Advances in molecular genetics and molecular biology are transforming the biology of human disease. Cures for diseases previously refractory to all treatments have become the reality for some disorders and the legitimate promise for others. In the case of the epilepsies, identification of mutant genes underlying familial epilepsies may lead to a new pharmacology, through the development of in vitro expression systems permitting rapid search for novel drugs, creation of highly specific animal models based on expression of the precise mutation, and correction of disease phenotype by introducing novel and highly specific genetic information into the person with epilepsy.