Two independent cohorts, comprised of heroin and other opioid abuse/dependent participants (henceforth referred to as heroin addiction cases) and their own controls, were used to replicate SNP associations with heroin addiction. First, we used African Americans from the “Alcohol Dependence [genome-wide association study] GWAS in European- and African Americans (CIDR – Gelernter Study)” (dbGaP accession number phs000425.v1.p1) (7). Our final analysis dataset included 852 African Americans (307 DSM-IV-defined cases of heroin/other opioid abuse or dependence and 545 controls with no illicit drug abuse or dependence, see Table S2 and Supplemental Methods). European Americans from this cohort were not analyzed because there was an insufficient number of independent controls (<5) who met our inclusion criteria.
