Toward this goal, we performed an analysis of genetic variations and haplogroups in the OPRM1 100 kb 5′ flanking region, exon 1, and the 50 kb intron 1, and searched for regions in high LD with the 118G and/or the intron 1 variants. Genotype data were obtained from the International HapMap Project and from tag SNPs in a sample of European Americans.
