IMPG2 and respiratory distress syndrome in premature infants: In the case of IRDs, several of these categories are accounted for, including collagen fibril organisation/catabolism (e.g., COL2A1), retinal/lens development (e.g., FBN1, RP genes), secretory proteins [i.e., extracellular matrix (e.g., IMPG1/IMPG2) and cell–cell junctions (e.g., RS1)] and perception of visible light (e.g., OPN1MW/OPN1LW, RHO).