SummaryMost human epilepsies are multifactorial, resulting from combined effects of genes and environment. The large number of genes whose variation and/or mutation influences the development and progression of epilepsy are only now beginning to be identified. Advanced methods of genetic analysis promise to facilitate understanding of pathogenesis and establishment of new effective treatments. For an expanded treatment of this topic see Jasper’s Basic Mechanisms of the Epilepsies, Fourth Edition (Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado‐Escueta AV, eds) published by Oxford University Press (available on the National Library of Medicine Bookshelf [NCBI] at http://www.ncbi.nlm.nih.gov/books).