RESUMEN
Prenatal diagnosis and prevention of live-born children with Down syndrome is a principle priority of Iran's ministry of health. The aim of this study was the rapid diagnosis of Down syndrome by quantitative real-time PCR technique as a new method for prenatal diagnosis. In this experimental study, two milliliters of peripheral blood was obtained from each patient and normal control. Then genomic DNA was extracted using salting out method. DYRK1A2 gene as target gene and PMP22 gene as reference gene were analyzed by quantitative real-time PCR technique. DYRK1A2/PMP22 gene ratio was 1.68 +/- 0.13 and 1.00 +/- 0.09 in Down syndrome and normal samples, respectively [p<0.001], demonstrating 3 copies of target [DYRK1A2] gene in trisomy 21 syndrome and 2 copies in normal individuals. DYRK1A2/PMP22 gene ratio is significantly higher in patients with Down syndrome compared with normal individuals. So, quantitative real-time PCR technique can be used as a sensitive, accurate and reliable technique for rapid diagnosis of trisomy 21 syndrome