the European-Americans as the discovery sample and the African-Americans as the validation sample, we identified KIAA0040 as risk gene for alcohol dependence (Zuo et al., 2012). Using the African-Americans as the discovery sample and the European-Americans as the validation sample, we identified PTP4A1-PHF3 as risk gene region for alcohol dependence (Zuo et al., 2011). In the present study, we used the European-Americans as the discovery sample and the European-Australians as the validation sample, with the goal of identifying novel (i.e., previously unimplicated) risk loci specific for alcohol dependence. Using these relatively homogenous samples in one association study might reduce the false negative rates due to sample heterogeneity, increasing the chance to detect novel risk loci.
