Alcohol has prominent effects on GABA-A receptors (e.g., Korpi et al., 1993; Ray and Hutchinson, 2009), variants of which may relate to AUD risks (e.g., Covault et al., 2008; Kareken et al., 2010; Kosobud et al., 2015; Krustal et al., 2006), and perhaps to sensitivity. Beginning with GABRA2 (chromosome 4p12), oral and IV alcohol challenges indicate relationships to sensitivity and heavier drinking for G-alleles of rs279858 (e.g., Arias et al., 2013; Covault et al., 2004, 2008; Kosobud et al., 2015; Lappalainen et al., 2005; Pierucci-Lagha et al., 2005; Roh et al., 2011; Uhart et al., 2012); rs279869 and rs279837 (Roh et al., 2011); rs279871 AA genotype (Kareken et al., 2010); the minor allele (T) for rs279844 (Uhart et al., 2012); and for a haplotype block of minor alleles for rs279858 (C-allele), rs279844 (T-allele), rs279845 (A-allele), rs279826 (G-allele), rs279828 (C-allele), and 279836 (A-allele) (Uhart et al., 2012).
