Linkage analysis is performed on specimens and analysis of shared marker alleles are used to identify genomic regions likely or unlikely to contain the epilepsy genes. Genotypes in family members are determined at microsatellite markers throughout the genome. Markers tested include chromosomes linked to human epilepsy syndromes (6p, 8p, 8q, 20q, 21q) and chromosome 3 (similar to mouse "epilepsy" genes). Linkage to markers on chromosome 10q are also tested.