FURTHER EVIDENCE FOR CLUSTERING OF HUMAN GABA(A) RECEPTOR SUBUNIT GENES - LOCALIZATION OF THE ALPHA(6)-SUBUNIT GENE (GABRA6) TO DISTAL CHROMOSOME-5Q BY LINKAGE ANALYSIS

GABA(A) receptors are hetero-oligomeric ion-channel complexes that are composed of combinations of alpha,beta, gamma, and delta subunits and play a major role in inhibitory neurotransmission in the mammalian br ain. We report here a microsatellite polymorphism within the human alp ha6-subunit gene (GABRA6). Mapping of this marker in a human-hamster h ybrid cell-line panel and typing of the repeat in the Centre d'Etude d u Polymorphisme Humain (CEPH) reference families enabled the localizat ion of this gene to chromosome 5q and established its linkage to the G ABA(A) receptor alpha1-subunit gene (GABRA1) with a maximum lod score (Z(max)) of 39.87 at a theta of 0.069 (males) and 0.100 (females). The se results reveal the clustering of GABRA6, GABRA1, and the GABA(A) re ceptor gamma2-subunit gene (GABRG2) on distal chromosome 5q. (C) 1994 Academic Press, Inc.