Drug screening in Scn1a zebrafish mutant identifies clemizole as a potential Dravet syndrome treatment

Nat Commun. 2013;4:2410. doi: 10.1038/ncomms3410.


Dravet syndrome is a catastrophic pediatric epilepsy with severe intellectual disability, impaired social development and persistent drug-resistant seizures. One of its primary monogenic causes are mutations in Nav1.1 (SCN1A), a voltage-gated sodium channel. Here we characterize zebrafish Nav1.1 (scn1Lab) mutants originally identified in a chemical mutagenesis screen. Mutants exhibit spontaneous abnormal electrographic activity, hyperactivity and convulsive behaviours. Although scn1Lab expression is reduced, microarray analysis is remarkable for the small fraction of differentially expressed genes (~3%) and lack of compensatory expression changes in other scn subunits. Ketogenic diet, diazepam, valproate, potassium bromide and stiripentol attenuate mutant seizure activity; seven other antiepileptic drugs have no effect. A phenotype-based screen of 320 compounds identifies a US Food and Drug Administration-approved compound (clemizole) that inhibits convulsive behaviours and electrographic seizures. This approach represents a new direction in modelling pediatric epilepsy and could be used to identify novel therapeutics for any monogenic epilepsy disorder.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anticonvulsants / pharmacology
  • Anticonvulsants / therapeutic use*
  • Benzimidazoles / pharmacology
  • Benzimidazoles / therapeutic use*
  • Bromides / pharmacology
  • Diazepam / pharmacology
  • Dioxolanes / pharmacology
  • Drug Evaluation, Preclinical*
  • Epilepsies, Myoclonic / drug therapy
  • Gene Expression Profiling
  • Mutation
  • NAV1.1 Voltage-Gated Sodium Channel / genetics
  • NAV1.1 Voltage-Gated Sodium Channel / metabolism*
  • Potassium Compounds / pharmacology
  • Seizures / drug therapy
  • Seizures / genetics
  • Valproic Acid / pharmacology
  • Voltage-Gated Sodium Channel beta-1 Subunit / genetics
  • Voltage-Gated Sodium Channel beta-1 Subunit / metabolism
  • Zebrafish / genetics
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism


  • Anticonvulsants
  • Benzimidazoles
  • Bromides
  • Dioxolanes
  • NAV1.1 Voltage-Gated Sodium Channel
  • Potassium Compounds
  • Voltage-Gated Sodium Channel beta-1 Subunit
  • Zebrafish Proteins
  • scn1ba protein, zebrafish
  • scn1laa protein, zebrafish
  • Valproic Acid
  • potassium bromide
  • Diazepam
  • stiripentol
  • clemizole