The mean activity levels of glutathione peroxidase (GPx), superoxide dismutase (Cu/ZnSOD), and catalase (CAT) were significantly lower (P < 0.001) in SCD with macroalbuminuria and CKD while MDA was higher (P < 0.001) in SCD with macroalbuminuria and CKD compared with controls. This evidence concerns the gene CAT and Schnyder corneal dystrophy.