实时荧光定量聚合酶链反应技术在产前诊断唐氏综合征中的应用

目的探讨实时荧光定量PCR技术用于产前诊断唐氏综合征的可行性。方法采用实时荧光定量PCR法,分别检测85例唐氏综合征高风险的中期妊娠妇女的羊水和7例智残儿外周血标本中,21号染色体上特异区域基因片段(DSCR3)和管家基因片段(GAPDH),并计算两者的比值。同时采用细胞遗传学方法分析其染色体核型。结果80例羊水细胞DNA检测DSCR3／GAPDH比值在0．46—1．30之间,染色体核型全部正常;而另5例羊水细胞和7例智残儿外周血DSCR,／GAPDH比值明显升高,达1．64～1．98,染色体核型均为21三体。5例中有3例核型为47,XY, 21;1例核型为47,XX, 21;另1例为易位型46,XY,-15, t(15;21)]。7例智残儿中4例为47,XY 21;3例为47,XX 21。结论实时荧光定量PCR技术可作为产前快速准确诊断唐氏综合征的有效方法。

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 64 to 1 98 while in the normal control the ratio was only from 0 46 to 1 30 Conclusion Real time fluorescence quantitative PCR is a valuable method for rapid and accurate prenatal diagnosis of Down syndrome in uncultured amniotic cells