Progress in the genetics of the partial epilepsies

The importance of genetic contributions to the partial epilepsies is now we ll established. Evidence for this genetic contribution has come from famili al aggregation studies, twin studies, positional cloning of specific genes that raise risk, and clinical descriptions of families. Familial aggregatio n studies are consistent in showing an increased risk of epilepsy in the re latives of patients with partial epilepsies that occur in the absence of en vironmental insults to the central nervous system. Susceptibility genes hav e been localized in five syndromes: autosomal dominant nocturnal frontal lo be epilepsy (20q, 1q, and 15q), autosomal dominant partial epilepsy with au ditory features (10q), familial partial epilepsy with variable foci (22q), benign epilepsy of childhood with centrotemporal spikes ( 15q), and benign familial infantile convulsions (19q). In nocturnal frontal lobe epilepsy, t he genes on chromosome 20q and Iq have been identified as subunits of the n euronal nicotinic acetylcholine receptor.