copies of the minor allele in the European-American sample; this coding choice is arbitrary but allows for consistent reporting. The full model includes both genotype (β2*G) and genotype-by-population (β3*G*s) terms: ln(P1−P)=α0+α1x1+...+αnxn+β1s+β2G+β3Gs and we test for significance of genetic effect by the standard likelihood ratio chi-square statistic with two degrees of freedom (df). The population-specific odds ratios for the effect of a copy of the minor allele are given by exp(β2) for the EA sample and exp(β2 + β3) for the AA sample.
