GRM1 and retinal degeneration: Additionally, downregulation of rhodopsin rho, gnat1, grm1, grm5, pde6b, and opn1mw2 in both Alström and BBS may be major drivers of the retinal degeneration that is characteristic of both disorders, as these genes were found in the majority of the downregulated visual and phototransduction pathways (Additional file 4: Figure S2A-B).