None of the quantitative alcohol consumption measure showed significant associations, including the MaxDr and MaxDr12 phenotypes which have previously been shown to be highly correlated with alcohol use disorders (Saccone et al., 2000). Overall, there is little support for GABRA2 allelic effects on alcohol intake in our population. Furthermore, GABRA2 was not associated overall with smoking, cannabis or other illicit drug use. However, evidence in a case-control subset suggested an association between GABRA2 and current smoking status among ever-smokers (i.e., smoking persistence), including the synonymous polymorphism, rs279858, which has recently been found to be associated with nicotine dependence in a sample of U.S. and Australian adults (Agrawal et al., 2008).
