In 173 Hispanics, methylation levels at the −60 (P = 0.025), −50 (P = 0.024), −25 (P < 0.001), −14 (P < 0.001), −10 (P = 0.045), +23 (P = 0.04), and the +27 (P < 0.001) CpG sites were significantly different point-wise between the cases and controls (Table 5). At six of these seven CpG sites, cases were hypermethylated compared with the controls. After correcting for multiple testing, the −25 (P < 0.001), −14 (P = 0.001), and the +27 (P < 0.001) CpG sites had experiment-wise significant differences in methylation levels. These three CpG sites were hypermethylated in the former heroin addicts as compared to the controls (−25 CpG site 30.5 vs. 23.4%; −14 CpG site 20.4 vs. 15.5%; +27 CpG site: 12.9 vs. 7.7%).
