Online databases can specifically be used to evaluate whether genes that were previously suggested in candidate gene studies are replicated in GWA studies. Research by Siontis et al. demonstrates that only a few of previously proposed candidate loci of common diseases reached genome-wide significance in GWA studies (Siontis et al., 2010). The loci that did replicate, however, had important genetic effects and included variants implicated in Alzheimer’s disease and statin-induced myopathy. Similarly, a recent analysis by Obeidat et al. examined genetic associations with lung function measures to evaluate the role of previously associated genes in a large GWA study and clarified the role of many controversial associations (Obeidat et al., 2011). This approach of comparing candidate gene and GWA studies is powerful because it highlights which findings have consistent scientific evidence and therefore merit being pursued in future studies. These findings prompted us to examine whether proposed candidate genes associated with alcohol dependence are supported by GWA data.
