Familial Epilepsy Syndrome Research Articles

Familial mesial temporal lobe epilepsy phenotype is associated with novel LGI1 variants: A report of two families

ObjectiveTo expand the clinical phenotype and mutation spectrum of familial mesial temporal lobe epilepsy (FMTLE) and provide a new perspective for exploring the pathological mechanisms of epilepsy caused by leucine-rich glioma inactivated 1 (LGI1) variants. MethodsWe reported clinical data from two families with FMTLE and screened patients for variants in the LGI1 gene using Whole-exome sequencing and Sanger sequencing. The clinical features of FMTLE were analysed. The pathogenicity of the causative loci was assessed according to the American College of Medical Genetics and Genomics guidelines, and potential pathogenic mechanisms were predicted through multiple bioinformatics and molecular dynamics software. ResultsWe identified two novel LGI1 truncating variants within two large families with FMTLE: LGI1 (c.1174C>T, p.Q392X) and LGI1 (c.703C>T, p.Q235X). Compared to previous reports, we found that focal to bilateral tonic-clonic seizures are a common type of seizure in FMTLE. The clinical phenotypes of patients with FMTLE caused by LGI1 variants were relatively mild, and all patients responded well to valproic acid. Bioinformatics analyses and molecular dynamics simulations showed that protein structure and interactions were considerably weakened or damaged as a result of both variants. ConclusionThis study presents the first report identifying LGI1 as a potential novel pathogenic gene within FMTLE families, thereby broadening the mutation spectrum associated with FMTLE. The findings of this study offer novel insights and avenues for understanding the intricate molecular mechanisms underlying LGI1 variants and their correlations with patient phenotypes. This study proposes the possibility of familial focal epilepsy syndromes overlapping.

“Fifth‐day fits” revisited: A literature review of benign idiopathic neonatal seizures and comparison with KCNQ2‐ and KCNQ3‐associated benign familial epilepsy syndromes

AbstractBenign idiopathic neonatal seizures (BINS), colloquially referred to as the “fifth‐day fits,” is a clinical neonatal epilepsy syndrome associated with early, spontaneous resolution of seizures and favorable developmental outcome. Although this disease entity was first described over four decades ago, the etiopathogenesis remains unknown, and it is unclear if the syndrome represents a single, cohesive disorder or a common manifestation of various unrelated neonatal neurological disturbances. As such, there are no standardized approaches to diagnostic workup and management. Benign familial neonatal seizures (BFNS) is a well‐characterized genetic syndrome associated with KCNQ2 and KCNQ3 pathogenic variants, which also manifests clinically with self‐resolving seizures in the neonatal period. While it remains unclear if there is any shared pathogenesis between these two disorders, the exceedingly similar phenotypic presentations and natural history raise the question of whether consensus management approaches used in genetic BFNS can also be applied to BINS. Here, we present a topical and historical review of BINS and BFNS literature and propose specific treatment recommendations based on extrapolation of limited existing clinical data.

ILAE Genetic Literacy Series: Self-limited familial epilepsy syndromes with onset in neonatal age and infancy.

The self-limited (familial) epilepsies with onset in neonates or infants, formerly called benign familial neonatal and/or infantile epilepsies, are autosomal dominant disorders characterized by neonatal- or infantile-onset focal motor seizures and the absence of neurodevelopmental complications. Seizures tend to remit during infancy or early childhood and are therefore called "self-limited". A positive family history for epilepsy usually suggests the genetic etiology, but incomplete penetrance and de novo inheritance occur. Here, we review the phenotypic spectrum and the genetic architecture of self-limited (familial) epilepsies with onset in neonates or infants. Using an illustrative case study, we describe important clues in recognition of these syndromes, diagnostic steps including genetic testing, management, and genetic counseling.

A founder event causing a dominant childhood epilepsy survives 800 years through weak selective pressure

Genetic epilepsy with febrile seizures plus (GEFS+) is an autosomal dominant familial epilepsy syndrome characterized by distinctive phenotypic heterogeneity within families. The SCN1B c.363C>G (p.Cys121Trp) variant has been identified in independent, multi-generational families with GEFS+. Although the variant is present in population databases (at very low frequency), there is strong clinical, genetic, and functional evidence to support pathogenicity. Recurrent variants may be due to a founder event in which the variant has been inherited from a common ancestor. Here, we report evidence of a single founder event giving rise to the SCN1B c.363C>G variant in 14 independent families with epilepsy. A common haplotype was observed in all families, and the age of the most recent common ancestor was estimated to be approximately 800 years ago. Analysis of UK Biobank whole-exome-sequencing data identified 74 individuals with the same variant. All individuals carried haplotypes matching the epilepsy-affected families, suggesting all instances of the variant derive from a single mutational event. This unusual finding of a variant causing an autosomal dominant, early-onset disease in an outbred population that has persisted over many generations can be attributed to the relatively mild phenotype in most carriers and incomplete penetrance. Founder events are well established in autosomal recessive and late-onset disorders but are rarely observed in early-onset, autosomal dominant diseases. These findings suggest variants present in the population at low frequencies should be considered potentially pathogenic in mild phenotypes with incomplete penetrance and may be more important contributors to the genetic landscape than previously thought.

Genetic Epilepsy Syndromes.

This article reviews the clinical features, typical EEG findings, treatment, prognosis, and underlying molecular etiologies of the more common genetic epilepsy syndromes. Genetic generalized epilepsy, self-limited focal epilepsy of childhood, self-limited neonatal and infantile epilepsy, select developmental and epileptic encephalopathies, progressive myoclonus epilepsies, sleep-related hypermotor epilepsy, photosensitive occipital lobe epilepsy, and focal epilepsy with auditory features are discussed. Also reviewed are two familial epilepsy syndromes: genetic epilepsy with febrile seizures plus and familial focal epilepsy with variable foci. Recent years have seen considerable advances in our understanding of the genetic factors underlying genetic epilepsy syndromes. New therapies are emerging for some of these conditions; in some cases, these precision medicine approaches may dramatically improve the prognosis. Many recognizable genetic epilepsy syndromes exist, the identification of which is a crucial skill for neurologists, particularly those who work with children. Proper diagnosis of the electroclinical syndrome allows for appropriate treatment choices and counseling regarding prognosis and possible comorbidities.

ILAE Genetic Literacy Series: familial focal epilepsy syndromes.

There are a number of familial focal epilepsy syndromes, each with distinct clinical characteristics. Here, we review the epilepsy phenotypes and the genetic architecture of these syndromes. Using an illustrative clinical case, we describe the important steps in making a diagnosis and ordering appropriate genetic tests. Our discussion on the genetics of the familial focal epilepsies will provide a framework for interpreting the results of genetic testing, and allow us to apply this information to patient management.

MRI-guided laser interstitial thermal therapy using the Visualase system and Navigus frameless stereotaxy in an infant: technical case report.

Laser interstitial thermal therapy (LITT) is increasingly used as a surgical option for the treatment of epilepsy. Placement of the laser fibers relies on stereotactic navigation with cranial fixation pins. In addition, the laser fiber is stabilized in the cranium during the ablation using a cranial bolt that assumes maturity of the skull. Therefore, younger infants (< 2 years of age) have traditionally not been considered as candidates for LITT. However, LITT is an appealing option for patients with familial epilepsy syndromes, such as tuberous sclerosis complex (TSC), due to the multiplicity of lesions and the likely need for multiple procedures. A 4-month-old infant with TSC presented with refractory focal seizures despite receiving escalating doses of 5 antiepileptic medications. Electrographic and clinical seizures occurred numerous times daily. Noninvasive evaluations, including MRI, magnetoencephalography, scalp EEG, and SPECT, localized the ictal onset to a left frontal cortical tuber in the premotor area. In this paper, the authors report a novel technique to overcome the challenges of performing LITT in an infant with an immature skull by repurposing the Navigus biopsy skull mount for stereotactic placement of a laser fiber using electromagnetic-based navigation. The patient underwent successful ablation of the tuber and remained seizure free 4 months postoperatively. To the authors' knowledge, this is the youngest reported patient to undergo LITT. A safe method is described to perform LITT in an infant using commonly available tools without dedicated instrumentation beyond standard stereotactic navigation, a biopsy platform, and the Visualase system.

SCN1B Gene: A Close Relative to SCN1A

AbstractOne of the first reported genes associated with epilepsy was SCN1B, which encodes for β-subunit of voltage-gated sodium channel of excitable cells and it is critical for neuronal function in both central and peripheral nervous system. β-subunits modulate the expression levels and functional properties of sodium channels and though their immunoglobulin domains may mediate interactions between channels and other proteins. Traditionally, SCN1B mutations were associated with generalized epilepsy with febrile seizures plus, a familial epilepsy syndrome characterized by heterogeneous phenotypes including febrile seizures (FS), febrile seizures plus (FS + ), mild generalized epilepsies, and severe epileptic encephalopathies. Throughout the years, SCN1B mutations have been also associated with Dravet syndrome and, more recently, with developmental and epileptic encephalopathies, expanding the spectrum associated with this gene mutations to more severe phenotypes.

Copy number variation in genetic epilepsy with febrile seizures plus.

Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which affected individuals may have a variety of epilepsy phenotypes, the most common being febrile seizures (FS) and febrile seizures plus (FS+). We investigated the possible contribution of copy number variation to GEFS+. We searched our epilepsy research database for patients in GEFS+families who underwent chromosomal microarray analysis. We reviewed the clinical features and results of genetic testing in these families. Of twelve families with available microarray data, four had at least one copy number variant (CNV) identified. In Family 1, the proband had a maternally-inherited 15q11.2 deletion. In Family 5, four different CNVs were identified, variably present in the affected individuals; this included a 19p13.3 deletion affecting CACNA1A. Finally, in both Families 9 and 10, the proband had Dravet syndrome with pathogenic SCN1A variant, as well as a CNV (10q11.22 duplication in Family 9 and 22q11.2 deletion in Family 10). The significance of these specific variants is difficult to precisely determine; however, there appeared to be an overrepresentation of CNVs in this small cohort. These findings suggest chromosomal microarray analysis could have clinical utility as part of the workup in GEFS+families.

Association Analysis of Interleukin-1β, Interleukin-6, and HMGB1 Variants with Postictal Serum Cytokine Levels in Children with Febrile Seizure and Generalized Epilepsy with Febrile Seizure Plus.

Background and PurposeFebrile seizure (FS) is a unique type of seizure that only occurs during childhood. Genelized epilepsy with febrile seizure plus (GEFS+) is a familial epilepsy syndrome associated with FS and afebrile seizure (AFS). Both seizure types are related to fever, but whether genetic susceptibility to inflammation is implicated in them is still unclear. To analyze the associations between postictal serum cytokine levels and genetic variants in the cytokine genes interleukin (IL)-1β, IL-6, and high mobility group box-1 (HMGB1) in FS and GEFS+.MethodsGenotyping was performed in 208 subjects (57 patients with FS, 43 patients with GEFS+, and 108 controls) with the SNaPshot assay for IL-1β-31 (rs1143627), IL-1β-511 (rs16944), IL-6-572 (rs1800796), and HMGB1 3814 (rs2249825). Serum IL-1β, IL-6, and HMGB1 levels were analyzed within 2 hours after seizure attacks using the ELISA in only 68 patients (38 FS, 10 GEFS+, and 20 controls). The allele distribution, genotype distribution, and correlations with serum cytokine levels were analyzed.ResultsNear-complete linkage disequilibrium exists between IL-1β-31 and IL-1β-511 variants. CT genotypes of these variants were associated with significantly higher postictal serum IL-1β levels than were CC+TT genotypes in FS (both p<0.05). CT genotypes of IL-1β-31 and IL-1β-511 variants were more strongly associated with FS than were CC+TT genotypes (odds ratio=1.691 and 1.731, respectively). For GEFS+, serum IL-1β levels after AFS for CT genotypes of IL-1β-31 and IL-1β-511 were also higher than for CC+TT genotypes. No significant associations were found for IL-6 and HMGB1.ConclusionsGenetic variants located in IL-1β-31 and IL-1β-511 promotor regions are correlated with higher postictal IL-1β levels in FS. These results suggest that IL-1 gene cluster variants in IL-1β-31 and IL-1β-511 are a host genetic factor for provoking FS in Korean children.

Genetic literacy series: genetic epilepsy with febrile seizures plus.

Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which affected individuals within a family typically have a variety of epilepsy phenotypes, varying from simple febrile seizures and febrile seizures plus with a good outcome to severe epileptic encephalopathies. Here, we review the spectrum of epilepsy phenotypes, the genetic architecture of GEFS+, and the implicated genes. Using an illustrative clinical case study, we describe important steps in managing patients with GEFS+: making the diagnosis of GEFS+, appropriate genetic testing, and counselling.

Study of candidate gene cHRNA4 for familial epilepsy syndrome.

To screen a three-generation familial partial epilepsy with variable foci (FPEVF) family with epilepsy to identify the cHRNA4 gene (a candidate gene). A total of 18 members of the three-generation FPEVF family with partial epilepsy were selected, and 18 blood samples were collected for investigation. Among them, five members were affected by epilepsy, and another 13 members were not affected. A pedigree chart was mapped to comprehensively analyze the clinical characteristics of each member, including ictal semiology, electroencephalogram (EEG), past medical history, MRI features, neuropsychological MMSE (mini-mental state examination) scores, etc. PCR and Sanger sequencing method were used to screen the mutant gene cHRNA4. cHRNA4 genes of all affected members were positively mutated, and that of the unaffected members were negative. The positive mutation was base A instead of base G. cHRNA4 is the causative gene of FPEVF, and genes of the affected members are all heterozygotes mutations.

Epilepsy syndromes during the first year of life and the usefulness of an epilepsy gene panel.

Recent advances in genetics have determined that a number of epilepsy syndromes that occur in the first year of life are associated with genetic etiologies. These syndromes range from benign familial epilepsy syndromes to early-onset epileptic encephalopathies that lead to poor prognoses and severe psychomotor retardation. An early genetic diagnosis can save time and overall cost by reducing the amount of time and resources expended to reach a diagnosis. Furthermore, a genetic diagnosis can provide accurate prognostic information and, in certain cases, enable targeted therapy. Here, several early infantile epilepsy syndromes with strong genetic associations are briefly reviewed, and their genotype-phenotype correlations are summarized. Because the clinical presentations of these disorders frequently overlap and have heterogeneous genetic causes, next-generation sequencing (NGS)-based gene panel testing represents a more powerful diagnostic tool than single gene testing. As genetic information accumulates, genetic testing will likely play an increasingly important role in diagnosing pediatric epilepsy. However, the efforts of clinicians to classify phenotypes in nondiagnosed patients and improve their ability to interpret genetic variants remain important in the NGS era.

Phenotypic analysis of 303 multiplex families with common epilepsies.

Gene identification in epilepsy has mainly been limited to large families segregating genes of major effect and de novo mutations in epileptic encephalopathies. Many families that present with common non-acquired focal epilepsies and genetic generalized epilepsies remain unexplained. We assembled a cohort of 'genetically enriched' common epilepsies by collecting and phenotyping families containing multiple individuals with unprovoked seizures. We aimed to determine if specific clinical epilepsy features aggregate within families, and whether this segregation of phenotypes may constitute distinct 'familial syndromes' that could inform genomic analyses. Families with three or more individuals with unprovoked seizures were studied across multiple international centres. Affected individuals were phenotyped and classified according to specific electroclinical syndromes. Families were categorized based on syndromic groupings of affected family members, examined for pedigree structure and phenotypic patterns and, where possible, assigned specific familial epilepsy syndromes. A total of 303 families were assembled and analysed, comprising 1120 affected phenotyped individuals. Of the 303 families, 117 exclusively segregated generalized epilepsy, 62 focal epilepsy, and 22 were classified as genetic epilepsy with febrile seizures plus. Over one-third (102 families) were observed to have mixed epilepsy phenotypes: 78 had both generalized and focal epilepsy features within the same individual (n = 39), or within first or second degree relatives (n = 39). Among the genetic generalized epilepsy families, absence epilepsies were found to cluster within families independently of juvenile myoclonic epilepsy, and significantly more females were affected than males. Of the 62 familial focal epilepsy families, two previously undescribed familial focal syndrome patterns were evident: 15 families had posterior quadrant epilepsies, including seven with occipito-temporal localization and seven with temporo-parietal foci, and four families displayed familial focal epilepsy of childhood with multiple affected siblings that was suggestive of recessive inheritance. The findings suggest (i) specific patterns of syndromic familial aggregation occur, including newly recognized forms of familial focal epilepsy; (ii) although syndrome-specificity usually occurs in multiplex families, the one-third of families with features of both focal and generalized epilepsy is suggestive of shared genetic determinants; and (iii) patterns of features observed across families including pedigree structure, sex, and age of onset may hold clues for future gene identification. Such detailed phenotypic information will be invaluable in the conditioning and interpretation of forthcoming sequencing data to understand the genetic architecture and inter-relationships of the common epilepsy syndromes.

DEPDC5 mutations in familial and sporadic focal epilepsy.

Mutations in the disheveled, Egl-10 and pleckstrin domain-containing protein 5 (DEPDC5) gene have emerged as an important cause of various familial focal epilepsy syndromes. However, the significance of DEPDC5 mutations in patients with sporadic focal epilepsy has yet to be characterized. We studied a kindred of familial focal epilepsy with variable foci using whole-exome sequencing. We subsequently studied a cohort of 293 patients with focal epilepsy and sequenced all exons of DEPDC5 using targeted resequencing. We reported a Taiwanese family with a novel splice site mutation which affected mRNA splicing and activated the downstream mammalian target of rapamycin (mTOR) pathway. Among patients with focal epilepsies, the majority (220/293) of these patients had sporadic focal epilepsy without malformation of cortical development. Two (0.9%) of these patients had probably pathogenic mutations in the DEPDC5 gene. Our finding suggests that DEPDC5 is not only the most common gene for familial focal epilepsy but also could be a significant gene for sporadic focal epilepsy. Since focal epilepsies account for more than 60% of all epilepsies, the effect of mTORC1 inhibitor on patients with focal epilepsy due to DEPDC5 mutations will be an important future direction of research.

De novo SCN1A pathogenic variants in the GEFS+ spectrum: Not always a familial syndrome.

Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome characterized by heterogeneous phenotypes ranging from mild disorders such as febrile seizures to epileptic encephalopathies (EEs) such as Dravet syndrome (DS). Although DS often occurs with de novo SCN1A pathogenic variants, milder GEFS+ spectrum phenotypes are associated with inherited pathogenic variants. We identified seven cases with non-EE GEFS+ phenotypes and de novo SCN1A pathogenic variants, including a monozygotic twin pair. Febrile seizures plus (FS+) occurred in six patients, five of whom had additional seizure types. The remaining case had childhood-onset temporal lobe epilepsy without known febrile seizures. Although early development was normal in all individuals, three later had learning difficulties, and the twin girls had language impairment and working memory deficits. All cases had SCN1A missense pathogenic variants that were not found in either parent. One pathogenic variant had been reported previously in a case of DS, and the remainder were novel. Our finding of de novo pathogenic variants in mild phenotypes within the GEFS+ spectrum shows that mild GEFS+ is not always inherited. SCN1A screening should be considered in patients with GEFS+ phenotypes because identification of pathogenic variants will influence antiepileptic therapy, and prognostic and genetic counseling.

Novel LGI1 mutation in a Japanese autosomal dominant lateral temporal lobe epilepsy family

Autosomal dominant lateral temporal lobe epilepsy (ADLTE) is a rare familial focal epilepsy syndrome with auditory features1. The leucine-rich glioma inactivated 1 (LGI1) was identified as a causative gene. About 40 LGI1 mutations have been reported1-7. Disease mechanisms caused by LGI1 mutations haven't been fully clarified. Accumulation of case reports with detailed descriptions will contribute to elucidate the mechanisms. Here we describe a novel LGI1 mutation identified in the new Japanese family (Fig. 1A). This article is protected by copyright. All rights reserved.

Multiplex families with epilepsy

To analyze the clinical syndromes and inheritance patterns of multiplex families with epilepsy toward the ultimate aim of uncovering the underlying molecular genetic basis. Following the referral of families with 2 or more relatives with epilepsy, individuals were classified into epilepsy syndromes. Families were classified into syndromes where at least 2 family members had a specific diagnosis. Pedigrees were analyzed and molecular genetic studies were performed as appropriate. A total of 211 families were ascertained over an 11-year period in Israel. A total of 169 were classified into broad familial epilepsy syndrome groups: 61 generalized, 22 focal, 24 febrile seizure syndromes, 33 special syndromes, and 29 mixed. A total of 42 families remained unclassified. Pathogenic variants were identified in 49/211 families (23%). The majority were found in established epilepsy genes (e.g., SCN1A, KCNQ2, CSTB), but in 11 families, this cohort contributed to the initial discovery (e.g., KCNT1, PCDH19, TBC1D24). We expand the phenotypic spectrum of established epilepsy genes by reporting a familial LAMC3 homozygous variant, where the predominant phenotype was epilepsy with myoclonic-atonic seizures, and a pathogenic SCN1A variant in a family where in 5 siblings the phenotype was broadly consistent with Dravet syndrome, a disorder that usually occurs sporadically. A total of 80% of families were successfully classified, with pathogenic variants identified in 23%. The successful characterization of familial electroclinical and inheritance patterns has highlighted the value of studying multiplex families and their contribution towards uncovering the genetic basis of the epilepsies.

Myoclonic occipital photosensitive epilepsy with dystonia (MOPED): A familial epilepsy syndrome

To describe clinical and EEG phenotypes of a family with an unusual familial epilepsy syndrome characterized by myoclonus and dystonia. Family members underwent electroclinical phenotyping including review of EEGs and MRI. DNA from family members was genotyped using Illumina OmniExpress genotyping arrays. Parametric and nonparametric linkage analyses were performed using MERLIN. The disorder followed autosomal dominant (AD) inheritance and affected seven individuals over two generations. Seizures began at a mean of 14.5 years. Six individuals had spontaneous myoclonic seizures, of which five also had photic-induced myoclonus and four had photic-induced occipital seizures. Six individuals had convulsive seizures; generalized in two and focal in four. Photosensitivity was prominent with generalized spike wave and polyspike wave in four individuals of which two also had occipital spikes. MRI scans were normal in the four individuals tested. Extensive metabolic investigation was normal. Juvenile myoclonic epilepsy (JME) occurred in two; and JME overlapping with idiopathic photosensitive epilepsy (IPOE) in four individuals. All three affected males had a more severe disorder than the four affected females. Two males had a progressive neurological disorder with progressive myoclonus epilepsy and deterioration in their early 30s. They developed episodes of paroxysmal cervical dystonia with cognitive decline during periods of poor seizure control. One plateaued after years of poor seizure control but remained intractable with periods of deterioration. The other deteriorated with episodes of status dystonicus and status epilepticus, ataxia and a progressive ophthalmoplegia before succumbing at 38 years. Parametric linkage analysis identified three peaks achieving a maximum LOD score of 1.21. Nonparametric analysis identified eight peaks achieving LOD scores above 0.80. These were not statistically significant. This is a novel autosomal dominant familial epilepsy syndrome. "Myoclonic occipital photosensitive epilepsy with dystonia" (MOPED) involves a spectrum of phenotypes from JME, sometimes with an IPOE overlap, to progressive myoclonus epilepsy with paroxysmal dystonia.

Identifying the biological pathways underlying human focal epilepsy: from complexity to coherence to centrality.

Numerous diverse biological pathways are dysregulated in the epileptic focus. Which of these pathways are most critical in producing the biological abnormalities that lead to epilepsy? Answering this question is key to identifying the primary causes of epilepsy and for discovering new therapeutic strategies with greater efficacy than currently available antiepileptics (AEDs). We have performed the largest genome-wide transcriptomic analysis to date comparing epileptic with normal human hippocampi. We have identified 118 differentially expressed and, for the first time, differentially connected pathways in the epileptic focus. Using network mapping techniques, we have shown that these dysregulated pathways, though seemingly disparate, form a coherent interconnected central network. Using closeness centrality analysis, we have identified that the most influential hub pathways in this network are signalling through G protein-coupled receptors, in particular opioid receptors, and their downstream effectors PKA/CREB and DAG/IP3. Next, we have objectively demonstrated that genetic association of gene sets in independent genome-wide association studies (GWASs) can be used to identify causally relevant gene sets: we show that proven causal epilepsy genes, which cause familial Mendelian epilepsy syndromes, are associated in published sporadic epilepsy GWAS results. Using the same technique, we have shown that central pathways identified (opioid receptor and PKA/CREB and DAG/IP3 signalling pathways) are genetically associated with focal epilepsy and, hence, likely causal. Published functional studies in animal models provide evidence of a role for these pathways in epilepsy. Our work shows that these pathways play a central role in human focal epilepsy and that they are important currently unexploited antiepileptic drug targets.