Publications by authors named "Simona Balestrini"

46 Publications

Real-life survey of pitfalls and successes of precision medicine in genetic epilepsies.

J Neurol Neurosurg Psychiatry 2021 Apr 26. Epub 2021 Apr 26.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, and Chalfont Centre for Epilepsy, Gerrard Cross, UK

Objective: The term 'precision medicine' describes a rational treatment strategy tailored to one person that reverses or modifies the disease pathophysiology. In epilepsy, single case and small cohort reports document nascent precision medicine strategies in specific genetic epilepsies. The aim of this multicentre observational study was to investigate the deeper complexity of precision medicine in epilepsy.

Methods: A systematic survey of patients with epilepsy with a molecular genetic diagnosis was conducted in six tertiary epilepsy centres including children and adults. A standardised questionnaire was used for data collection, including genetic findings and impact on clinical and therapeutic management.

Results: We included 293 patients with genetic epilepsies, 137 children and 156 adults, 162 females and 131 males. Treatment changes were undertaken because of the genetic findings in 94 patients (32%), including rational precision medicine treatment and/or a treatment change prompted by the genetic diagnosis, but not directly related to known pathophysiological mechanisms. There was a rational precision medicine treatment for 56 patients (19%), and this was tried in 33/56 (59%) and was successful (ie, >50% seizure reduction) in 10/33 (30%) patients. In 73/293 (25%) patients there was a treatment change prompted by the genetic diagnosis, but not directly related to known pathophysiological mechanisms, and this was successful in 24/73 (33%).

Significance: Our survey of clinical practice in specialised epilepsy centres shows high variability of clinical outcomes following the identification of a genetic cause for an epilepsy. Meaningful change in the treatment paradigm after genetic testing is not yet possible for many people with epilepsy. This systematic survey provides an overview of the current application of precision medicine in the epilepsies, and suggests the adoption of a more considered approach.
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http://dx.doi.org/10.1136/jnnp-2020-325932DOI Listing
April 2021

The aetiologies of epilepsy.

Epileptic Disord 2021 Feb;23(1):1-16

UCL Queen Square Institute of Neurology, Member of the ERN EpiCARE, London, UK.

The identification of the aetiology of a patient's epilepsy is instrumental in the diagnosis, prognostic counselling and management of the epilepsies. Indeed, the aetiology can be important for determining the recurrence risk of single seizures and so for making a diagnosis of epilepsy. Here, we divide the aetiologies into six categories: structural, genetic, infectious, metabolic, immune (all of which are part of the International League Against Epilepsy [ILAE] classification system) and neurodegenerative (which we have considered separately because of its growing importance in epilepsy). These are not mutually exclusive categories and many aetiologies fall into more than one category. Indeed, genetic factors probably play a role, to varying degrees, in the risk of seizures in all people with epilepsy. In each of the categories, we discuss what we regard as the most important aetiologies; importance being determined not only by prevalence but also by clinical significance. The introduction contains information suitable for level 1 competency (entry level), whilst the subsequent sections contain information aimed at level 2 competency (proficiency level) as part of the new ILAE competency-based curriculum. As we move towards precision medicine and targeted therapies, so aetiologies will play an even greater role in the management of epilepsy.
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http://dx.doi.org/10.1684/epd.2021.1255DOI Listing
February 2021

The impact of COVID-19 in Dravet syndrome: A UK survey.

Acta Neurol Scand 2021 Apr 11;143(4):389-395. Epub 2021 Feb 11.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.

Objectives: To understand the risks, impact and outcome of COVID-19 in people affected by Dravet Syndrome (DS).

Materials And Methods: An anonymous cross-sectional online survey was conducted between June 17 and July 13, 2020, addressed to families of people with DS.

Results: A total of 116 responses were collected, from families of children (n = 86; 74%) and adults (30; 26%) with DS. The majority (106; 91%) were shielded at the family home during lockdown. Symptoms compatible with COVID-19 were reported in 22 (19%) individuals. Only four individuals with symptoms had a PCR swab test, none of which was positive. Only one symptomatic person had antibody testing (but not swab testing), which was positive. One person had repeatedly positive swab tests whilst in hospital for renal failure, but had no typical symptoms of COVID-19. In 50% of people with DS who developed possible or probable COVID-19 symptoms, seizure worsening was reported, in terms of increased seizure frequency or duration or both. Medical attention was required in 9/22 (41%), all of whom were children.

Conclusions: In this cohort of people with DS, we observed an infection rate, determined by compatible symptoms, of 19%, with no deaths and benign outcome in most cases despite the underlying complex epilepsy although children often required medical attention. Early adoption of preventative measures, including testing of symptomatic individuals, regular surveillance for people living in residential care facilities, and shielding of individuals with comorbidities increasing the risk of severe outcome, may limit the impact of COVID-19.
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http://dx.doi.org/10.1111/ane.13405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8013591PMC
April 2021

Ammonia: what adult neurologists need to know.

Pract Neurol 2020 Dec 11. Epub 2020 Dec 11.

Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK

Hyperammonaemia is often encountered in acute neurology and can be the cause of acute or chronic neurological symptoms. Patients with hyperammonaemia may present with seizures or encephalopathy, or may be entirely asymptomatic. The underlying causes are diverse but often straightforward to diagnose, although sometimes require specialist investigations. Haemodialysis or haemo(dia)filtration is the first-line treatment for acute severe hyperammonaemia (of any cause) in an adult. Here we discuss our approach to adult patients with hyperammonaemia identified by a neurologist.
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http://dx.doi.org/10.1136/practneurol-2020-002654DOI Listing
December 2020

Clinical outcomes of COVID-19 in long-term care facilities for people with epilepsy.

Epilepsy Behav 2021 02 5;115:107602. Epub 2020 Nov 5.

Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK; Chalfont Centre for Epilepsy (CCE), Chalfont St Peter, Bucks SL9 0RJ, UK.

In this cohort study, we aim to compare outcomes from coronavirus disease 2019 (COVID-19) in people with severe epilepsy and other co-morbidities living in long-term care facilities which all implemented early preventative measures, but different levels of surveillance. During 25-week observation period (16 March-6 September 2020), we included 404 residents (118 children), and 1643 caregivers. We compare strategies for infection prevention, control, and containment, and related outcomes, across four UK long-term care facilities. Strategies included early on-site enhancement of preventative and infection control measures, early identification and isolation of symptomatic cases, contact tracing, mass surveillance of asymptomatic cases and contacts. We measured infection rate among vulnerable people living in the facilities and their caregivers, with asymptomatic and symptomatic cases, including fatality rate. We report 38 individuals (17 residents) who tested severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive, with outbreaks amongst residents in two facilities. At Chalfont Centre for Epilepsy (CCE), 10/98 residents tested positive: two symptomatic (one died), eight asymptomatic on weekly enhanced surveillance; 2/275 caregivers tested positive: one symptomatic, one asymptomatic. At St Elizabeth's (STE), 7/146 residents tested positive: four symptomatic (one died), one positive during hospital admission for symptoms unrelated to COVID-19, two asymptomatic on one-off testing of all 146 residents; 106/601 symptomatic caregivers were tested, 13 positive. In addition, during two cycles of systematically testing all asymptomatic carers, four tested positive. At The Meath (TM), 8/80 residents were symptomatic but none tested; 26/250 caregivers were tested, two positive. At Young Epilepsy (YE), 8/80 children were tested, all negative; 22/517 caregivers were tested, one positive. Infection outbreaks in long-term care facilities for vulnerable people with epilepsy can be quickly contained, but only if asymptomatic individuals are identified through enhanced surveillance at resident and caregiver level. We observed a low rate of morbidity and mortality, which confirmed that preventative measures with isolation of suspected and confirmed COVID-19 residents can reduce resident-to-resident and resident-to-caregiver transmission. Children and young adults appear to have lower infection rates. Even in people with epilepsy and multiple co-morbidities, we observed a high percentage of asymptomatic people suggesting that epilepsy-related factors (anti-seizure medications and seizures) do not necessarily lead to poor outcomes.
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http://dx.doi.org/10.1016/j.yebeh.2020.107602DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7643621PMC
February 2021

Complex epilepsy: it's all in the history.

Pract Neurol 2020 Oct 17. Epub 2020 Oct 17.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK

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http://dx.doi.org/10.1136/practneurol-2020-002522DOI Listing
October 2020

Cardiac phenotype in -related syndromes: A multicenter cohort study.

Neurology 2020 11 10;95(21):e2866-e2879. Epub 2020 Sep 10.

From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS "E. Medea," Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), "Agia Sofia" Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy.

Objective: To define the risks and consequences of cardiac abnormalities in -related syndromes.

Methods: Patients meeting clinical diagnostic criteria for rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) with genetic analysis and at least 1 cardiac assessment were included. We evaluated the cardiac phenotype in an knock-in mouse (Mashl) to determine the sequence of events in seizure-related cardiac death.

Results: Ninety-eight patients with AHC, 9 with RDP, and 3 with CAPOS (63 female, mean age 17 years) were included. Resting ECG abnormalities were found in 52 of 87 (60%) with AHC, 2 of 3 (67%) with CAPOS, and 6 of 9 (67%) with RDP. Serial ECGs showed dynamic changes in 10 of 18 patients with AHC. The first Holter ECG was abnormal in 24 of 65 (37%) cases with AHC and RDP with either repolarization or conduction abnormalities. Echocardiography was normal. Cardiac intervention was required in 3 of 98 (≈3%) patients with AHC. In the mouse model, resting ECGs showed intracardiac conduction delay; during induced seizures, heart block or complete sinus arrest led to death.

Conclusions: We found increased prevalence of ECG dynamic abnormalities in all -related syndromes, with a risk of life-threatening cardiac rhythm abnormalities equivalent to that in established cardiac channelopathies (≈3%). Sudden cardiac death due to conduction abnormality emerged as a seizure-related outcome in murine -related disease. -related syndromes are cardiac diseases and neurologic diseases. We provide guidance to identify patients potentially at higher risk of sudden cardiac death who may benefit from insertion of a pacemaker or implantable cardioverter-defibrillator.
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http://dx.doi.org/10.1212/WNL.0000000000010794DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7734736PMC
November 2020

Transcranial magnetic stimulation as a tool to understand genetic conditions associated with epilepsy.

Epilepsia 2020 09 12;61(9):1818-1839. Epub 2020 Aug 12.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.

Advances in genetics may enable a deeper understanding of disease mechanisms and promote a shift to more personalised medicine in the epilepsies. At present, understanding of consequences of genetic variants mainly relies on preclinical functional work; tools for acquiring similar data from the living human brain are needed. Transcranial magnetic stimulation (TMS), in particular paired-pulse TMS protocols which depend on the function of cortical GABAergic interneuron networks, has the potential to become such a tool. For this report, we identified and reviewed 23 publications on TMS studies of cortical excitability and inhibition in 15 different genes or conditions relevant to epilepsy. Reduced short-interval intracortical inhibition (SICI) and reduced cortical silent period (CSP) duration were the most commonly reported findings, suggesting abnormal GABA - (SICI) or GABA ergic (CSP) signalling. For several conditions, these findings are plausible based on established evidence of involvement of the GABAergic system; for some others, they may inform future research around such mechanisms. Challenges of TMS include lack of complete understanding of the neural underpinnings of the measures used: hypotheses and analyses should be based on existing clinical and preclinical data. Further pitfalls include gathering sufficient numbers of participants, and the effect of confounding factors, especially medications. TMS-EEG is a unique perturbational technique to study the intrinsic properties of the cortex with excellent temporal resolution; while it has the potential to provide further information of use in interpreting effects of genetic variants, currently the links between measures and neurophysiology are less established. Despite these challenges, TMS is a tool with potential for elucidating the system-level in vivo functional consequences of genetic variants in people carrying genetic changes of interest, providing unique insights.
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http://dx.doi.org/10.1111/epi.16634DOI Listing
September 2020

Perampanel Confirms to Be Effective and Well-Tolerated as an Add-On Treatment in Patients With Brain Tumor-Related Epilepsy (PERADET Study).

Front Neurol 2020 25;11:592. Epub 2020 Jun 25.

Center for Tumor-Related Epilepsy, UOSD Neuroncology, IRCCS IFO Regina Elena National Cancer Institute, Rome, Italy.

Epilepsy is one of the most common symptoms of brain tumors. It is often drug resistant and generally worsen patients' quality of life (QoL). Brain tumors release glutamate among other mediators, contributing to seizures onset, and this is accompanied by an increased AMPA receptors' expression on neuronal cells' membrane. Perampanel (PER) is a relatively new antiseizure medication (ASM) that acts as a selective non-competitive AMPA receptors' antagonist. Given its mechanism of action, we aimed to evaluate through a prospective, observational study, the efficacy and safety of PER as an add-on treatment in patients with brain tumor-related epilepsy (BTRE). The study was called PERADET. Thirty-six adult patients (intention to treat population-ITT) affected by BTRE, with uncontrolled focal-onset seizures treated with 1-3 ASMs were recruited from four Italian epilepsy centers. Perampanel was added-on, titrated from 2 mg/day up to a maximum of 12 mg/day. Tumor history and therapy, type, and seizures frequency, previous ASMs were collected at 6 and 12 months. A battery of QoL tests were administered at baseline, 6 and 12 months. The primary endpoint was to assess the efficacy of PER by calculating the percent change in seizure frequency and the responder rate. The secondary endpoints were tolerability, retention rate at 12 months, and improvement in quality of life. At the end of 12 months, 21 patients (per protocol population-PP) were available for evaluation. In this population the responder rate (percentage of patients who experienced a 50% or greater reduction in seizure frequency) was 90.4 with 33.3% of patients being seizure-free. In the ITT group the responder rate at the end of 12 months was 66.6 with 25% of patients being seizure free. PER was well tolerated (30.6% of patients experienced an adverse event, none was severe; three needed a treatment interruptions). Our study indicate that PER may be efficacious against BTRE as suggested by its mechanism of action and our current knowledge on mechanisms of brain tumor epileptogenicity. (Prot. n° 0008872.25-06-2019); RS 919/17.
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http://dx.doi.org/10.3389/fneur.2020.00592DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7336340PMC
June 2020

Cortical myoclonus and epilepsy in a family with a new SLC20A2 mutation.

J Neurol 2020 Aug 9;267(8):2221-2227. Epub 2020 Apr 9.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK.

Idiopathic basal ganglia calcification (IBGC) or primary familial brain calcification is a rare genetic condition characterized by an autosomal dominant inheritance pattern and the presence of bilateral calcifications in the basal ganglia, thalami, cerebellum and cerebral subcortical white matter. The syndrome is genetically and phenotypically heterogeneous. Causal mutations have been identified in four genes: SLC20A2, PDGFRB, PDGFB and XPR1. A variety of progressive neurological and psychiatric symptoms have been described, including cognitive impairment, movement disorders, bipolar disorder, chronic headaches and migraine, and epilepsy. Here we describe a family with a novel SLC20A2 mutation mainly presenting with neurological symptoms including cortical myoclonus and epilepsy. While epilepsy, although rare, has been reported in patients with IBGC associated with SLC20A2 mutations, cortical myoclonus seems to be a new manifestation.
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http://dx.doi.org/10.1007/s00415-020-09821-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7359151PMC
August 2020

Muscle and brain sodium channelopathies: genetic causes, clinical phenotypes, and management approaches.

Lancet Child Adolesc Health 2020 07 3;4(7):536-547. Epub 2020 Mar 3.

Department of Neuromuscular Diseases, Medical Research Council Centre for Neuromuscular Diseases, University College London Queen Square Institute of Neurology, London, UK; National Hospital for Neurology and Neurosurgery, University College London Hospitals National Health Service Foundation Trust, London, UK.

Voltage-gated sodium channels are essential for excitability of skeletal muscle fibres and neurons. An increasing number of disabling or fatal paediatric neurological disorders linked to mutations of voltage-gated sodium channel genes are recognised. Muscle phenotypes include episodic paralysis, myotonia, neonatal hypotonia, respiratory compromise, laryngospasm or stridor, congenital myasthenia, and myopathy. Evidence suggests a possible link between sodium channel dysfunction and sudden infant death. Increasingly recognised phenotypes of brain sodium channelopathies include several epilepsy disorders and complex encephalopathies. Together, these early-onset muscle and brain phenotypes have a substantial morbidity and a considerable mortality. Important advances in understanding the pathophysiological mechanisms underlying these channelopathies have helped to identify effective targeted therapies. The availability of effective treatments underlines the importance of increasing clinical awareness and the need to achieve a precise genetic diagnosis. In this Review, we describe the expanded range of phenotypes of muscle and brain sodium channelopathies and the underlying knowledge regarding mechanisms of sodium channel dysfunction. We also outline a diagnostic approach and review the available treatment options.
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http://dx.doi.org/10.1016/S2352-4642(19)30425-0DOI Listing
July 2020

Transcranial magnetic stimulation as a biomarker of treatment response in children with epilepsy.

Dev Med Child Neurol 2020 07 24;62(7):770. Epub 2020 Feb 24.

NIHR Biomedical Research Centre at University College London Hospitals, UCL Queen Square Institute of Neurology, London, UK.

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http://dx.doi.org/10.1111/dmcn.14496DOI Listing
July 2020

Intronic ATTTC repeat expansions in STARD7 in familial adult myoclonic epilepsy linked to chromosome 2.

Nat Commun 2019 10 29;10(1):4920. Epub 2019 Oct 29.

Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185, Rome, Italy.

Familial Adult Myoclonic Epilepsy (FAME) is characterised by cortical myoclonic tremor usually from the second decade of life and overt myoclonic or generalised tonic-clonic seizures. Four independent loci have been implicated in FAME on chromosomes (chr) 2, 3, 5 and 8. Using whole genome sequencing and repeat primed PCR, we provide evidence that chr2-linked FAME (FAME2) is caused by an expansion of an ATTTC pentamer within the first intron of STARD7. The ATTTC expansions segregate in 158/158 individuals typically affected by FAME from 22 pedigrees including 16 previously reported families recruited worldwide. RNA sequencing from patient derived fibroblasts shows no accumulation of the AUUUU or AUUUC repeat sequences and STARD7 gene expression is not affected. These data, in combination with other genes bearing similar mutations that have been implicated in FAME, suggest ATTTC expansions may cause this disorder, irrespective of the genomic locus involved.
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http://dx.doi.org/10.1038/s41467-019-12671-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6820779PMC
October 2019

Comparative effectiveness of antiepileptic drugs in juvenile myoclonic epilepsy.

Epilepsia Open 2019 Sep 4;4(3):420-430. Epub 2019 Jul 4.

Department of Neurology Hôpital Erasme, Université Libre de Bruxelles Brussels Belgium.

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],  < 0.001) and female sex (1.41 [1.07-1.85],  = 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],  < 0.001 and 1.93 [1.31-2.86],  < 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%,  = 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. With appropriate selection and safeguards in place, valproate should remain available as a therapy, including as an alternative for women of childbearing potential whose seizures are resistant to other treatments.
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http://dx.doi.org/10.1002/epi4.12349DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6698679PMC
September 2019

Drug-resistant epilepsy, early-onset hypertension and white matter lesions: a hidden paraganglioma.

BMJ Case Rep 2019 Jun 21;12(6). Epub 2019 Jun 21.

Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.

We describe the case of a 35-year-old man with focal epilepsy since age 16. Due to a refractory course, several treatments were tried over the years, including insertion of a deep brain stimulator. At the time of his first assessment at our unit, he had recently been diagnosed with hypertension. An MR scan of brain revealed multiple T2 hyperintense white matter lesions, and evidence of previous haemorrhage in the left basal ganglia and pons. On follow-up imaging, the changes were considered to be in keeping with hypertensive arteriopathy. He was referred for further assessment of his hypertension and was found to have a para-aortic paraganglioma. This was excised 16 months after his initial presentation to us. The surgery was associated with an improvement in his seizure control. This case serves as a reminder of the need to be vigilant about the possibility of coexisting conditions in people with epilepsy.
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http://dx.doi.org/10.1136/bcr-2018-228348DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6605913PMC
June 2019

Cerebellar, limbic, and midbrain volume alterations in sudden unexpected death in epilepsy.

Epilepsia 2019 04 14;60(4):718-729. Epub 2019 Mar 14.

Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK.

Objective: The processes underlying sudden unexpected death in epilepsy (SUDEP) remain elusive, but centrally mediated cardiovascular or respiratory collapse is suspected. Volume changes in brain areas mediating recovery from extreme cardiorespiratory challenges may indicate failure mechanisms and allow prospective identification of SUDEP risk.

Methods: We retrospectively imaged SUDEP cases (n = 25), patients comparable for age, sex, epilepsy syndrome, localization, and disease duration who were high-risk (n = 25) or low-risk (n = 23), and age- and sex-matched healthy controls (n = 25) with identical high-resolution T1-weighted scans. Regional gray matter volume, determined by voxel-based morphometry, and segmentation-derived structure sizes were compared across groups, controlling for total intracranial volume, age, and sex.

Results: Substantial bilateral gray matter loss appeared in SUDEP cases in the medial and lateral cerebellum. This was less prominent in high-risk subjects and absent in low-risk subjects. The periaqueductal gray, left posterior and medial thalamus, left hippocampus, and bilateral posterior cingulate also showed volume loss in SUDEP. High-risk subjects showed left thalamic volume reductions to a lesser extent. Bilateral amygdala, entorhinal, and parahippocampal volumes increased in SUDEP and high-risk patients, with the subcallosal cortex enlarged in SUDEP only. Disease duration correlated negatively with parahippocampal volume. Volumes of the bilateral anterior insula and midbrain in SUDEP cases were larger the closer to SUDEP from magnetic resonance imaging.

Significance: SUDEP victims show significant tissue loss in areas essential for cardiorespiratory recovery and enhanced volumes in areas that trigger hypotension or impede respiratory patterning. Those changes may shed light on SUDEP pathogenesis and prospectively detect patterns identifying those at risk.
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http://dx.doi.org/10.1111/epi.14689DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6479118PMC
April 2019

Clinical spectrum of -related epileptic disorders.

Neurology 2019 03 8;92(11):e1238-e1249. Epub 2019 Feb 8.

From the University of Tübingen (S. Wolking, J.M., Y.G.W., H.L., J.S.), Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tübingen, Germany; Luxembourg Centre for Systems Biomedicine (P.M.), University of Luxembourg, Esch-sur-Alzette; Pediatric Neurology and Neurogenetics Unit and Laboratories (D.M., R.G., C.M.), Children's Hospital Anna Meyer, University of Florence, Italy; Danish Epilepsy Centre (R.S.M.), Dianalund; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Clinical and Experimental Epilepsy (S.B.), UCL Institute of Neurology and Epilepsy Society, UK, London; Division of Neurology (K.L.H., I.H.), Children's Hospital of Philadelphia, PA; Department of Pediatric Neurology (C.D.A.), Centre de Compétences Maladies Rares, CHU Besançon; Service de Génétique (N.C.), Hospices Civils des Lyon, Bron; GENDEV Team (N.C.), Neurosciences Research Center of Lyon, Bron, France; Neuropediatric Clinic and Clinic for Neurorehabilitation (K.S.), Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Germany; Beaumont Hospital (P.W.-W.), Dublin, Ireland; Department of Pediatrics, Division of Medical Genetics, Institute of Human Genetics (B.A.M.), Departments of Neurology and Pediatrics (A.N.), and Departments of Neurology and Pediatrics, and Institute of Human Genetics (M.R.C.), University of California, San Francisco; Department of Neurology (W.V.P.), University Hospitals Leuven, Belgium; Department of Pediatrics (L.L.S.), Hvidovre Hospital, Denmark; King's College Hospital (S.O., E.H., S.G., D.K.P.), London; Evelina London Children's Hospital (S.O., E.H., S.G.), London, UK; Section of Genetics (K.B., M.S.S.), Department of Pediatrics, University of Colorado and Children's Hospital Colorado, Aurora; Clinique Bernoise Montana (T.D.), Crans-Montana, Switzerland; Department of Neuropediatrics (H.M.), University Medical Center Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany; National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics (A.T.P., S.J.L.K., J.C.T.) and Department of Oncology (D.V.V.), University of Oxford, UK; Epilepsy Center (M.P.C.), Health Sciences Department, San Paolo Hospital, University of Milan; Child Neuropsychiatry (F.D.), Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Italy; Departments of Neurology and Clinical Genomics (R.H.G.) and Health Sciences Research and Clinical Genomics (E.W.K., C.K.), Mayo Clinic, Rochester, MN; Ambry Genetics (Z.P.), Aliso Viejo, CA; Department of Clinical Neuroscience (S.T.), King's College London; New Medicines (M.A., D.M.), UCB Pharma, Slough, UK; Neuropediatric Clinic and Clinic for Neurorehabilitation (G.J.K.), Epilepsy Center for Children and Adolescents, Schoen Klinik Vogtareuth, Germany; Research Institute for Rehabilitation, Transition and Palliation (G.J.K.), PMU Salzburg, Austria; Department of Neurology (D.H.L.), University of California, San Francisco; Neurogenetics Group (S. Weckhuysen), Center for Molecular Neurology, VIB, Antwerp; Laboratory of Neurogenetics (S. Weckhuysen), Institute Born-Bunge, University of Antwerp; Department of Neurology (S. Weckhuysen), Antwerp University Hospital, Antwerp, Belgium; Department of Basic & Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience (D.K.P.), MRC Centre for Neurodevelopmental Disorders (D.K.P.), King's College London, UK; Evelina London Children's Hospital (D.K.P.), London, UK; Department of Neuropediatrics (I.H.), University Medical Center Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany; Institute of Neuroscience (R.H.T.), Henry Wellcome Building, Newcastle University; Neurology Research Group (M.I.R.), Institute of Life Science, Swansea University Medical School, Swansea, UK; Service de Génétique (G.L.), Hospices Civils des Lyon, Bron; GENDEV Team (G.L.), Neurosciences Research Center of Lyon, Bron, France; NIHR University College London Hospitals Biomedical Research Centre (S.M.S.), UCL Institute of Neurology, London, UK; Cologne Center for Genomics (D.L.), University of Cologne, Germany; Stanley Center for Psychiatric Research (D.L.) and Program in Medical and Population Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge; Psychiatric and Neurodevelopmental Genetics Unit (D.L.), Massachusetts General Hospital and Harvard Medical School, Boston.

Objective: The aim of this study was to expand the spectrum of epilepsy syndromes related to , encoding the presynaptic protein syntaxin-1B, and establish genotype-phenotype correlations by identifying further disease-related variants.

Methods: We used next-generation sequencing in the framework of research projects and diagnostic testing. Clinical data and EEGs were reviewed, including already published cases. To estimate the pathogenicity of the variants, we used established and newly developed in silico prediction tools.

Results: We describe 17 new variants in , which are distributed across the whole gene. We discerned 4 different phenotypic groups across the newly identified and previously published patients (49 patients in 23 families): (1) 6 sporadic patients or families (31 affected individuals) with febrile and afebrile seizures with a benign course, generally good drug response, normal development, and without permanent neurologic deficits; (2) 2 patients with genetic generalized epilepsy without febrile seizures and cognitive deficits; (3) 13 patients or families with intractable seizures, developmental regression after seizure onset and additional neuropsychiatric symptoms; (4) 2 patients with focal epilepsy. More often, we found loss-of-function mutations in benign syndromes, whereas missense variants in the SNARE motif of syntaxin-1B were associated with more severe phenotypes.

Conclusion: These data expand the genetic and phenotypic spectrum of -related epilepsies to a diverse range of epilepsies that span the International League Against Epilepsy classification. Variants in are protean and contribute to many different epilepsy phenotypes, similar to , the most important gene associated with fever-associated epilepsies.
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http://dx.doi.org/10.1212/WNL.0000000000007089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6511102PMC
March 2019

Neurologic phenotypes associated with / mutations: Expanding the spectrum of disease.

Neurology 2018 11 9;91(22):e2078-e2088. Epub 2018 Nov 9.

From the Department of Clinical and Experimental Epilepsy (S.Z., Z.M., L.H.-H., S.K., S. Balestrini, S.M.S.) and Division of Neuropathology (Z.M., M.T.), UCL Institute of Neurology, London, UK; Clinic of Neurology (S.Z.), Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy; Department of Pediatric Neurology and Neurological Rehabilitation (C.S., T.H., P.W., G.J.K.) and Neurosurgery Clinic and Clinic for Epilepsy Surgery (M.K.), Schön Klinik Vogtareuth; Department of Pediatrics (C.S., M.S.), Children's Hospital Augsburg, Germany; UCL Great Ormond Street Institute of Child Health (J.R.N., K.V., S.M.V., J.H.C.), London, UK; Paediatric Neurology and Neurogenetics Unit and Laboratories (D.M., R.G.), A. Meyer Children's Hospital, University of Florence, Italy; Chalfont Centre for Epilepsy (Z.M., L.H.-H., S.K., S. Balestrini, S.M.S.), Chalfont-St-Peter, Buckinghamshire, UK; CeGaT-Center for Genomics and Transcriptomics (A.P., S. Biskup), Tübingen, Germany; Neurogenetics Unit (M.L.), Department of Medical Genetics, Hospital de São João, Porto, Portugal; Department of Pediatrics and Adolescent Medicine (J.G.), University Medical Center Göttingen; Hospital for Children and Adolescents (A.M.), University Clinic Leipzig, Germany; Freiburg Medical Laboratory (M.J.), Dubai; The Danish Epilepsy Centre (R.S.M., E.G.), Dianalund; Institute for Regional Health Services (R.S.M., E.G.), University of Southern Denmark, Odense; Department of Clinical Genetics (B.S.K.), Odense University Hospital; Hans Christian Andersen Children's Hospital (L.K.H.), Odense, Denmark; Pediatric Neurology and Muscular Diseases Unit (M.S.V., P.S.), Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa "G. Gaslini" Institute, Italy; Division of Neurology (K.L.H.), Children's Hospital of Philadelphia, PA; Department of Neurology (S.D., C.L.S.-H.), Division of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD; Center for Genomic Medicine (N.H.-F.), Tohoku University; Department of Pediatrics (N.H.-F.), Tohoku University School of Medicine, Sendai, Japan; Department of Pediatrics (T.T., R.L.) and Institute of Clinical Medicine (K.O.), University of Tartu; Children's Clinic (T.T., R.L.), Department of Radiology (P.I.), and Department of Clinical Genetics, United Laboratories (K.O.), Tartu University Hospital, Estonia; Ludwig-Maximilians-University Munich (I.K.); Department of Pediatric Neurology (A.H.), Clinic Traunstein; Children's Hospital (M.K.), Dr. Horst Schmidt Klinik, Wiesbaden; Altona Children's Hospital (J.H.), Hamburg; Department of Pediatrics (C. Makowski), Technische Universität München, Germany; Department of Clinical Genetics (S.G.), Royal North Shore Hospital, St Leonards; John Hunter Children's Hospital (G.M.S.), New Lambton Heights, New South Wales, Australia; Department of Neurology (R.T.), University Hospital of Wales; Institute of Psychological Medicine and Clinical Neurosciences (R.H.T.), Cardiff University; Division of Neuroradiology (C. Micallef), National Hospital for Neurology and Neurosurgery, London; Department of Brain Repair & Rehabilitation (D.J.W.), Stroke Research Centre, UCL Institute of Neurology, London, UK; Paracelsus Medical University (G.J.K.), Salzburg, Austria; and IRCCS Stella Maris Foundation (R.G.), Pisa, Italy.

Objective: To characterize the neurologic phenotypes associated with mutations and to seek genotype-phenotype correlation.

Methods: We analyzed clinical, EEG, and neuroimaging data of 44 new and 55 previously reported patients with mutations.

Results: Childhood-onset focal seizures, frequently complicated by status epilepticus and resistance to antiepileptic drugs, was the most common phenotype. EEG typically showed focal epileptiform discharges in the context of other abnormalities, including generalized sharp waves or slowing. In 46.4% of new patients with focal seizures, porencephalic cysts on brain MRI colocalized with the area of the focal epileptiform discharges. In patients with porencephalic cysts, brain MRI frequently also showed extensive white matter abnormalities, consistent with the finding of diffuse cerebral disturbance on EEG. Notably, we also identified a subgroup of patients with epilepsy as their main clinical feature, in which brain MRI showed nonspecific findings, in particular periventricular leukoencephalopathy and ventricular asymmetry. Analysis of 15 pedigrees suggested a worsening of the severity of clinical phenotype in succeeding generations, particularly when maternally inherited. Mutations associated with epilepsy were spread across and a clear genotype-phenotype correlation did not emerge.

Conclusion: mutations typically cause a severe neurologic condition and a broader spectrum of milder phenotypes, in which epilepsy is the predominant feature. Early identification of patients carrying mutations may have important clinical consequences, while for research efforts, omission from large-scale epilepsy sequencing studies of individuals with abnormalities on brain MRI may generate misleading estimates of the genetic contribution to the epilepsies overall.
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http://dx.doi.org/10.1212/WNL.0000000000006567DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6282239PMC
November 2018

The landscape of epilepsy-related GATOR1 variants.

Genet Med 2019 02 10;21(2):398-408. Epub 2018 Aug 10.

Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands.

Purpose: To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway METHODS: We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants.

Results: The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign.

Conclusion: Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.
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http://dx.doi.org/10.1038/s41436-018-0060-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6292495PMC
February 2019

Genome-wide association study: Exploring the genetic basis for responsiveness to ketogenic dietary therapies for drug-resistant epilepsy.

Epilepsia 2018 08 16;59(8):1557-1566. Epub 2018 Jul 16.

Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK.

Objective: With the exception of specific metabolic disorders, predictors of response to ketogenic dietary therapies (KDTs) are unknown. We aimed to determine whether common variation across the genome influences the response to KDT for epilepsy.

Methods: We genotyped individuals who were negative for glucose transporter type 1 deficiency syndrome or other metabolic disorders, who received KDT for epilepsy. Genotyping was performed with the Infinium HumanOmniExpressExome Beadchip. Hospital records were used to obtain demographic and clinical data. KDT response (≥50% seizure reduction) at 3-month follow-up was used to dissect out nonresponders and responders. We then performed a genome-wide association study (GWAS) in nonresponders vs responders, using a linear mixed model and correcting for population stratification. Variants with minor allele frequency <0.05 and those that did not pass quality control filtering were excluded.

Results: After quality control filtering, the GWAS of 112 nonresponders vs 123 responders revealed an association locus at 6p25.1, 61 kb upstream of CDYL (rs12204701, P = 3.83 × 10 , odds ratio [A] = 13.5, 95% confidence interval [CI] 4.07-44.8). Although analysis of regional linkage disequilibrium around rs12204701 did not strengthen the likelihood of CDYL being the candidate gene, additional bioinformatic analyses suggest it is the most likely candidate.

Significance: CDYL deficiency has been shown to disrupt neuronal migration and to influence susceptibility to epilepsy in mice. Further exploration with a larger replication cohort is warranted to clarify whether CDYL is the causal gene underlying the association signal.
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http://dx.doi.org/10.1111/epi.14516DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6099477PMC
August 2018

Diagnostic Biomarkers of Epilepsy.

Curr Pharm Biotechnol 2018 ;19(6):440-450

Regional Epilepsy Centre, Great Metropolitan Hospital, Reggio Calabria, Italy.

Background: Diagnostic biomarkers of epilepsy are objectively measurable variables associated with the development of epilepsy or the propensity to generate seizures. Identification of biomarkers could be helpful for differential diagnosis and for tailored therapeutic approaches.

Objective: This review focuses on diagnostic biomarkers of epilepsy, including genetic, serological, neuroimaging and electrophysiological variables.

Methods: References were mainly identified through PubMed search until December 2017 and backtracking of references in pertinent studies.

Results: Several promising diagnostic biomarkers of epilepsy exist, with causative value or predicting liability to develop seizures after acquired brain injuries. Short non-coding RNAs are deregulated in serum and cerebral tissue of epilepsy subjects: these molecules are promising diagnostic biomarkers, being easy to assess and reproducible. Advanced imaging techniques may allow identification of subtle epileptogenic lesions, often with prognostic value. Novel electrophysiological biomarkers of epilepsy include perturbed cortical connectivity and excitability induced by transcranial magnetic stimulation, as well as high-frequency oscillations detected by intracranial and scalp electroencephalographic recordings. Finally, serological biomarkers may support the differential diagnosis between epileptic seizures and non-epileptic events.

Conclusion: Ongoing research on diagnostic biomarkers of epilepsy is promising and future preclinical and clinical studies are warranted.
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http://dx.doi.org/10.2174/1389201019666180713095251DOI Listing
December 2018

Ring Chromosome 17 Not Involving the Miller-Dieker Region: A Case with Drug-Resistant Epilepsy.

Mol Syndromol 2017 Dec 15;9(1):38-44. Epub 2017 Sep 15.

Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK.

Chromosomal abnormalities are often identified in people with neurodevelopmental disorders including intellectual disability, autism, and epilepsy. Ring chromosomes, which usually involve gene copy number loss, are formed by fusion of subtelomeric or telomeric chromosomal regions. Some ring chromosomes, including ring 14, 17, and 20, are strongly associated with seizure disorders. We report an individual with a ring chromosome 17, r(17)(p13.3q25.3), with a terminal 17q25.3 deletion and no short arm copy number loss, and with a phenotype characterized by intellectual disability and drug-resistant epilepsy, including a propensity for nonconvulsive status epilepticus.
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http://dx.doi.org/10.1159/000479949DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803681PMC
December 2017

Clinical spectrum and genotype-phenotype associations of KCNA2-related encephalopathies.

Brain 2017 Sep;140(9):2337-2354

Medical Genetics Department, National Institute for Women, Children and Adolescents Health Fernandes Figueira - Fiocruz, Rio de Janeiro, Brazil.

Recently, de novo mutations in the gene KCNA2, causing either a dominant-negative loss-of-function or a gain-of-function of the voltage-gated K+ channel Kv1.2, were described to cause a new molecular entity within the epileptic encephalopathies. Here, we report a cohort of 23 patients (eight previously described) with epileptic encephalopathy carrying either novel or known KCNA2 mutations, with the aim to detail the clinical phenotype associated with each of them, to characterize the functional effects of the newly identified mutations, and to assess genotype-phenotype associations. We identified five novel and confirmed six known mutations, three of which recurred in three, five and seven patients, respectively. Ten mutations were missense and one was a truncation mutation; de novo occurrence could be shown in 20 patients. Functional studies using a Xenopus oocyte two-microelectrode voltage clamp system revealed mutations with only loss-of-function effects (mostly dominant-negative current amplitude reduction) in eight patients or only gain-of-function effects (hyperpolarizing shift of voltage-dependent activation, increased amplitude) in nine patients. In six patients, the gain-of-function was diminished by an additional loss-of-function (gain-and loss-of-function) due to a hyperpolarizing shift of voltage-dependent activation combined with either decreased amplitudes or an additional hyperpolarizing shift of the inactivation curve. These electrophysiological findings correlated with distinct phenotypic features. The main differences were (i) predominant focal (loss-of-function) versus generalized (gain-of-function) seizures and corresponding epileptic discharges with prominent sleep activation in most cases with loss-of-function mutations; (ii) more severe epilepsy, developmental problems and ataxia, and atrophy of the cerebellum or even the whole brain in about half of the patients with gain-of-function mutations; and (iii) most severe early-onset phenotypes, occasionally with neonatal onset epilepsy and developmental impairment, as well as generalized and focal seizures and EEG abnormalities for patients with gain- and loss-of-function mutations. Our study thus indicates well represented genotype-phenotype associations between three subgroups of patients with KCNA2 encephalopathy according to the electrophysiological features of the mutations.
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http://dx.doi.org/10.1093/brain/awx184DOI Listing
September 2017

Treatment of Epileptic Encephalopathies.

Curr Pharm Des 2017 ;23(37):5667-5690

Neuroscience Department, Polytechnic University of Marche, Ancona, Italy.

Background: Epileptic encephalopathies represent the most severe epilepsies, with onset in infancy and childhood and seizures continuing in adulthood in most cases. New genetic causes are being identified at a rapid rate. Treatment is challenging and the overall outcome remains poor. Available targeted treatments, based on the precision medicine approach, are currently few.

Objective: To provide an overview of the treatment of epileptic encephalopathies with known genetic determinants, including established treatment, anecdotal reports of specific treatment, and potential tailored precision medicine strategies.

Method: Genes known to be associated to epileptic encephalopathy were selected. Genes where the association was uncertain or with no reports of details on treatment, were not included. Although some of the genes included are associated with multiple epilepsy phenotypes or other organ involvement, we have mainly focused on the epileptic encephalopathies and their antiepileptic treatments.

Results: Most epileptic encephalopathies show genotypic and phenotypic heterogeneity. The treatment of seizures is difficult in most cases. The available evidence may provide some guidance for treatment: for example, ACTH seems to be effective in controlling infantile spams in a number of genetic epileptic encephalopathies. There are potentially effective tailored precision medicine strategies available for some of the encephalopathies, and therapies with currently unexplained effectiveness in others.

Conclusions: Understanding the effect of the mutation is crucial for targeted treatment. There is a broad range of disease mechanisms underlying epileptic encephalopathies, and this makes the application of targeted treatments challenging. However, there is evidence that tailored treatment could significantly improve epilepsy treatment and prognosis.
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http://dx.doi.org/10.2174/1381612823666170809115827DOI Listing
July 2019

Pharmacogenomics in epilepsy.

Neurosci Lett 2018 02 10;667:27-39. Epub 2017 Jan 10.

NIHR University College London Hospitals Biomedical Research Centre, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, and Epilepsy Society, Chalfont-St-Peter, Bucks, United Kingdom. Electronic address:

There is high variability in the response to antiepileptic treatment across people with epilepsy. Genetic factors significantly contribute to such variability. Recent advances in the genetics and neurobiology of the epilepsies are establishing the basis for a new era in the treatment of epilepsy, focused on each individual and their specific epilepsy. Variation in response to antiepileptic drug treatment may arise from genetic variation in a range of gene categories, including genes affecting drug pharmacokinetics, and drug pharmacodynamics, but also genes held to actually cause the epilepsy itself. From a purely pharmacogenetic perspective, there are few robust genetic findings with established evidence in epilepsy. Many findings are still controversial with anecdotal or less secure evidence and need further validation, e.g. variation in genes for transporter systems and antiepileptic drug targets. The increasing use of genetic sequencing and the results of large-scale collaborative projects may soon expand the established evidence. Precision medicine treatments represent a growing area of interest, focussing on reversing or circumventing the pathophysiological effects of specific gene mutations. This could lead to a dramatic improvement of the effectiveness and safety of epilepsy treatments, by targeting the biological mechanisms responsible for epilepsy in each specific individual. Whilst much has been written about epilepsy pharmacogenetics, there does now seem to be building momentum that promises to deliver results of use in clinic.
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http://dx.doi.org/10.1016/j.neulet.2017.01.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846849PMC
February 2018

From Cannabis to Cannabidiol to Treat Epilepsy, Where Are We?

Curr Pharm Des 2016 ;22(42):6426-6433

Department of Science of Health, School of Medicine, University of Catanzaro, Via T. Campanella, 115; 88100 Catanzaro, Italy.

Background: Several antiepileptic drugs (AEDs), about 25, are currently clinically available for the treatment of patients with epilepsy. Despite this armamentarium and the many recently introduced AEDs, no major advances have been achieved considering the number of drug resistant patients, while many benefits have been indeed obtained for other clinical outcomes (e.g. better tolerability, less interactions). Cannabinoids have long been studied for their potential therapeutical use and more recently phytocannabinoids have been considered a valuable tool for the treatment of several neurological disorders including epilepsy. Among this wide class, the most studied is cannabidiol (CBD) considering its lack of psychotropic effects and its anticonvulsant properties.

Objective: Analyse the currently available literature on CBD also in light of other data on phytocannabinoids, reviewing data spanning from the mechanism of action, pharmacokinetic to clinical evidences.

Results: Several preclinical studies have tried to understand the mechanism of action of CBD, which still remains largely not understood. CBD has shown significant anticonvulsant effects mainly in acute animal models of seizures; beneficial effects were reported also in animal models of epileptogenesis and chronic models of epilepsy, although not substantial. In contrast, data coming from some studies raise questions on the effects of other cannabinoids and above all marijuana.

Conclusion: There is indeed sufficient supporting data for clinical development and important antiepileptic effects and the currently ongoing clinical studies will permit the real usefulness of CBD and possibly other cannabinoids. Undoubtedly, several issues also need to be addressed in the next future (e.g. better pharmacokinetic profiling). Finally, shading light on the mechanism of action and the study of other cannabinoids might represent an advantage for future developments.
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http://dx.doi.org/10.2174/1381612822666160831122722DOI Listing
December 2017

De novo mutations of KIAA2022 in females cause intellectual disability and intractable epilepsy.

J Med Genet 2016 12 29;53(12):850-858. Epub 2016 Jun 29.

Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands.

Background: Mutations in the KIAA2022 gene have been reported in male patients with X-linked intellectual disability, and related female carriers were unaffected. Here, we report 14 female patients who carry a heterozygous de novo KIAA2022 mutation and share a phenotype characterised by intellectual disability and epilepsy.

Methods: Reported females were selected for genetic testing because of substantial developmental problems and/or epilepsy. X-inactivation and expression studies were performed when possible.

Results: All mutations were predicted to result in a frameshift or premature stop. 12 out of 14 patients had intractable epilepsy with myoclonic and/or absence seizures, and generalised in 11. Thirteen patients had mild to severe intellectual disability. This female phenotype partially overlaps with the reported male phenotype which consists of more severe intellectual disability, microcephaly, growth retardation, facial dysmorphisms and, less frequently, epilepsy. One female patient showed completely skewed X-inactivation, complete absence of RNA expression in blood and a phenotype similar to male patients. In the six other tested patients, X-inactivation was random, confirmed by a non-significant twofold to threefold decrease of RNA expression in blood, consistent with the expected mosaicism between cells expressing mutant or normal KIAA2022 alleles.

Conclusions: Heterozygous loss of KIAA2022 expression is a cause of intellectual disability in females. Compared with its hemizygous male counterpart, the heterozygous female disease has less severe intellectual disability, but is more often associated with a severe and intractable myoclonic epilepsy.
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http://dx.doi.org/10.1136/jmedgenet-2016-103909DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264224PMC
December 2016

TBC1D24 genotype-phenotype correlation: Epilepsies and other neurologic features.

Neurology 2016 07 8;87(1):77-85. Epub 2016 Jun 8.

Objective: To evaluate the phenotypic spectrum associated with mutations in TBC1D24.

Methods: We acquired new clinical, EEG, and neuroimaging data of 11 previously unreported and 37 published patients. TBC1D24 mutations, identified through various sequencing methods, can be found online (http://lovd.nl/TBC1D24).

Results: Forty-eight patients were included (28 men, 20 women, average age 21 years) from 30 independent families. Eighteen patients (38%) had myoclonic epilepsies. The other patients carried diagnoses of focal (25%), multifocal (2%), generalized (4%), and unclassified epilepsy (6%), and early-onset epileptic encephalopathy (25%). Most patients had drug-resistant epilepsy. We detail EEG, neuroimaging, developmental, and cognitive features, treatment responsiveness, and physical examination. In silico evaluation revealed 7 different highly conserved motifs, with the most common pathogenic mutation located in the first. Neuronal outgrowth assays showed that some TBC1D24 mutations, associated with the most severe TBC1D24-associated disorders, are not necessarily the most disruptive to this gene function.

Conclusions: TBC1D24-related epilepsy syndromes show marked phenotypic pleiotropy, with multisystem involvement and severity spectrum ranging from isolated deafness (not studied here), benign myoclonic epilepsy restricted to childhood with complete seizure control and normal intellect, to early-onset epileptic encephalopathy with severe developmental delay and early death. There is no distinct correlation with mutation type or location yet, but patterns are emerging. Given the phenotypic breadth observed, TBC1D24 mutation screening is indicated in a wide variety of epilepsies. A TBC1D24 consortium was formed to develop further research on this gene and its associated phenotypes.
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http://dx.doi.org/10.1212/WNL.0000000000002807DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932231PMC
July 2016