There are two recent linkage studies on opioid dependence using single nucleotide polymorphisms (Lachman et al., 2007, Yu et al., 2008). The Gelernter group found eight variants with point-wise significance in an association study of opiate dependence (Yu et al., 2008), and Lachman et al. found one region at chromosome 14q in their Hispanic group that was “suggestive” of genome-wide evidence for linkage (Lachman et al., 2007). We did not confirm these linkage findings in our study.
