Since variation in GABRA2 has been associated with childhood conduct disorder symptoms, EEG-β and alcoholism, we hypothesized that it may also influence behavioral traits such as impulsivity, an externalizing risk behavior for AUD. Here we report testing for a genetic association between two GABRA2 SNPs and the NEO-PI-R Impulsiveness facet. The test was carried out in a community-recruited sample of families which had at least one member with DSM-IV AUD diagnosis or were from an age and socioeconomically comparable group of control families 29. A subset of this sample comprising adolescent and young adult offspring underwent an fMRI study using a modification of the Monetary Incentive Delay Task 30. Given the role of the anterior insula cortex in the representation of interoceptive responses to emotionally salient and rewarding stimuli, the blood-oxygenation-level-dependent (BOLD) activation of this region was obtained during anticipation of a monetary reward or loss. We anticipated that genetic variation in GABRA2 would be associated with Impulsiveness, as well as with insula cortex activation, which in turn would be positively correlated with Impulsiveness.
