不同妊娠状态下母体循环中胎儿游离DNA—SRY基因的定量检测  

Value of the Detection of Fetal SRY Gene in Maternal Plasma at Different Pregnant States by Real-time Fluorescence Quantitative PCR

作　　者：汤冬玲[1] 李艳[1] 段峰[1] 

机构地区：[1]武汉大学人民医院检验科,武汉430060

出　　处：《现代检验医学杂志》2009年第4期37-40,共4页Journal of Modern Laboratory Medicine

摘　　要：目的依据孕妇血浆中存在游离胎儿DNA的理论，从孕妇外周血浆中分离出胎儿DNA并加以鉴定，预防X连锁遗传病患儿的出生。方法从孕早期、中期及晚期共80名孕妇外周血浆中分离胎儿DNA，采用实时荧光定量PCR（real-time fluorescence quantitative polymerase chain—reaction，FQ—PCR）方法对不同妊娠状态下孕妇外周血中游离的胎儿DNA（fDNA）进行定量分析，初步探讨游离fDNA在不同妊娠状态下的浓度变化，为尽早应用于临床提供科学依据。结果早孕组28例血浆标本中有25例检测到SRY基因，其平均浓度为58．82copies／ml，实测浓度范围为33．7～126．2copies／ml；中孕组20例血浆标本中均检测到SRY基因，其平均浓度为152．08copies／ml，实测浓度范围为37．7～390．2copies／ml；晚孕组32例血浆标本中均检测到SRY基因，其平均浓度为212．34copies／ml，实测浓度范围为87．90～493．56copies／ml。组间两两比较，差异有统计学显著性意义（P〈0．01）。结论用实时荧光定量PCR的方法最早在孕62d的孕妇外周血浆中就可以检测到胎儿sRY基因，随孕周的增加，母血中胎儿DNA的量也在逐渐增加。实时荧光定量PCR技术在进行无创性产前诊断中有重要的价值。Objective To isolate fetal DNA from maternal plasma and examine its fetal origin. Methods Fetal DNA in maternal plasma was isolated from 28 cases bearing male fetuses in the first trimester,20 in the mid-trimester of pregnancy and 32 in the late-trimester of pregnancy,respectively. Real-time fluorescence quantitative polymerase chain-reaction （FQ- PCR） was used to determine sex-determlning region Y （SRY） gene on Y chromosome. Results It showed that cell-free fetal DNA was present in high concentration in maternal plasma,reaching a mean and 95% confidence interval for parame- ter;58.82 copies/ml,33. 7~126.2 copies/ml：152. 08 copies/ml,37.7~390. 2 copies/ml and 212.34 eopies/ml, 87. 90- 493.56 copies/ml in early normal pregnancy,in middle normal pregnancy and in late normal pregnancy,respectively. Differ- ences were observed among the three groups（P〈0. 01）. Conclusion The results showed that fetal SRY gene could be found as early as 62 days of gestation in maternal plasma by the use of FQ-PCR. The number of fetal DNA increased with gestational age, so the high sensitivity of PCR-based detection, together with quantification provided by real-time DNA analysis. FQ-PCR has clear potential for clinical application in non-invasive prenatal diagnosis.

关 键 词：实时荧光定量聚合酶链反应 母体血浆 Y性别决定区基因 

分 类 号：Q503[生物学—生物化学]