Publications
121 results found
Jesuthasan A, Barwick T, Dixon L, et al., 2023, LGI1 Encephalitis and IgG4-Related Disease: Rare Conditions Collide., Neurol Neuroimmunol Neuroinflamm, Vol: 10
OBJECTIVES: Leucine-rich glioma-inactivated 1 (LGI1) encephalitis and IgG4-related disease (IgG4RD) have traditionally been regarded as 2 distinct disease entities. METHODS: We detail the presentation, investigations, and management of a patient who showed typical signs and symptoms of LGI1 encephalitis and also found to possess pancreatic changes and a serum profile in keeping with IgG4RD. RESULTS: Serum and CSF analyses at presentation showed a significant hyponatraemia (117 mmol/L), elevated IgG4 concentration (1.73 g/L), and the presence of LGI1 antibodies. MRI revealed symmetrical diffuse T2-weighted hyperintensity and mild swelling throughout both medial temporal lobes. CT of the chest, abdomen and pelvis revealed an edematous, bulky pancreas with loss of lobulation, typical for IgG4RD. A glucocorticoid weaning regimen was commenced, facilitated by 2 rituximab infusions, with the patient showing an effective treatment response. HLA testing confirmed the presence of HLA DRB1 and HLA DQB1 risk alleles. DISCUSSION: This case suggests that there may be shared mechanisms between LGI1 encephalitis and IgG4RD, supported by common risk HLA associations and treatment strategies/responses. To our knowledge, this represents the first instance that LGI1 encephalitis and IgG4RD have been reported in the same patient and emphasizes the continued development of our understanding of the wide range of IgG4-mediated conditions.
International League Against Epilepsy Consortium on Complex Epilepsies, 2023, GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture, Nature Genetics, Vol: 55, Pages: 1471-1482, ISSN: 1061-4036
Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment.
Montanucci L, Lewis-Smith D, Collins RL, et al., 2023, Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals, Nature Communications, Vol: 14, Pages: 1-19, ISSN: 2041-1723
Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice.
Jesuthasan A, Barwick T, Dixon L, et al., 2023, Rare conditions collide: LGI1 encephalitis and IGG4-related disease, Neurology: Neuroimmunology & Neuroinflammation, ISSN: 2332-7812
Mahmud M, Wade C, Jawad S, et al., 2023, Translocator protein PET imaging in temporal lobe epilepsy: a reliable test-retest study using laterality index, Frontiers in Neuroimaging, Vol: 2, Pages: 1-10, ISSN: 2813-1193
ObjectiveTranslocator-protein (TSPO) targeting positron emission tomography (PET) imaging radioligands have potential utility in epilepsy to assess the efficacy of novel therapeutics for targeting neuroinflammation. However, previous studies in healthy volunteers have indicated limited test-retest reliability of TSPO ligands. Here we examine test retest measures using TSPO PET imaging in subjects with epilepsy and healthy controls, to explore whether this biomarker can be used an endpoint in clinical trials for epilepsy.MethodsFive subjects with epilepsy and confirmed mesial temporal lobe sclerosis (mean age 36 years, 3 male) were scanned twice – on average 8 weeks apart – using a second generation TSPO targeting radioligand, [11C]PBR28. We evaluated the test-retest reliability of the volume of distribution and derived hemispheric asymmetry index of [11C]PBR28 binding in these subjects and compared the results with 8 (mean age 45, 6 male) previously studied healthy volunteers.ResultsThe mean (± SD) of the volume of distribution (VT), of all subjects, in patients living with epilepsy for both test and retest scans on all regions of interest is 4.49 ± 1.54, versus 5.89 ±1.23 in healthy volunteers. The bias between test and retest in asymmetry index as % was small (-1.5%) and reliability is demonstrated here with Bland-Altman Plots (test mean 1.062, retest mean 2.56). In subjects with epilepsy, VT of [11C]PBR28 is higher in the (ipsilateral) hippocampal region where sclerosis is present than in the contralateral region.ConclusionWhen using TSPO PET in epilepsy patients with hippocampal sclerosis, inter-hemispheric asymmetry index in the hippocampus is a measure with good test-retest reliability. We provide estimates of test-retest variability that may be useful for estimating power where group change in VT represents the clinic outcome.
Feleke R, Jazayeri D, Abouzeid M, et al., 2022, Integrative genomics reveals pathogenic mediator of valproate-induced neurodevelopmental disability, Brain: a journal of neurology, Vol: 145, Pages: 3832-3842, ISSN: 0006-8950
Prenatal exposure to the anti-seizure medication sodium valproate (VPA) is associated with an increased risk of adverse postnatal neurodevelopmental outcomes, including lowered intellectual ability, autism spectrum disorder and attention-deficit hyperactivity disorder. In this study, we aimed to clarify the molecular mechanisms underpinning the neurodevelopmental consequences of gestational VPA exposure using integrative genomics. First, we assessed the effect of gestational VPA on fetal brain gene expression using a validated rat model of valproate teratogenicity that mimics the human scenario of chronic oral valproate treatment during pregnancy at doses which are therapeutically relevant to the treatment of epilepsy. Two different rat strains were studied - inbred Genetic Absence Epilepsy Rats from Strasbourg (GAERS), a model of genetic generalized epilepsy, and inbred Non-Epileptic Control rats. Female rats were fed standard chow or VPA mixed in standard chow for 2 weeks prior to conception and then mated with same-strain males. In the VPA-exposed rats maternal oral treatment was continued throughout pregnancy. Fetuses were extracted via C-section on gestational day 21 (one day prior to birth) and fetal brains were snap frozen and genome-wide gene expression data generated. We found that gestational VPA exposure via chronic maternal oral dosing was associated with substantial drug-induced differential gene expression in the pup brains, including dysregulated splicing, and observed that this occurred in the absence of evidence for significant neuronal gain or loss. The functional consequences of VPA-induced gene expression were explored using pathway analysis and integration with genetic risk data for psychiatric disease and behavioural traits. The set of genes down-regulated by VPA in the pup brains were significantly enriched for pathways related to neurodevelopment and synaptic function, and significantly enriched for heritability to human intelligence, schizop
Olona A, Hateley C, Guerrero A, et al., 2022, Cardiac glycosides cause cytotoxicity in human macrophages and ameliorate white adipose tissue homeostasis, British Journal of Pharmacology, Vol: 179, Pages: 1874-1886, ISSN: 0007-1188
Background and purpose: Cardiac glycosides (CGs) inhibit the Na+,K+‐ATPase and are widely prescribed medicines for chronic heart failure and cardiac arrhythmias. Recently, CGs have been described to induce inflammasome activation and pyroptosis in human macrophages, suggesting a cytotoxicity that remains to be elucidated in tissues.Experimental approach: To determine the cell type specificity of CG‐mediated cytotoxicity, we used human primary monocyte‐derived macrophages (hMDMs) and non‐adherent peripheral blood cells isolated from healthy donors. Omental white adipose tissue (WAT) and stromal vascular fraction (SVF)‐derived pre‐adipocytes and adipocytes were isolated from obese patients undergoing bariatric surgery. All these primary cells/tissues were treated with nanomolar concentrations of ouabain (50nM, 100nM and 500nM) to investigate its degree of cytotoxicity and mechanisms leading to cell death. In WAT, we further explored the consequences of ouabain‐mediated cytotoxicity by measuring insulin sensitivity, adipose tissue function and extracellular matrix (ECM) deposition ex vivo.Key results: The ouabain‐induced cell death is through pyroptosis and apoptosis, and more efficient in hMDMs compared to non‐adherent PBMC populations. This selective cytotoxicity is dependent on K+ flux, as ouabain causes an intracellular depletion of K+, while inducing accumulation of Na+ and Ca2+ levels. Consistently, the cell‐death caused by these ion imbalances can be rescued by addition of potassium chloride in hMDMs. Remarkably, when WAT explants from obese patients are cultured with nanomolar concentrations of ouabain, this causes depletion of macrophages, down‐regulation of type VI collagen levels, and amelioration of insulin sensitivity ex vivo.Conclusions and implications: These results suggest that the usage of nanomolar concentration of CGs can be an attractive therapeutic avenue in metabolic syndrome characterised by pathogenic infiltration and activation of macrophages.
Campbell C, Lewis-Smith D, Leu C, et al., 2022, Polygenic risk score analysis reveals shared genetic burden between epilepsy and psychiatric comorbidities, ., Publisher: SPRINGERNATURE, Pages: 31-32, ISSN: 1018-4813
Meijer M, Agirre E, Kabbe M, et al., 2022, Epigenomic priming of immune genes implicates oligodendroglia in multiple sclerosis susceptibility, Neuron, Vol: 110, Pages: 1193-1210.e13, ISSN: 0896-6273
Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG) and myelin by immune cells, which are thought to be the main drivers of MS susceptibility. We found that immune genes exhibit a primed chromatin state in single mouse and human OLG in a non-disease context, compatible with transitions to immune-competent states in MS. We identified BACH1 and STAT1 as transcription factors involved in immune gene regulation in oligodendrocyte precursor cells (OPCs). A subset of immune genes presents bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon gamma (IFN-γ) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse and human OLG. Treatment of mouse OPCs with IFN-γ leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Thus, the susceptibility for MS may involve OLG, which therefore constitutes novel targets for immunological-based therapies for MS.
Motelow JE, Povysil G, Dhindsa RS, et al., 2021, Sub-genic intolerance, ClinVar, and the epilepsies: A whole-exome sequencing study of 29,165 individuals, The American Journal of Human Genetics, Vol: 108, Pages: 2024-2024, ISSN: 0002-9297
Koko M, Krause R, Sander T, et al., 2021, Distinct gene-set burden patterns underlie common generalized and focal epilepsies, EBioMedicine, Vol: 72, Pages: 1-13, ISSN: 2352-3964
BACKGROUND: Analyses of few gene-sets in epilepsy showed a potential to unravel key disease associations. We set out to investigate the burden of ultra-rare variants (URVs) in a comprehensive range of biologically informed gene-sets presumed to be implicated in epileptogenesis. METHODS: The burden of 12 URV types in 92 gene-sets was compared between cases and controls using whole exome sequencing data from individuals of European descent with developmental and epileptic encephalopathies (DEE, n = 1,003), genetic generalized epilepsy (GGE, n = 3,064), or non-acquired focal epilepsy (NAFE, n = 3,522), collected by the Epi25 Collaborative, compared to 3,962 ancestry-matched controls. FINDINGS: Missense URVs in highly constrained regions were enriched in neuron-specific and developmental genes, whereas genes not expressed in brain were not affected. GGE featured a higher burden in gene-sets derived from inhibitory vs. excitatory neurons or associated receptors, whereas the opposite was found for NAFE, and DEE featured a burden in both. Top-ranked susceptibility genes from recent genome-wide association studies (GWAS) and gene-sets derived from generalized vs. focal epilepsies revealed specific enrichment patterns of URVs in GGE vs. NAFE. INTERPRETATION: Missense URVs affecting highly constrained sites differentially impact genes expressed in inhibitory vs. excitatory pathways in generalized vs. focal epilepsies. The excess of URVs in top-ranked GWAS risk-genes suggests a convergence of rare deleterious and common risk-variants in the pathogenesis of generalized and focal epilepsies. FUNDING: DFG Research Unit FOR-2715 (Germany), FNR (Luxembourg), NHGRI (US), NHLBI (US), DAAD (Germany).
De T, Goncalves A, Speed D, et al., 2021, Signatures of TSPAN8 variants associated with human metabolic regulation and diseases, iScience, Vol: 24, ISSN: 2589-0042
Here, with the example of common copy number variation (CNV) in the TSPAN8 gene, we present an important piece of work in the field of CNV detection, that is, CNV association with complex human traits such as 1H NMR metabolomic phenotypes and an example of functional characterization of CNVs among human induced pluripotent stem cells (HipSci). We report TSPAN8 exon 11 (ENSE00003720745) as a pleiotropic locus associated with metabolomic regulation and show that its biology is associated with several metabolic diseases such as type 2 diabetes (T2D) and cancer. Our results further demonstrate the power of multivariate association models over univariate methods and define metabolomic signatures for variants in TSPAN8.
Feleke R, Reynolds RH, Smith AM, et al., 2021, Cross-platform transcriptional profiling identifies common and distinct molecular pathologies in Lewy body diseases, Acta Neuropathologica, Vol: 142, Pages: 449-474, ISSN: 0001-6322
Parkinson's disease (PD), Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) are three clinically, genetically and neuropathologically overlapping neurodegenerative diseases collectively known as the Lewy body diseases (LBDs). A variety of molecular mechanisms have been implicated in PD pathogenesis, but the mechanisms underlying PDD and DLB remain largely unknown, a knowledge gap that presents an impediment to the discovery of disease-modifying therapies. Transcriptomic profiling can contribute to addressing this gap, but remains limited in the LBDs. Here, we applied paired bulk-tissue and single-nucleus RNA-sequencing to anterior cingulate cortex samples derived from 28 individuals, including healthy controls, PD, PDD and DLB cases (n = 7 per group), to transcriptomically profile the LBDs. Using this approach, we (i) found transcriptional alterations in multiple cell types across the LBDs; (ii) discovered evidence for widespread dysregulation of RNA splicing, particularly in PDD and DLB; (iii) identified potential splicing factors, with links to other dementia-related neurodegenerative diseases, coordinating this dysregulation; and (iv) identified transcriptomic commonalities and distinctions between the LBDs that inform understanding of the relationships between these three clinical disorders. Together, these findings have important implications for the design of RNA-targeted therapies for these diseases and highlight a potential molecular "window" of therapeutic opportunity between the initial onset of PD and subsequent development of Lewy body dementia.
Wolking S, Campbell C, Stapleton C, et al., 2021, Role of Common Genetic Variants for Drug-Resistance to Specific Anti-Seizure Medications, FRONTIERS IN PHARMACOLOGY, Vol: 12, ISSN: 1663-9812
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Wolking S, Moreau C, McCormack M, et al., 2021, Assessing the role of rare genetic variants in drug-resistant, non-lesional focal epilepsy, ANNALS OF CLINICAL AND TRANSLATIONAL NEUROLOGY, Vol: 8, Pages: 1376-1387, ISSN: 2328-9503
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- Citations: 9
Allen AS, Aggarwal V, Berkovic SF, et al., 2021, Diverse genetic causes of polymicrogyria with epilepsy, EPILEPSIA, Vol: 62, Pages: 973-983, ISSN: 0013-9580
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- Citations: 9
Schijven D, Stevelink R, McCormack M, et al., 2020, Analysis of shared common genetic risk between amyotrophic lateral sclerosis and epilepsy, Neurobiology of Aging, Vol: 92, Pages: 153.e1-153.e5, ISSN: 0197-4580
Wolking S, Schulz H, Nies AT, et al., 2020, Pharmacoresponse in genetic generalized epilepsy: a genome-wide association study, PHARMACOGENOMICS, Vol: 21, Pages: 325-335, ISSN: 1462-2416
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- Citations: 11
Kobow K, Reid CA, van Vliet EA, et al., 2020, Epigenetics explained: a topic "primer" for the epilepsy community by the ILAE Genetics/Epigenetics Task Force, EPILEPTIC DISORDERS, Vol: 22, Pages: 127-141, ISSN: 1294-9361
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- Citations: 11
Wolking S, Moreau C, Nies AT, et al., 2020, Testing association of rare genetic variants with resistance to three common antiseizure medications, Epilepsia, Vol: 61, Pages: 657-666, ISSN: 0013-9580
OBJECTIVE: Drug resistance is a major concern in the treatment of individuals with epilepsy. No genetic markers for resistance to individual antiseizure medication (ASM) have yet been identified. We aimed to identify the role of rare genetic variants in drug resistance for three common ASMs: levetiracetam (LEV), lamotrigine (LTG), and valproic acid (VPA). METHODS: A cohort of 1622 individuals of European descent with epilepsy was deeply phenotyped and underwent whole exome sequencing (WES), comprising 575 taking LEV, 826 LTG, and 782 VPA. We performed gene- and gene set-based collapsing analyses comparing responders and nonresponders to the three drugs to determine the burden of different categories of rare genetic variants. RESULTS: We observed a marginally significant enrichment of rare missense, truncating, and splice region variants in individuals who were resistant to VPA compared to VPA responders for genes involved in VPA pharmacokinetics. We also found a borderline significant enrichment of truncating and splice region variants in the synaptic vesicle glycoprotein (SV2) gene family in nonresponders compared to responders to LEV. We did not see any significant enrichment using a gene-based approach. SIGNIFICANCE: In our pharmacogenetic study, we identified a slightly increased burden of damaging variants in gene groups related to drug kinetics or targeting in individuals presenting with drug resistance to VPA or LEV. Such variants could thus determine a genetic contribution to drug resistance.
Schidlitzki A, Bascuñana P, Srivastava PK, et al., 2020, Proof-of-concept that network pharmacology is effective to modify development of acquired temporal lobe epilepsy, Neurobiology of Disease, Vol: 134, Pages: 1-16, ISSN: 0969-9961
Epilepsy is a complex network phenomenon that, as yet, cannot be prevented or cured. We recently proposed network-based approaches to prevent epileptogenesis. For proof of concept we combined two drugs (levetiracetam and topiramate) for which in silico analysis of drug-protein interaction networks indicated a synergistic effect on a large functional network of epilepsy-relevant proteins. Using the intrahippocampal kainate mouse model of temporal lobe epilepsy, the drug combination was administered during the latent period before onset of spontaneous recurrent seizures (SRS). When SRS were periodically recorded by video-EEG monitoring after termination of treatment, a significant decrease in incidence and frequency of SRS was determined, indicating antiepileptogenic efficacy. Such efficacy was not observed following single drug treatment. Furthermore, a combination of levetiracetam and phenobarbital, for which in silico analysis of drug-protein interaction networks did not indicate any significant drug-drug interaction, was not effective to modify development of epilepsy. Surprisingly, the promising antiepileptogenic effect of the levetiracetam/topiramate combination was obtained in the absence of any significant neuroprotective or anti-inflammatory effects as indicated by multimodal brain imaging and histopathology. High throughput RNA-sequencing (RNA-seq) of the ipsilateral hippocampus of mice treated with the levetiracetam/topiramate combination showed that several genes that have been linked previously to epileptogenesis, were significantly differentially expressed, providing interesting entry points for future mechanistic studies. Overall, we have discovered a novel combination treatment with promise for prevention of epilepsy.
Miller TD, Chong TT-J, Aimola Davies AM, et al., 2020, Human hippocampal CA3 damage disrupts both recent and remote episodic memories, eLife, Vol: 9, ISSN: 2050-084X
Neocortical-hippocampal interactions support new episodic (event) memories, but there is conflicting evidence about the dependence of remote episodic memories on the hippocampus. In line with systems consolidation and computational theories of episodic memory, evidence from model organisms suggests that the cornu ammonis 3 (CA3) hippocampal subfield supports recent, but not remote, episodic retrieval. In this study, we demonstrated that recent and remote memories were susceptible to a loss of episodic detail in human participants with focal bilateral damage to CA3. Graph theoretic analyses of 7.0-Tesla resting-state fMRI data revealed that CA3 damage disrupted functional integration across the medial temporal lobe (MTL) subsystem of the default network. The loss of functional integration in MTL subsystem regions was predictive of autobiographical episodic retrieval performance. We conclude that human CA3 is necessary for the retrieval of episodic memories long after their initial acquisition and functional integration of the default network is important for autobiographical episodic memory performance.
Johnson MR, 2020, Re: Time to move beyond genetics towards biomedical data-driven translational genomic research in severe paediatric epilepsies., European Journal of Paediatric Neurology, Vol: 24, Pages: 4-4, ISSN: 1090-3798
Heavin SB, McCormack M, Wolking S, et al., 2019, Genomic and clinical predictors of lacosamide response in refractory epilepsies, Epilepsia Open, Vol: 4, Pages: 563-571, ISSN: 2470-9239
Objective: Clinical and genetic predictors of response to antiepileptic drugs (AEDs) are largely unknown. We examined predictors of lacosamide response in a real-world clinical setting. Methods: We tested the association of clinical predictors with treatment response using regression modeling in a cohort of people with refractory epilepsy. Genetic assessment for lacosamide response was conducted via genome-wide association studies and exome studies, comprising 281 candidate genes. Results: Most patients (479/483) were treated with LCM in addition to other AEDs. Our results corroborate previous findings that patients with refractory genetic generalized epilepsy (GGE) may respond to treatment with LCM. No clear clinical predictors were identified. We then compared 73 lacosamide responders, defined as those experiencing greater than 75% seizure reduction or seizure freedom, to 495 nonresponders (<25% seizure reduction). No variants reached the genome-wide significance threshold in our case-control analysis. Significance: No genetic predictor of lacosamide response was identified. Patients with refractory GGE might benefit from treatment with lacosamide.
Johnson MR, Kaminski RM, 2019, A systems-level framework for anti-epilepsy drug discovery, Neuropharmacology, Vol: 170, Pages: 1-15, ISSN: 0028-3908
Modern anti-seizure drug development yielded benefits in terms of improved pharmacokinetics, safety and tolerability profiles, but offered no advances in efficacy compared to previous older generations of anti-seizure drugs. Despite significant advances in our understanding of the genetic bases to epilepsy, and a welcome renewed interest on the severe monogenic epilepsies, modern genetics has yet to directly inform more effective or disease-modifying anti-seizure drugs. Here, we describe a new approach to the identification of novel disease modifying anti-epilepsy drugs. The systems genetics approach aims to first identify pathophysiological mechanisms by integrating polygenic risk with cellular gene expression profiles and then to relate these molecular mechanisms to druggable targets using a gene regulatory (regulome) framework. The approach offers an exciting and flexible framework for future drug discovery in epilepsy, and is applicable to any disease for which appropriate cell-type and disease-context specific data exist.
Leu C, Stevelink R, Smith AW, et al., 2019, Polygenic burden in focal and generalized epilepsies., Brain, Vol: 142, Pages: 3473-3481
Rare genetic variants can cause epilepsy, and genetic testing has been widely adopted for severe, paediatric-onset epilepsies. The phenotypic consequences of common genetic risk burden for epilepsies and their potential future clinical applications have not yet been determined. Using polygenic risk scores (PRS) from a European-ancestry genome-wide association study in generalized and focal epilepsy, we quantified common genetic burden in patients with generalized epilepsy (GE-PRS) or focal epilepsy (FE-PRS) from two independent non-Finnish European cohorts (Epi25 Consortium, n = 5705; Cleveland Clinic Epilepsy Center, n = 620; both compared to 20 435 controls). One Finnish-ancestry population isolate (Finnish-ancestry Epi25, n = 449; compared to 1559 controls), two European-ancestry biobanks (UK Biobank, n = 383 656; Vanderbilt biorepository, n = 49 494), and one Japanese-ancestry biobank (BioBank Japan, n = 168 680) were used for additional replications. Across 8386 patients with epilepsy and 622 212 population controls, we found and replicated significantly higher GE-PRS in patients with generalized epilepsy of European-ancestry compared to patients with focal epilepsy (Epi25: P = 1.64×10-15; Cleveland: P = 2.85×10-4; Finnish-ancestry Epi25: P = 1.80×10-4) or population controls (Epi25: P = 2.35×10-70; Cleveland: P = 1.43×10-7; Finnish-ancestry Epi25: P = 3.11×10-4; UK Biobank and Vanderbilt biorepository meta-analysis: P = 7.99×10-4). FE-PRS were significantly higher in patients with focal epilepsy compared to controls in the non-Finnish, non-biobank cohorts (Epi25: P = 5.74×10-19; Cleveland: P = 1.69×10-6). European ancestry-derived PRS did not predict generalized epilepsy or focal epilepsy in Japanese-ancestry individuals. Finally, we observed a significant 4.6-fold and a 4.5-fold enrichment of patients with generalized epilepsy compared to controls in the top 0.5% highest GE-PRS of the two non-Finnish Europ
Laaniste L, Srivastava P, Stylianou T, et al., 2019, Integrated systems-genetic analyses reveal a network target for delaying glioma progression, Annals of Clinical and Translational Neurology, Vol: 6, Pages: 1616-1638, ISSN: 2328-9503
ObjectiveTo identify a convergent, multitarget proliferation characteristic for astrocytoma transformation that could be targeted for therapy discovery.MethodsUsing an integrated functional genomics approach, we prioritized networks associated with astrocytoma progression using the following criteria: differential co‐expression between grade II and grade III IDH1‐mutated and 1p/19q euploid astrocytomas, preferential enrichment for genetic risk to cancer, association with patient survival and sample‐level genomic features. Drugs targeting the identified multitarget network characteristic for astrocytoma transformation were computationally predicted using drug transcriptional perturbation data and validated using primary human astrocytoma cells.ResultsA single network, M2, consisting of 177 genes, was associated with glioma progression on the basis of the above criteria. Functionally, M2 encoded physically interacting proteins regulating cell cycle processes and analysis of genome‐wide gene‐regulatory interactions using mutual information and DNA–protein interactions revealed the known regulators of cell cycle processes FoxM1, B‐Myb, and E2F2 as key regulators of M2. These results suggest functional disruption of M2 via gene mutation or altered expression as a convergent pathway regulating astrocytoma transformation. By considering M2 as a multitarget drug target regulating astrocytoma transformation, we identified several drugs that are predicted to restore M2 expression in anaplastic astrocytoma toward its low‐grade profile and of these, we validated the known antiproliferative drug resveratrol as down‐regulating multiple nodes of M2 including at nanomolar concentrations achievable in human cerebrospinal fluid by oral dosing.InterpretationOur results identify M2 as a multitarget network characteristic for astrocytoma progression and encourage M2‐based drug screening to identify new compounds for preventing glioma transformation.
Silvennoinen K, de Lange N, Zagaglia S, et al., 2019, Comparative effectiveness of antiepileptic drugs in juvenile myoclonic epilepsy, Epilepsia Open, Vol: 4, Pages: 420-430, ISSN: 2470-9239
Objective: To study the effectiveness and tolerability of antiepileptic drugs (AEDs) commonly used in juvenile myoclonic epilepsy (JME). Methods: People with JME were identified from a large database of individuals with epilepsy, which includes detailed retrospective information on AED use. We assessed secular changes in AED use and calculated rates of response (12-month seizure freedom) and adverse drug reactions (ADRs) for the five most common AEDs. Retention was modeled with a Cox proportional hazards model. We compared valproate use between males and females. Results: We included 305 people with 688 AED trials of valproate, lamotrigine, levetiracetam, carbamazepine, and topiramate. Valproate and carbamazepine were most often prescribed as the first AED. The response rate to valproate was highest among the five AEDs (42.7%), and significantly higher than response rates for lamotrigine, carbamazepine, and topiramate; the difference to the response rate to levetiracetam (37.1%) was not significant. The rates of ADRs were highest for topiramate (45.5%) and valproate (37.5%). Commonest ADRs included weight change, lethargy, and tremor. In the Cox proportional hazards model, later start year (1.10 [1.08-1.13], P < 0.001) and female sex (1.41 [1.07-1.85], P = 0.02) were associated with shorter trial duration. Valproate was associated with the longest treatment duration; trials with carbamazepine and topiramate were significantly shorter (HR [CI]: 3.29 [2.15-5.02], P < 0.001 and 1.93 [1.31-2.86], P < 0.001). The relative frequency of valproate trials shows a decreasing trend since 2003 while there is an increasing trend for levetiracetam. Fewer females than males received valproate (76.2% vs 92.6%, P = 0.001). Significance: In people with JME, valproate is an effective AED; levetiracetam emerged as an alternative. Valproate is now contraindicated in women of childbearing potential without special precautions. Wi
Feng Y-CA, Howrigan DP, Abbott LE, et al., 2019, Ultra-rare genetic variation in the epilepsies: A whole-exome sequencing study of 17,606 individuals, The American Journal of Human Genetics, Vol: 105, Pages: 267-282, ISSN: 0002-9297
Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABAA receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.
Berghuis B, Stapleton C, Sonsma ACM, et al., 2019, A genome-wide association study of sodium levels and drug metabolism in an epilepsy cohort treated with carbamazepine and oxcarbazepine, Epilepsia Open, Vol: 4, Pages: 102-109, ISSN: 2470-9239
Epilepsia Open published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy. Objective: To ascertain the clinical and genetic factors contributing to carbamazepine- and oxcarbazepine-induced hyponatremia (COIH), and to carbamazepine (CBZ) metabolism, in a retrospectively collected, cross-sectional cohort of people with epilepsy. Methods: We collected data on serum sodium levels and antiepileptic drug levels in people with epilepsy attending a tertiary epilepsy center while on treatment with CBZ or OXC. We defined hyponatremia as Na+ ≤134 mEq/L. We estimated the CBZ metabolic ratio defined as the log transformation of the ratio of metabolite CBZ-diol to unchanged drug precursor substrate as measured in serum. Results: Clinical and genetic data relating to carbamazepine and oxcarbazepine trials were collected in 1141 patients. We did not observe any genome-wide significant associations with sodium level in a linear trend or hyponatremia as a dichotomous trait. Age, sex, number of comedications, phenytoin use, phenobarbital use, and sodium valproate use were significant predictors of CBZ metabolic ratio. No genome-wide significant associations with CBZ metabolic ratio were found. Significance: Although we did not detect a genetic predictor of hyponatremia or CBZ metabolism in our cohort, our findings suggest that the determinants of CBZ metabolism are multifactorial.
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