title: SCN2A mutation in a Chinese boy with infantile spasm - response to Modified Atkins Diet.
abstract: BACKGROUND
  Mutation of SCN2A, encoding for voltage-gated sodium channel type II alpha subunit, has been demonstrated in various epilepsy phenotypes, ranging from benign to severe epileptic disorders and recently this had been reported for cases with infantile spasm (IS).
  
  
  METHODS
  We study a 6 years-old Chinese boy with severe developmental delay who had infantile spasm since 15 months. He later had severe intellectual disability and autistic features. He failed to respond to most anticonvulsants. Modified Atkins Diet was introduced at 4 years of age and he showed a seizure remission for 12 months with only 1 anticonvulsants. To clarify the unknown etiology, mutations were screened for genes associated with brain development or synaptic function.
  
  
  RESULTS
  A heterozygous mutation (c.3631G>A; p.E1211K) was identified in exon 21 of SCN2A gene. This mutation has been reported previously only in a Japanese patient with IS.
  
  
  CONCLUSIONS
  This is the first case of SCN2A mutation identified in Chinese. Similarity of our case and one Japanese case of infantile spasm indicated that this E1211K mutation is important as possible etiology of IS. Trial of Modified Atkins Diet for other cases of infantile spasm with similar SCN2A mutations is worthwhile pursuing.
authors.affiliation: Division of Paediatric Neurology/Developmental Behavioural Paediatrics/NeuroHabilitation, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong Special Administrative Region, China; Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China. Electronic address: vcnwong@hku.hk.
authors.forename: Virginia C N
authors.initials: VC
authors.lastname: Wong
authors.affiliation: Division of Paediatric Neurology/Developmental Behavioural Paediatrics/NeuroHabilitation, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong Special Administrative Region, China; Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: C W
authors.initials: CW
authors.lastname: Fung
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Anna K Y
authors.initials: AK
authors.lastname: Kwong
mesh_terms: D044466:Asian People; D002648:Child; D002681:China; D050528:Diet, Carbohydrate-Restricted; D005091:Exons; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D062551:NAV1.2 Voltage-Gated Sodium Channel / Q000235:genetics*; D013036:Spasms, Infantile / Q000178:diet therapy* / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: D062551:NAV1.2 Voltage-Gated Sodium Channel; C568251:SCN2A protein, human
keywords: Epilepsy; Infantile spasm (IS); Modified Atkins Diet; SCN2A; Sodium channel