Interneuron, interrupted: molecular pathogenesis of ARX mutations and X-linked infantile spasms

► ARX is a transcription factor deeply involved in interneuron development. ► ARX mutations can cause epilepsy, infantile spasms, and intellectual disability. ► Downstream consequences of Arx mutations reveal complex molecular pathogenesis. ► Mouse models of human ARX mutations are valuable tools to study role of Arx in vivo. ► New mouse models provide a substrate for the investigation of novel therapies.