GABRA2 has been extensively investigated for its role in alcoholism, alcohol sensitivity, anxiolytic effects of benzodiazepines, and its effect on EEG β patterns. The evidence suggests that this gene may have a pleiotropic effect on brain function involving overlapping mechanisms. The presence of alcohol and benzodiazepine binding sites in this subunit reveals the role of GABRA2 on alcohol sensitivity and anxiety (Low et al., 2000, Uhart et al., 2012), while the effect of GABRA2 genetic variation on the EEG β wave suggests a different mechanism, involving the excitation-inhibition homeostatic balance and impulsivity. Converging lines of evidence point to the role of GABRA2 on impulsive related-behavior. Both in ADHD children and alcoholics with impulsive behaviors show increase in the EEG β activity (Bauer and Hesselbrock, 1993, Clarke et al., 2001). The frontal region is associated with self-regulation and inhibition/control behavior. It appears that genetic variation in GABRA2 that influences the β activity in EEG may also influence inhibitory control behaviors such as impulsiveness. The moody and temper tantrum behavior may be related to the kinds of impulsiveness we describe here, involving lack of control under distress.
