Two other GWAS of alcohol consumption phenotypes have been reported in European-ancestry populations. Heath et al (2011) conducted a GWAS analysis with a well characterized quantitative phenotype for heaviness of alcohol consumption that included MaxDrinks in the Australian Twin Registry sample (a total of 8,300 subjects), and failed to identify a genome wide significant association (Heath et al., 2011). Our success in identifying potential novel loci for MaxDrinks is likely due to a higher density genotyping array and a greater proportion of affected subjects in the present study. Approximately 890,000 SNPs were genotyped in our samples compared to only 30K SNPs in Heath et al.'s study. More recently, Pan et al (2013) reported several SNPs at DDC that were associated with MaxDrinks in the SAGE sample (p=2.87 x 10-5) (Pan et al., 2013). They also reported an association of rs1128951 on chromosome 3 with MaxDrinks in the combined SAGE and COGA samples (p=4.3 x 10-8). It is noteworthy that the p value in that study did not reach the conventional value of 5x10-8. We did not replicate either finding. The
