ANTIOXIDATIVE METABOLISM IN DOWN-SYNDROME

Down syndrome is the most common cause of mental retardation, affectin g 1 in 700-800 liveborn infants. Although numerous biochemical abnorma lities accompanying the syndrome have not yet been completely clarifie d, the antioxidant defense system enzymes have shown to be altered due to increased gene dosage on chromosome 21 and overproduction of super oxide dismutase (SOD-1 or Cu/Zn SOD). The purpose of this study was to investigate the activities of SOD-1 and glutathione peroxidase (GSH-P x) enzymes and the levels of their cofactors zinc (Zn), copper (Cu) an d selenium (Se) in plasma of 20 Down syndrome patients. In comparison with age and sex-matched controls (n = 15), plasma GSH-Px, SOD, and Cu levels were significantly decreased in the patient group, but Zn and Se concentrations remained unchanged.