Childhood absence epilepsy in 8q24: refinement of candidate region and construction of physical map.

Childhood absence epilepsy (CAE), one of the common idiopathic generalized epilepsies, accounts for 8 to 15% of all childhood epilepsies. Inherited as an autosomal dominant trait, frequent absence attacks start in early or midchildhood and disappear by 30 years of age or may persist through life. Recently, we mapped the locus for CAE persisting with tonic-clonic seizures to chromosome 8q24 (ECA1) by genetic linkage analysis. As a further step in the identification of the ECA1 gene, we constructed a bacterial artificial chromosome- and yeast artificial chromosome-based physical map for the 8q24 region, spanning about 3 Mb between D8S1710 and D8S523. Accurately ordered STS markers within the physical map aided in the analysis of haplotypes and recombinations and reduced the ECA1 region to 1.5 Mb flanked by D8S554 and D8S502. Pairwise analysis in six families confirmed linkage with a pooled lod score of 4.10 (θ = 0) at D8S534. The sequence-ready physical map as well as the narrowed candidate region described here should contribute to the identification of the ECA1 gene. Copyright 2000 Academic Press.