定量荧光PCR在唐氏综合征快速产前诊断中的应用研究

目的 :了解中国人 D2 1 S1 1、D2 1 S1 2 70、D2 1 S2 2 6、D2 1 S1 41 1四个短串联重复序列 ( STR)位点的多态性信息含量 ( PIC) ,建立定量荧光 PCR快速产前诊断唐氏综合征的方法。方法 :以染色体2 1 q2 1～ q2 2 .3区段内四个短串联重复序列作为遗传标记 ,采用定量荧光 PCR对 5 0例正常人外周血 DNA进行分析 ,计算中国人该四对 STR位标的多态性信息含量 ( PIC) ,并用该方法对 1 1例正常孕妇羊水 DNA进行分析 ,及对唐氏综合征血清生化指标筛查阳性孕妇羊水标本进行产前诊断。结果 :D2 1 S1 1、D2 1 S1 2 70、D2 1 S2 2 6、D2 1 S1 41 1的多态性信息含量分别是 0 .90 2、0 .889、0 .5 2 1、0 .775 ,建立了定量荧光 PCR产前诊断唐氏综合征的方法。应用该技术产前诊断出 3例唐氏综合征患儿 ,并经染色体核型分析所证实。结论 :以上四对 STR在中国人中均具有较高多态性信息含量 ,可应用于唐氏综合征的定量荧光 PCR产前诊断技术中

The Investigation of the Application of Quantitative Fluorescent PCR for Fast Prenatal Diagnosis of Down's Syndrome

Objective: To investigate the polymorphism information content (PIC) of the four short tandem repeats D21S11, D21S1270, D21S226, D21S1411 in Chinese people and to investigate the feasibility of fast prenatal diagnosis of Down's syndrome using quantitative fluorescent PCR. Methods: With the four highly polymorphic small tandem repeat markers located 21q21～q22.3, peripheral blood DNA samples from 50 normal people were analyzed using quantitative fluorescent PCR; the PIC of each marker was calculated. The prenatal diagnosis of Down's syndrome was done on amniotic fluid samples from Down's syndrome screening positive mothers. Results: The PICs of D21S11, D21S1270, D21S226, D21S1411 were 0.902,0.889,0.521,0.775 respectively and the technique of applying quantitative fluorescent PCR on the prenatal diagnosis of Down's syndrome was established. Three Down's syndrome cases were detected and confirmed by chromosome karyotype analysis. Conclusion: The four STR markers, whose PICs were high in Chinese people, may be applied on quantitative fluorescent PCR for the prenatal diagnosis of Down's syndrome.