that could account for the association. The previously reported associations between GABRA2 and AD could be attributable in part to the adjacent gene, GABRG1, which is located 90kb distant in the 3′ direction, and is in strong LD with GABRA2 in many populations (Ittiwut et al 2008). This explanation was first suggested by Covault et al., (2008) in a study of European Americans and was replicated and extended in a study of Plains Indians and Finns (Enoch et al., 2009). The aim of the present study was to investigate these two candidate genes in AAs, where linkage disequilibrium is lower than that in other populations (Ittiwut et al., 2008), possibly permitting the source of an association signal (or signals) to be resolved.
