Foveal rod photoreceptors were enriched in the RNA-binding gene PNO1, which is required for ribosome assembly (27) and the retinol binding protein RBP7. In contrast, parafoveal rods were enriched for several cilia-localized genes including SCAPER, which has been implicated in Bardet-Biedl syndrome (28), and AHI1, which is a mendelian cause and modifier of Joubert syndrome (29). This evidence concerns the gene PNO1 and Joubert syndrome.