An exploratory representative group of 103 subjects was selected, based on their 118A>G genotype, from our European American cohort, which was collected for genetic studies with heroin addiction as described.9 To reduce the potential effect of population stratification, only subjects with a European ancestry proportion of >0.7 based on AIMs analysis were included (see below). The group can be divided as follows: 1) ”118G”/”118G” (n=5); 2) “REF”/”118G” (n=52); 3); “IVS1”/”118G” (n=17); and 4) ”REF”/“REF” (n=29). Since the 118G allele was not found to be associated with heroin addiction in this cohort, both cases (former heroin addicts in methadone maintenance treatment) and controls were included, except for subgroup 3 that included only control subjects. Subjects were recruited at the Rockefeller University Hospital, Weill Medical College of Cornell University, and the Dr. Miriam and Sheldon G. Adelson Clinic for Drug Abuse Treatment and Research in Las Vegas, NV. The Institutional Review Boards of the Rockefeller University Hospital and Cornell University approved the study for the three institutions. All subjects signed informed consent for genetic studies.
