[Application of real-time fluorescence quantitative polymerase chain reaction techniques for prenatal diagnosis of Down syndrome].

Objective: To investigate the value of real-time fluorescence quantitative PCR in diagnosis of Down syndrome with uncultured amniotic cells.

Methods: The uncultured amniocytes of 80 fetuses who were confirmed disomy 21 by chromosome analysis and 5 fetuses detected trisomy 21 and peripheral blood samples of 7 children diagnosed as Down syndrome were collected to extract gDNA and the real-time fluorescence quantitative PCR method was used to detect the original copies of Down syndrome critical region gene(3) (DSCR(3)) and GAPDH gene and then the ratio of DSCR(3)/GAPDH was calculated.

Results: The PCR product ratios of DSCR(3) to GAPDH in trisomy 21 from amniocytes and peripheral blood were ranged from 1.