The genomic organization of the OPRM1 gene region is shown in Figure 1a. OPRM1 is mapped to chromosome 6q25.2 at position 154.4–154.7 Mb (NCBI build 37.1) and is flanked at the 5′ end by three non-functional pseudogenes. The next gene upstream to OPRM1, the regulator of G-protein signaling 17 gene (RGS17), is located at a 1 mega base distance at position 153.4. At the 3′ end, OPRM1 is overlapped by the phosphoinositide-binding protein PIP3-E gene (IPCEF1), in the opposite orientation.
