Modelling human KCNT1-epilepsy in Drosophila: a seizure phenotype and drug responses

Abstract

Mutations in the KCNT1 potassium channel cause severe forms of epilepsy which are resistant to current treatments. In vitro studies have shown that KCNT1-epilepsy mutations are gain of function, significantly increasing K+ current amplitudes. To investigate if Drosophila can be used to model human KCNT1 epilepsy, we generated Drosophila melanogaster lines carrying human KCNT1 with the patient mutation G288S, R398Q or R928C. Expression of each mutant channel in GABAergic neurons gave a seizure phenotype which was sensitive to drugs currently used to treat patients with KCNT1-epilepsy. Cannabidiol showed the greatest reduction of the seizure phenotype while some drugs increased the seizure phenotype. Our study shows that Drosophila can be used to model human KCNT1-epilepsy and potentially used as a tool to assess new treatments for KCNT1 epilepsy.