Alcohol dependence is a common disorder affecting 4–5% of the United States population at any given time, (Li et al., 2007) with a lifetime prevalence of 12.5% (Hasin et al., 2007). Family, twin and adoption studies have consistently demonstrated a substantial genetic contribution to disease etiology (Cloninger et al., 1981; Heath et al., 1997; Kendler et al., 1994; McGue, 1999; Pickens et al., 1991;). Recent human studies have identified several genes associated with alcohol dependence, including GABRA2 (Covault et al., 2004; Edenberg et al., 2004; Fehr et al., 2006; Lappalainen et al., 2005), ADH4 (Edenberg et al., 2006; Guindalini et al., 2005; Luo et al., 2005b), GABRG3 (Dick et al., 2004), CHRM2 (Luo et al., 2005a; Wang et al., 2004), NFKB1 (Edenberg et al., 2007), OPRK1 and PDYN (Edenberg et al 2008; Xuei et al 2006) and TAS2R16 (Hinrichs et al., 2006).
