De novo SCN1A, SCN8A, and CLCN2 mutations in childhood absence epilepsy

Epilepsy Res. 2019 Aug:154:55-61. doi: 10.1016/j.eplepsyres.2019.04.005. Epub 2019 Apr 22.

Abstract

This study aimed to identify monogenic mutations from Chinese patients with childhood absence epilepsy (CAE) and summarize their characteristics. A total of 100 patients with CAE were recruited in Peking University First Hospital from 2005 to 2016 and underwent telephone and outpatient follow-up review. We used targeted disease-specific gene capture sequencing (involving 300 genes) to identify pathogenic variations for these patients. We identified three de novo epilepsy-related gene mutations, including missense mutations of SCN1A (c. 5399 T > A; p. Val1800Asp), SCN8A (c. 2371 G > T; p. Val791Phe), and CLCN2 (c. 481 G > A; p. Gly161Ser), from three patients, separately. All recruited patients presented typical CAE features and good prognosis. To date, CAE has been considered a complex disease caused by multiple susceptibility genes. In this study, we observed that 3% of typical CAE patients had a de novo mutation of a known monogenic epilepsy-related gene. Our study suggests that a significant proportion of typical CAE cases may be monogenic forms of epilepsy. For genetic generalized epilepsies, such as CAE, further studies are needed to clarify the contributions of de novo or inherited rare monogenic coding, noncoding and copy number variants.

Keywords: CLCN2; Childhood absence epilepsy; SCN1A; SCN8A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CLC-2 Chloride Channels
  • Child
  • Child, Preschool
  • China / epidemiology
  • Chloride Channels / chemistry
  • Chloride Channels / genetics*
  • Cohort Studies
  • Epilepsy, Absence / diagnosis*
  • Epilepsy, Absence / epidemiology
  • Epilepsy, Absence / genetics*
  • Female
  • Genetic Variation / genetics
  • Humans
  • Male
  • Mutation, Missense / genetics*
  • NAV1.1 Voltage-Gated Sodium Channel / chemistry
  • NAV1.1 Voltage-Gated Sodium Channel / genetics*
  • NAV1.6 Voltage-Gated Sodium Channel / chemistry
  • NAV1.6 Voltage-Gated Sodium Channel / genetics*
  • Protein Structure, Secondary

Substances

  • CLC-2 Chloride Channels
  • Chloride Channels
  • NAV1.1 Voltage-Gated Sodium Channel
  • NAV1.6 Voltage-Gated Sodium Channel
  • SCN1A protein, human
  • SCN8A protein, human