The POMC gene is located on chromosome 2p23 and all the variants in the coding regions are rare. In one reported association study, seven SNPs were genotyped in a sample of alcoholic families (COGA) and association was found for intronic SNP rs934778 and general illicit drug dependence. Two intronic SNPs (rs934778 and rs1009388) were associated with opioid dependence in a small subsample of this cohort (Xuei et al. 2007). In a second association study of AD in European sample, nine SNPs were analyzed. Three SNPs were associated with AD, out of which SNP rs934778 was associated after Bonferroni correction. The T-A haplotype (rs934778 and rs3769671) was associated with AD in women only (Racz et al. 2008). A third association study of five SNPs with AD, CD or OD was reported in AA and EA (Zhang et al. 2009). The main finding is of SNP rs1866146 in the 3′ flanking region that was associated with OD or CD in AAs, and with AD, CD or OD in EAs. In addition, the intronic SNP rs6713532 was marginally associated with AD or CD
