CHILDHOOD ABSENCE EPILEPSY WITH TONIC-CLONIC SEIZURES AND ELECTROENCEPHALOGRAM 3-4-HZ SPIKE AND MULTISPIKE-SLOW WAVE COMPLEXES - LINKAGE TOCHROMOSOME 8Q24

Childhood absence epilepsy (CAE), a common form of idiopathic generali zed epilepsy, accounts for 5%-15% of childhood epilepsies. To map the chromosomal locus of persisting CAE, we studied the clinical and elect roencephalographic traits of 78 members of a five-generation family fr om Bombay, India. The model-free affected-pedigree member method was u sed during initial screening with chromosome Gp, 8q, and Ip microsatel lites, and only individuals with absence seizures and/or electroenceph alogram 3-4-Hz spike- and multi-spike-slow wave complexes were conside red to be affected. Significant P values of .00000-.02 for several mar kers on 8q were obtained. Two-point linkage analysis, assuming autosom al dominant inheritance with 50% penetrance, yielded a maximum LOD sco re (Z(max)) of 3.6 for D8S502. No other locus in the genome achieved a significant Z(max). For five smaller multiplex families, summed Z(max ) was 2.4 for D8S537 and 1.7 for D8S1761. Haplotypes composed of the s ame 8q24 microsatellites segregated with affected members of the large family from India and with all five smaller families. Recombinations positioned the CAE gene in a 3.2-cM interval.