Nociceptin is a 17-amino acid neuropeptide that binds OPRL1. The PNOC gene is located on chromosome 8p21. Ten rare coding SNPs were described and one non-synonymous SNP (rs76786693, Ala118Gly) is common in Asian populations. Only three association studies have been reported with PNOC SNPs. Fifteen PNOC SNPs were analyzed in the COGA cohort. Two SNPs (rs17058952, in the 5′ flanking region, and rs351779, in the 3′ flanking region) were associated with AD, and one SNP (rs4732636, in the 5′ flanking region) was associated with illicit drug dependence (Xuei et al. 2008). No associations were reported for seven SNPs studied in EAs and AAs (Levran et al. 2008; Levran et al. 2009). The only SNP that was common to these studies is rs351784.
