Heath et al., 2011 performed a GWAS of alcohol dependence using several quantitative phenotypes: alcohol dependence factor score, heaviness of drinking factor score, and several measures of consumption (e.g., past 12-month frequency and maximum drinks per day) (Heath et al., 2011). Cases (n = 2062) were obtained from an Australian twin community sample and their nuclear families, while the control sample was drawn from the Australian population (n = 3393). This was the largest GWAS to date in terms of the sample size. However, even with the increased sample size and the presumed increased power from the use of quantitative phenotypes, Heath et al., 2011 report no SNPs that meet a genome-wide significance level. SNPs with the most significant p values (p < 10–7) of the study were found in or near these candidate genes: SNP (rs9512637) RASL11A, and a SNP (rs9556711) MBNL2. Several of these top signals may have functional relevance underlying alcohol dependence.
