- Congenital dyserythropoietic anemia type 1 (CDA1) patients may suffer from iron overload, associated with oxidative damage. The aim of this study was to evaluate possible involvement of oxidative stress in the pathogenesis of CDA1. : Blood samples from 10 children diagnosed as CDA1 patients from five Bedouin families, were studied. In this study, activities of superoxide dismutase and catalase were evaluated as well as methemoglobin, plasma total thiols, plasma total antioxidant capacity and glycerol lysis time. Normal values were found for superoxide dismutase, methemoglobin, trolox equivalent antioxidant capacity and total plasma thiols in CDA1 patients. However average catalase levels were significantly reduced (P<0.001) and glycerol lysis test was significantly prolonged (P<0.001). Ferritin levels, which were slightly increased in all patients, positively correlated with catalase values (r = 0.74, P = 0.022). Oxidative stress has not been proven in CDA1 pediatric patients. Some indications of oxidative damage exist, but it may not be directly related to the mechanism of anemia.