For replication, we considered samples similar to S4S with respect to age and/or alcohol phenotypes in order to minimize lack of replication due to differences in ascertainment and phenotypes. ALSPAC met these criteria due to being a sample similar in age and the derived variables being nearly identical. Replication was attempted for (1) individual variants with FDR q < 0.50 and (2) p-value threshold based polygene scores. Importantly, only results based on equivalent phenotypes were examined (e.g., markers associated with Problems in S4S were not examined for their association with Maxdrinks or Consumption). While several variants with q < 0.50 exhibited nominal associations (p < 0.05) in ALSPAC, we did not observe robust variant level replication after correction for multiple testing for any phenotype. Results are presented in Supplementary Table 2. In contrast to specific SNP results, each GPS showed some evidence for replication, with support varying across outcomes. Consumption and Problems both showed nominal significance (p < 0.05) for a wide (pthreshold 0.01 to 0.5) and narrow range (pthreshold 0.01) of thresholds, respectively. The Maxdrinks PRS was robustly associated
