the gene cluster and only detected significant allelic and haplotypic association with SNPs in GABRA2, where the region of strongest association with alcohol dependence extended from intron 3 past the 3’ end of GABRA2. A recent study by Covault and colleagues (2008) has extended the observed association from the GABRA2 locus to potential regulatory regions immediately upstream of GABRG1 (downstream of GABRA2). Independent studies have confirmed the association between GABRA2 and AD in other Caucasian populations from the U.S. (Covault et al., 2004), Russia (Lappalainen et al., 2005) and Germany (Fehr et al., 2006; Soyka et al., (2008)) using a case-control approach, while others groups have found no association (Drgon et al., 2006; Matthews et al., 2007)
