dependence on at least one illegal substance and 320 controls [25]; iii) 500 K SNP genotype data from 140 methamphetamine abusers of ethnic Han Chinese origin, with 240 Han Chinese controls [26]; iv) 500 K SNP genotype data from 100 methamphetamine abusers of Japanese origin, with 100 Japanese controls [26] and v) 100 K SNP genotype data from 120 alcohol-dependent individuals and 160 unrelated unaffected controls with European-American ethnicities [27]. Initial data analyses were performed and statistical tests were conducted to assess the susceptibility of each SNP marker [25].
