The chance that someone will develop any disease is influenced by heredity and environment. Epilepsy is not an exception. Everybody inherits a unique degree of susceptibility to seizures. About 3 percent of the United States population is prone to seizures and will get epilepsy at some point of their lives (1). Two thirds of the people with epilepsy develop the disorder because their genetic makeup plays a major role. The following article will explain some basic principles of genetics, how genes may affect the development of epilepsy and how people respond to treatment. While general information for everyone, teens with epilepsy, their parents and other caregivers can use this information to understand the role genes may play and what they can do to help assess their own genetic picture. (Contains 2 figures.)