The two markers robustly GWS are rs11201929 for Maxdrinks (p = 4.11 × 10−9, q = 0.06) and rs73317305 for Problems (p = 9.02 × 10−9, q = 0.11). rs11201929 is in the third intron of glutamate ionotropic receptor delta type 1 (GRID1) and was of sufficient frequency and quality to be tested in all five ancestry groups. Figure 1 depicts the regional association plot for GRID1. The direction of effect was consistent across ancestries, though the strength of the association varied (rs11201929 p-values by group: 5 × 10−7 AFR, 0.046 AMR, 0.07 EAS, 0.0067 EUR, 0.13 SAS). The other GWS marker, rs73317305 (Problems), is in the second intron of sterile alpha motif domain containing 12 (SAMD12) on chromosome 8 and is rare in non-African populations (MAFs: AFR 0.0898, AMR 0.0175, EAS 0, EUR 0.0021, SAS 0.0008; Figure 2).
