of Pediatrics and Child Neuropsychiatry, Division of Child Neurology , Policlinico Hospital, Sapienza University , Roma , Italy
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31
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Abstract
Angelman syndrome (AS) is a neurogenetic disorder. The goal of this study was to investigate the primary health issues affecting adults with AS and to further characterize the natural history and genotype-phenotype correlations. Standardized phone interviews with caregivers for 110 adolescents and adults with AS were conducted. The impact of age, sex, and genotype on specific outcomes in neurology, orthopedics, internal medicine, and psychiatry were investigated. The mean age of individuals with AS was 24 years (range 16-50y). Active seizures were present in 41% of individuals, and 72% had sleep dysfunction. Significant constipation was present in 85%, and 32% were overweight or obese, with obesity disproportionately affecting women. Scoliosis affected 50% with a mean age at diagnosis of 12 years, and 24% of those diagnosed with scoliosis required surgery, an intervention disproportionately affecting men. Sixty-eight percent were able to walk independently, and 13% were able to speak 5 or more words. Self-injurious behavior was exhibited in 52% of individuals. The results of this study indicate that epilepsy severity may assume a bimodal age distribution: seizures are typically most severe in early childhood but may recur in adulthood. While late-adolescent and adult sleep patterns were improved when compared to the degree of sleep dysfunction present during infancy and childhood, the prevalence of poor sleep in adults remained quite high. Primary areas of clinical management identified include the following: seizures, sleep, aspiration risk, GERD, constipation, dental care, vision, obesity, scoliosis, bone density, mobility, communication, behavior, and anxiety.
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Affiliation(s)
- Anna M Larson
- Pediatric Epilepsy Program, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts
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Alfei E, Raviglione F, Franceschetti S, D'Arrigo S, Milani D, Selicorni A, Riva D, Zuffardi O, Pantaleoni C, Binelli S. Seizures and EEG features in 74 patients with genetic-dysmorphic syndromes. Am J Med Genet A 2014; 164A:3154-61. [PMID: 25257908 DOI: 10.1002/ajmg.a.36746] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 07/31/2014] [Indexed: 12/27/2022]
Abstract
Epilepsy is one of the most common findings in chromosome aberrations. Types of seizures and severity may significantly vary both between different conditions and within the same aberration. Hitherto specific seizures and EEG patterns are identified for only few syndromes. We studied 74 patients with defined genetic-dysmorphic syndromes with and without epilepsy in order to assess clinical and electroencephalographic features, to compare our observation with already described electro-clinical phenotypes, and to identify putative electroencephalographic and/or seizure characteristics useful to address the diagnosis. In our population, 10 patients had chromosomal disorders, 19 microdeletion or microduplication syndromes, and 32 monogenic syndromes. In the remaining 13, syndrome diagnosis was assessed on clinical grounds. Our study confirmed the high incidence of epilepsy in genetic-dysmorphic syndromes. Moreover, febrile seizures and neonatal seizures had a higher incidence compared to general population. In addition, more than one third of epileptic patients had drug-resistant epilepsy. EEG study revealed poor background organization in 42 patients, an excess of diffuse rhythmic activities in beta, alpha or theta frequency bands in 34, and epileptiform patterns in 36. EEG was completely normal only in 20 patients. No specific electro-clinical pattern was identified, except for inv-dup15, Angelman, and Rett syndromes. Nevertheless some specific conditions are described in detail, because of notable differences from what previously reported. Regarding the diagnostic role of EEG, we found that--even without any epileptiform pattern--the generation of excessive rhythmic activities in different frequency bandwidths might support the diagnosis of a genetic syndrome.
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Affiliation(s)
- Enrico Alfei
- Developmental Neurology Division, Carlo Besta Neurological Institute, I.R.C.C.S. Foundation, Milan, Italy
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Kuroda Y, Ohashi I, Saito T, Nagai JI, Ida K, Naruto T, Wada T, Kurosawa K. Deletion ofUBE3Ain brothers with Angelman syndrome at the breakpoint with an inversion at 15q11.2. Am J Med Genet A 2014; 164A:2873-8. [DOI: 10.1002/ajmg.a.36704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 06/27/2014] [Indexed: 01/18/2023]
Affiliation(s)
- Yukiko Kuroda
- Division of Medical Genetics; Kanagawa Children's Medical Center; Yokohama Japan
| | - Ikuko Ohashi
- Division of Medical Genetics; Kanagawa Children's Medical Center; Yokohama Japan
| | - Toshiyuki Saito
- Department of Clinical Laboratory; Kanagawa Children's Medical Center; Yokohama Japan
| | - Jun-Ichi Nagai
- Department of Clinical Laboratory; Kanagawa Children's Medical Center; Yokohama Japan
| | - Kazumi Ida
- Division of Medical Genetics; Kanagawa Children's Medical Center; Yokohama Japan
| | - Takuya Naruto
- Division of Medical Genetics; Kanagawa Children's Medical Center; Yokohama Japan
| | - Takahito Wada
- Division of Pediatric Neurology; Kanagawa Children's Medical Center; Yokohama Japan
| | - Kenji Kurosawa
- Division of Medical Genetics; Kanagawa Children's Medical Center; Yokohama Japan
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Abstract
INTRODUCTION Epigenetics is the study of heritable modifications in gene expression that do not change the DNA nucleotide sequence. Some of the most thoroughly studied epigenetic mechanisms at present are DNA methylation, post-transcriptional modifications of histones, and the effect of non-coding RNA molecules. Gene expression is regulated by means of these mechanisms and disruption of these molecular pathways may elicit development of diseases. DEVELOPMENT We describe the main epigenetic regulatory mechanisms and review the most recent literature about epigenetic mechanisms and how those mechanisms are involved in different epileptic syndromes. CONCLUSION Identifying the epigenetic mechanisms involved in epilepsy is a promising line of research that will deliver more in-depth knowledge of epilepsy pathophysiology and treatments.
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Affiliation(s)
- L Pulido Fontes
- Servicio de Neurología, Complejo Hospitalario de Navarra, Pamplona, Navarra, España; Navarrabiomed, Pamplona, Navarra, España.
| | - P Quesada Jimenez
- Servicio de Neurología, Complejo Hospitalario de Navarra, Pamplona, Navarra, España
| | - M Mendioroz Iriarte
- Servicio de Neurología, Complejo Hospitalario de Navarra, Pamplona, Navarra, España; Navarrabiomed, Pamplona, Navarra, España
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Abstract
"Angelman syndrome" (AS) is a neurodevelopmental disorder whose main features are intellectual disability, lack of speech, seizures, and a characteristic behavioral profile. The behavioral features of AS include a happy demeanor, easily provoked laughter, short attention span, hypermotoric behavior, mouthing of objects, sleep disturbance, and an affinity for water. Microcephaly and subtle dysmorphic features, as well as ataxia and other movement disturbances, are additional features seen in most affected individuals. AS is due to deficient expression of the ubiquitin protein ligase E3A (UBE3A) gene, which displays paternal imprinting. There are four molecular classes of AS, and some genotype-phenotype correlations have emerged. Much remains to be understood regarding how insufficiency of E6-AP, the protein product of UBE3A, results in the observed neurodevelopmental deficits. Studies of mouse models of AS have implicated UBE3A in experience-dependent synaptic remodeling.
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Affiliation(s)
- Lynne M Bird
- Department of Pediatrics, University of California, Division of Genetics, Rady Children’s Hospital, San Diego, California, USA
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Verrotti A, Soldani C, Laino D, d'Alonzo R, Grosso S. Epilepsy in Prader-Willi syndrome: clinical, diagnostic and treatment aspects. World J Pediatr 2014; 10:108-13. [PMID: 24801229 DOI: 10.1007/s12519-014-0478-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/06/2014] [Indexed: 12/29/2022]
Abstract
BACKGROUND Epilepsy associated with Prader-Willi syndrome (PWS) represents an early and important complication, often not clearly reported and described in the literature. Consequently, there are controversial data about the clinical characteristics of epilepsy and electroencephalographic (EEG) abnormalities found in these patients. DATA SOURCES Based on recent original publications, we have reviewed the different types of seizures and EEG findings in PWS patients, the response to antiepileptic treatment, and the prognosis of epilepsy. RESULTS The frequency of epilepsy in PWS patients ranges from 4% to 26%. The types of seizure include generalized tonic-clonic seizures, complex partial seizures, atypical absence, staring spells, and myoclonic, tonic and hemiclonic seizures, but the most frequent type is focal epilepsy. Status epilepticus has never been reported. EEG abnormalities are not typical but variable in different patients. However, generalized and focal discharges are the most frequently reported findings. There is no evidence of relationship between the course of epilepsy and frequency, morphology and spread of EEG discharges. However, epilepsy in PWS patients is usually responsive to antiepileptic monotherapy with rapid seizure control and a good outcome. CONCLUSIONS The frequency of epilepsy is higher in PWS patients than in general populations and this complication can be a challenge for the clinicians of these patients. Prospective studies are needed to confirm the good long-term prognosis.
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Abstract
The γ-aminobutyric acid receptor type A (GABAA receptor) is a ligand-gated chloride channel that mediates major inhibitory functions in the central nervous system. GABAA receptors function mainly as pentamers containing α, β, and either γ or δ subunits. A number of antiepileptic drugs have agonistic effects on GABAA receptors. Hence, dysfunctions of GABAA receptors have been postulated to play important roles in the etiology of epilepsy. In fact, mutations or genetic variations of the genes encoding the α1, α6, β2, β3, γ2, or δ subunits (GABRA1, GABRA6, GABRB2, GABRB3, GABRG2, and GABRD, respectively) have been associated with human epilepsy, both with and without febrile seizures. Epilepsy resulting from mutations is commonly one of following, genetic (idiopathic) generalized epilepsy (e.g., juvenile myoclonic epilepsy), childhood absence epilepsy, genetic epilepsy with febrile seizures, or Dravet syndrome. Recently, mutations of GABRA1, GABRB2, and GABRB3 were associated with infantile spasms and Lennox-Gastaut syndrome. These mutations compromise hyperpolarization through GABAA receptors, which is believed to cause seizures. Interestingly, most of the insufficiencies are not caused by receptor gating abnormalities, but by complex mechanisms, including endoplasmic reticulum (ER)-associated degradation, nonsense-mediated mRNA decay, intracellular trafficking defects, and ER stress. Thus, GABAA receptor subunit mutations are now thought to participate in the pathomechanisms of epilepsy, and an improved understanding of these mutations should facilitate our understanding of epilepsy and the development of new therapies.
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Abstract
From early embryonic development to adulthood, GABA release participates in the construction of the mammalian cerebral cortex. The maturation of GABAergic neurotransmission is a protracted process which takes place in discrete steps and results from the dynamic interaction between developmentally directed gene expression and brain activity. During the course of development, GABAergic interneurons contribute to key aspects of the functional maturation of the cortex in different ways, from exerting a trophic role to pacing immature neural networks. In this review, we provide an overview of the maturation of GABAergic neurotransmission and discuss the role of GABAergic interneurons in cortical wiring, plasticity, and network activity during pre- and postnatal development. We also discuss psychiatric diseases that may be considered at least in part developmental disorders of the GABAergic system.
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Affiliation(s)
- Corentin Le Magueresse
- Department of Clinical Neurobiology, Medical Faculty of Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
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39
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Abstract
Angelman syndrome is a neurogenetic disorder characterized by the loss or reduction of the ubiquitin-protein ligase E3A enzyme. Angelman syndrome results from a deletion or mutation of the maternally inherited 15q11.2-13.1 region, paternal uniparental disomy of chromosome 15, or an imprinting error. Epilepsy is common and may present with multiple seizure types, including nonconvulsive status epilepticus. Seizures are often intractable and typically require broad-spectrum antiepileptic medications. Dietary therapy has also proved successful in Angelman syndrome. Electroencephalographic patterns include notched δ and rhythmic θ activity and epileptiform discharges. Sleep disorders are also common, often characterized by abnormal sleep-wake cycles. Movement disorders are nearly universal in Angelman syndrome, most frequently presenting with ataxia and tremor. Neurocognitive impairment is always present to varying degrees, and expressive speech is typically severely affected. Individuals with Angelman syndrome often manifest psychiatric comorbidities including hyperactivity, anxiety, and challenging behaviors such as aggression and self-injury. We focus on a comprehensive whole-child approach to the diagnosis and long-term clinical care of individuals with Angelman syndrome.
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Affiliation(s)
- Ronald L Thibert
- Pediatric Epilepsy Program and Angelman Syndrome Clinic, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
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40
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Valente KD, Varela MC, Koiffmann CP, Andrade JQ, Grossmann R, Kok F, Marques-Dias MJ. Angelman syndrome caused by deletion: a genotype-phenotype correlation determined by breakpoint. Epilepsy Res 2013; 105:234-9. [PMID: 23352739 DOI: 10.1016/j.eplepsyres.2012.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 11/28/2012] [Accepted: 12/17/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Deletion of the chromosome 15q11-q13, the most common genetic mechanism associated with Angelman syndrome (AS), is highly associated with a severe phenotype. However, deletion is not a genetically homogeneous group as it is composed by two main groups: Class I with breakpoints at BP1 (proximal) and BP3 (distal) and Class II present breakpoints at BP2 (proximal) and BP3 (distal). In this study, we aimed to evaluate the impact of the breakpoint on the electroclinical profile. METHODS We evaluated 16 patients with AS caused by 15q11-13 deletion (6 were Class I; 10 were Class II). We characterized epilepsy features by clinical history obtained from parents and caretakers with a pre-standard questionnaire. These data were corroborated by medical records, contact with previous physicians, and video-EEG monitoring. Suggestive EEG patterns for AS were classified according to the classical description of Boyd et al. (1988). RESULTS AS patients with BP1-BP3 deletion had significantly more daily and disabling seizures than AS patients with BP1-BP2 deletion. They also presented a significant higher frequency of status epilepticus and epilepsy aggravated by fever. Need for polytherapy was significantly more frequent in BP1-BP3 patients. EEG features were similar in both groups. CONCLUSION This study shows a significant correlation between the two deletion classes and AS clinical, but not the electrographic phenotype. Epilepsy is more severe and refractory to treatment in patients with larger deletions. Deletion is not a homogeneous group and knowledge on the breakpoint may have a clinical implication and represent an important factor in parental counseling.
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Affiliation(s)
- Kette D Valente
- Laboratory of Clinical Neurophysiology, Institute and Department of Psychiatry, University of São Paulo, São Paulo, SP, Brazil.
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41
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Abstract
Epileptic myoclonus can be defined as an elementary electroclinical manifestation of epilepsy involving descending neurons, whose spatial (spread) or temporal (self-sustained repetition) amplification can trigger overt epileptic activity and can be classified as cortical (positive and negative), secondarily generalized, thalamo-cortical, and reticular. Cortical epileptic myoclonus represents a fragment of partial or symptomatic generalized epilepsy; thalamo-cortical epileptic myoclonus is a fragment of idiopathic generalized epilepsy. Reflex reticular myoclonus represents the clinical counterpart of fragments of hypersynchronous epileptic activity of neurons in the brainstem reticular formation. Epileptic myoclonus, in the setting of an epilepsy syndrome, can be only one component of a seizure, the only seizure manifestations, one of the multiple seizure types or a more stable condition that is manifested in a nonparoxysmal fashion and mimics a movement disorder. This complex correlation is more obvious in patients with epilepsia partialis continua in which cortical myoclonus and overt focal motor seizures usually start in the same somatic (and cortical) region. In patients with cortical tremor this correlation is less obvious and requires neurophysiological studies to be demonstrated.
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Affiliation(s)
- Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer - University of Florence, Florence, Italy.
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42
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Abstract
BACKGROUND Epilepsy occurs with increased frequency in people with an intellectual disability (ID) compared to the rest of the population. A variety of research has in recent years shed light on genetic and biochemical aetiologies of epilepsy and, often in a different literature, on syndromes of ID. The aims of this annotation are to review developments in understanding of the pathophysiology of several ID syndromes in which epilepsy is a frequent co-occurrence and to relate these observations to recent advances in understanding of how these pathophysiological disturbances may lead to epilepsy. METHOD The ID syndromes selected for review were fragile X (FXS), Rett (RTT) and Angelman syndromes (AS) and tuberous sclerosis complex (TSC). Epilepsy is a significant aspect of these syndromes and relevant research into the genetic and biochemical pathophysiology of these four ID syndromes may be informative in establishing the association between epilepsy and ID. Employing a structured approach the authors initially searched the PubMed database for large case series describing the characteristics of epilepsy as manifested in these ID syndromes. The criteria for inclusion of the case series in the review were a sample size of greater than 50 and the description of several of the characteristic features of epilepsy, namely prevalence of seizures, age of seizure onset, seizure frequency, seizure semiology, severity and treatment. Following this, studies of the genetic and biochemical pathophysiology of these four ID syndromes were reviewed and the potential relevance of this research in understanding the association with epilepsy highlighted. Findings were considered in a focused manner in terms of effects on excitatory and inhibitory neurotransmitter systems and on glial function. RESULTS Diverse genetic pathologies underlying several ID syndromes can lead to alterations in the functioning of the glutamatergic and GABAergic neurotransmitter systems. The mechanisms involved include transcriptional regulation in RTT, translational regulation in FXS and TSC, and UBE3A-mediated proteolysis in AS. Expression or functioning of receptor subunits, uptake sites and enzymes involved in neurotransmitter metabolism are often affected by these changes, and may lead to modifications in network excitability and neuronal plasticity that may contribute to epileptogenesis and ID. Dysfunction in astrocytes may also contribute to epileptogenesis and ID in FXS, RTT and TSC with potential mechanisms including failure of astrocytic support functions, glial inflammation and homeostatic disturbances that affect the excitability and architecture of neuronal networks. CONCLUSIONS The annotation highlights research describing disturbances in excitatory and inhibitory neurotransmitter systems, neuronal ion channel and glial functions that provide possible explanations for the co-occurrence of seizures within several ID syndromes, in some cases suggesting possible avenues for research into novel therapeutic targets. Phenotypic overlaps between syndromes may also relate to roles for the implicated genes in different disturbances in linked biochemical pathways.
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Affiliation(s)
- H T T Leung
- Christ's College, University of Cambridge, UK
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Candee MS, Carey JC, Krantz ID, Filloux FM. Seizure characteristics in Pallister-Killian syndrome. Am J Med Genet A 2012; 158A:3026-32. [PMID: 23169688 DOI: 10.1002/ajmg.a.35567] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Accepted: 06/18/2012] [Indexed: 11/11/2022]
Abstract
Pallister-Killian syndrome (PKS) is a congenital disorder attributed to supernumerary isochromosome 12p mosaicism. Craniofacial dysmorphism, learning impairment and seizures are considered cardinal features. However, little is known regarding the seizure and epilepsy patterns in PKS. To better define the prevalence and spectrum of seizures in PKS, we studied 51 patients (39 male, 12 female; median age 4 years and 9 months; age range 7 months to 31 years) with confirmed 12p tetrasomy. Using a parent-based structured questionnaire, we collected data regarding seizure onset, frequency, timing, semiology, and medication therapy. Patients were recruited through our practice, at PKS Kids family events, and via the PKS Kids website. Epilepsy occurred in 27 (53%) with 23 (85%) of those with seizures having seizure onset prior to 3.5 years of age. Mean age at seizure onset was 2 years and 4 months. The most common seizure types were myoclonic (15/27, 56%), generalized convulsions (13/27, 48%), and clustered tonic spasms (similar to infantile spasms; 8/27, 30%). Thirteen of 27 patients with seizures (48%) had more than one seizure type with 26 out of 27 (96%) ever having taken antiepileptic medications. Nineteen of 27 (70%) continued to have seizures and 17/27 (63%) remained on antiepileptic medication. The most commonly used medications were: levetiracetam (10/27, 37%), valproic acid (10/27, 37%), and topiramate (9/27, 33%) with levetiracetam felt to be "most helpful" by parents (6/27, 22%). Further exploration of seizure timing, in-depth analysis of EEG recordings, and collection of MRI data to rule out confounding factors is warranted.
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Affiliation(s)
- Meghan S Candee
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA.
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Abstract
Inhibitory interneurons in the brain provide the balance to excitatory signaling. On the basis of brain imaging and human genetics, a deficit in GABAergic inhibition (GABA, γ-aminobuiyric acid) has been identified as contributing to the pathophysiology of anxiety disorders, epilepsy, and schizophrenia. Therapeutically, GABAA receptors play a major role as targets for benzodiazepine drugs. The therapeutic relevance of the multitude of structurally diverse GABAA receptor subtypes has only recently been identified. α1-GABAA receptors were found to mediate sedation, anterograde amnesia, and part of the seizure protection of these drugs, whereas α2-GABAA receptors, but not α3-GABAA receptors, mediate anxiolysis. Rational drug targeting to specific receptor subtypes has now become possible. Only restricted neuronal networks will be modulated by the upcoming subtype-selective drugs. For instance, anxiolytics devoid of drowsiness and sedation promise more sophisticated interventions in anxiety disorders. A new pharmacology of the benzodiazepine site is on the horizon.
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Affiliation(s)
- Hanns Möhler
- Institute of Pharmacology and Toxicology, University of Zurich and Department of Applied Biosciences, Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
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Abstract
PURPOSE The low glycemic index treatment (LGIT) is a high fat, limited carbohydrate diet used in the treatment of epilepsy. The purpose of this study was to assess the efficacy and tolerability of the LGIT for the treatment of refractory seizures in pediatric patients with Angelman syndrome. METHODS A pediatric Angelman syndrome cohort with refractory epilepsy was treated with the LGIT and followed prospectively over 4 months. Parents recorded a daily seizure log for a minimum of 1 month prior to the start of treatment as well as throughout the LGIT trial. Electroencephalography (EEG) and neuropsychological assessments (Scales of Independent Behavior-Revised and the Vineland Adaptive Behavior Scales-2nd Edition were obtained for each subject at both baseline and 4-month follow-up time points. Clinical evaluations of subjects were completed by a neurologist and dietitian at the time of enrollment, as well as following both the first and fourth months of dietary therapy. At each time point, blood for laboratory chemistries was drawn and anthropometric measures were obtained. KEY FINDINGS Six children (mean age 3.3 years, range 1.1-4.8) with genetically confirmed Angelman syndrome initiated the LGIT, and completed the trial with no significant adverse events. Cohort averages for indices of seizure severity were as follows: age of 1.6 years at seizure onset, 3 lifetime antiepileptic drugs tried (range 1-6), and baseline seizure frequency of 10.1 events/week (range: 0.4-30.9). All subjects had a decrease in seizure frequency on the LGIT, with five of six exhibiting >80% seizure frequency reduction. All posttrial EEG studies showed improvement and three of four children with epileptiform activity on his or her baseline EEG had no discharges present on follow-up EEG. Developmental gains were noted by parents in all cases, although few of these neurocognitive gains were statistically significant on neuropsychological assessment. SIGNIFICANCE This is the first prospective study assessing the LGIT for epilepsy. Our results indicate that this dietary therapy is highly effective in treating Angelman syndrome-related seizures. The diet was well tolerated by subjects as evidenced by five of six subjects remaining on the LGIT after completion of the trial. Beyond the prospective trial window, all five subjects who remained on the diet had >90% seizure reduction after 1 year of LGIT therapy. Despite the small sample size in this prospective study, the results indicate a potentially higher degree of efficacy of the LGIT for the Angelman syndrome population than that observed in the general epilepsy population. Although this study is too small to make definitive recommendations, these results suggest that the LGIT is a promising treatment option for Angelman syndrome-related epilepsy.
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Affiliation(s)
- Ronald L Thibert
- Department of Neurology, Pediatric Epilepsy Program and Angelman Syndrome Clinic, Massachusetts General Hospital, Boston, Massachusetts, USA
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Park SH, Yoon JR, Kim HD, Lee JS, Lee YM, Kang HC. Epilepsy in Korean patients with Angelman syndrome. Korean J Pediatr 2012; 55:171-6. [PMID: 22670152 PMCID: PMC3362731 DOI: 10.3345/kjp.2012.55.5.171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/07/2011] [Accepted: 12/15/2011] [Indexed: 11/30/2022]
Abstract
Purpose The aim of this study was to investigate the natural history of epilepsy and response to anti-epileptic drug treatment in patients with Angelman syndrome (AS) in Korea. Methods We retrospectively reviewed the clinical records of 14 patients diagnosed with epilepsy out of a total of 17 patients with a genetic diagnosis of AS. These patients were seen at the Department of Pediatric Neurology at Severance Children's Hospital from March 2005 to March 2011. Results Fourteen (9 males and 5 females) subjects (82.3%) were diagnosed with epilepsy in AS. The most common seizure types were generalized tonic-clonic (n=9, 27%) and myoclonic (n=9, 27%), followed by atonic (n=8, 24%), atypical absence (n=4, 12%) and complex partial seizure (n=3, 9%). The most commonly prescribed antiepileptic drug (AED) was valproic acid (VPA, n=12, 86%), followed by lamotrigine (LTG, n=9, 64%), and topiramate (n=8, 57%). According to questionnaires that determined whether each AED was efficacious or not, VPA had the highest response rate and LTG was associated with the highest rate of seizure exacerbation. Complete control of seizures was achieved in 6 patients. Partial control was achieved in 7 patients, while one patient was not controlled. Conclusion Epilepsy is observed in the great majority of AS patients. It may have early onset and is often refractory to treatment. There are few reports about epilepsy in AS in Korea. This study will be helpful in understanding epilepsy in AS in Korea.
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Affiliation(s)
- Sung-Hee Park
- Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinics, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Vendrame M, Loddenkemper T, Zarowski M, Gregas M, Shuhaiber H, Sarco DP, Morales A, Nespeca M, Sharpe C, Haas K, Barnes G, Glaze D, Kothare SV. Analysis of EEG patterns and genotypes in patients with Angelman syndrome. Epilepsy Behav 2012; 23:261-5. [PMID: 22341959 DOI: 10.1016/j.yebeh.2011.11.027] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/14/2011] [Accepted: 11/25/2011] [Indexed: 10/28/2022]
Abstract
We prospectively analyzed EEGs from participants in the ongoing NIH Rare Diseases Clinical Research Network Angelman Syndrome Natural History Study. Of the one-hundred-sixty enrolled patients (2006-2010), 115 had complete data (58 boys, median age 3.6 years). Distinct EEG findings were intermittent rhythmic delta waves (83.5%), interictal epileptiform discharges (74.2%), intermittent rhythmic theta waves (43.5%), and posterior rhythm slowing (43.5%). Centro-occipital and centro-temporal delta waves decreased with age (p=0.01, p=0.03). There were no specific correlations between EEG patterns and genotypes. A classification tree allowed the prediction of deletions class-1 (5.9 Mb) in patients with intermittent theta waves in <50% of EEG and interictal epileptiform abnormalities; UPD, UBE3A mutation or imprinting defects in patients with intermittent theta in <50% of EEG without interictal epileptiform abnormalities; deletions class-2 (5.0 Mb) in patients with >50% theta and normal posterior rhythm; atypical deletions in patients with >50% theta but abnormal posterior rhythm. EEG patterns are important biomarkers in Angelman syndrome and may suggest the underlying genetic etiology.
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Affiliation(s)
- Martina Vendrame
- Boston University, Neurology Department, C-3, Boston, MA 02118, USA
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Filloux FM, Carey JC, Krantz ID, Ekstrand JJ, Candee MS. Occurrence and clinical features of epileptic and non-epileptic paroxysmal events in five children with Pallister-Killian syndrome. Eur J Med Genet 2012; 55:367-73. [PMID: 22349688 DOI: 10.1016/j.ejmg.2012.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/03/2012] [Indexed: 10/14/2022]
Abstract
Pallister-Killian syndrome (PKS) is a rare, sporadic genetic disorder caused by tetrasomy 12p mosaicism associated with a supernumerary isochromosome. Craniofacial dysmorphism, learning impairment and seizures are considered characteristic. However, little is known of the seizure and epilepsy patterns seen in PKS. To better define the occurrence and nature of epileptic and non-epileptic paroxysmal events in PKS, we describe our experience with 5 patients and compare their features with data from a larger cohort of PKS patients ascertained via a web-based parental questionnaire. Three of the 5 patients have had definite epileptic seizures, and one other has had paroxysmal events as yet not clarified. Four of the 5 have also had either non-epileptic paroxysmal events or episodes of uncertain nature. In those with epilepsy, all have had some period of relatively refractory seizures, all have required more than one antiepileptic drug, but none experienced status epilepticus. Only one of the patients with epilepsy (the oldest) has gone into remission. In two of the four with non-epileptic events, video-electroencephalographic monitoring has been valuable in clarifying the nature of the events. EEG characteristics include a slow dominant frequency as well as generalized and focal epileptiform features. Brain MRI findings can be normal but are variable. These specific findings correspond well to information reported by parents in a larger cohort of 51 individuals with PKS. Better understanding of the nature of epileptic and non-epileptic events in PKS will result from a more detailed analysis of objective data obtained from this larger cohort, and from deeper understanding of the molecular impact of 12p tetrasomy in selected cell lines.
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Affiliation(s)
- Francis M Filloux
- Division of Pediatric Neurology, University of Utah School of Medicine and Primary Children's Medical Center, 100 N. Mario Capecchi Drive, Salt Lake City, UT 84113, USA.
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Noh GJ, Jane Tavyev Asher Y, Graham JM. Clinical review of genetic epileptic encephalopathies. Eur J Med Genet 2012; 55:281-98. [PMID: 22342633 DOI: 10.1016/j.ejmg.2011.12.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 12/27/2011] [Indexed: 11/29/2022]
Abstract
Seizures are a frequently encountered finding in patients seen for clinical genetics evaluations. The differential diagnosis for the cause of seizures is quite diverse and complex, and more than half of all epilepsies have been attributed to a genetic cause. Given the complexity of such evaluations, we highlight the more common causes of genetic epileptic encephalopathies and emphasize the usefulness of recent technological advances. The purpose of this review is to serve as a practical guide for clinical geneticists in the evaluation and counseling of patients with genetic epileptic encephalopathies. Common syndromes will be discussed, in addition to specific seizure phenotypes, many of which are refractory to anti-epileptic agents. Divided by etiology, we overview the more common causes of infantile epileptic encephalopathies, channelopathies, syndromic, metabolic, and chromosomal entities. For each condition, we will outline the diagnostic evaluation and discuss effective treatment strategies that should be considered.
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Affiliation(s)
- Grace J Noh
- Clinical Genetics and Dysmorphology, Medical Genetics Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA 90048, USA
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50
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Abstract
GABAergic interneurons control neuronal excitability, integration, and plasticity. Further, they regulate the generation of temporal synchrony and oscillatory behavior among networks of pyramidal neurons. Such oscillations within and across neural systems are believed to serve various complex functions, such as perception, movement initiation, and memory. Alterations in the development of GABAergic circuits have been implicated in various brain diseases with neurodevelopmental origin. Here, we highlight recent studies suggesting a role for alterations of GABA transmission in the pathophysiology of two neurodevelopmental diseases, schizophrenia, and autism. We further discuss how manipulations of GABA signaling may be used for novel therapeutic interventions.
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