ALDH2 and Stroke: For the two behavioral traits, we found that a long region (~2 Mbp) crossing the ALDH2 gene on chromosome 12 (lead SNP rs671) was strongly associated with heavy drinking behavior (> 20 g/day) among the stroke patients (rs671-G, OR = 3.18, 95% CI = 2.83–3.59, MAF = 0.16, P = 2.43 × 10–83) (Fig. 4; Supplementary Figs. S19, S21 and Table S18).