[The use of oxidant-antioxidant system indices in forming groups at high genetic risk].

While studying the pathogenetic mechanisms of Down syndrome, the imbalance of oxidant-antioxidant system in donors of extrachromosome 21 was detected. This fact was a basis for screening of new prenatal biochemical markers of Down syndrome. The ratio of free radical processes intensity and SOD activity was found as most informative index reflecting the state of oxidant-antioxidant system. It was proposed as additional criterion for the formation of high risk groups to increase the efficiency of prenatal diagnostics of Down syndrome.