This study identified a genomewide significant locus on chromosome 10 for cannabis dependence diagnosis in subjects of European descent. To date, only one other (Table 1) study (8) identified genomewide significant loci for cannabis dependence criterion count. The novel locus identified in the present study included a representative SNP, rs1409568, which showed modest evidence for replication in the AA, but not EA, participants from the independent Yale-Penn sample that was part of the only other study with genomewide significant SNPs. The lack of replication in the EA component of Yale-Penn may reflect lower power (i.e., fewer cases than the AA component, or higher minor allele frequency in AA than EA) or ascertainment differences. It is also noteworthy that patterns of LD for the SNPs in Table 3 differ across CEU and ASW populations (based on 1000 Genomes data; Supplemental Figure S8)(50); replication that was noted in the AAs was present in spite of these differences. Nonetheless, associations in the Yale-Penn EA participants were in the same direction as the current meta-analysis.
