Genetic aspects of childhood epilepsy.

The extensive studies pertinent to these problems cannot be elaborated here. We have restricted ourselves to a few representative concepts, which can be summarized as follows. The genetic aspects of convulsibility and epilepsy are highly complex phenomena. The level of convulsibility is determined by a number of different excitatory (and inhibitory) genetic factors. None of these factors is strictly specific to epilepsy. Each one is only a partial aspect of a complex genetic constitution which is strikingly common in perfectly healthy individuals, and which is related to a variety of psychic and somatic particularities. Almost all of these genetic factors seem to be polygenetically determined; in other words, they seem to reflect the actions of many genes. An increased liability to convulsions, and, finally, to epilepsy, is induced by an accumulation of these factorial sets, and, of course, by the effects of exogenous lesional factors. Special constellation of these polygenic sets may lead to the manifestation of different epileptic syndromes and may also explain the segregation of seizure types in the descendants of patients with seemingly uniform epileptic syndromes, as observed, for instance, in absence epilepsy and in juvenile myoclonic epilepsy.