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1.
Ann Neurol ; 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600826

RESUMO

OBJECTIVE: Pathogenic variants in KCNB1, encoding the voltage-gated potassium channel KV 2.1, are associated with developmental and epileptic encephalopathy (DEE). Previous functional studies on a limited number of KCNB1 variants indicated a range of molecular mechanisms by which variants affect channel function, including loss of voltage sensitivity, loss of ion selectivity, and reduced cell-surface expression. METHODS: We evaluated a series of 17 KCNB1 variants associated with DEE or other neurodevelopmental disorders (NDDs) to rapidly ascertain channel dysfunction using high-throughput functional assays. Specifically, we investigated the biophysical properties and cell-surface expression of variant KV 2.1 channels expressed in heterologous cells using high-throughput automated electrophysiology and immunocytochemistry-flow cytometry. RESULTS: Pathogenic variants exhibited diverse functional defects, including altered current density and shifts in the voltage dependence of activation and/or inactivation, as homotetramers or when coexpressed with wild-type KV 2.1. Quantification of protein expression also identified variants with reduced total KV 2.1 expression or deficient cell-surface expression. INTERPRETATION: Our study establishes a platform for rapid screening of KV 2.1 functional defects caused by KCNB1 variants associated with DEE and other NDDs. This will aid in establishing KCNB1 variant pathogenicity and the mechanism of dysfunction, which will enable targeted strategies for therapeutic intervention based on molecular phenotype. This article is protected by copyright. All rights reserved.

2.
JCI Insight ; 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31573978

RESUMO

Accumulation of lysosomal storage material and late-stage neurodegeneration are hallmarks of lysosomal storage disorders (LSDs) affecting the brain. Yet, for most LSDs, including CLN3 disease, the most common form of childhood dementia, it is unclear what mechanisms drive neurologic symptoms. Do deficits arise from loss of function of the mutated protein or toxicity from storage accumulation? Here, using in vitro voltage sensitive dye imaging and in vivo electrophysiology, we find progressive hippocampal dysfunction occurs prior to notable lysosomal storage and neuronal loss in two CLN3 disease mouse models. Pharmacologic reversal of lysosomal storage deposition in young mice does not rescue this circuit dysfunction. Additionally, we find that CLN3 disease mice lose an electrophysiologic marker of new memory encoding - hippocampal sharp wave ripples. This discovery, which is also seen in Alzheimer's disease, suggests the possibility of a shared electrophysiologic signature of dementia. Overall, our data describes new insights into previously unknown network-level changes occurring in LSDs affecting the central nervous system, and highlight the need for new therapeutic interventions targeting early circuit defects.

3.
Nat Commun ; 10(1): 2655, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201320

RESUMO

CDKL5 deficiency disorder (CDD) is characterized by epilepsy, intellectual disability, and autistic features, and CDKL5-deficient mice exhibit a constellation of behavioral phenotypes reminiscent of the human disorder. We previously found that CDKL5 dysfunction in forebrain glutamatergic neurons results in deficits in learning and memory. However, the pathogenic origin of the autistic features of CDD remains unknown. Here, we find that selective loss of CDKL5 in GABAergic neurons leads to autistic-like phenotypes in mice accompanied by excessive glutamatergic transmission, hyperexcitability, and increased levels of postsynaptic NMDA receptors. Acute, low-dose inhibition of NMDAR signaling ameliorates autistic-like behaviors in GABAergic knockout mice, as well as a novel mouse model bearing a CDD-associated nonsense mutation, CDKL5 R59X, implicating the translational potential of this mechanism. Together, our findings suggest that enhanced NMDAR signaling and circuit hyperexcitability underlie autistic-like features in mouse models of CDD and provide a new therapeutic avenue to treat CDD-related symptoms.


Assuntos
Síndromes Epilépticas/patologia , Neurônios GABAérgicos/patologia , Proteínas Serina-Treonina Quinases/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais/genética , Espasmos Infantis/patologia , Animais , Comportamento Animal/efeitos dos fármacos , Códon sem Sentido , Modelos Animais de Doenças , Síndromes Epilépticas/tratamento farmacológico , Síndromes Epilépticas/genética , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Feminino , Humanos , Masculino , Memantina/farmacologia , Memantina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Prosencéfalo/citologia , Prosencéfalo/efeitos dos fármacos , Prosencéfalo/patologia , Proteínas Serina-Treonina Quinases/deficiência , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Espasmos Infantis/tratamento farmacológico , Espasmos Infantis/genética , Resultado do Tratamento
4.
Pediatr Neurol ; 97: 38-42, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31147226

RESUMO

BACKGROUND: Pathologic mutations in cyclin-dependent kinase-like 5 cause CDKL5 deficiency disorder, a genetic syndrome associated with severe epilepsy and cognitive, motor, visual, and autonomic disturbances. This disorder is a relatively common genetic cause of early-life epilepsy. A specific severity assessment is lacking, required to monitor the clinical course and needed to define the natural history and for clinical trial readiness. METHODS: A severity assessment was developed based on clinical and research experience from the International Foundation for CDKL5 Research Centers of Excellence consortium and the National Institutes of Health Rett and Rett-Related Disorders Natural History Study consortium. An initial draft severity assessment was presented and reviewed at the annual CDKL5 Forum meeting (Boston, 2017). Subsequently it was iterated through four cycles of a modified Delphi process by a group of clinicians, researchers, industry, patient advisory groups, and parents familiar with this disorder until consensus was achieved. The revised version of the severity assessment was presented for review, comment, and piloting to families at the International Foundation for CDKL5 Research-sponsored family meeting (Colorado, 2018). Final revisions were based on this additional input. RESULTS: The final severity assessment comprised 51 items that comprehensively describe domains of epilepsy; motor; cognition, behavior, vision, and speech; and autonomic functions. Parental ratings of therapy effectiveness and child and family functioning are also included. CONCLUSIONS: A severity assessment was rapidly developed with input from multiple stakeholders. Refinement through ongoing validation is required for future clinical trials. The consensus methods employed for the development of severity assessment may be applicable to similar rare disorders.

5.
JAMA Netw Open ; 2(4): e192129, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30977854

RESUMO

Importance: Although genetic testing is important for bringing precision medicine to children with epilepsy, it is unclear what genetic testing strategy is best in maximizing diagnostic yield. Objectives: To evaluate the diagnostic yield of an exome-based gene panel for childhood epilepsy and discuss the value of follow-up testing. Design, Setting, and Participants: A case series study was conducted on data from clinical genetic testing at Children's Hospital of Philadelphia was conducted from September 26, 2016, to January 8, 2018. Initial testing targeted 100 curated epilepsy genes for sequence and copy number analysis in 151 children with idiopathic epilepsy referred consecutively by neurologists. Additional genetic testing options were offered afterward. Exposures: Clinical genetic testing. Main Outcomes and Measures: Molecular diagnostic findings. Results: Of 151 patients (84 boys [55.6%]; median age, 4.2 years [interquartile range, 1.4-8.7 years]), 16 children (10.6%; 95% CI, 6%-16%) received a diagnosis after initial panel analysis. Parental testing for 15 probands with inconclusive results revealed de novo variants in 7 individuals (46.7%), resulting in an overall diagnostic yield of 15.3% (23 of 151; 95% CI, 9%-21%). Twelve probands with nondiagnostic panel findings were reflexed to exome sequencing, and 4 were diagnostic (33.3%; 95% CI, 6%-61%), raising the overall diagnostic yield to 17.9% (27 of 151; 95% CI, 12%-24%). The yield was highest (17 of 44 [38.6%; 95% CI, 24%-53%]) among probands with epilepsy onset in infancy (age, 1-12 months). Panel diagnostic findings involved 16 genes: SCN1A (n = 4), PRRT2 (n = 3), STXBP1 (n = 2), IQSEC2 (n = 2), ATP1A2, ATP1A3, CACNA1A, GABRA1, KCNQ2, KCNT1, SCN2A, SCN8A, DEPDC5, TPP1, PCDH19, and UBE3A (all n = 1). Exome sequencing analysis identified 4 genes: SMC1A, SETBP1, NR2F1, and TRIT1. For the remaining 124 patients, analysis of 13 additional genes implicated in epilepsy since the panel was launched in 2016 revealed promising findings in 6 patients. Conclusions and Relevance: Exome-based targeted panels appear to enable rapid analysis of a preselected set of genes while retaining flexibility in gene content. Successive genetic workup should include parental testing of select probands with inconclusive results and reflex to whole-exome trio analysis for the remaining nondiagnostic cases. Periodic reanalysis is needed to capture information in newly identified disease genes.

6.
Epilepsia ; 60(5): 898-910, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31006860

RESUMO

OBJECTIVE: Interictal spikes are a characteristic feature of invasive electroencephalography (EEG) recordings in children with refractory epilepsy. Spikes frequently co-occur across multiple brain regions with discernable latencies, suggesting that spikes can propagate through distributed neural networks. The purpose of this study was to examine the long-term reproducibility of spike propagation patterns over hours to days of interictal recording. METHODS: Twelve children (mean age 13.1 years) were retrospectively studied. A mean ± standard deviation (SD) of 47.2 ± 40.1 hours of interictal EEG recordings were examined per patient (range 17.5-166.5 hours). Interictal recordings were divided into 30-minute segments. Networks were extracted based on the frequency of spike coactivation between pairs of electrodes. For each 30-minute segment, electrodes were assigned a "Degree Preference (DP)" based on the tendency to appear upstream or downstream within propagation sequences. The consistency of DPs across segments ("DP-Stability") was quantified using the Spearman rank correlation. RESULTS: Regions exhibited highly stable preferences to appear upstream, intermediate, or downstream in spike propagation sequences. Across networks, the mean ± SD DP-Stability was 0.88 ± 0.07, indicating that propagation patterns observed in 30-minute segments were representative of the patterns observed in the full interictal window. At the group level, regions involved in seizure generation appeared more upstream in spike propagation sequences. SIGNIFICANCE: Interictal spike propagation is a highly reproducible output of epileptic networks. These findings shed new light on the spatiotemporal dynamics that may constrain the network mechanisms of refractory epilepsy.

7.
Epilepsy Res ; 154: 13-20, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31022635

RESUMO

BACKGROUND: Since 2014, patients with severe treatment-resistant epilepsies (TREs) have been receiving add-on cannabidiol (CBD) in an ongoing, expanded access program (EAP), which closely reflects clinical practice. We conducted an interim analysis of long-term efficacy and tolerability in patients with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) who received CBD treatment through December 2016. METHODS: Children and adults with LGS/DS taking stable doses of antiepileptic drugs (AEDs) at baseline were included from 25 EAP sites across the United States. During the 4-week baseline period, parents/caregivers kept diaries of all countable seizure types. Patients received a pharmaceutical formulation of highly purified CBD (Epidiolex®; 100 mg/mL) in oral solution at 2-10 mg/kg/day, titrated until tolerability limit or a maximum dose of 25-50 mg/kg/day. Patient visits were every 2-4 weeks. The percentage change from baseline in median monthly convulsive (ie, major motor) and total seizures was evaluated at 12-week intervals through 96 weeks. The percentages of patients who had ≥50%, ≥75%, and 100% reduction in monthly seizures relative to the baseline period were also evaluated. Adverse events (AEs) were monitored and summarized for the safety analysis set (SAS) through 144 weeks. RESULTS: Of the 607 patients in the SAS, 58 had DS and 94 had LGS (N = 152); 455 patients had other TREs. Twenty-eight percent of LGS/DS patients withdrew, primarily owing to lack of efficacy (20%). LGS/DS patients were taking a median of 3 (0-10) concomitant AEDs. Median treatment duration was 78.3 (range, 4.1-146.4) weeks. Between weeks 12 and 96, median CBD dose ranged from 21 to 25 mg/kg/day. At 12 weeks, add-on CBD reduced median monthly major motor seizures by 50% and total seizures by 44%, with consistent reductions in both seizure types through 96 weeks. At 12 weeks, the proportions of patients with ≥50%, ≥75%, and 100% reductions in major motor seizures were 53%, 23%, and 6%; the proportions with corresponding reductions in total seizures were 46%, 26%, and 5%. Responder rates for both seizure types were consistent through 96 weeks. CBD had an acceptable safety profile; the most common AEs were somnolence (30%) and diarrhea (24%). CONCLUSIONS: Results from this interim analysis support add-on CBD as an effective long-term treatment option in LGS or DS.

8.
Clin Genet ; 95(5): 575-581, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30788845

RESUMO

Individuals with methyl CpG binding protein 2 (MECP2) duplication syndrome (MDS) have varying degrees of severity in their mobility, hand use, developmental skills, and susceptibility to infections. In the present study, we examine the relationship between duplication size, gene content, and overall phenotype in MDS using a clinical severity scale. Other genes typically duplicated within Xq28 (eg, GDI1, RAB39B, FLNA) are associated with distinct clinical features independent of MECP2. We additionally compare the phenotype of this cohort (n = 48) to other reported cohorts with MDS. Utilizing existing indices of clinical severity in Rett syndrome, we found that larger duplication size correlates with higher severity in total clinical severity scores (r = 0.36; P = 0.02), and in total motor behavioral assessment inventory scores (r = 0.31; P = 0.05). Greater severity was associated with having the RAB39B gene duplicated, although most of these participants also had large duplications. Results suggest that developmental delays in the first 6 months of life, hypotonia, vasomotor disturbances, constipation, drooling, and bruxism are common in MDS. This is the first study to show that duplication size is related to clinical severity. Future studies should examine whether large duplications which do not encompass RAB39B also contribute to clinical severity. Results also suggest the need for creating an MDS specific severity scale.

9.
Epilepsia ; 60(3): 419-428, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30740695

RESUMO

OBJECTIVE: Patients with Lennox-Gastaut syndrome (LGS) who completed 1 of 2 randomized, double-blind, placebo-controlled trials of add-on cannabidiol (CBD) (GWPCARE3, NCT02224560 or GWPCARE4, NCT02224690) were invited to enroll in an open-label extension (OLE) study evaluating the long-term safety and efficacy of CBD (GWPCARE5, NCT02224573). Herein we present an interim analysis of the safety, efficacy, and patient-reported outcomes from this trial. METHODS: Patients received a pharmaceutical formulation of highly purified CBD oral solution (Epidiolex; 100 mg/mL), titrated from 2.5 to 20 mg/kg/d over a 2-week titration period, in addition to their existing medications. Doses could be reduced if not tolerated or increased up to 30 mg/kg/d if thought to be of benefit. RESULTS: This interim analysis was based on a November 2016 data cut. Of 368 patients who completed treatment in GWPCARE3 and GWPCARE4, 366 (99.5%) enrolled in the OLE study (GWPCARE5). Median treatment duration was 38 weeks at a mean modal dose of 23 mg/kg/d. Most patients (92.1%) experienced adverse events (AEs), primarily of mild (32.5%) or moderate (43.4%) severity. The most common AEs were diarrhea (26.8%), somnolence (23.5%), and convulsion (21.3%). Thirty-five patients (9.6%) discontinued treatment due to AEs. Liver transaminase elevations were reported in 37 patients (10.1%), of whom 29 were receiving concomitant valproic acid; 34 cases resolved spontaneously or with dose modification of CBD or concomitant medication. Median reduction from baseline in drop seizure frequency (quantified monthly over 12-week periods) ranged from 48% to 60% through week 48. Median reduction in monthly total seizure frequency ranged from 48% to 57% across all 12-week periods through week 48. Eighty-eight percent of patients/caregivers reported an improvement in the patient's overall condition per the Subject/Caregiver Global Impression of Change scale. SIGNIFICANCE: In this study, long-term add-on CBD treatment had an acceptable safety profile in patients with LGS and led to sustained reductions in seizures.

10.
Curr Opin Neurol ; 32(2): 220-226, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30676535

RESUMO

PURPOSE OF REVIEW: To review the history, pharmacology, and clinical science of cannabidiol (CBD) in the treatment of epilepsy. RECENT FINDINGS: Phase III randomized controlled trials and prospective open label trials have provided efficacy and safety data for the use of CBD in pediatric onset severe epilepsies. The product that was studied in the vast majority of these published trials, Epidiolex (>99% of CBD and <0.10% Δ9-tetrahydrocannabinol (THC); GW pharmaceuticals, Cambridge, UK), has now been FDA approved based on this published data. SUMMARY: Identification of CBD, Δ9-THC, and the endocannabinoid system in the mid-20th century has led to advancement of cannabis-based therapies for epilepsy. Based on clinical trial data, Epidiolex is the first CBD medication approved by a national regulatory agency (US Food and Drug Administration for Dravet and Lennox Gastaut syndrome; European Medicines Agency for Lennox Gastaut syndrome). Approval of CBD as a treatment for these rare and severe pediatric-onset epilepsy syndromes is an important milestone, but the complete spectrum of use of cannabis-derived products, and the use of CBD for other epilepsy syndromes remains to be determined.

11.
Am J Med Genet B Neuropsychiatr Genet ; 180(1): 55-67, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30536762

RESUMO

Mutations in the X-linked gene MECP2 are associated with a severe neurodevelopmental disorder, Rett syndrome (RTT), primarily in girls. It had been suspected that mutations in Methyl-CpG-binding protein 2 (MECP2) led to embryonic lethality in males, however such males have been reported. To enhance understanding of the phenotypic spectrum present in these individuals, we identified 30 males with MECP2 mutations in the RTT Natural History Study databases. A wide phenotypic spectrum was observed, ranging from severe neonatal encephalopathy to cognitive impairment. Two males with a somatic mutation in MECP2 had classic RTT. Of the remaining 28 subjects, 16 had RTT-causing MECP2 mutations, 9 with mutations that are not seen in females with RTT but are likely pathogenic, and 3 with uncertain variants. Two subjects with RTT-causing mutations were previously diagnosed as having atypical RTT; however, careful review of the clinical history determined that an additional 12/28 subjects met criteria for atypical RTT, but with more severe clinical presentation and course, and less distinctive RTT features, than females with RTT, leading to the designation of a new diagnostic entity, male RTT encephalopathy. Increased awareness of the clinical spectrum and widespread comprehensive genomic testing in boys with neurodevelopmental problems will lead to improved identification.

13.
Neuroscience ; 384: 350-360, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29885523

RESUMO

The perineuronal net (PN), a highly organized extracellular matrix structure, is believed to play an important role in synaptic function, including maturation and stabilization. In addition to its role in restricting plasticity, alterations in the PN are implicated in disorders such as epilepsy and schizophrenia. However, the time course of PN development is not known in humans. Therefore we set out to document the developmental timeline of the PN formation in humans in 14 frontal and hippocampal specimens from donors aged 27 days to 31 years old. Using immunohistochemistry and western blotting, we demonstrate that the PN begins to form as early as the second month of life but does not reach its robust, mature appearance until around 8 years of age, though aggrecan cleavage products are observed prior to this. A similar developmental time course was observed in specimens from epilepsy patients. Our data suggest that aggrecan is present early in development but the structured PN develops throughout early childhood, similar to what has been observed in rodents. This timeline provides information for future pathological studies on the role of the PN in disease and an additional parallel between human and rodent development.

14.
Epilepsy Res ; 143: 41-49, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29655171

RESUMO

OBJECTIVE: Post-ictal EEG alterations have been identified in studies of intracranial recordings, but the clinical significance of post-ictal EEG activity is undetermined. The purpose of this study was to examine the relationship between peri-ictal EEG activity, surgical outcome, and extent of seizure propagation in a sample of pediatric epilepsy patients. METHODS: Intracranial EEG recordings were obtained from 19 patients (mean age = 11.4 years, range = 3-20 years) with 57 seizures used for analysis (mean = 3.0 seizures per patient). For each seizure, 3-min segments were extracted from adjacent pre-ictal and post-ictal epochs. To compare physiology of the epileptic network between epochs, we calculated the relative delta power (Δ) using discrete Fourier transformation and constructed functional networks based on broadband connectivity (conn). We investigated differences between the pre-ictal (Δpre, connpre) and post-ictal (Δpost, connpost) segments in focal-network (i.e., confined to seizure onset zone) versus distributed-network (i.e., diffuse ictal propagation) seizures. RESULTS: Distributed-network (DN) seizures exhibited increased post-ictal delta power and global EEG connectivity compared to focal-network (FN) seizures. Following DN seizures, patients with seizure-free outcomes exhibited a 14.7% mean increase in delta power and an 8.3% mean increase in global connectivity compared to pre-ictal baseline, which was dramatically less than values observed among seizure-persistent patients (29.6% and 47.1%, respectively). SIGNIFICANCE: Post-ictal differences between DN and FN seizures correlate with post-operative seizure persistence. We hypothesize that post-ictal deactivation of subcortical nuclei recruited during seizure propagation may account for this result while lending insights into mechanisms of post-operative seizure recurrence.

15.
Lancet ; 391(10125): 1085-1096, 2018 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-29395273

RESUMO

BACKGROUND: Patients with Lennox-Gastaut syndrome, a rare, severe form of epileptic encephalopathy, are frequently treatment resistant to available medications. No controlled studies have investigated the use of cannabidiol for patients with seizures associated with Lennox-Gastaut syndrome. We therefore assessed the efficacy and safety of cannabidiol as an add-on anticonvulsant therapy in this population of patients. METHODS: In this randomised, double-blind, placebo-controlled trial done at 24 clinical sites in the USA, the Netherlands, and Poland, we investigated the efficacy of cannabidiol as add-on therapy for drop seizures in patients with treatment-resistant Lennox-Gastaut syndrome. Eligible patients (aged 2-55 years) had Lennox-Gastaut syndrome, including a history of slow (<3 Hz) spike-and-wave patterns on electroencephalogram, evidence of more than one type of generalised seizure for at least 6 months, at least two drop seizures per week during the 4-week baseline period, and had not responded to treatment with at least two antiepileptic drugs. Patients were randomly assigned (1:1) using an interactive voice response system, stratified by age group, to receive 20 mg/kg oral cannabidiol daily or matched placebo for 14 weeks. All patients, caregivers, investigators, and individuals assessing data were masked to group assignment. The primary endpoint was percentage change from baseline in monthly frequency of drop seizures during the treatment period, analysed in all patients who received at least one dose of study drug and had post-baseline efficacy data. All randomly assigned patients were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT02224690. FINDINGS: Between April 28, 2015, and Oct 15, 2015, we randomly assigned 171 patients to receive cannabidiol (n=86) or placebo (n=85). 14 patients in the cannabidiol group and one in the placebo group discontinued study treatment; all randomly assigned patients received at least one dose of study treatment and had post-baseline efficacy data. The median percentage reduction in monthly drop seizure frequency from baseline was 43·9% (IQR -69·6 to -1·9) in the cannibidiol group and 21·8% (IQR -45·7 to 1·7) in the placebo group. The estimated median difference between the treatment groups was -17·21 (95% CI -30·32 to -4·09; p=0·0135) during the 14-week treatment period. Adverse events occurred in 74 (86%) of 86 patients in the cannabidiol group and 59 (69%) of 85 patients in the placebo group; most were mild or moderate. The most common adverse events were diarrhoea, somnolence, pyrexia, decreased appetite, and vomiting. 12 (14%) patients in the cannabidiol group and one (1%) patient in the placebo group withdrew from the study because of adverse events. One patient (1%) died in the cannabidiol group, but this was considered unrelated to treatment. INTERPRETATION: Add-on cannabidiol is efficacious for the treatment of patients with drop seizures associated with Lennox-Gastaut syndrome and is generally well tolerated. The long-term efficacy and safety of cannabidiol is currently being assessed in the open-label extension of this trial. FUNDING: GW Pharmaceuticals.


Assuntos
Anticonvulsivantes/uso terapêutico , Canabidiol/uso terapêutico , Síndrome de Lennox Gastaut/tratamento farmacológico , Convulsões/tratamento farmacológico , Adolescente , Adulto , Criança , Pré-Escolar , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Síndrome de Lennox Gastaut/complicações , Masculino , Pessoa de Meia-Idade , Convulsões/etiologia , Resultado do Tratamento , Adulto Jovem
16.
Genet Med ; 20(3): 329-336, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29389922

RESUMO

PurposeThe objective of this study was to assess the ability of our laboratory's exome-sequencing test to detect known and novel sequence variants and identify the critical factors influencing the interpretation of a clinical exome test.MethodsWe developed a two-tiered validation strategy: (i) a method-based approach that assessed the ability of our exome test to detect known variants using a reference HapMap sample, and (ii) an interpretation-based approach that assessed our relative ability to identify and interpret disease-causing variants, by analyzing and comparing the results of 19 randomly selected patients previously tested by external laboratories.ResultsWe demonstrate that this approach is reproducible with >99% analytical sensitivity and specificity for single-nucleotide variants and indels <10 bp. Our findings were concordant with the reference laboratories in 84% of cases. A new molecular diagnosis was applied to three cases, including discovery of two novel candidate genes.ConclusionWe provide an assessment of critical areas that influence interpretation of an exome test, including comprehensive phenotype capture, assessment of clinical overlap, availability of parental data, and the addressing of limitations in database updates. These results can be used to inform improvements in phenotype-driven interpretation of medical exomes in clinical and research settings.


Assuntos
Confiabilidade dos Dados , Exoma , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Biologia Computacional/métodos , Estudos de Associação Genética , Predisposição Genética para Doença , Testes Genéticos/métodos , Testes Genéticos/normas , Genômica/métodos , Genômica/normas , Humanos , Mutação INDEL , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Am J Med Genet A ; 176(1): 56-67, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29150892

RESUMO

PURA syndrome is a recently described developmental encephalopathy presenting with neonatal hypotonia, feeding difficulties, global developmental delay, severe intellectual disability, and frequent apnea and epilepsy. We describe 18 new individuals with heterozygous sequence variations in PURA. A neuromotor disorder starting with neonatal hyptonia, but ultimately allowing delayed progression to walking, was present in nearly all individuals. Congenital apnea was present in 56% during infancy, but all cases in this cohort resolved during the first year of life. Feeding difficulties were frequently reported, with gastrostomy tube placement required in 28%. Epilepsy was present in 50% of the subjects, including infantile spasms and Lennox-Gastaut syndrome. Skeletal complications were found in 39%. Disorders of gastrointestinal motility and nystagmus were also recurrent features. Autism was diagnosed in one individual, potentially expanding the neurodevelopmental phenotype associated with this syndrome. However, we did not find additional PURA sequence variations in a cohort of 120 subjects with autism. We also present the first neuropathologic studies of PURA syndrome, and describe chronic inflammatory changes around the arterioles within the deep white matter. We did not find significant correlations between mutational class and severity, nor between location of the sequence variation in PUR repeat domains. Further studies are required in larger cohorts of subjects with PURA syndrome to clarify these genotype-phenotype associations.


Assuntos
Encefalopatias/diagnóstico , Encefalopatias/genética , Proteínas de Ligação a DNA/genética , Estudos de Associação Genética , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Fenótipo , Fatores de Transcrição/genética , Adolescente , Adulto , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 5 , Análise Mutacional de DNA , Gerenciamento Clínico , Epilepsia , Facies , Feminino , Humanos , Lactente , Imagem por Ressonância Magnética/métodos , Masculino , Síndrome , Substância Branca/patologia , Sequenciamento Completo do Exoma , Adulto Jovem
19.
Brain ; 140(9): 2337-2354, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29050392

RESUMO

Recently, de novo mutations in the gene KCNA2, causing either a dominant-negative loss-of-function or a gain-of-function of the voltage-gated K+ channel Kv1.2, were described to cause a new molecular entity within the epileptic encephalopathies. Here, we report a cohort of 23 patients (eight previously described) with epileptic encephalopathy carrying either novel or known KCNA2 mutations, with the aim to detail the clinical phenotype associated with each of them, to characterize the functional effects of the newly identified mutations, and to assess genotype-phenotype associations. We identified five novel and confirmed six known mutations, three of which recurred in three, five and seven patients, respectively. Ten mutations were missense and one was a truncation mutation; de novo occurrence could be shown in 20 patients. Functional studies using a Xenopus oocyte two-microelectrode voltage clamp system revealed mutations with only loss-of-function effects (mostly dominant-negative current amplitude reduction) in eight patients or only gain-of-function effects (hyperpolarizing shift of voltage-dependent activation, increased amplitude) in nine patients. In six patients, the gain-of-function was diminished by an additional loss-of-function (gain-and loss-of-function) due to a hyperpolarizing shift of voltage-dependent activation combined with either decreased amplitudes or an additional hyperpolarizing shift of the inactivation curve. These electrophysiological findings correlated with distinct phenotypic features. The main differences were (i) predominant focal (loss-of-function) versus generalized (gain-of-function) seizures and corresponding epileptic discharges with prominent sleep activation in most cases with loss-of-function mutations; (ii) more severe epilepsy, developmental problems and ataxia, and atrophy of the cerebellum or even the whole brain in about half of the patients with gain-of-function mutations; and (iii) most severe early-onset phenotypes, occasionally with neonatal onset epilepsy and developmental impairment, as well as generalized and focal seizures and EEG abnormalities for patients with gain- and loss-of-function mutations. Our study thus indicates well represented genotype-phenotype associations between three subgroups of patients with KCNA2 encephalopathy according to the electrophysiological features of the mutations.


Assuntos
Encefalopatias/diagnóstico , Encefalopatias/genética , Epilepsia/diagnóstico , Canal de Potássio Kv1.2/genética , Animais , Encefalopatias/complicações , Epilepsia/complicações , Epilepsia/genética , Estudos de Associação Genética , Mutação , Oócitos/fisiologia , Fenótipo , Xenopus
20.
JAMA Neurol ; 74(10): 1228-1236, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28806457

RESUMO

Importance: Knowing the range of symptoms seen in patients with a missense or loss-of-function variant in KCNB1 and how these symptoms correlate with the type of variant will help clinicians with diagnosis and prognosis when treating new patients. Objectives: To investigate the clinical spectrum associated with KCNB1 variants and the genotype-phenotype correlations. Design, Setting, and Participants: This study summarized the clinical and genetic information of patients with a presumed pathogenic variant in KCNB1. Patients were identified in research projects or during clinical testing. Information on patients from previously published articles was collected and authors contacted if feasible. All patients were seen at a clinic at one of the participating institutes because of presumed genetic disorder. They were tested in a clinical setting or included in a research project. Main Outcomes and Measures: The genetic variant and its inheritance and information on the patient's symptoms and characteristics in a predefined format. All variants were identified with massive parallel sequencing and confirmed with Sanger sequencing in the patient. Absence of the variant in the parents could be confirmed with Sanger sequencing in all families except one. Results: Of 26 patients (10 female, 15 male, 1 unknown; mean age at inclusion, 9.8 years; age range, 2-32 years) with developmental delay, 20 (77%) carried a missense variant in the ion channel domain of KCNB1, with a concentration of variants in region S5 to S6. Three variants that led to premature stops were located in the C-terminal and 3 in the ion channel domain. Twenty-one of 25 patients (84%) had seizures, with 9 patients (36%) starting with epileptic spasms between 3 and 18 months of age. All patients had developmental delay, with 17 (65%) experiencing severe developmental delay; 14 (82%) with severe delay had behavioral problems. The developmental delay was milder in 4 of 6 patients with stop variants and in a patient with a variant in the S2 transmembrane element rather than the S4 to S6 region. Conclusions and Relevance: De novo KCNB1 missense variants in the ion channel domain and loss-of-function variants in this domain and the C-terminal likely cause neurodevelopmental disorders with or without seizures. Patients with presumed pathogenic variants in KCNB1 have a variable phenotype. However, the type and position of the variants in the protein are (imperfectly) correlated with the severity of the disorder.


Assuntos
Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/fisiopatologia , Canais de Potássio Shab/genética , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Imagem por Ressonância Magnética , Masculino , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Fenótipo , Adulto Jovem
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