Refined mapping of CHRNA3/A5/B4 gene cluster and its implications in ADNFLE

The chromosome 15q24 region, containing the CHRNA3/A5/B4 gene cluster, codi ng for the alpha 3, alpha 5 and beta 4 subunits of neuronal nicotinic acety lcholine receptors, has been reported to be linked to autosomal dominant no cturnal frontal lobe epilepsy (ADNFLE) in one family. However, nor the gene nor the mutation involved have been identified. We report the refined mapp ing of CHRNA3/A5/B4 cluster. Segregation analyses of CHRNA3/A5/B4 polymorph isms in families showing recombinations for 15q24 Genethon STR markers allo wed to position the cluster in a 0.6 cM interval, between STRs D15S1027 and D15S1005. This location is external to the 15q24-ADNFLE-linked region, the refore excluding the involvement of this cluster in the pathogenesis of ADN FLE in the 15q24-linked family. Moreover, these data provide more precise i nformation for further linkage studies. NeuroReport 11:2097-2101 (C) 2000 L ippincott Williams & Wilkins.