Homozygous or compound-heterozygous pathogenic variants in the PEX26 gene cause ZSD of complementation group 8, which have variable clinical manifestations ranging from a severe ZS (PBD7A; OMIM# 615872) to a less severe IRD (PBD7B; OMIM# 614873). This evidence concerns the gene PEX26 and peroxisome biogenesis disorder.