title: SCN1A Gene Mutation and Adaptive Functioning in 18 Vietnamese Children with Dravet Syndrome.
abstract: OBJECTIVE
  Dravet syndrome is a rare and severe type of epilepsy in infants. The heterogeneity in the overall intellectual disability that these patients suffer from has been attributed to differences in genetic background and epilepsy severity.
  
  
  METHODS
  Eighteen Vietnamese children diagnosed with Dravet syndrome were included in this study. SCN1A variants were screened by direct sequencing and multiplex ligation-dependent probe amplification. Adaptive functioning was assessed in all patients using the Vietnamese version of the Vineland Adaptive Behavior Scales, and the results were analyzed relative to the SCN1A variants and epilepsy severity.
  
  
  RESULTS
  We identified 13 pathogenic or likely pathogenic variants, including 6 that have not been reported previously. We found no correlations between the presence or type of SCN1A variants and the level of adaptive functioning impairment or severity of epilepsy. Only two of nine patients aged at least 5 years had an adaptive functioning score higher than 50. Both of these patients had a low frequency of convulsive seizures and no history of status epilepticus or prolonged seizures. The remaining seven had very low adaptive functioning scores (39 or less) despite the variability in the severity of their epilepsy confirming the involvement of factors other than the severity of epilepsy in determining the developmental outcome.
  
  
  CONCLUSIONS
  Our study expands the spectrum of known SCN1A variants and confirms the current understanding of the role of the genetic background and epilepsy severity in determining the developmental outcome of Dravet syndrome patients.
authors.affiliation: Research Center for Genetics and Reproductive Health, School of Medicine, Vietnam National University HCMC, Ho Chi Minh City, Vietnam. hangdo009@gmail.com.
authors.forename: Thi Thu Hang
authors.initials: TT
authors.lastname: Do
authors.affiliation: Center for Molecular Biomedicine, University of Medicine and Pharmacy HCMC, Ho Chi Minh City, Vietnam.
authors.forename: Diem My
authors.initials: DM
authors.lastname: Vu
authors.affiliation: Neurology Department, Children Hospital 2, Ho Chi Minh City, Vietnam.
authors.forename: Thi Thuy Kieu
authors.initials: TT
authors.lastname: Huynh
authors.affiliation: Neurology Department, Children Hospital 2, Ho Chi Minh City, Vietnam.
authors.forename: Thi Khanh Van
authors.initials: TK
authors.lastname: Le
authors.affiliation: Department of Herbal Medicine Resource, Institute of Bioscience and Biotechnology, Kangwon National University, Samcheok, Korea.
authors.forename: Eun Hwa
authors.initials: EH
authors.lastname: Sohn
authors.affiliation: Department of Laboratory Medicine, Faculty of Nursing and Medical Technology, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam.
authors.forename: Thieu Mai Thao
authors.initials: TM
authors.lastname: Le
authors.affiliation: National Institute of Forensic Medicine, Hanoi, Vietnam.
authors.forename: Huu Hao
authors.initials: HH
authors.lastname: Ha
authors.affiliation: Center for Molecular Biomedicine, University of Medicine and Pharmacy HCMC, Ho Chi Minh City, Vietnam.
authors.forename: Chi Bao
authors.initials: CB
authors.lastname: Bui
keywords: SCN1A; Vietnamese; adaptive functioning; dravet syndrome