摘要
为了探讨定量ＰＣＲ方法在分子水平对先天愚型基因诊断意义，本实验以ＳＴＲ（Ｄ２１Ｓ１１ＩＦＮＡＲ）做为遗传标记，合成特异引物对１１例正常人（６例外周血，５例羊水）及２８例先天愚型患者外周血进行同位素标记ＰＣＲ扩增后定量分析，结果显示在Ｄ２１Ｓ１１位点１１例正常人中１０人呈ＤＮＡ含量为１∶１关系的两条带，１人为１条带。２８例患者中２４人呈ＤＮＡ含量为２∶１的两条带，３人为ＤＮＡ含量为１∶１∶１关系的三条带，１人为１条带。在ＩＦＮＡＲ位点５例为纯合子，其余均为杂合子。实验表明Ｄ２１Ｓ１１和ＩＦＮＡＲ位点多态是对先天愚型基因诊断很有应用价值的遗传标记，应用定量ＰＣＲ的方法可在２４ｈ内对先天愚型做出快速、准确的产前及临床基因诊断。
For studying clinic diagnosis to trisoym 21 at level of molecule by quantitative PCR, Polymorphic STR at D21S11 and IFNAR was served as the gene mark and primers were synthesizedThe samples from normal 11 cases and 28 cases with trisomy 21 were detected by quantitative PCRResults shew that at D21S11 10 cases were with two bents with a ratio of 11, and a case was with a bentOf 28 cases with trisomy 21, 24 cases shew two bents with a ratio of 21, 3 cases were three bents with a ratio of 111 and 1 case was one bentAt IFNAR, 5 cases were one bentFrom our test the conclusion was made that polymorphic STR at D21S11 and IFNAR were a valuable gene mark to diagnose trisomy 21 and prenatal and clinic diagnosis of trisomy 21 can rapidly and accuratly be made within 24 hour by quantivatire PCR
