应用短串联重复序列多态性快速基因诊断先天愚型

Rapid Detection of Down Syndrome by Gene Diagnosis Using Short Tandem Repeat Polymorphisms

目的建立快速基因诊断先天愚型(21三体)的方法。方法选择先天愚型关键区域(DSCR)内部及其附近的短串联重复序列(STR)D21S11、D21S1270、D21S1437,对11个核心家系进行PCR扩增,并进行DNA定量分析。结果不同个体在某一STR位点的DNA电泳定量分析可出现下列4种情况之一:1.只出现一条DNA深带,为一纯合子;2.出现两条DNA带,比例接近1∶1,为正常杂合子;3.出现两条DNA带,比例接近2∶1,为21三体患者;4.出现三条DNA带,比例接近1∶1∶1,为21三体患者。结论应用STR多态位点结合DNA定量分析可对21三体患儿进行快速基因诊断与产前基因诊断。

Objective To set a rapid, simple gene diagnosis method for Down syndrome. Methods Three short tandem repeats （D21S11 ,D21S1270,D21S1437）loci in or near Down syndrome critical region（DSCR） were analyzed and detected by polymerase chain reaction and DNA quantitative analysis in 11 core ancestry. Results There were four types by DNA quantitative analysis to different individuals at a short tandem repeats（STR） locus. In type one,a homozygote of one allelic gene was detected. In type two,a normal heterozygote of two allelic genes was found, the content or two DNA electrophoresis bands was approximately 1 ： 1. In type three, a Down syndrome patient of two allelic genes was discovered. The quantity of two electrophoresis bands was nearly 2 ： 1. In type four, the patient showed three DNA electmphoresis bands which the content was approximately 1 ： 1 ： 1. Conclusion A rapid gene diagnosis and prenatal diagnosis method for Down syndrome can be used for quantitative analysis of STR polymorphism loci.