Peroxisome biogenesis disorders are a result of peroxisomal fatty acid metabolism defect and constitute a spectrum of three phenotypes, Zellweger sydnrome, Neonatal adrenoleukodystrophy, and Infantile Refsum disease. Zellweger syndrome is the most severe and presents in the neonatal period with hypotonia, seizures, inability to feed, characteristic facies, liver dysfunction, and specific skeletal findings. These infants typically die within the first year of life.
Infantile Refsum disease, the least severe form, and neonatal adrenoleukodystrophy generally present later in infancy or early childhood. Vision loss due to retinal dystrophy, sensorineural hearing loss, hypotonia, developmental delay, and episodes of hemorrhage or intracranial bleeding are all common features in later presentations. Older children will typically have a slowly progressive disease.