LATE-ONSET GENERALIZED DISORDER OF PEROXISOMES

We diagnosed a unique peroxisomal disorder in a 32-year-old man with p rofound mental retardation, mild facial dysmorphism, retinal pigmentar y degeneration, seizures, and sensorineural deafness. Although plasma very-long-chain fatty acid profile suggested X-linked adrenoleukodystr ophy, marked reduction in fibroblast lignoceric acid oxidation and the presence of cytosolic catalase were consistent with Zellweger syndrom e (ZS). Unlike ZS, functional peroxisomes were present as indicated by density of peroxisomes (1.175 gm/ml) similar to peroxisomes from cont rol cells and by partial deficiencies of fibroblast phytanic acid oxid ation and dihydroxyacetone phosphate acyltransferase activity. These f indings indicate that this patient has a previously undescribed group 3 peroxisomal disorder (multiple peroxisomal enzyme deficiencies with preserved peroxisomes).