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ZusammenfassungDie genetische Diagnostik bei an Epilepsie erkrankten Personen ist inzwischen weit verbreitet und unstrittig sinnhaft geworden. Die Kenntnis einer genetischen Ätiologie kann die Identifikation der Diagnose, genetische Beratung, Therapie und Prognoseeinschätzung der Grunderkrankung maßgeblich unterstützen. Methoden der Hochdurchsatz-Sequenzierung erlauben inzwischen eine rasche, umfassende und kosteneffektive Diagnostik. Diese aktuellen Empfehlungen der Kommission „Epilepsie und Genetik“ der Deutschen Gesellschaft für Epileptologie (DGfE) bauen auf den Empfehlungen der International League Against Epilepsie (ILAE) Commission on Genetics auf. Wir bieten einen praxisnahen Überblick über die Indikationsstellung, praktische Umsetzung, Befundbewertung, und Möglichkeiten der Präzisionsmedizin.

Mobile Apps (Applikationen) fur das Smartphone machen es moglich, Beschwerden und Krankheiten zu monitoren, sie zu behandeln und Komplikationen insbesondere durch Non-Compliance und fehlende Adharenz vorzubeugen. Es wird ein Uberblick uber den derzeitigen Status von Apps im Gesundheitswesen im Hinblick auf ihre Einsatzmoglichkeiten in der Behandlung von Menschen mit Epilepsie gegeben.

We present a female patient in her early twenties with global development delay, progressive ataxia, epilepsy, and myoclonus caused by a stop mutation in the SEMA6B gene. Truncating DNA variants located in the last exon of SEMA6B have recently been identified as a cause of autosomal dominant progressive myoclonus epilepsy. In many cases, myoclonus in the context of progressive myoclonic epilepsy is refractory to medical treatment. In the present case, treatment with zonisamide caused clinical improvement, particularly of positive and negative truncal myoclonus, considerably improving patient’s gait and thus mobility.

Summary More than 100 genetic etiologies have been identified in developmental and epileptic encephalopathies (DEEs), but correlating genetic findings with clinical features at scale has remained a hurdle because of a lack of frameworks for analyzing heterogenous clinical data. Here, we analyzed 31,742 Human Phenotype Ontology (HPO) terms in 846 individuals with existing whole-exome trio data and assessed associated clinical features and phenotypic relatedness by using HPO-based semantic similarity analysis for individuals with de novo variants in the same gene. Gene-specific phenotypic signatures included associations of SCN1A with “complex febrile seizures” (HP: 0011172; p = 2.1 × 10−5) and “focal clonic seizures” (HP: 0002266; p = 8.9 × 10−6), STXBP1 with “absent speech” (HP: 0001344; p = 1.3 × 10−11), and SLC6A1 with “EEG with generalized slow activity” (HP: 0010845; p = 0.018). Of 41 genes with de novo variants in two or more individuals, 11 genes showed significant phenotypic similarity, including SCN1A (n = 16, p < 0.0001), STXBP1 (n = 14, p = 0.0021), and KCNB1 (n = 6, p = 0.011). Including genetic and phenotypic data of control subjects increased phenotypic similarity for all genetic etiologies, whereas the probability of observing de novo variants decreased, emphasizing the conceptual differences between semantic similarity analysis and approaches based on the expected number of de novo events. We demonstrate that HPO-based phenotype analysis captures unique profiles for distinct genetic etiologies, reflecting the breadth of the phenotypic spectrum in genetic epilepsies. Semantic similarity can be used to generate statistical evidence for disease causation analogous to the traditional approach of primarily defining disease entities through similar clinical features.

Chatron et al. describe a novel syndrome caused by bi-allelic loss-of-function mutations in GAD1, the gene encoding the GABA synthetic enzyme GAD67. The syndrome is characterized by the unique association of developmental and epileptic encephalopathy, cleft palate, joint contractures and/or omphalocele., Developmental and epileptic encephalopathies are a heterogeneous group of early-onset epilepsy syndromes dramatically impairing neurodevelopment. Modern genomic technologies have revealed a number of monogenic origins and opened the door to therapeutic hopes. Here we describe a new syndromic developmental and epileptic encephalopathy caused by bi-allelic loss-of-function variants in GAD1, as presented by 11 patients from six independent consanguineous families. Seizure onset occurred in the first 2 months of life in all patients. All 10 patients, from whom early disease history was available, presented with seizure onset in the first month of life, mainly consisting of epileptic spasms or myoclonic seizures. Early EEG showed suppression-burst or pattern of burst attenuation or hypsarrhythmia if only recorded in the post-neonatal period. Eight patients had joint contractures and/or pes equinovarus. Seven patients presented a cleft palate and two also had an omphalocele, reproducing the phenotype of the knockout Gad1−/− mouse model. Four patients died before 4 years of age. GAD1 encodes the glutamate decarboxylase enzyme GAD67, a critical actor of the γ-aminobutyric acid (GABA) metabolism as it catalyses the decarboxylation of glutamic acid to form GABA. Our findings evoke a novel syndrome related to GAD67 deficiency, characterized by the unique association of developmental and epileptic encephalopathies, cleft palate, joint contractures and/or omphalocele.

Pathogenic missense variants in GRIN2A and GRIN2B may result in gain or loss of function (GoF/LoF) of the N-methyl-D-aspartate receptor (NMDAR). This observation gave rise to the hypothesis of successfully treating GRIN-related disorders due to LoF variants with co-agonists of the NMDAR. In this respect, we describe a retrospectively collected series of ten individuals with GRIN2A- or GRIN2B-related disorders who were treated with L-serine, each within an independent n-of-1 trial. Our cohort comprises one individual with a LoF missense variant with clinical improvements confirming the above hypothesis and replicating a previous n-of-1 trial. A second individual with a GoF missense variant was erroneously treated with L-serine and experienced immediate temporary behavioral deterioration further supporting the supposed functional pathomechanism. Eight additional individuals with null variants (that had been interpreted as loss-of-function variants despite not being missense) again showed clinical improvements. Among all nine individuals with LoF missense or null variants, L-serine treatment was associated with improvements in behavior in eight (89%), in development in four (44%), and/or in EEG or seizure frequency in four (44%). None of these nine individuals experienced side effects or adverse findings in the context of L-serine treatment. In summary, we describe the first evidence that L-serine treatment may not only be associated with clinical improvements in GRIN-related disorders due to LoF missense but particularly also null variants.

The 2-oxoglutarate dehydrogenase-like (OGDHL) protein is a rate-limiting enzyme in the Krebs cycle that plays a pivotal role in mitochondrial metabolism. OGDHL expression is restricted mainly to the brain in humans. Here, we report nine individuals from eight unrelated families carrying bi-allelic variants in OGDHL with a range of neurological and neurodevelopmental phenotypes including epilepsy, hearing loss, visual impairment, gait ataxia, microcephaly, and hypoplastic corpus callosum. The variants include three homozygous missense variants (p.Pro852Ala, p.Arg244Trp, and p.Arg299Gly), three compound heterozygous single-nucleotide variants (p.Arg673Gln/p.Val488Val, p.Phe734Ser/p.Ala327Val, and p.Trp220Cys/p.Asp491Val), one homozygous frameshift variant (p.Cys553Leufs∗16), and one homozygous stop-gain variant (p.Arg440Ter). To support the pathogenicity of the variants, we developed a novel CRISPR-Cas9-mediated tissue-specific knockout with cDNA rescue system for dOgdh, the Drosophila ortholog of human OGDHL. Pan-neuronal knockout of dOgdh led to developmental lethality as well as defects in Krebs cycle metabolism, which was fully rescued by expression of wild-type dOgdh. Studies using the Drosophila system indicate that p.Arg673Gln, p.Phe734Ser, and p.Arg299Gly are severe loss-of-function alleles, leading to developmental lethality, whereas p.Pro852Ala, p.Ala327Val, p.Trp220Cys, p.Asp491Val, and p.Arg244Trp are hypomorphic alleles, causing behavioral defects. Transcript analysis from fibroblasts obtained from the individual carrying the synonymous variant (c.1464T>C [p.Val488Val]) in family 2 showed that the synonymous variant affects splicing of exon 11 in OGDHL. Human neuronal cells with OGDHL knockout exhibited defects in mitochondrial respiration, indicating the essential role of OGDHL in mitochondrial metabolism in humans. Together, our data establish that the bi-allelic variants in OGDHL are pathogenic, leading to a Mendelian neurodevelopmental disease in humans.

Background Lafora progressive myoclonus epilepsy (Lafora disease) is a rare, usually childhood-onset, fatal neurodegenerative disease caused by biallelic mutations in EPM2A (Laforin) or EPM2B (NHLRC1; Malin). The epidemiology of Lafora disease in Germany is largely unknown. The objective of this retrospective case series is to characterize the genotypes and phenotypes of patients with Lafora disease living in Germany. Methods The patients described in this case series initially had the suspected clinical diagnosis of Lafora disease, or unclassified progressive myoclonus epilepsy. Molecular genetic diagnostics including next generation sequencing-based diagnostic panel analysis or whole exome sequencing was performed. Results The parents of four out of the 11 patients are nonconsanguineous and of German origin while the other patients had consanguineous parents. Various variants were found in EPM2A (six patients) and in EPM2B (five patients). Eight variants have not been reported in the literature so far. The patients bearing novel variants had typical disease onset during adolescence and show classical disease courses. Conclusions This is the first larger case series of Lafora patients in Germany. Our data enable an approximation of the prevalence of manifest Lafora disease in Germany to 1,69 per 10 million people. Broader application of gene panel or whole-exome diagnostics helps clarifying unclassified progressive myoclonus epilepsy and establish an early diagnosis, which will be even more important as causal therapy approaches have been developed and are soon to be tested in a phase I study.

Zusammenfassung Fragestellung Ziel der prospektiven, multizentrischen Studie ist die Erfassung klinischer Charakteristika, des Ressourcenverbrauches sowie der Lebensqualität bei Patienten mit der Diagnose eines Dravet-Syndroms (DS) und deren Eltern in Deutschland. Methoden Die Datenerhebung erfolgte mit einem validierten retrospektiven Fragebogen über 3 bzw. 12 Monate sowie mit einem prospektiven Tagebuch über 3 Monate. Es wurden Daten zur Anfallssituation, Medikamenteneinnahme, Therapieinanspruchnahme sowie zu direkten und indirekten Kosten und zur Lebensqualität erhoben. Die Fragebögen und das Tagebuch wurden den Eltern über den Dravet-Syndrom e. V. sowie beteiligte Zentren ausgehändigt. Ergebnisse Der Fragebogen wurde von 93 Eltern der DS-Patienten und das Tagebuch von 77 ausgefüllt. Das mittlere Alter der Patienten betrug 10 Jahre (Spannweite 15 Monate bis 33,7 Jahre). Die Zeit bis zur Syndromdiagnose eines DS war in den letzten beiden Jahrzehnten deutlich kürzer. In den letzten 12 Monaten ereignete sich bei 95 % der Patienten mindestens ein epileptischer Anfall. Als anfallsauslösende Faktoren wurden Fieber (93,4 %), Aufregung (56 %), Schlafmangel (51,6 %) und starke körperliche Anstrengung (50,5 %) berichtet. Die Lebenszeitprävalenz des Status epilepticus lag bei 77 %, und bei 28 % war mindestens 1 Episode eines Status epilepticus innerhalb des letzten Jahres aufgetreten. Die Lebensqualität (QoL) der Patienten war niedriger als die der Allgemeinbevölkerung, und von 46 % der Eltern wurden Depressionssymptome berichtet. Die direkten Kosten in 3 Monaten betrugen 6043 € pro Patient. Den größten Kostenfaktor stellten die stationären Kosten dar (1702 €), gefolgt von den Leistungen für Pflege (1130 €), den Kosten für die antikonvulsiven Medikamente (892 €) und für Therapien (559 €). Bei den Müttern betrugen die gesamten indirekten Kosten 4399 € und bei den Vätern 391 € bezogen auf 3 Monate. Schlussfolgerung Das Dravet-Syndrom ist mit häufigen, oft therapierefraktären epileptischen Anfällen und Status epilepticus vergesellschaftet. Diese Studie zeigt die erhebliche Krankheitslast und die damit verbundenen Einschränkungen in der Lebensqualität sowie die hohen direkten und indirekten Kosten auf. Um eine Verbesserung der Lebensqualität bei Patienten mit DS und deren Eltern zu erreichen, bedarf es neuer Therapie- und Versorgungskonzepte.

Objective The aim of this study was to describe the treatment pattern of patients with Dravet syndrome (DS) in Germany with routine antiepileptic drugs (AEDs) and emergency medication, and to review the literature of real-world evidence on medicine utilization of patients with DS in Europe. Methods Patient use of routine AEDs and emergency medications over 3–6 months was analyzed from a 2018 multicenter survey of 93 caregivers of patients with DS throughout Germany. Results were contextualized in a review of real-world evidence on medicine utilization of patients with DS in Europe. Results The variety of medications and the most frequent combinations routinely used by patients with DS (AEDs and others) are described. Patients use a large number of pharmaceutical treatments to manage seizures. The five most commonly used AEDs were sodium valproate (66% of the patients; mean daily dose: 660 mg; 24.5 mg per kg bodyweight), bromide (44%; 1462 mg; 51.2 mg per kg), clobazam (41%; 10.4 mg; 0.32 mg per kg), stiripentol (35%; 797 mg; 27.6 mg per kg), and topiramate (24%; 107 mg; 3.5 mg per kg). Ninety percent had reported using emergency medications in the last 3 months;, with the most common medications being Buccolam (40%, an oromucosal form of midazolam) and diazepam (20%, mostly rectal application). No discernable relationships between current medication and age or seizure frequency were observed. Significance This is the first comprehensive report of routine AEDs and emergency medication use in a large sample of patients with DS in Germany over a period of 3–6 months and shows that despite the most common AED combinations being in line with clinical guidelines/best practice, there is no discernable impact of best treatment on seizure frequency. We find a higher use of bromide in Germany compared with other real-world evidence in Europe.

Niedrige Serotonin- und Tryptophan-Konzentrationen im ZNS-Gewebe von Epilepsiepatienten weisen auf die mogliche pathophysiologische Bedeutung der serotoninergen Neurotransmission hin. Das serotoninerg wirkende Fenfluramin, ein nicht stimulierendes Amphetaminanalogon, wurde als Appetitzugler verwendet, bis es wegen schwerer kardiovaskularer Nebenwirkungen vom Markt genommen wurde. Fenfluramin steigert prasynaptisch die Serotoninausschuttung in den synaptischen Spalt und vermindert dort auch die Wiederaufnahme. Wahrend der Zeit der Zulassung wurden bei Epilepsiepatienten antiepileptische Wirkungen von Fenfluramin beobachtet, die aufgrund besonderer Regelungen nur in Belgien nach dem Zulassungsentzug weiterverfolgt werden konnten. Hier zeigte sich eine besonders hohe therapeutische Effektivitat von niedrig dosiertem Fenfluramin bei Patienten mit Dravet-Syndrom, einer genetisch bedingten, therapieschwierigen Epilepsie. Systematische internationale multizentrische Phase 3‑Studien mit niedrigen Wirkstoffdosierungen haben diese belgischen Berichte bestatigt. In Tierversuchen (z. B. im Zebrafisch-Modell des Dravet-Syndroms) wird dieser antiepileptische Effekt von Fenfluramin ebenfalls beobachtet. Weitere Studien werden helfen, die Bedeutung von Fenfluramin in der Behandlung anderer Epilepsien und seine Sicherheit in der Langzeittherapie zu klaren.

The developmental and epileptic encephalopathies (DEEs) are heterogeneous disorders with a strong genetic contribution, but the underlying genetic etiology remains unknown in a significant proportion of individuals. To explore whether statistical support for genetic etiologies can be generated on the basis of phenotypic features, we analyzed whole-exome sequencing data and phenotypic similarities by using Human Phenotype Ontology (HPO) in 314 individuals with DEEs. We identified a de novo c.508C>T (p.Arg170Trp) variant in AP2M1 in two individuals with a phenotypic similarity that was higher than expected by chance (p = 0.003) and a phenotype related to epilepsy with myoclonic-atonic seizures. We subsequently found the same de novo variant in two individuals with neurodevelopmental disorders and generalized epilepsy in a cohort of 2,310 individuals who underwent diagnostic whole-exome sequencing. AP2M1 encodes the mu-subunit of the adaptor protein complex 2 (AP-2), which is involved in clathrin-mediated endocytosis (CME) and synaptic vesicle recycling. Modeling of protein dynamics indicated that the p.Arg170Trp variant impairs the conformational activation and thermodynamic entropy of the AP-2 complex. Functional complementation of both the mu-subunit carrying the p.Arg170Trp variant in human cells and astrocytes derived from AP-2 mu conditional knockout mice revealed a significant impairment of CME of transferrin. In contrast, stability, expression levels, membrane recruitment, and localization were not impaired, suggesting a functional alteration of the AP-2 complex as the underlying disease mechanism. We establish a recurrent pathogenic variant in AP2M1 as a cause of DEEs with distinct phenotypic features, and we implicate dysfunction of the early steps of endocytosis as a disease mechanism in epilepsy.

Das Dravet-Syndrom beschreibt eine seltene, im ersten Lebensjahr beginnende und meist therapieschwierig verlaufende Epilepsieform des Kindesalters. Ursachlich sind bei ca. 80 % der Erkrankten Veranderungen des SCN1A-Gens, das fur eine Untereinheit eines spannungsabhangigen Natriumkanals kodiert. Der Epilepsieverlauf erfordert meist eine medikamentose Polytherapie, die eine differenzierte Therapiesteuerung in Bezug auf Wirksamkeit und Nebenwirkungen erfordert. Neben der Dauertherapie ist die Festlegung eines Notfallregimes aufgrund des haufigen Auftretens prolongierter Anfalle und epileptischer Status erforderlich. Komorbiditaten, psychosoziale Belastungen und sozialmedizinische Probleme sollten gleichfalls betrachtet und behandelt werden.

Der Vorstand der Deutschen Gesellschaft für Epileptologie und die Kommission „Epilepsie und Synkopen“ der Deutschen Gesellschaft für Neurologie haben die aktuelle Datenlage zur Impfung zur Vorbeugung der Corona-Virus-Krankheit 2019 (COVID-19) sowie zur Impfpriorisierung bei Menschen mit Epilepsie gesichtet, diese zusammengefasst und geben die unten genannten Empfehlungen ab. The Board of Directors of the German Society of Epileptology and the committee on epilepsy and syncope of the German Society of Neurology have reviewed the current data on vaccination to prevent coronavirus disease 2019 (COVID-19) and vaccination prioritization in people with epilepsy and provide a summary and recommendations.

Summary Both mild and severe epilepsies are influenced by variants in the same genes, yet an explanation for the resulting phenotypic variation is unknown. As part of the ongoing Epi25 Collaboration, we performed a whole-exome sequencing analysis of 13,487 epilepsy-affected individuals and 15,678 control individuals. While prior Epi25 studies focused on gene-based collapsing analyses, we asked how the pattern of variation within genes differs by epilepsy type. Specifically, we compared the genetic architectures of severe developmental and epileptic encephalopathies (DEEs) and two generally less severe epilepsies, genetic generalized epilepsy and non-acquired focal epilepsy (NAFE). Our gene-based rare variant collapsing analysis used geographic ancestry-based clustering that included broader ancestries than previously possible and revealed novel associations. Using the missense intolerance ratio (MTR), we found that variants in DEE-affected individuals are in significantly more intolerant genic sub-regions than those in NAFE-affected individuals. Only previously reported pathogenic variants absent in available genomic datasets showed a significant burden in epilepsy-affected individuals compared with control individuals, and the ultra-rare pathogenic variants associated with DEE were located in more intolerant genic sub-regions than variants associated with non-DEE epilepsies. MTR filtering improved the yield of ultra-rare pathogenic variants in affected individuals compared with control individuals. Finally, analysis of variants in genes without a disease association revealed a significant burden of loss-of-function variants in the genes most intolerant to such variation, indicating additional epilepsy-risk genes yet to be discovered. Taken together, our study suggests that genic and sub-genic intolerance are critical characteristics for interpreting the effects of variation in genes that influence epilepsy.

Because hyper-excitability has been shown to be a shared pathophysiological mechanism, we used the latest and largest genome-wide studies in amyotrophic lateral sclerosis (n = 36,052) and epilepsy (n = 38,349) to determine genetic overlap between these conditions. First, we showed no significant genetic correlation, also when binned on minor allele frequency. Second, we confirmed the absence of polygenic overlap using genomic risk score analysis. Finally, we did not identify pleiotropic variants in meta-analyses of the 2 diseases. Our findings indicate that amyotrophic lateral sclerosis and epilepsy do not share common genetic risk, showing that hyper-excitability in both disorders has distinct origins. ispartof: NEUROBIOLOGY OF AGING vol:92 ispartof: location:United States status: published

Bei der Kommunikation zwischen Klinikern und Patienten ist aktuell nicht mehr Frage, ob diese auch digital stattfindet, sondern wie. Die bisherige Evidenz zeigt Ansätze, die internetbasierte und traditionelle Interventionen kombinieren. Interessant sind dabei u. a. die Möglichkeiten, die für Verlaufskontrolle und Nachsorge im klinischen Bereich entstehen. Der Beitrag skizziert Chancen und Grenzen zur Bestimmung von Qualitätskriterien.

ZusammenfassungEpilepsien zählen zu den häufigsten neurologischen Erkrankungen mit etwa 600 000 Betroffenen in Deutschland. Symptome epileptischer Anfälle, die Vielzahl möglicher Epilepsieursachen und die unterschiedlichen Krankheitsverläufe erschweren sowohl die korrekte Diagnosestellung als auch die Auswahl einer geeigneten Therapie (Antikonvulsiva, epilepsiechirurgische Eingriffe, Neurostimulationsverfahren, ketogene Ernährungstherapien, Verhaltensstrategien u. a.). Zudem haben krankheitsspezifische Risiken sowie häufig auftretende Komorbiditäten nicht selten gravierende psychosoziale Konsequenzen. Daher wird bei der Versorgung von Menschen mit Epilepsie neben der vollständigen Anfallskontrolle ohne Nebenwirkungen und der Lebensqualität auch die Kontrolle bzw. Linderung typischer Begleiterkrankungen und Risiken angestrebt. Um diese Behandlungsziele zu erreichen, sind spezifische Fachkenntnisse und Untersuchungsmöglichkeiten erforderlich, die von spezialisierten Zentren vorgehalten werden. Epilepsiezentren sind als überregionale Kompetenzzentren definiert, die über spezielle Expertise und eine besondere Ausstattung zur ambulanten und stationären Versorgung von Patienten mit Epilepsien und verwandten Erkrankungen verfügen. Zu ihren Aufgaben zählen u. a. die umfassende Diagnostik, Differenzialdiagnostik und Therapie von Epilepsiepatienten sowie die multiprofessionelle und interdisziplinäre Beratung von Angehörigen und Eltern. Dieser Artikel fasst die diagnostischen und therapeutischen Herausforderungen bei der Versorgung von Menschen mit Epilepsien zusammen, beschreibt die personellen, apparativen und institutionellen Voraussetzungen von Epilepsiezentren und gibt eine Übersicht über die Vergütung epileptologischer Spezialleistungen nach G-DRG. Darüber hinaus werden Merkmale einzelner Epilepsiezentren in Deutschland skizziert sowie Perspektiven und Möglichkeiten zur Verbesserung der Versorgung von Epilepsiepatienten diskutiert.

Epilepsy is a common neurological disorder characterized by recurrent unprovoked seizures. More than 500 epilepsy-associated genes have been described in the literature. Most of these genes play an important role in neuronal excitability, cortical development or synaptic transmission. A growing number of genetic variations have implications on diagnosis and prognostic or therapeutic advice in terms of a personalized medicine. Area covered: The review presents the different forms of genetic epilepsies with respect to their underlying genetic and functional pathophysiology and aims to give advice for recommended genetic testing. Moreover, it discusses ethical and legal guidelines, costs and technical limitations which should be considered. Expert commentary: Genetic testing is an important component in the diagnosis and treatment of many forms of epilepsy.

Objective:To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes.Methods:We performed massive parallel sequencing of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs.Results:We identified 22 patients with heterozygous mutations in GABRB3, including 3 probands from multiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy with myoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies. Electrophysiologic analysis of 7 mutations in Xenopus laevis oocytes, using coexpression of wild-type or mutant β3, together with α5 and γ2s subunits and an automated 2-microelectrode voltage-clamp system, revealed reduced GABA-induced current amplitudes or GABA sensitivity for 5 of 7 mutations.Conclusions:Our results indicate that GABRB3 mutations are associated with a broad phenotypic spectrum of epilepsies and that reduced receptor function causing GABAergic disinhibition represents the relevant disease mechanism.

Infantile spasms (IS) is a developmental and epileptic encephalopathy with heterogeneous etiologies including many genetic causes. Genetic studies have identified pathogenic variants in over 30 genes as causes of IS. Many of these genetic causes are extremely rare, with only one reported incidence in an individual with IS. To better understand the genetic landscape of IS, we used targeted sequencing to screen 42 candidate IS genes and 53 established developmental and epileptic encephalopathy genes in 92 individual with IS. We identified a genetic diagnosis for 7.6% of our cohort, including pathogenic variants in KCNB1 (n = 2), GNA01 (n = 1), STXBP1 (n = 1), SLC35A2 (n = 1), TBLIXR1 (n = 1), and K1F1A (n = 1). Our data emphasize the genetic heterogeneity of IS and will inform the diagnosis and management of individuals with this devastating disorder.

Objective: Pathogenic variants in SCN 8A have been associated with a wide spectrum of epilepsy phenotypes, ranging from benign familial infantile seizures (BFIS ) to epileptic encephalopathies with variable severity. Furthermore, a few patients with intellectual disability (ID ) or movement disorders without epilepsy have been reported. The vast majority of the published SCN 8A patients suffer from severe developmental and epileptic encephalopathy (DEE ). In this study, we aimed to provide further insight on the spectrum of milder SCN 8A‐related epilepsies. Methods: A cohort of 1095 patients were screened using a next generation sequencing panel. Further patients were ascertained from a network of epilepsy genetics clinics. Patients with severe DEE and BFIS were excluded from the study. Results: We found 36 probands who presented with an SCN 8A‐related epilepsy and normal intellect (33%) or mild (61%) to moderate ID (6%). All patients presented with epilepsy between age 1.5 months and 7 years (mean = 13.6 months), and 58% of these became seizure‐free, two‐thirds on monotherapy. Neurological disturbances included ataxia (28%) and hypotonia (19%) as the most prominent features. Interictal electroencephalogram was normal in 41%. Several recurrent variants were observed, including Ile763Val, Val891Met, Gly1475Arg, Gly1483Lys, Phe1588Leu, Arg1617Gln, Ala1650Val/Thr, Arg1872Gln, and Asn1877Ser. Significance: With this study, we explore the electroclinical features of an intermediate SCN 8A‐related epilepsy with mild cognitive impairment, which is for the majority a treatable epilepsy.

OBJECTIVE To compare direct and indirect costs and quality of life (QoL) of pediatric and adult patients with Dravet syndrome (DS), with drug-resistant epilepsy (DRE) and in seizure remission (SR), and their caregivers, in Germany. METHODS Questionnaire responses from 93 DS patients and their caregivers were matched by age and gender with responses from 93 DRE and 93 SR patients collected in independent studies, and were compared across main components of QoL, direct costs (patient visits, medication use, care level, medical equipment, and ancillary treatments), and indirect costs (quitting job, reduced working hours, missed days). RESULTS Mean total direct costs were highest for DS patients (€4864 [median €3564] vs €3049 [median €1506] for DRE [excluding outliers], P = 0.01; and €1007 [median €311], P

Introduction Dravet syndrome (DS) is a rare developmental and epileptic encephalopathy. This study estimated cost, cost-driving factors and quality of life (QoL) in patients with Dravet syndrome and their caregivers in a prospective, multicenter study in Germany. Methods A validated 3–12-month retrospective questionnaire and a prospective 3-month diary assessing clinical characteristics, QoL, and direct, indirect and out-of-pocket (OOP) costs were administered to caregivers of patients with DS throughout Germany. Results Caregivers of 93 patients (mean age 10.1 years, ±7.1, range 15 months–33.7 years) submitted questionnaires and 77 prospective diaries. The majority of patients (95%) experienced at least one seizure during the previous 12 months and 77% a status epilepticus (SE) at least once in their lives. Over 70% of patients had behavioural problems and delayed speech development and over 80% attention deficit symptoms and disturbance of motor skills and movement coordination. Patient QoL was lower than in the general population and 45% of caregivers had some form of depressive symptoms. Direct health care costs per three months were a mean of €6,043 ± €5,825 (median €4054, CI €4935-€7350) per patient. Inpatient costs formed the single most important cost category (28%, €1,702 ± €4,315), followed by care grade benefits (19%, €1,130 ± €805), anti-epileptic drug (AED) costs (15%, €892 ± €1,017) and ancillary treatments (9%, €559 ± €503). Total indirect costs were €4,399 ±€ 4,989 (median €0, CI €3466-€5551) in mothers and €391 ± €1,352 (median €0, CI €195-€841) in fathers. In univariate analysis seizure frequency, experience of SE, nursing care level and severe additional symptoms were found to be associated with total direct healthcare costs. Severe additional symptoms was the single independently significant explanatory factor in a multivariate analysis. Conclusions This study over a period up to 15 months revealed substantial direct and indirect healthcare costs of DS in Germany and highlights the relatively low patient and caregiver QoL compared with the general population.

Sequencing-based studies have identified novel risk genes for rare, severe epilepsies and revealed a role of rare deleterious variation in common epilepsies. To identify the shared and distinct ultra-rare genetic risk factors for rare and common epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,364 controls of European ancestry. We focused on three phenotypic groups; the rare but severe developmental and epileptic encephalopathies (DEE), and the commoner phenotypes of 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, with the strongest enrichment seen in DEE and the least in NAFE. Moreover, we found that inhibitory GABAA receptor genes were enriched for missense variants across all three classes of epilepsy, while 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 DEE 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 top associations, including CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study confirms a convergence in the genetics of common and rare epilepsies associated with ultra-rare coding variation and highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology in the largest epilepsy WES study to date.

Epilepsien zahlen weltweit zu den haufigsten neurologischen Erkrankungen. Je nach Schweregrad der Epilepsie konnen Betroffene ein nahezu unbeschwertes Leben fuhren oder grose Einschrankungen ihrer Autonomie erleben. Charakteristisches Symptom sind wiederkehrende epileptische Anfalle, die aufgrund der Unvorhersehbarkeit des Zeitpunkts, an dem Anfalle auftreten, als auch der Bewusstseinsstorungen und des Kontrollverlustes uber verschiedene Korperfunktionen fur Betroffene, Angehorige und Pflegende sehr belastend sein konnen. Die fruhzeitige Erkennung von Anfallen kann ggf. das Ergreifen entsprechender Sicherheitsmasnahmen fur den Betroffenen beschleunigen. Neben einer solchen Fruherkennung hilft eine akkurate Aufzeichnung der Anfalle zudem bei der individuellen Abstimmung der Therapie. Im Rahmen des hier vorgestellten Projekts werden technische Innovationen fur die Unterstutzung epilepsieerkrankter Menschen durch sensorische Anfallsdetektion und -dokumentation sowie den Aufbau einer interoperablen Gesundheitsinfrastruktur und von Gesundheitsanwendungen entwickelt.

The epilepsies affect around 65 million people worldwide and have a substantial missing heritability component. We report a genome-wide mega-analysis involving 15,212 individuals with epilepsy and 29,677 controls, which reveals 16 genome-wide significant loci, of which 11 are novel. Using various prioritization criteria, we pinpoint the 21 most likely epilepsy genes at these loci, with the majority in genetic generalized epilepsies. These genes have diverse biological functions, including coding for ion-channel subunits, transcription factors and a vitamin-B6 metabolism enzyme. Converging evidence shows that the common variants associated with epilepsy play a role in epigenetic regulation of gene expression in the brain. The results show an enrichment for monogenic epilepsy genes as well as known targets of antiepileptic drugs. Using SNP-based heritability analyses we disentangle both the unique and overlapping genetic basis to seven different epilepsy subtypes. Together, these findings provide leads for epilepsy therapies based on underlying pathophysiology., SCOPUS: ar.j, info:eu-repo/semantics/published

SummaryObjective The aim of our study was to investigate the neuronal networks underlying background oscillations of epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS). Methods Sleep electroencephalography (EEG) studies before and after the treatment were investigated in 15 patients with CSWS. To investigate functional and effective connectivity within the network generating the delta activity in the background sleep EEG, the methods of dynamic imaging of coherent sources (DICS) and renormalized partial directed coherence (RPDC) were applied. Results Independent of etiology and severity of epilepsy, background EEG pattern in patients with CSWS before treatment is associated with the complex network of coherent sources in medial prefrontal cortex, somatosensory association cortex/posterior cingulate cortex, medial prefrontal cortex, middle temporal gyrus/parahippocampal gyrus/insular cortex, thalamus, and cerebellum. The analysis of information flow within this network revealed that the medial parietal cortex, the precuneus, and the thalamus act as central hubs, driving the information flow to other areas, especially to the temporal and frontal cortex. The described CSWS-specific pattern was no longer observed in patients with normalized sleep EEG. In addition, frequency of spiking showed a strong linear correlations with absolute source power, source coherence strength, and source RPDC strength at both time points: (1) Spike and wave index (SWI) versus absolute source power at EEG1 (r = 0.56; p = 0.008) and at EEG2 (r = 0.45; p = 0.009); (2) SWI versus source coherence strength at EEG1 (r = 0.71; p = 0.005) and at EEG2 (r = 0.52; p = 0.006); and (3) SWI versus source RPDC strength at EEG1 (r = 0.65; p = 0.003) and at EEG2 (r = 0.47; p = 0.009). Significance The leading role of the precuneus and thalamus in the hierarchical organization of the network underlying the background EEG points toward the significance of fluctuations of vigilance in the generation of CSWS. This hierarchical network organization appears to be specific for CSWS as it is resolved after successful treatment.

Epileptische Enzephalopathien sind definiert als Krankheitsverlaufe, bei denen die epileptische Aktivitat in Form von Anfallen oder EEG-Auffalligkeiten zu zunehmenden Funktionsstorungen des Gehirns fuhrt. Haufig, aber nicht ausschlieslich, handelt es sich dabei um fruh beginnende und schwer behandelbare Epilepsien. Dazu gehoren definierte elektroklinische Syndrome wie z. B. das West-Syndrom oder das Lennox-Gastaut-Syndrom. Im klinischen Alltag ist jedoch eine eindeutige Zuordnung zu den spezifischen Syndromen in vielen Fallen nicht moglich. Diese „nichtklassischen“ epileptischen Enzephalopathien zeigen neben Uberschneidungen zu den klassischen Syndromen auch distinkte Charakteristika. Neben strukturellen und metabolischen Ursachen konnten in den letzten Jahren zahlreiche neue Genveranderungen in Zusammenhang mit epileptischen Enzephalopathien nachgewiesen werden. Hierbei wird zunehmend die genetische Heterogenitat dieser Erkrankungsgruppe deutlich. Es werden aber auch funktionelle Gemeinsamkeiten der ursachlichen Gene erkennbar. So verursachen verschiedene Gene gleichartige Krankheitsbilder und im Gegenzug konnen Veranderungen im gleichen Gen sehr unterschiedliche Phanotypen bedingen. Um dieser Tatsache auch im klinischen Alltag gerecht zu werden, bietet insbesondere die Gen-Panel-Diagnostik eine effektive und schnelle diagnostische Methode. Die Bedeutung der Sicherung der genetischen Diagnose liegt nicht nur in der Ersparnis weiterer, moglicherweise belastender Diagnostik. Sie dient auch der genetischen und prognostischen Beratung und eroffnet zudem zunehmend spezifische Therapieoptionen. In dieser Ubersichtsarbeit werden die wesentlichen epileptischen Enzephalopathien mit entsprechenden genetischen Veranderungen dargestellt.

Electroencephalography (EEG) is a core element in the diagnosis of epilepsy syndromes and can help to monitor antiseizure treatment. Mobile EEG (mEEG) devices are increasingly available on the consumer market and may offer easier access to EEG recordings especially in rural or resource-poor areas. The usefulness of consumer-grade devices for clinical purposes is still underinvestigated. Here, we compared EEG traces of a commercially available mEEG device (Emotiv EPOC) to a simultaneously recorded clinical video EEG (vEEG). Twenty-two adult patients (11 female, mean age 40.2 years) undergoing noninvasive vEEG monitoring for clinical purposes were prospectively enrolled. The EEG recordings were evaluated by 10 independent raters with unmodifiable view settings. The individual evaluations were compared with respect to the presence of abnormal EEG findings (regional slowing, epileptiform potentials, seizure pattern). Video EEG yielded a sensitivity of 56% and specificity of 88% for abnormal EEG findings, whereas mEEG reached 39% and 85%, respectively. Interrater reliability coefficients were better in vEEG as compared to mEEG (ϰ = 0.50 vs. 0.30), corresponding to a moderate and fair agreement. Intrarater reliability between mEEG and vEEG evaluations of simultaneous recordings of a given participant was moderate (ϰ = 0.48). Given the limitations of our exploratory pilot study, our results suggest that vEEG is superior to mEEG, but that mEEG can be helpful for diagnostic purposes. We present the first quantitative comparison of simultaneously acquired clinical and mobile consumer-grade EEG for a clinical use-case.

Developmental and epileptic encephalopathies (DEEs) are a group of severe epilepsies characterized by refractory seizures and developmental impairment. Sequencing approaches have identified causal genetic variants in only about 50% of individuals with DEEs.1-3 This suggests that unknown genetic etiologies exist, potentially in the ∼98% of human genomes not covered by exome sequencing (ES). Here we describe seven likely pathogenic variants in regions outside of the annotated coding exons of the most frequently implicated epilepsy gene, SCN1A, encoding the alpha-1 sodium channel subunit. We provide evidence that five of these variants promote inclusion of a "poison" exon that leads to reduced amounts of full-length SCN1A protein. This mechanism is likely to be broadly relevant to human disease; transcriptome studies have revealed hundreds of poison exons,4,5 including some present within genes encoding other sodium channels and in genes involved in neurodevelopment more broadly.6 Future research on the mechanisms that govern neuronal-specific splicing behavior might allow researchers to co-opt this system for RNA therapeutics. ispartof: AMERICAN JOURNAL OF HUMAN GENETICS vol:103 issue:6 pages:1022-1029 ispartof: location:United States status: published

Fever-associated syndromic epilepsies ranging from febrile seizures plus (FS+) to Dravet syndrome have a significant genetic component. However, apart from SCN1A mutations in >80% of patients with Dravet syndrome, the genetic underpinnings of these epilepsies remain largely unknown. Therefore, we performed a genome-wide screening for copy number variations (CNVs) in 36 patients with SCN1A-negative fever-associated syndromic epilepsies. Phenotypes included Dravet syndrome (n = 23; 64%), genetic epilepsy with febrile seizures plus (GEFS+) and febrile seizures plus (FS+) (n = 11; 31%) and unclassified fever-associated epilepsies (n = 2; 6%). Array comparative genomic hybridization (CGH) was performed using Agilent 4 x 180K arrays. We identified 13 rare CNVs in 8 (22%) of 36 individuals. These included known pathogenic CNVs in 4 (11%) of 36 patients: a 1q21.1 duplication in a proband with Dravet syndrome, a 14q23.3 deletion in a proband with FS+, and two deletions at 16p11.2 and 1q44 in two individuals with fever-associated epilepsy with concomitant autism and/or intellectual disability. In addition, a 3q13.11 duplication in a patient with FS+ and two de novo duplications at 7p14.2 and 18q12.2 in a patient with atypical Dravet syndrome were classified as likely pathogenic. Six CNVs were of unknown significance. The identified genomic aberrations overlap with known neurodevelopmental disorders, suggesting that fever-associated epilepsy syndromes may be a recurrent clinical presentation of known microdeletion syndromes.

We report two siblings with infantile onset seizures, severe developmental delay and spastic paraplegia, in whom whole genome sequencing revealed compound heterozygous mutations in the AP4S1 gene, encoding the sigma subunit of the adaptor protein complex 4 (AP-4). The effect of the predicted loss-of-function variants (p.Gln46Profs*9 and p.Arg97*) was further investigated in a patient's fibroblast cell line. We show that the premature stop mutations in AP4S1 result in a reduction of all AP-4 subunits and loss of AP-4 complex assembly. Recruitment of the AP-4 accessory protein tepsin, to the membrane was also abolished. In retrospect, the clinical phenotype in the family is consistent with previous reports of the AP-4 deficiency syndrome. Our study reports the second family with mutations in AP4S1 and describes the first two patients with loss of AP4S1 and seizures. We further discuss seizure phenotypes in reported patients, highlighting that seizures are part of the clinical manifestation of the AP-4 deficiency syndrome. We also hypothesize that endosomal trafficking is a common theme between heritable spastic paraplegia and some inherited epilepsies.

Emerging evidence indicates that epileptic encephalopathies are genetically highly heterogeneous, underscoring the need for large cohorts of well-characterized individuals to further define the genetic landscape. Through a collaboration between two consortia (EuroEPINOMICS and Epi4K/EPGP), we analyzed exome-sequencing data of 356 trios with the "classical" epileptic encephalopathies, infantile spasms and Lennox Gastaut syndrome, including 264 trios previously analyzed by the Epi4K/EPGP consortium. In this expanded cohort, we find 429 de nova mutations, including de novo mutations in DNM1 in five individuals and de nova mutations in GABBR2, FASN, and RYR3 in two individuals each. Unlike previous studies, this cohort is sufficiently large to show a significant excess of de nova mutations in epileptic encephalopathy probands compared to the general population using a likelihood analysis (p = 8.2 x 10(-4)), supporting a prominent role for de novo mutations in epileptic encephalopathies. We bring statistical evidence that mutations in DNM1 cause epileptic encephalopathy, find suggestive evidence for a role of three additional genes, and show that at least 12% of analyzed individuals have an identifiable causal de novo mutation. Strikingly, 75% of mutations in these probands are predicted to disrupt a protein involved in regulating synaptic transmission, and there is a significant enrichment of de nova mutations in genes in this pathway in the entire cohort as well. These findings emphasize an important role for synaptic dysregulation in epileptic encephalopathies, above and beyond that caused by ion channel dysfunction.

Microdeletions at 15q11.2, 15q13.3 and 16p13.11 are known genetic risk factors for idiopathic generalized epilepsies and other neurodevelopmental disorders. The full phenotypic range of this microdeletion triad in pediatric epilepsies is unknown. We attempted to describe associated phenotypes in a cohort of pediatric epilepsy patients. We screened 570 patients with pediatric epilepsies including idiopathic generalized epilepsies, focal epilepsies and fever-associated epilepsy syndromes for microdeletions at 15q11.2, 15q13.3 and 16p13.11 using quantitative polymerase chain reaction. Identified microdeletions were confirmed using array comparative hybridization. Ten microdeletions in 15q11.2 (n=3), 15q13.3 (n=3) and 16p13.11 (n=4) were identified (1.8%). 9/10 microdeletions were identified in patients with IGE (6/101, 6.0%) or patients with generalized EEG patterns without seizures (3/122, 2.5%). 6/10 microdeletion carriers had various degrees of ID; the frequency of microdeletions in patients with epilepsy and ID was higher (4.6%) compared to patients with normal intellect (0.9%). Iterative phenotyping revealed a wide range of generalized epilepsy phenotypes. In our pediatric cohort, recurrent microdeletions at 15q11.2, 15q13.3 and 16p13.11 are mainly associated with phenotypes related to idiopathic generalized epilepsies or related EEG patterns. In contrast to previous reports, these recurrent microdeletions are virtually absent in focal epilepsies, FS, FS+ and GEFS+. Microdeletion carriers have a five-fold risk to present with various degrees of ID compared to patients without these risk factors. This microdeletion triad might help delineate a novel spectrum of epilepsy phenotypes classifiable through clinical, electrographic and genetic data.

Objective Childhood and Juvenile Absence Epilepsy account for 30% of all genetic generalized epilepsies with a strong genetic contribution. At the current state the genetic background remains to be resolved. The aim of this study was to identify disease associated transcripts pinpointing potential underlying disease mechanisms in patients with CAE and JAE. Methods We performed gene expression analysis from peripheral blood mononuclear cells (PBMCs) in 30 patients with newly-diagnosed absence epilepsy prior to initiating treatment and 30 healthy age – and gender-matched pediatric controls. In a first group (group 1), 10 patients and controls we performed genome-wide transcriptome analysis using the Affymetrix HG U133 2.0+ microarray. 75 differentially expressed genes were followed up by qRT-PCR in two independent groups of 10 patients and controls (group 2 and 3). Furthermore, we analyzed 18 candidate genes by qRT-PCR in groups 2 and 3, which had previously been considered strong candidates for genetic epilepsies. Results Genome-wide gene expression analysis in group 1 revealed 601 differentially regulated genes. Independent validation of 75 group 1-derived genes by qRT-PCR in groups 2 and 3 confirmed candidate genes with a consistent, but non-significant pattern of up- or down-regulation across all groups ( ATP1B3 , CAND1 , PRPF6 , TRIM8 ). Previously known genes including GABRA1 , GABRB3 , GABRG2 , and RCN2 showed evidence for up- or down-regulation in individual experiments, but were not reliable across groups either. Discussion Gene expression analysis in absence epilepsy from PMBCs displayed a high degree of heterogeneity between different patient groups. Our study provides several potentially interesting candidate genes, while demonstrating the limits of using gene expression analysis from blood in the identification of novel pathogenic mechanisms. In particular, we found that gene expression levels vary in response to altered experimental conditions, representing a substantial challenge for the identification of disease-related gene expression signatures for neurological diseases from whole blood.

Dravet syndrome is a severe epilepsy syndrome characterized by infantile onset of therapy-resistant, fever-sensitive seizures followed by cognitive decline. Mutations in SCN1A explain about 75% of cases with Dravet syndrome; 90% of these mutations arise de novo. We studied a cohort of nine Dravet-syndrome-affected individuals without an SCN1A mutation (these included some atypical cases with onset at up to 2 years of age) by using whole-exome sequencing in proband-parent trios. In two individuals, we identified a de novo loss-of-function mutation in CHD2 (encoding chromodomain helicase DNA binding protein 2). A third CHD2 mutation was identified in an epileptic proband of a second (stage 2) cohort. All three individuals with a CHD2 mutation had intellectual disability and fever-sensitive generalized seizures, as well as prominent myoclonic seizures starting in the second year of life or later. To explore the functional relevance of CHD2 haploinsufficiency in an in vivo model system, we knocked down chd2 in zebrafish by using targeted morpholino antisense oligomers. chd2-knockdown larvae exhibited altered locomotor activity, and the epileptic nature of this seizure-like behavior was confirmed by field-potential recordings that revealed epileptiform discharges similar to seizures in affected persons. Both altered locomotor activity and epileptiform discharges were absent in appropriate control larvae. Our study provides evidence that de novo loss-of-function mutations in CHD2 are a cause of epileptic encephalopathy with generalized seizures. publisher: Elsevier articletitle: De Novo Loss-of-Function Mutations in CHD2 Cause a Fever-Sensitive Myoclonic Epileptic Encephalopathy Sharing Features with Dravet Syndrome journaltitle: The American Journal of Human Genetics articlelink: http://dx.doi.org/10.1016/j.ajhg.2013.09.017 content_type: article copyright: Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved. ispartof: American Journal Of Human Genetics vol:93 issue:5 pages:967-975 ispartof: location:United States status: published

Summary Purpose Dravet syndrome (DS) or severe myoclonic epilepsy of infancy is an intractable epileptic encephalopathy of early childhood that is caused by a mutation in the SCN1A gene in most patients. The aim of this study was to identify a syndrome-specific epileptic network underlying interictal epileptiform discharges (IEDs) in patients with DS. Methods Ten patients with the diagnosis of DS associated with mutations in the SCN1A gene were investigated using simultaneous recording of electroencephalography and functional magnetic resonance imaging ((EEG-fMRI). Time series of IEDs were used as regressors for the statistical fMRI analysis. Key Findings In nine patients with DS, individual blood oxygenation level–dependent (BOLD) signal changes were seen. In three patients the thalamus was involved. Furthermore, regions of the default mode network were activated in seven patients. However, a common activation pattern associated with IEDs could not be detected. Significance The study demonstrates that, despite a common genetic etiology in DS, different neuronal networks underlie the individual IEDs.

BACKGROUND: Sanger sequencing, still the standard technique for genetic testing in most diagnostic laboratories and until recently widely used in research, is gradually being complemented by next-generation sequencing (NGS). No single mutation detection technique is however perfect in identifying all mutations. Therefore, we wondered to what extent inconsistencies between Sanger sequencing and NGS affect the molecular diagnosis of patients. Since mutations in SCN1A, the major gene implicated in epilepsy, are found in the majority of Dravet syndrome (DS) patients, we focused on missed SCN1A mutations.METHODS: We sent out a survey to 16 genetic centers performing SCN1A testing.RESULTS: We collected data on 28 mutations initially missed using Sanger sequencing. All patients were falsely reported as SCN1A mutation-negative, both due to technical limitations and human errors.CONCLUSION: We illustrate the pitfalls of Sanger sequencing and most importantly provide evidence that SCN1A mutations are an even more frequent cause of DS than already anticipated.

CDKL5 mutations cause severe epilepsy in infancy with subsequent epileptic encephalopathy. As yet, few studies report on long-term observations in patients with CDKL5-related epileptic encephalopathy. In this study, we describe the evolution of the epilepsy phenotype and the electroencephalographic (EEG) features in 4 patients during a maximum observation period of 22 years. All 4 patients had epilepsy starting with focal seizures in the first 3 months of life, evolving to epileptic spasms between the ages of 2 and 6 years and later on to tonic seizures. In 3 patients, epilepsy was resistant to antiepileptic therapy. Although there was no common EEG pattern in all patients, late hypsarrhythmia until the age of 9 years was observed in 2 patients. CDKL5-related epileptic encephalopathies are a group of refractory seizure disorders starting in early infancy. The phenomenon of late hypsarrhythmia may help define a subgroup of patients with severe and adverse outcomes.

Summary The first mutations identified in SLC2A1, encoding the glucose transporter type 1 (GLUT1) protein of the blood-brain barrier, were associated with severe epileptic encephalopathy. Recently, dominant SLC2A1 mutations were found in rare autosomal dominant families with various forms of epilepsy including early onset absence epilepsy (EOAE), myoclonic astatic epilepsy (MAE), and genetic generalized epilepsy (GGE). Our study aimed to investigate the possible role of SLC2A1 in various forms of epilepsy including MAE and absence epilepsy with early onset. We also aimed to estimate the frequency of GLUT1 deficiency syndrome in the Danish population. One hundred twenty patients with MAE, 50 patients with absence epilepsy, and 37 patients with unselected epilepsies, intellectual disability (ID), and/or various movement disorders were screened for mutations in SLC2A1. Mutations in SLC2A1 were detected in 5 (10%) of 50 patients with absence epilepsy, and in one (2.7%) of 37 patient with unselected epilepsies, ID, and/or various movement disorders. None of the 120 MAE patients harbored SLC2A1 mutations. We estimated the frequency of SLC2A1 mutations in the Danish population to be approximately 1:83,000. Our study confirmed the role of SLC2A1 mutations in absence epilepsy with early onset. However, our study failed to support the notion that SLC2A1 aberrations are a cause of MAE without associated features such as movement disorders.