Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.001
Filtrar
1.
BMC Med Genet ; 21(1): 93, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375772

RESUMO

BACKGROUND: Pathogenic SLC6A1 variants have been reported in patients with myoclonic-atonic epilepsy (MAE). NOTCH1, encoding a member of the Notch family of proteins, is known to be associated with aortic valve disease. The PRIMPOL variant has only been identified in Chinese patients with high myopia. Exome sequencing analysis now allows the simultaneous detection of multiple genetic etiologies for patients with complicated clinical features. However, the presence of three Mendelian disorders in one patient supported by their respective pathogenic variants and clinical phenotypes is very rare. CASE PRESENTATION: Here, we report a 4-year-old Chinese boy who presented with MAE, delayed language, borderline intellectual disability (ID), mildly impaired social skills and attention deficit hyperactivity disorder (ADHD). He also had mild aortic valve stenosis and high myopia. Using whole-exome sequencing (WES), we identified three variants: (1) SLC6A1, NM_003042.4: c.881-883del (p.Phe294del), (2) NOTCH1, NM_017617.5:c.1100-2A > G and (3) PRIMPOL, NM_152683.4:c.265 T > G (p.Tyr89Asp). Parental Sanger sequencing confirmed that SLC6A1 and NOTCH1 variants were de novo, whereas the PRIMPOL variant was inherited from the father who also had high myopia. Furthermore, the PRIMPOL variant was absent from the genomes of the paternal grandparents, and thus was also a de novo event in the family. All three variants are classified as pathogenic. CONCLUSION: The SLC6A1 variant could explain the features of MAE, delayed language, borderline ID, impaired social skills and ADHD in this patient, whereas the features of aortic valve stenosis and high myopia of the patient may be explained by variants in NOTCH1 and PRIMPOL, respectively. This case demonstrated the utility of exome sequencing in uncovering the multiple pathogenic variants in a patient with complicated phenotypes due to the blending of three Mendelian disorders.


Assuntos
Epilepsias Mioclônicas/genética , Epilepsia Generalizada/genética , Predisposição Genética para Doença , Miopia/genética , Estenose da Valva Aórtica/genética , Estenose da Valva Aórtica/patologia , Pré-Escolar , DNA Primase/genética , DNA Polimerase Dirigida por DNA/genética , Epilepsias Mioclônicas/patologia , Epilepsia Generalizada/patologia , Proteínas da Membrana Plasmática de Transporte de GABA/genética , Testes Genéticos , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Masculino , Enzimas Multifuncionais/genética , Mutação/genética , Miopia/patologia , Receptor Notch1/genética , Sequenciamento Completo do Exoma
3.
Proc Natl Acad Sci U S A ; 117(12): 6836-6843, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32144139

RESUMO

Visuomotor impairments characterize numerous neurological disorders and neurogenetic syndromes, such as autism spectrum disorder (ASD) and Dravet, Fragile X, Prader-Willi, Turner, and Williams syndromes. Despite recent advances in systems neuroscience, the biological basis underlying visuomotor functional impairments associated with these clinical conditions is poorly understood. In this study, we used neuroimaging connectomic approaches to map the visuomotor integration (VMI) system in the human brain and investigated the topology approximation of the VMI network to the Allen Human Brain Atlas, a whole-brain transcriptome-wide atlas of cortical genetic expression. We found the genetic expression of four genes-TBR1, SCN1A, MAGEL2, and CACNB4-to be prominently associated with visuomotor integrators in the human cortex. TBR1 gene transcripts, an ASD gene whose expression is related to neural development of the cortex and the hippocampus, showed a central spatial allocation within the VMI system. Our findings delineate gene expression traits underlying the VMI system in the human cortex, where specific genes, such as TBR1, are likely to play a central role in its neuronal organization, as well as on specific phenotypes of neurogenetic syndromes.


Assuntos
Canais de Cálcio/genética , Córtex Motor/fisiopatologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Transtornos do Neurodesenvolvimento/patologia , Proteínas/genética , Proteínas com Domínio T/genética , Córtex Visual/fisiopatologia , Adulto , Idoso , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Mapeamento Encefálico , Estudos de Coortes , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Neurodesenvolvimento/genética , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/patologia , Desempenho Psicomotor , Percepção Visual
5.
Epilepsia ; 61(4): e30-e36, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32190912

RESUMO

Early onset seizures are a hallmark of Dravet syndrome. Previous studies in rodent models have shown that the epileptic phenotype is caused by loss-of-function of voltage-gated NaV 1.1 sodium channels, which are chiefly expressed in γ-aminobutyric acid (GABA)ergic neurons. Recently, a possibly critical role has been attributed to the hippocampus in the seizure phenotype, as local hippocampal ablation of NaV 1.1 channels decreased the threshold for hyperthermia-induced seizures. However, the effect of ablation of NaV 1.1 channels restricted to cortical sites has not been tested. Here we studied local field potential (LFP) and behavior in mice following local hippocampal and cortical ablation of Scn1a, a gene encoding the α1 subunit of NaV 1.1 channels, and we compared seizure characteristics with those of heterozygous global knockout Scn1-/+ mice. We found a high incidence of spontaneous seizures following either local hippocampal or cortical ablation, notably during a transient time window, similar to Scn1a-/+ mice. Nonconvulsive seizure activity in the injected area was common and preceded generalized seizures. Moreover, mice were susceptible to hyperthermia-induced seizures. In conclusion, local ablation of NaV 1.1 channels in the hippocampus and cortex results in focal seizure activity that can generalize. These data indicate that spontaneous epileptic activity may initiate in multiple brain regions in Dravet syndrome.


Assuntos
Córtex Cerebral/fisiopatologia , Hipocampo/fisiopatologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Convulsões/genética , Convulsões/fisiopatologia , Animais , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
6.
Epilepsia ; 61(3): 549-560, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32096222

RESUMO

OBJECTIVE: To pinpoint the earliest cellular defects underlying seizure onset (epileptogenic period) during perinatal brain development in a new zebrafish model of Dravet syndrome (DS) and to investigate potential disease-modifying activity of the 5HT2 receptor agonist fenfluramine. METHODS: We used CRISPR/Cas9 mutagenesis to introduce a missense mutation, designed to perturb ion transport function in all channel isoforms, into scn1lab, the zebrafish orthologue of SCN1A (encoding voltage-gated sodium channel alpha subunit 1). We performed behavioral analysis and electroencephalographic recordings to measure convulsions and epileptiform discharges, followed by single-cell RNA-Seq, morphometric analysis of transgenic reporter-labeled γ-aminobutyric acidergic (GABAergic) neurons, and pharmacological profiling of mutant larvae. RESULTS: Homozygous mutant (scn1labmut/mut ) larvae displayed spontaneous seizures with interictal, preictal, and ictal discharges (mean = 7.5 per 20-minute recording; P < .0001; one-way analysis of variance). Drop-Seq analysis revealed a 2:1 shift in the ratio of glutamatergic to GABAergic neurons in scn1labmut/mut larval brains versus wild type (WT), with dynamic changes in neuronal, glial, and progenitor cell populations. To explore disease pathophysiology further, we quantified dendritic arborization in GABAergic neurons and observed a 40% reduction in arbor number compared to WT (P < .001; n = 15 mutant, n = 16 WT). We postulate that the significant reduction in inhibitory arbors causes an inhibitory to excitatory neurotransmitter imbalance that contributes to seizures and enhanced electrical brain activity in scn1labmut/mut larvae (high-frequency range), with subsequent GABAergic neuronal loss and astrogliosis. Chronic fenfluramine administration completely restored dendritic arbor numbers to normal in scn1labmut/mut larvae, whereas similar treatment with the benzodiazepine diazepam attenuated seizures, but was ineffective in restoring neuronal cytoarchitecture. BrdU labeling revealed cell overproliferation in scn1labmut/mut larval brains that were rescued by fenfluramine but not diazepam. SIGNIFICANCE: Our findings provide novel insights into early mechanisms of DS pathogenesis, describe dynamic cell population changes in the scn1labmut/mut brain, and present first-time evidence for potential disease modification by fenfluramine.


Assuntos
Encéfalo/fisiopatologia , Epilepsias Mioclônicas/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Plasticidade Neuronal/genética , Proteínas de Peixe-Zebra/genética , Animais , Anticonvulsivantes/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Sistemas CRISPR-Cas , Proliferação de Células/efeitos dos fármacos , Diazepam/farmacologia , Modelos Animais de Doenças , Eletroencefalografia , Epilepsias Mioclônicas/metabolismo , Epilepsias Mioclônicas/patologia , Epilepsias Mioclônicas/fisiopatologia , Fenfluramina/farmacologia , Neurônios GABAérgicos/efeitos dos fármacos , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/patologia , Perfilação da Expressão Gênica , Gliose/genética , Gliose/patologia , Locomoção/efeitos dos fármacos , Mutação de Sentido Incorreto , Canal de Sódio Disparado por Voltagem NAV1.1/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real , Agonistas do Receptor 5-HT2 de Serotonina/farmacologia , Análise de Célula Única , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
7.
J Neurosci ; 40(13): 2764-2775, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-32102923

RESUMO

Recurrent seizures, which define epilepsy, are transient abnormalities in the electrical activity of the brain. The mechanistic basis of seizure initiation, and the contribution of defined neuronal subtypes to seizure pathophysiology, remains poorly understood. We performed in vivo two-photon calcium imaging in neocortex during temperature-induced seizures in male and female Dravet syndrome (Scn1a+/-) mice, a neurodevelopmental disorder with prominent temperature-sensitive epilepsy. Mean activity of both putative principal cells and parvalbumin-positive interneurons (PV-INs) was higher in Scn1a+/- relative to wild-type controls during quiet wakefulness at baseline and at elevated core body temperature. However, wild-type PV-INs showed a progressive synchronization in response to temperature elevation that was absent in PV-INs from Scn1a+/- mice. Hence, PV-IN activity remains intact interictally in Scn1a+/- mice, yet exhibits decreased synchrony immediately before seizure onset. We suggest that impaired PV-IN synchronization may contribute to the transition to the ictal state during temperature-induced seizures in Dravet syndrome.SIGNIFICANCE STATEMENT Epilepsy is a common neurological disorder defined by recurrent, unprovoked seizures. However, basic mechanisms of seizure initiation and propagation remain poorly understood. We performed in vivo two-photon calcium imaging in an experimental model of Dravet syndrome (Scn1a+/- mice)-a severe neurodevelopmental disorder defined by temperature-sensitive, treatment-resistant epilepsy-and record activity of putative excitatory neurons and parvalbumin-positive GABAergic neocortical interneurons (PV-INs) during naturalistic seizures induced by increased core body temperature. PV-IN activity was higher in Scn1a+/- relative to wild-type controls during quiet wakefulness. However, wild-type PV-INs showed progressive synchronization in response to temperature elevation that was absent in PV-INs from Scn1a+/- mice before seizure onset. Hence, impaired PV-IN synchronization may contribute to transition to seizure in Dravet syndrome.


Assuntos
Epilepsias Mioclônicas/fisiopatologia , Interneurônios/fisiologia , Convulsões/fisiopatologia , Potenciais de Ação/fisiologia , Animais , Modelos Animais de Doenças , Epilepsias Mioclônicas/genética , Feminino , Masculino , Camundongos , Camundongos Knockout , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Convulsões/genética
8.
Biochim Biophys Acta Proteins Proteom ; 1868(4): 140363, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31954927

RESUMO

Neuroserpin (NS) is predominantly expressed in brain and inhibits tissue-type plasminogen activator (tPA) with implications in brain development and memory. Nature of conformational change in pathological variants in strand 6B and helix B of NS that cause a relatively mild to severe epilepsy (and/or dementia) remains largely elusive. MD simulation with wild type (WT) NS, strand 6B and helix B variants indicated that substitution in this region affects the conformation of the strands 5B, 5A and reactive centre loop. Therefore, we designed variants of NS in strand 6B (I46D and F48S) and helix B (A54F, L55A and L55P) to investigate their role in tPA inhibition mechanism and propensity to aggregate. An interaction analysis showed disturbance of a hydrophobic patch centered at strands 5B, 6B and helix B in I46D and F48S but not in A54F, L55A, L55P and WT NS. Purified I46D, F48S and L55P variants showed decrease in fluorescence emission intensity but have similar α-helical content, however results of A54F and L55A were comparable to WT NS. Analysis of tPA inhibition showed marginal effect on A54F and L55A variant with tPA-NS complex formation. In contrast, I46D, F48S and L55P variants showed massive decrease in tPA inhibition, with no tPA-NS complex formation. Analysis of native PAGE under under polymerization condition showed prompt conversion of I46D, F48S and L55P to latent conformation but not A54F and L55A variants. Identification of these novel conformational changes will aid in the understanding of variable clinical phenotype of shutter region NS variants and other serpins.


Assuntos
Neuropeptídeos/química , Serpinas/química , Epilepsias Mioclônicas/genética , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Humanos , Interações Hidrofóbicas e Hidrofílicas , Simulação de Dinâmica Molecular , Mutação , Neuropeptídeos/genética , Neuropeptídeos/isolamento & purificação , Neuropeptídeos/metabolismo , Fenótipo , Polimerização , Agregados Proteicos , Conformação Proteica , Conformação Proteica em alfa-Hélice , Serpinas/genética , Serpinas/isolamento & purificação , Serpinas/metabolismo , Ativador de Plasminogênio Tecidual/antagonistas & inibidores
9.
Eur J Paediatr Neurol ; 24: 134-141, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31879226

RESUMO

OBJECTIVE: To evaluate the capability of children with Dravet syndrome to generate brain γ-oscillatory activity in response to auditory steady-state stimulation. METHODS: Fifty-one subjects were included: 13 with Dravet syndrome with SCN1A gene alterations, 26 with non-Dravet epilepsies and 12 healthy controls. Responses to auditory steady-state stimulation elicited with a chirp-modulated tone between 1 and 120 Hz were collected in subjects and compared across groups. RESULTS: Subjects with Dravet syndrome showed weak or no responses in the 1-120 Hz frequency range. Healthy controls showed oscillatory responses following the frequency of the modulation that were maximal in the low (30-70 Hz) and high (80-120) γ-ranges both, in the power and inter-trial coherence estimates. Non-Dravet epileptic children showed differences in the auditory responses when compared with the healthy controls but were able to generate oscillatory evoked activities following the frequency-varying stimulation. CONCLUSIONS: The ability to generate brain γ-oscillatory activity of children with Dravet in response to a chirp-modulated auditory stimulus is highly impaired, is not due to epilepsy and is consistent with the Nav1.1 channel dysfunction affecting interneuron activity seen in Dravet mouse models. SIGNIFICANCE: The reported deficits in the brain oscillatory activity evoked by chirp modulated tones in children with Dravet is compatible with Dravet syndrome disease mechanisms and constitutes a potential biomarker for future disease-modifying interventions.


Assuntos
Encéfalo/fisiopatologia , Epilepsias Mioclônicas/fisiopatologia , Ritmo Gama/fisiologia , Estimulação Acústica , Adolescente , Animais , Criança , Pré-Escolar , Epilepsias Mioclônicas/genética , Feminino , Humanos , Masculino , Camundongos
10.
Epilepsy Behav ; 103(Pt A): 106842, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31870807

RESUMO

Dravet syndrome is an intractable pediatric epilepsy associated with SCN1A mutations. In addition to having a large seizure burden and a reduced lifespan, patients with Dravet syndrome also exhibit delays in reaching normal developmental milestones in attentional, emotional, and cognitive function. These developmental delays manifest in autistic-like social withdrawal and compulsive behavior. Additionally, cognitive impairments including deficits in sensorimotor processing and memory function are present. Several mouse models utilizing heterozygous deletion of Scn1a (Scn1a+/- mice) have been generated that recapitulate many aspects of Dravet syndrome. Studies in these mouse models of Dravet syndrome have characterized behavioral phenotypes in adult mice. In the present study, we characterized the behavioral phenotype of Scn1a+/- mice generated by targeted deletion of Scn1a exon 1 (Scn1atm1Kea) during adolescence. Identifying behavioral deficits in adolescent mice would more closely model the early onset of attentional, emotional, and cognitive delays observed in patients with Dravet syndrome. The behaviors of adolescent Scn1a+/- and wildtype (WT) mice were compared across several behavioral domains. We assessed motor function (open-field test), sociability and social recognition memory (three-chambered social preference and social interaction tests), memory function (novel object recognition, Barnes maze, fear conditioning paradigm), anxiety-related behavior (elevated plus maze and open-field thigmotaxis), startle reflex and sensorimotor gating (prepulse inhibition of startle (PPI) tests), and repetitive compulsive behavior (marble burying test). Adolescent Scn1a+/- mice exhibited normal locomotor activity, marble burying behavior, sociability, and sensorimotor gating. However, adolescent Scn1a+/- mice displayed increased anxiety-related thigmotactic behavior, atypical fear expression, blunted acoustic startle responses, and impaired social recognition and spatial memory. Our results show that Scn1a+/- mice display various behavioral impairments during adolescence, which provides a foundation for testing early intervention therapies targeting developmental delays modeled in Dravet syndrome mice.


Assuntos
Modelos Animais de Doenças , Epilepsias Mioclônicas/genética , Aprendizagem em Labirinto/fisiologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Reflexo de Sobressalto/genética , Fatores Etários , Animais , Epilepsias Mioclônicas/fisiopatologia , Humanos , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Convulsões/genética , Convulsões/fisiopatologia , Memória Espacial/fisiologia
11.
Seizure ; 75: 1-6, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31864146

RESUMO

PURPOSE: Dravet syndrome is an early-onset epileptic encephalopathy caused most often by loss-of-function SCN1A variants. Following recognition of its genetic basis and unique clinical features, Dravet syndrome has become one of the most well-studied genetic epilepsies. We sought to evaluate the genetic diversity and correlative seizure phenotype, comorbidities, and response to antiepileptic therapies of patients with clinically-diagnosed Dravet syndrome seen in a tertiary care center. The goal of this study was to examine genotype-phenotype correlations and to ascertain if specific antiepileptic therapies may be more effective on the basis of genetic test result alone. METHOD: Retrospective chart review of demographics, comorbidities, seizure types, and responses to antiepileptic therapies of all patients (n = 137) with a clinical diagnosis of Dravet syndrome seen at Lurie Children's Hospital of Chicago from 2008 to 2016. RESULTS: Of the 96% of Dravet syndrome patients with pathogenic SCN1A variants subdivided by missense or truncating variant, there was no difference in clinical presentation. Response to antiepileptic therapies did not differ by genotype with regard to medication class. CONCLUSIONS: This is the largest cohort of Dravet patients from within the US to report medication response with respect to genotype. Missense variants in SCN1A were most common in the voltage-sensor and pore domains. All patients were most likely to respond to the recommended medication triad compared to other antiepileptic therapies.


Assuntos
Anticonvulsivantes/farmacologia , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/fisiopatologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Adolescente , Adulto , Criança , Pré-Escolar , Comorbidade , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Farmacogenética , Medicina de Precisão , Estudos Retrospectivos , Adulto Jovem
12.
Zhonghua Er Ke Za Zhi ; 57(11): 857-862, 2019 Nov 02.
Artigo em Chinês | MEDLINE | ID: mdl-31665840

RESUMO

Objective: To analyze the clinical characteristics of patients with PCDH19-female limited epilepsy (PCDH19-FE). Methods: The clinical data of 60 female epilepsy patients with PCDH19 gene heterozygous variations at the Department of Pediatrics, Peking University First Hospital from October 2007 to December 2018 were collected and analyzed retrospectively, their clinical manifestations, accessory examination and follow-up treatment were summarized. Results: Data of a total of 60 cases of PCDH19-FE were collected. The seizure onset occurred between 4 and 42 months of age (median: 11 months of age). Focal seizures occurred in 47 patients (78%), generalized tonic-clonic seizures (GTCS) occurred in 30 patients (50%), and other rare types of seizures included atypical absence, myoclonic, clonic, tonic, and atonic seizures. Two or more seizures types existed in 24 patients (40%), and seven patients (12%) had attacks of status epilepticus. Sensitivity to fever was observed in 47 out of them (78%) and clustering of seizures as found in all patients. During the interictal phase, focal discharges were monitored in 22 cases (22/45, 49%), multifocal discharges in 12 cases (12/45, 27%), widely discharging in 2 cases (4%), and both focal and widely discharging in 9 cases (20%). Clinical seizures were detected in 30 patients during the electroencephalogram (EEG) recording, including focal seizures in 22 cases, GTCS seizures in 8 cases, tonic seizure in three cases, myoclonic seizure followed by GTCS in one case, and two types of seizures in four cases. Before seizure onset, 57 patients had normal development and three patients had delayed language development. After seizure onset, varied degrees of intelligence disability were present in 38 cases (63%), language delay in 36 cases (60%), and gait instability in 10 cases (17%). Autistic features occurred in 17 cases (28%); and other behavioral problems like learning difficulties, personality, or emotional disorders existed in 33 cases (55%). Age at last follow-up ranged from one year and 3 months to 22 years and 3 months of age, 17 patients (28%) were seizure-free for more than 2 years (5 to 22 years at the last follow-up). The efficiency of antiepileptic drugs were 65% (33/51) in sodium valproate, 63% (27/43) in levetiracetam and 59% (20/34) in topiramate. Conclusions: The clinical features of PCDH19-FE are characterized by clustering of seizures, focal seizures in most cases, sensitivity to fever mostly, focal discharges principally in EEG, varied degrees of intellectual disability or movement disorder, combined with autism spectrum disorders in partial and high efficiency in sodium valproate or levetiracetam treatment.


Assuntos
Caderinas/genética , Epilepsias Mioclônicas/genética , Epilepsia/genética , Convulsões/genética , Adolescente , Transtorno do Espectro Autista , Criança , Pré-Escolar , Eletroencefalografia , Epilepsia/fisiopatologia , Feminino , Humanos , Lactente , Mutação , Estudos Retrospectivos , Convulsões/fisiopatologia , Adulto Jovem
13.
Nat Commun ; 10(1): 4920, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664034

RESUMO

Familial Adult Myoclonic Epilepsy (FAME) is characterised by cortical myoclonic tremor usually from the second decade of life and overt myoclonic or generalised tonic-clonic seizures. Four independent loci have been implicated in FAME on chromosomes (chr) 2, 3, 5 and 8. Using whole genome sequencing and repeat primed PCR, we provide evidence that chr2-linked FAME (FAME2) is caused by an expansion of an ATTTC pentamer within the first intron of STARD7. The ATTTC expansions segregate in 158/158 individuals typically affected by FAME from 22 pedigrees including 16 previously reported families recruited worldwide. RNA sequencing from patient derived fibroblasts shows no accumulation of the AUUUU or AUUUC repeat sequences and STARD7 gene expression is not affected. These data, in combination with other genes bearing similar mutations that have been implicated in FAME, suggest ATTTC expansions may cause this disorder, irrespective of the genomic locus involved.


Assuntos
Proteínas de Transporte/genética , Cromossomos Humanos Par 2/genética , Expansão das Repetições de DNA , Epilepsias Mioclônicas/genética , Íntrons , Adolescente , Adulto , Criança , Pré-Escolar , Mapeamento Cromossômico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Adulto Jovem
14.
Nat Commun ; 10(1): 4919, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664039

RESUMO

Familial Adult Myoclonic Epilepsy (FAME) is a genetically heterogeneous disorder characterized by cortical tremor and seizures. Intronic TTTTA/TTTCA repeat expansions in SAMD12 (FAME1) are the main cause of FAME in Asia. Using genome sequencing and repeat-primed PCR, we identify another site of this repeat expansion, in MARCH6 (FAME3) in four European families. Analysis of single DNA molecules with nanopore sequencing and molecular combing show that expansions range from 3.3 to 14 kb on average. However, we observe considerable variability in expansion length and structure, supporting the existence of multiple expansion configurations in blood cells and fibroblasts of the same individual. Moreover, the largest expansions are associated with micro-rearrangements occurring near the expansion in 20% of cells. This study provides further evidence that FAME is caused by intronic TTTTA/TTTCA expansions in distinct genes and reveals that expansions exhibit an unexpectedly high somatic instability that can ultimately result in genomic rearrangements.


Assuntos
Expansão das Repetições de DNA , Epilepsias Mioclônicas/genética , Proteínas de Membrana/genética , Ubiquitina-Proteína Ligases/genética , Adolescente , Adulto , Idoso , Mapeamento Cromossômico , Feminino , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Linhagem , Adulto Jovem
15.
Epilepsia ; 60(11): 2224-2234, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31625159

RESUMO

OBJECTIVE: Cannabidiol (CBD) has been approved by the US Food and Drug Administration (FDA) to treat intractable childhood epilepsies, such as Dravet syndrome and Lennox-Gastaut syndrome. However, the intrinsic anticonvulsant activity of CBD has been questioned due to a pharmacokinetic interaction between CBD and a first-line medication, clobazam. This recognized interaction has led to speculation that the anticonvulsant efficacy of CBD may simply reflect CBD augmenting clobazam exposure. The present study aimed to address the nature of the interaction between CBD and clobazam. METHODS: We examined whether CBD inhibits human CYP3A4 and CYP2C19 mediated metabolism of clobazam and N-desmethylclobazam (N-CLB), respectively, and performed studies assessing the effects of CBD on brain and plasma pharmacokinetics of clobazam in mice. We then used the Scn1a+/- mouse model of Dravet syndrome to examine how CBD and clobazam interact. We compared anticonvulsant effects of CBD-clobazam combination therapy to monotherapy against thermally-induced seizures, spontaneous seizures and mortality in Scn1a+/- mice. In addition, we used Xenopus oocytes expressing γ-aminobutyric acid (GABA)A receptors to investigate the activity of GABAA receptors when treated with CBD and clobazam together. RESULTS: CBD potently inhibited CYP3A4 mediated metabolism of clobazam and CYP2C19 mediated metabolism of N-CLB. Combination CBD-clobazam treatment resulted in greater anticonvulsant efficacy in Scn1a+/- mice, but only when an anticonvulsant dose of CBD was used. It is important to note that a sub-anticonvulsant dose of CBD did not promote greater anticonvulsant effects despite increasing plasma clobazam concentrations. In addition, we delineated a novel pharmacodynamic mechanism where CBD and clobazam together enhanced inhibitory GABAA receptor activation. SIGNIFICANCE: Our study highlights the involvement of both pharmacodynamic and pharmacokinetic interactions between CBD and clobazam that may contribute to its efficacy in Dravet syndrome.


Assuntos
Anticonvulsivantes/farmacocinética , Canabidiol/farmacocinética , Clobazam/farmacocinética , Epilepsias Mioclônicas/metabolismo , Animais , Anticonvulsivantes/administração & dosagem , Canabidiol/administração & dosagem , Clobazam/administração & dosagem , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Interações Medicamentosas/fisiologia , Quimioterapia Combinada , Epilepsias Mioclônicas/tratamento farmacológico , Epilepsias Mioclônicas/genética , Humanos , Camundongos , Camundongos Transgênicos , Canal de Sódio Disparado por Voltagem NAV1.1/genética
16.
Medicina (B Aires) ; 79 Suppl 3: 42-47, 2019.
Artigo em Espanhol | MEDLINE | ID: mdl-31603843

RESUMO

Epileptic encephalopathies is a group of epileptic syndromes characterized by progressive cognitive impairment beyond the expected for the epilepsy activity. They are characterized by severe pharmaco-resistant epilepsy, severely abnormal electroencephalograms, early-age onset, neurocognitve impairment, variable phenotype and usually normal brain MRI. These syndromes are usually genetically determined. A correct and timely diagnosis could help and guide the medical counselling and the correct therapeutic approach improving the short, medium and long term outcomes. In this article we review the electroencephalographic and genetic findings along with the most recommended therapeutic options facilitating the clinical management. We include the following epileptic encephalopathy syndromes: Ohtahara, early myoclonic encephalopathy, epilepsy of infancy with migrating focal seizures, West, Dravet, non-progressive myoclonic status, Doose, Lennox-Gastaut, Landau-Kleffner and continuous spike-wave during sleep epilepsy.


Assuntos
Encefalopatias/genética , Epilepsias Mioclônicas/genética , Espasmos Infantis , Anticonvulsivantes/classificação , Anticonvulsivantes/uso terapêutico , Encefalopatias/classificação , Encefalopatias/diagnóstico , Encefalopatias/tratamento farmacológico , Eletroencefalografia , Epilepsias Mioclônicas/diagnóstico , Epilepsias Mioclônicas/tratamento farmacológico , Humanos , Síndrome
18.
Stem Cell Res ; 39: 101523, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31400703

RESUMO

Dravet syndrome (DS) is a childhood epilepsy syndrome caused by heterozygous mutations in the SCN1A gene encoding voltage-gated sodium channel Nav1.1. We generated iPSCs from fibroblasts of three DS patients carrying distinct SCN1A mutations (c.5502-5509dupGCTTGAAC, c.2965G>C and c.651C>G). The iPSC lines were genetically stable and each line retained the SCN1A gene mutation of the donor fibroblasts. Characterization of the iPSC lines confirmed expression of pluripotency markers, absence of exogenous vector expression and trilineage differentiation potential. These iPSC lines offer a useful resource to investigate the molecular mechanisms underlying Nav1.1 haploinsufficiency and for drug development to improve treatment of DS patients.


Assuntos
Epilepsias Mioclônicas/genética , Células-Tronco Pluripotentes Induzidas/citologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Mutação/genética , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo
19.
Seizure ; 71: 222-228, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31401500

RESUMO

PURPOSE: Although the genetic and clinical aspects of epilepsy with myoclonic-atonic seizures (MAE) and early onset absence epilepsy (EOAE) have been investigated thoroughly, other early childhood-onset generalized epilepsies that share clinical features with MAE and EOAE have not been characterized. In this study, we aimed to delineate the genetic and phenotypic spectrum of early childhood-onset generalized epilepsies, including MAE and EOAE. METHODS: We recruited 61 patients diagnosed with MAE, EOAE, genetic epilepsy with febrile seizure plus (GEFS+) and unclassified generalized epilepsies that shared seizure onset age and seizure types. Genetic causes were investigated through targeted gene panel testing, whole exome sequencing, chromosomal microarray, and single-gene Sanger sequencing. RESULTS: We classified 11 patients with MAE, 20 with EOAE, 9 with GEFS + spectrum. Epilepsy syndrome was not specified in the remaining 21 patients. The clinical features were comparable across groups. Nevertheless, patients with EOAE tended to show better developmental and seizure outcomes. A total of 23 pathogenic sequences and copy number variants from 12 genes were identified (23/61, 37.7%). Genetic etiologies were confirmed in 36.4% (4/11) of the MAE group, 45% (9/20) of the EOAE group, 22.2% (2/9) of the GEFS + spectrum, and 38.1% (8/21) of the unclassified group. The most frequently identified genes with pathogenic variants were SLC6A1 (7 patients), SLC2A1 (4 patients), and SYNGAP1 (4 patients). CONCLUSION: Early childhood-onset generalized epilepsy appeared to be characterized by an overlapping genetic and phenotypic spectrum. SLC6A1 and SLC2A1 appeared to be important genetic causes of early childhood-onset generalized epilepsy.


Assuntos
Epilepsia Generalizada/genética , Epilepsia Generalizada/fisiopatologia , Convulsões Febris/genética , Convulsões Febris/fisiopatologia , Idade de Início , Pré-Escolar , Eletroencefalografia , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/fisiopatologia , Epilepsia Tipo Ausência/genética , Epilepsia Tipo Ausência/fisiopatologia , Feminino , Proteínas da Membrana Plasmática de Transporte de GABA/genética , Testes Genéticos , Transportador de Glucose Tipo 1/genética , Humanos , Lactente , Masculino
20.
Sleep ; 42(12)2019 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-31346614

RESUMO

STUDY OBJECTIVES: Sleep disturbances are common co-morbidities of epileptic disorders. Dravet syndrome (DS) is an intractable epilepsy accompanied by disturbed sleep. While there is evidence that daily sleep timing is disrupted in DS, the difficulty of chronically recording polysomnographic sleep from patients has left our understanding of the effect of DS on circadian sleep regulation incomplete. We aim to characterize circadian sleep regulation in a mouse model of DS. METHODS: Here we exploit long-term electrocorticographic recordings of sleep in a mouse model of DS in which one copy of the Scn1a gene is deleted. This model both genocopies and phenocopies the disease in humans. We test the hypothesis that the deletion of Scn1a in DS mice is associated with impaired circadian regulation of sleep. RESULTS: We find that DS mice show impairments in circadian sleep regulation, including a fragmented rhythm of non-rapid eye movement (NREM) sleep and an elongated circadian period of sleep. Next, we characterize re-entrainment of sleep stages and siesta following jet lag in the mouse. Strikingly, we find that re-entrainment of sleep following jet lag is normal in DS mice, in contrast to previous demonstrations of slowed re-entrainment of wheel-running activity. Finally, we report that DS mice are more likely to have an absent or altered daily "siesta". CONCLUSIONS: Our findings support the hypothesis that the circadian regulation of sleep is altered in DS and highlight the value of long-term chronic polysomnographic recording in studying the role of the circadian clock on sleep/wake cycles in pre-clinical models of disease.


Assuntos
Ritmo Circadiano/fisiologia , Epilepsias Mioclônicas/fisiopatologia , Síndrome do Jet Lag/fisiopatologia , Fases do Sono/fisiologia , Transtornos do Sono-Vigília/fisiopatologia , Animais , Relógios Circadianos/fisiologia , Eletrocorticografia/métodos , Epilepsias Mioclônicas/genética , Feminino , Síndrome do Jet Lag/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Transtornos do Sono-Vigília/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA