title: Duplication of the sodium channel gene cluster on 2q24 in children with early onset epilepsy.
abstract: OBJECTIVE
  Sodium channel gene aberrations are associated with a wide range of seizure disorders, particularly Dravet syndrome. They usually consist of missense or truncating gene mutations or deletions. Duplications involving multiple genes encoding for different sodium channels are not widely known. This article summarizes the clinical, radiologic, and genetic features of patients with 2q24 duplication involving the sodium channel gene cluster.
  
  
  METHODS
  A systematic review of the literature and report of two cases.
  
  
  RESULTS
  Nine individuals with 2q24 duplication involving the sodium channel gene cluster are described (seven female, two male). All presented with severe seizures refractory to anticonvulsant drugs. Seizure onset was in the neonatal period in eight patients with SCN1A-involvement, in infancy in one patient with SCN2A and SCN3A, but no SCN1A involvement. Seizure activity decreased and eventually stopped at 5-20 months of age. Seizures recurred at the age of 3 years in the patient with SCN2A and SCN3A, but no SCN1A involvement. Eight patients had a poor neurodevelopmental outcome despite seizure freedom.
  
  
  CONCLUSIONS
  This article describes a distinct seizure disorder associated with a duplication of the sodium gene cluster on 2q24 described in otherwise healthy neonates and infants with severe, anticonvulsant refractory seizures and poor developmental outcome despite seizure freedom occurring at the age of 5-20 months.
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Inselspital, University of Berne, Berne, Switzerland. barbara.goeggel-simonetti@insel.ch
authors.forename: Barbara
authors.initials: B
authors.lastname: Goeggel Simonetti
authors.forename: Claudine
authors.initials: C
authors.lastname: Rieubland
authors.forename: Carolina
authors.initials: C
authors.lastname: Courage
authors.forename: Susi
authors.initials: S
authors.lastname: Strozzi
authors.forename: Sibylle
authors.initials: S
authors.lastname: Tschumi
authors.forename: Sabina
authors.initials: S
authors.lastname: Gallati
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Lemke
mesh_terms: D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D016208:Databases, Factual / Q000706:statistics & numerical data; D004569:Electroencephalography; D004827:Epilepsy / Q000235:genetics*; D005260:Female; D020440:Gene Duplication / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D015222:Sodium Channels