孕妇血浆中游离DNA在无创性产前诊断胎儿ABO血型中的应用

Noninvasive prenatal diagnosis of fetal ABO blood genotype using fetal DNA in maternal plasma

目的探讨利用孕妇血浆中游离胎儿DNA进行无创性产前诊断胎儿ABO血型的可行性和准确性。方法选择2005年6月至2006年7月在山东省立医院检查的孕中晚期单胎O型血孕妇105例,采用QIAamp DNA Blood Mini Kit提取孕妇血浆中游离DNA;聚合酶链反应-序列特异性引物(PCR-SSP)方法检测ABO血型基因型。血清学方法检测ABO血型表现型。结果93例胎儿利用孕妇血浆中游离DNA与利用脐血DNA检测的血型基因型相符,即诊断符合率为88.6%(93/105)。12例血型产前诊断不符的胎儿均来自于66例妊娠非O型血胎儿的孕妇,39例O型血孕妇其胎儿的血型基因型均正确检出。5例经产妇本次妊娠胎儿血型与以前不同,但利用孕妇血浆中游离DNA均能准确检测。结论利用O型血孕妇血浆中游离DNA进行无创性产前诊断胎儿ABO血型是一种可行途径,值得推广应用。

Objective To investigate the accuracy and feasibility of this noninvasive prenatal diagnosis of fetal blood type by using fetal DNA in maternal plasma. Methods 105 middle-late pregnant women were studied in Shandong Provincial Hospital from June 2005 to July 2006. Fetal free DNA from maternal plasma sample was extracted by use of QIAamp DNA Blood Mini Kit. DNA was amplified to detect ABO genotype by polymerase chain reaction with sequence-specific primers （PCR-SSP）. The results of fetal ABO genotype were evaluated by the serologic methods of ABO phenotypes. Results Using fetal DNA from maternal plasma, 93 fetal ABO blood genotypes were detected correctly; the concordance rate was 88.6% （93/105）. 12 false fetal genotypes were from 66 pregnant women with non-O type fetus; 39 fetal genotypes of pregnant women with O type fetus were detected accurately. Each of fetal blood types of 5 muhiparas was different with the types of previous child, but we detected them accurately. Conclusion Noninvasive prenatal diagnosis of fetal ABO genotype is feasible by using fetal free DNA from blood group O mother＇s maternal plasma.