A group of autosomal recessive disorders affecting the formation of functional peroxisomes, with characteristics of sensorineural hearing loss, pigmentary retinal degeneration, multiple organ dysfunction and psychomotor impairment and is comprised of the phenotypic variants Zellweger syndrome, neonatal adrenoleukodystrophy and infantile Refsum disease. The mutations found in 90% of PBD-ZSS patients are in the PEX1, PEX6, PEX10, PEX12 or PEX26 genes. Impaired metabolism results in the accumulation of very-long-chain fatty acids which damage developing neural cells. Accumulation of toxic bile acid intermediates damages the liver. The decreased synthesis of docosahexanoic acid (DHA) and ether phospholipids (plasmalogens) impairs cell membranes.