(the remaining SNPs will be analyzed in stage two). Data are thus reported here for the 142 SNPs genotyped in the opioid receptor genes: OPRM1, OPRD1, and OPRK1 (for details, see Table 1, Supplementary Tables 1 and 2). We provide data cleaning information below for the entire set of markers since we utilized all retained SNPs to generate the principal components used to control for admixture.
