Antioxidant enzyme activity in children with Down syndrome

Down syndrome or trisomy 21 is the single most common genetic cause of mental retardation. It has been postulated that there is oxidative stress in Down syndrome due to over expression of superoxide dismutase 1 (SOD -1) , an antioxidant enzyme which is coded on chromosome 21(21q22.1). The present study included 31 clinically diagnosed children with Down syndrome. The diagnosis of trisomy 21 was confirmed by chromosomal analysis and activity of antioxidant enzymes like erythrocytic SOD (SOD-1), erythrocytic catalase (CAT) and erythrocytic glutathione peroxidase (GPx) were estimated. The results of biochemical analysis showed elevated activities of SOD-1, GPx and decreased activity of catalase .The variations in the activities of antioxidant enzymes were statistically not significant, whereas the ratio of SOD -1 to CAT and GPx (SOD-1/CAT+GPx) was significantly elevated indicating oxidative stress in Down syndrome.