Having established the areas of exonic conservation within the OPRM1 gene locus, we selected a set of 30 candidate SNPs that potentially cover the functional allelic diversity of the gene, with an emphasis on the newly identified exons and promoter regions. Genotyping data were collected from 196 healthy Caucasian female volunteers, characterized for their sensitivity to noxious stimuli by calculating a summary pain-sensitivity score. From the examined 30 SNPs, five (rs1323040, rs7775848, rs1799972, rs1042753 and 12205732) were found to be monomorphic. The remaining 25 SNPs were analyzed. All markers were found to conform to Hardy–Weinberg equilibrium, with the exception of the rs1294094 and rs6912029, which were removed from the association analysis (Table 2).
