Although Rom1−/− mice exhibit much milder phenotype than Prph2 knockouts, and retinal disease attributable to pathogenic mutations in ROM1 alone has yet to be described, ROM1 has been shown to play a significant role in OS biogenesis, especially in the maturation of the OS with PRPH2 (Sato et al. 2010; Zulliger et al. 2018). This evidence concerns the gene PRPH2 and Abnormal retinal morphology.