alcoholism and the GABRA2 gene (Enoch et al., 2009; Enoch et al., 2010; Onori et al., in press), or have found the GABRA2 association with alcoholism to be mediated by anxiety (Enoch et al., 2006). Nevertheless, others report a relationship between GABRA2 and reduced pleasurable effects from alcohol (Pierucci-Lagha et al., 2005), early onset and familial alcoholism (Fehr et al., 2006), drinking frequency in alcoholics in treatment (Bauer et al., 2007), and alcoholic withdrawal signs (Soyka et al., 2008). Although no apparent coding differences have been found in GABRA2 that could account for the reported association (Edenberg et al., 2004), Hurley et al (2009) mimicked gene expression by altering the relative concentrations of GABA-A subunits— a manipulation that changed GABA current amplitudes both in the absence of alcohol as well as during alcohol exposure. Thus, given associations between GABRA2 gene variation and alcoholism, the response to alcohol, related behavioral characteristics, and a particular β-EEG endophenotype, this gene seems a promising candidate to pursue in human neuroimaging studies.
