Remarkable advances in our understanding of epilepsies have occurred over the last 15 years. Concepts about etiology of epilepsies have been transformed from largely unknown to predominantly genetic through clinical genetic and molecular genetic advances. In this review we contrast the early breakthroughs in epilepsy genetics including the contribution of susceptibility alleles, de novo mutations and copy number variants using traditional genetic approaches with the rapid gene discovery now possible using new sequencing technologies. The successful rise of this latter technology provides the first real opportunity to unravel the complex genetic epilepsies and allow widespread clinical application of the discoveries. (By Drs. Sam Berkovic and Michael Hildebrand, http://jmg.bmj.com/content/early/2013/03/05/jmedgenet-2012-101448 )