Generalized peroxisomal disorders are classified in three main groups in a review article from the Kennedy Institute and the Departments of Neurology and Pediatrics, Johns Hopkins University, 707 N. Broadway, Baltimore, MD. Group 1 includes Zellweger (cerebro-hepato-renal) syndrome, neonatal adrenoleukodystrophy, infantile Refsum disease, and hyperpipecolic acidemia, all characterized by a reduction in the number of peroxisomes and deficiency of multiple peroxisomal enzymes.

Group 2 contains only one rare disorder, rhizomelic chondrodysplasia punctata, characterized by stippled calcification of hyaline cartilage, dwarfing, cataracts, multiple malformations with contractures, koala bear facies, and sever mental retardation. Peroxisomes are normal in number but functionally impaired.

Group 3 includes Refsum disease, X-linked adrenoleukodystrophy, pseudo-Zellweger syndrome, hyperoxaluria type 1, acatalasemia and an undescribed variant. All have a normal number of peroxisomes and the activity of only one peroxisomal enzyme is reduced.

Peroxisomal disorders are a newly recognized and heterogeneous group of diseases with variable manifestations transmitted as autosomal recessive or sex-linked recessive traits and have in common one or more peroxisomal enzyme defects. The term peroxisome is coined from the hydrogen peroxide-forming enzymes found within the subcellular organelle. More than 40 enzymes have now been localized to the peroxisomes. [1]

COMMENT. This is an excellent review of the various entities now classified as generalized peroxisomal disorders. See Ped Neuro Briefs (March 1988; 2: 22-23, and Oct 1987; 1:32) for case reports of infantile Refsum and Zellweger syndromes.