In the AA-only sample, none of the SNPs pass multiple-test correction for significance (Table 2). However, the top SNPs suggest some interesting findings. First, rs1881492 in CHRNG is the most significant SNP in AAs (OR = 1.57 (1.17-2.11), p = 0.00245), and is also associated in EAs, but the odds ratio is in the opposite direction (OR = 0.77 (0.66-0.90), p = 0.0012). Therefore, the 2-df test of SNP and SNP × population, which allows effects to differ between populations, yields a p-value of 4.25 × 10−5.
