title: When is a child with status epilepticus likely to have Dravet syndrome?
abstract: OBJECTIVE
  To identify clinical risk factors for Dravet syndrome (DS) in a population of children with status epilepticus (SE).
  
  
  METHODS
  Children aged between 1 month and 16 years with at least one episode of SE were referred from 6 pediatric neurology centers in Switzerland. SE was defined as a clinical seizure lasting for more than 30min without recovery of normal consciousness. The diagnosis of DS was considered likely in previously healthy patients with seizures of multiple types starting before 1 year and developmental delay on follow-up. The presence of a SCN1A mutation was considered confirmatory for the diagnosis. Data such as gender, age at SE, SE clinical presentation and recurrence, additional seizure types and epilepsy diagnosis were collected. SCN1A analyses were performed in all patients, initially with High Resolution Melting Curve Analysis (HRMCA) and then by direct sequencing on selected samples with an abnormal HRMCA. Clinical and genetic findings were compared between children with DS and those with another diagnosis, and statistical methods were applied for significance analysis.
  
  
  RESULTS
  71 children with SE were included. Ten children had DS, and 61 had another diagnosis. SCN1A mutations were found in 12 of the 71 patients (16.9%; ten with DS, and two with seizures in a Generalized Epilepsy with Febrile Seizures+(GEFS+) context). The median age at first SE was 8 months in patients with DS, and 41 months in those with another epilepsy syndrome (p<0.001). Nine of the 10 DS patients had their initial SE before 18 months. Among the 26 patients aged 18 months or less at initial SE, the risk of DS was significantly increased for patients with two or more episodes (56.3%), as compared with those who had only one episode (0.0%) (p=0.005).
  
  
  CONCLUSIONS
  In a population of children with SE, patients most likely to have DS are those who present their initial SE episode before 18 months, and who present with recurrent SE episodes.
authors.affiliation: Psychiatric Genetic Unit, Genetic Medicine Service, University Hospitals, Geneva, Switzerland; Molecular Diagnostic Laboratory, Genetic Medicine Service, University Hospitals, Geneva, Switzerland.
authors.forename: François
authors.initials: F
authors.lastname: Le Gal
authors.affiliation: Pediatric Neurology, CHUV, Lausanne, Switzerland.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lebon
authors.affiliation: Pediatric Neurology, Regional Hospital, Bellinzona, Switzerland.
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Ramelli
authors.affiliation: Pediatric Neurology, Cantonal Hospital, Basel, Switzerland.
authors.forename: Alexandre N
authors.initials: AN
authors.lastname: Datta
authors.affiliation: Pediatric Neurology, Cantonal Hospital, Neuchâtel, Switzerland.
authors.forename: Danielle
authors.initials: D
authors.lastname: Mercati
authors.affiliation: Pediatric Neurology, Children's Hospital, St. Gallen, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Maier
authors.affiliation: Clinical Research Center, Division of Clinical Epidemiology, Department of Health and Community Medicine, University of Geneva and University Hospitals, Geneva, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Combescure
authors.affiliation: Clinical Research Platform, Child and Adolescent Department, University Hospitals, Geneva, Switzerland.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Rodriguez
authors.affiliation: Clinical Neurosciences Department, University Hospitals, Geneva, Switzerland.
authors.forename: Margitta
authors.initials: M
authors.lastname: Seeck
authors.affiliation: Pediatric Neurology, CHUV, Lausanne, Switzerland.
authors.forename: Eliane
authors.initials: E
authors.lastname: Roulet
authors.affiliation: Pediatric Neurology, Child and Adolescent Department, University Hospitals, Geneva, Switzerland. Electronic address: christian.korff@hcuge.ch.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Korff
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004831:Epilepsies, Myoclonic / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D062550:NAV1.1 Voltage-Gated Sodium Channel / Q000235:genetics; D013226:Status Epilepticus / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics
chemical_list: D062550:NAV1.1 Voltage-Gated Sodium Channel; C568242:SCN1A protein, human
keywords: Children; SCN1A; Status epilepticus