In the present study, although we studied alcohol and nicotine co-dependence, we obtained results that were similar to a previous GWAS that examined alcohol dependence using SAGE data[Bierut et al., 2010]. Many top-ranked risk SNPs (p<10-5) for alcohol dependence in that previous study (i.e., KIAA0040, HTR1A, PKNOX2, HAO2, CTTNBP2, TMEM47, SH3BP5 and PLEKHG1) were also listed as top-ranked genes in the present study (Table S3). Another study found that SH3BP5 was associated with polysubstance dependence in NIDA/MNB sample (rs9310472; p=0.008) and with cocaine dependence in SAGE sample (rs1318937; p=1.6×10-7) (both SNPs were claimed to be in CAPN7 in that study)[Drgon et al., 2010].
