Genetic investigations of the epileptic encephalopathies: Recent advances

The epileptic encephalopathies (EEs) are a group of epilepsy syndromes characterized by multiple seizure types, abundant epileptiform activity, and developmental delay or regression. Advances in genomic technologies over the past decade have accelerated our understanding of the genetic etiology of EE, which is largely due to de novo mutations. Chromosome microarrays to detect copy number variants identify a genomic cause in at least 5-10% of cases. Next-generation sequencing in the form of gene panels or whole exome sequencing have highlighted the role of de novo sequence changes and revealed extensive genetic heterogeneity. The novel gene discoveries in EE implicate diverse cellular pathways including chromatin remodeling, transcriptional regulation, and mTOR regulation in the etiology of epilepsy, highlighting new targets for potential therapeutic intervention. In this chapter, we discuss the rapid pace of gene discovery in EE facilitated by genomic technologies and highlight several novel genes and potential therapies.