GENETICS OF THE EPILEPSIES

The risk of progeny developing epilepsy is increased in idiopathic epi lepsy and in children whose mothers are epileptic. Even in members of family without manifest signs of the disease, there is an increased in cidence of epilepsy-specific EEG characteristics in addition to EEG an omalies. Genetic research and molecular genetic analyses aim toward as signing the international classification to syndromes that are phenoty pically as homogeneous as possible. Understanding of the familial dist ribution of idiopathic focal forms of epilepsy is still incomplete. Au tosomal dominant hereditary benign familial neonatal seizures have pro ved to be heterogeneous, both clinically and with regard to gene local isation. Juvenile myoclonic epilepsy is probably also associated with genetic heterogeny. If one compares the symptoms of idiopathic general ised epilepsy (IGE) in close relatives with the syndromes of the subje ct it can be seen that, although all the syndromes of IGE occur, the s ubject's syndromes manifest most frequently. Hence, one must assume po lygenetic conditions with both common and syndrome-specific factors. i n the rare form of progressive myoclonic, Unverricht-Lundborg, epileps y, which is an autosomal recessive condition, a systematic genome sear ch has uncovered a gene locus on chromosome 21. None of the investigat ions to date have demonstrated heterogeny.