Another prediction from the transcriptomic data was perturbed visual perception in the pex1–/– larvae, based on the downregulation of genes encoding light-sensitive receptors such as rhodopsin, opn1sw2, and opn1sw1. This molecular signature was corroborated by histopathological analysis of adult pex1–/– fish, which revealed disorganization of the retinal layers, reminiscent of the progressive retinopathy observed in ZSD patients (Yergeau et al., 2023). Here, PEX1 is linked to peroxisome biogenesis disorder.