Genetic etiology of new forms of familial epilepsy.

Epilepsy is a common neurological disorder with an incidence of approximately 0.5%. In order to develop better strategies for treatment of epilepsy, more insight on the etiology and pathogenesis of epilepsy is required. In 2001, based on the diagnostic scheme of the International League Against Epilepsy, three new forms of familial epilepsy were identified. These include familial temporal lobe epilepsy, familial focal epilepsy with variable foci, and generalized epilepsy with febrile seizure plus. Mutation of a distinct set of genes has been reported in several forms of epilepsy. Mutation of LGI1 gene has been identified in familial lateral temporal lobe epilepsy while mutations of genes which encode sodium channels and GABAA receptors have been reported in generalized epilepsy with febrile seizure plus. However, no disease-causing gene has yet been found in families with familial mesial temporal lobe epilepsy or those with familial focal epilepsy with variable foci. Here, we review the genetic background of these three familial epilepsy syndromes, and provide a better insight on their genetic etiology.