Clinical and molecular characterization of -related severe early-onset epilepsy.
Journal: Neurology
Volume: 90
Issue: 1
Year of Publication: 2019
Affiliated Institutions:
From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK. a.mctague@ucl.ac.uk manju.kurian@ucl.ac.uk.
From Molecular Neurosciences (A.M., E.M., A., A.N., M.A.K.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health; Department of Neurology (A.M., A., A.N., C.E., J.H.C., M.A.K.) and Neuroradiology (W.K.C.), Great Ormond Street Hospital for Children, London, UK; Florey Institute of Neuroscience and Mental Health (U.N., E.V.G., I.E.S., S.P.), Melbourne, Australia; Department of Biological Sciences (S.M., M.T.), Institute of Structural and Molecular Biology, Birkbeck College, University of London; Regional Molecular Genetics Laboratory (N.T., R.H.S.), North East Thames Regional Genetics Service, and Department of Clinical Genetics (A.V.K., R.H.S.), Great Ormond Street Hospital, London, UK; Department of Paediatric Neurology (S.A.), Red Cross War Memorial Children's Hospital, Cape Town, South Africa; Department of Paediatric Neurology (G.A.), Addenbrooke's Hospital, Cambridge; Roald Dahl EEG Unit (R.A.), Department of Neurology, and Department of Neurology (R.K.), Alder Hey Children's Hospital, Liverpool; Department of Paediatric Neurology (A.D.), Sheffield Children's Hospital; Clinical Neurosciences (C.E., J.H.C.), Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London; Institute of Infection and Global Health (R.K.), University of Liverpool; Department of Paediatric Neurology (K.L.), Evelina Children's Hospital, Guys and St. Thomas' NHS Foundation Trust, London; Department of Clinical Genetics (T.M.), Northern Genetics Service; Department of Pediatric Neurology (V.R.), Great North Children's Hospital, Newcastle Upon Tyne; Department of Paediatric Neurology (R.S.), University Hospital Leicester Children's Hospital; Department of Paediatric Neurology (J.T.), Royal Manchester Children's Hospital; Department of Paediatric Neurology (W.W.), Nottingham University Hospitals NHS Trust, UK; Epilepsy Genetics Program (A. Poduri), Department of Neurology, Boston Children's Hospital; Department of Neurology (A. Poduri), Harvard Medical School, Boston, MA; University of Melbourne (I.E.S.), Austin Health and Royal Children's Hospital, Australia; and Department of Medicine (S.P.), Royal Melbourne Hospital, University of Melbourne, Australia. Dr. Malhotra is currently at the Department of Biochemistry, University of Cambridge, UK.
Abstract summary
To characterize the phenotypic spectrum, molecular genetic findings, and functional consequences of pathogenic variants in early-onset epilepsy.We identified a cohort of 31 patients with epilepsy of infancy with migrating focal seizures (EIMFS) and screened for variants in using direct Sanger sequencing, a multiple-gene next-generation sequencing panel, and whole-exome sequencing. Additional patients with non-EIMFS early-onset epilepsy in whom we identified variants on local diagnostic multiple gene panel testing were also included. When possible, we performed homology modeling to predict the putative effects of variants on protein structure and function. We undertook electrophysiologic assessment of mutant KCNT1 channels in a oocyte model system.We identified pathogenic variants in in 12 patients, 4 of which are novel. Most variants occurred de novo. Ten patients had a clinical diagnosis of EIMFS, and the other 2 presented with early-onset severe nocturnal frontal lobe seizures. Three patients had a trial of quinidine with good clinical response in 1 patient. Computational modeling analysis implicates abnormal pore function (F346L) and impaired tetramer formation (F502V) as putative disease mechanisms. All evaluated variants resulted in marked gain of function with significantly increased channel amplitude and variable blockade by quinidine.Gain-of-function pathogenic variants cause a spectrum of severe focal epilepsies with onset in early infancy. Currently, genotype-phenotype correlations are unclear, although clinical outcome is poor for the majority of cases. Further elucidation of disease mechanisms may facilitate the development of targeted treatments, much needed for this pharmacoresistant genetic epilepsy.
Authors & Co-authors:
McTague Amy A
Nair Umesh U
Malhotra Sony S
Meyer Esther E
Trump Natalie N
Gazina Elena V EV
Papandreou Apostolos A
Ngoh Adeline A
Ackermann Sally S
Ambegaonkar Gautam G
Appleton Richard R
Desurkar Archana A
Eltze Christin C
Kneen Rachel R
Kumar Ajith V AV
Lascelles Karine K
Montgomery Tara T
Ramesh Venkateswaran V
Samanta Rajib R
Scott Richard H RH
Tan Jeen J
Whitehouse William W
Poduri Annapurna A
Scheffer Ingrid E IE
Chong W K Kling WKK
Cross J Helen JH
Topf Maya M
Petrou Steven S
Kurian Manju A MA
Study Outcome
Source Link: Visit source