A new peroxisomal beta-oxidation disorder in twin neonates: defective oxidation of both cerotic and pristanic acids.

Twin brothers were born with clinical symptoms indicating that they were suffering from Zellweger syndrome. However, instead of a generalized peroxisomal dysfunction, only very long-chain fatty acids and the pristanic acid/phytanic acid ratio were elevated in plasma and decreased oxidation of very long-chain fatty acids and pristanic acid was the only impairment found in fibroblasts. The other peroxisomal parameters tested were normal, including normal oxidation of phytanic acid and normal activity of dihydroxyacetonephosphate acyltransferase in fibroblasts as well as normal plasma bile acids. Although the biochemical results point to a defect in peroxisomal beta-oxidation, the isolated finding of impaired oxidation of very long-chain fatty acids and pristanic acid has to our knowledge not been reported previously and is difficult to explain by a deficiency of a known peroxisomal beta-oxidation enzyme.