title: Seizure variables and their relationship to genotype and functional abilities in the CDKL5 disorder.
abstract: OBJECTIVE
  To investigate seizure outcomes and their relationships to genotype and functional abilities in individuals with the cyclin-dependent kinase-like-5 (CDKL5) disorder.
  
  
  METHODS
  Using the International CDKL5 Disorder Database, we identified 172 cases with a pathogenic CDKL5 mutation. We categorized individual mutations into 4 groups based on predicted structural and functional consequences. Negative binomial regression was used to model the linear association between current seizure rate and mutation group, current level of assistance required to walk 10 steps, and the highest level of expressive communication used to convey refusal or request.
  
  
  RESULTS
  All but 3 (169/172) patients had a history of epilepsy. The median age at seizure onset was 6 weeks (range 1 week-1.5 years) and the median seizure rate at ascertainment was 2 per day (range 0-20 per day). After adjusting for walking ability and confounders including use or otherwise of polytherapy, seizure rate was lower in those with truncating mutations between aa172 and aa781 compared to those with no functional protein (incidence rate ratio [IRR] 0.57; 95% confidence interval [CI] 0.35-0.93). Ability to walk and use of spoken language were associated with lower rates of current seizures when compared to those with the least ability after adjusting for genotype (walking: IRR 0.62; 95% CI 0.39-0.99, communication: IRR 0.48; 95% CI 0.23-1.02). At a median age at questionnaire completion of 5 years, those previously treated with corticosteroids had more frequent seizures than those who have never been treated, whether or not there was a history of infantile spasms.
  
  
  CONCLUSIONS
  Epilepsy is pervasive but not mandatory for the CDKL5 disorder. Genotype and functional abilities were related to seizure frequency, which appears refractory to antiepileptic drugs.
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Stephanie
authors: S
authors: Fehr
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Kingsley
authors: K
authors: Wong
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Richard
authors: R
authors: Chin
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Simon
authors: S
authors: Williams
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Nick
authors: N
authors: de Klerk
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: David
authors: D
authors: Forbes
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Rahul
authors: R
authors: Krishnaraj
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: John
authors: J
authors: Christodoulou
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia.
authors: Jenny
authors: J
authors: Downs
authors: From Telethon Kids Institute (S.F., K.W., N.d.K., J.D., H.L.) and the School of Paediatrics and Child Health (D.F.), The University of Western Australia, Perth; Muir Maxwell Epilepsy Centre (R.C.), Child Life and Health, The University of Edinburgh, UK; Department of Neurology and Rehabilitation (S.W.), Princess Margaret Hospital, Perth; Western Sydney Genetics Program (R.K.), The Children's Hospital at Westmead, Sydney; Department of Paediatrics (J.C.), University of Melbourne; Murdoch Childrens Research Institute (J.C.), The Royal Children's Hospital, Melbourne; and School of Physiotherapy and Exercise Science (J.D.), Curtin University, Perth, Australia. Helen.Leonard@telethonkids.org.au.
authors: Helen
authors: H
authors: Leonard
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000927:Anticonvulsants / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D000073376:Epileptic Syndromes; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D008297:Male; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D015518:Rett Syndrome / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology*; D012640:Seizures / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology*; D013036:Spasms, Infantile / Q000188:drug therapy / Q000235:genetics* / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D017346:Protein Serine-Threonine Kinases; C114482:CDKL5 protein, human