Five DRD1 (rs4532, rs686, rs265978, rs265975, rs265973), three HOMER1 (rs4323213, rs13356332, rs4293896) and three DLG4 (rs2521985, rs507506, rs2242449) SNPs were selected for genotyping. All of the selected SNPs were either functional, in strong linkage disequilibrium with a functional polymorphism, or were previously associated with addiction-related phenotypes.23–28 See Supplemental Table 3 for a list of all SNPs genotyped, including SNP location, alleles and minor allele frequency.
