Using a population-based study of emerging adults at a diverse mid-Atlantic university, the Spit for Science sample, we present evidence of replicable aggregate genetic influences on three alcohol-related phenotypes: typical monthly consumption (Consumption), maximum drinks in 24 h (MaxDrinks), and an alcohol problems sum score (Problems). We find further support that Consumption is heritable (h2SNP 0.19, SE = 0.11). At the marker level, variation in a previously implicated (see below) gene, GRID1, surpasses stringent genome-wide significance criteria for association with MaxDrinks. Furthermore, polygenic scores derived from S4S for Consumption and Maxdrinks, and Problems to a lesser extent, are significantly associated with the equivalent outcomes in an independent and comparably-aged sample. These results provide empirical support for the influence of aggregate molecular variation on multiple alcohol outcomes.
