利用孕妇血浆游离胎儿DNA产前诊断胎儿RhD血型的研究

Detection of fetal RhD types with maternal plasma for prenatal diagnosis.

目的 探讨无损伤性产前诊断胎儿RhD血型的方法。方法 西安交通大学第二医院 1999年 2月至2 0 0 1年 12月 ,以妊娠 14～ 4 0周的单胎孕妇为对象 ,其中RhD阴性孕妇 8例 ,RhD阳性孕妇 12例 ,利用PCR技术对孕妇血浆中游离胎儿DNA进行RhD基因第 10外显子的特异性扩增 ,扩增片段长度为 186bp ,另外以等位基因RhCE基因为内对照 ,扩增片段长度为 136bp。结果 能同时扩增出 186bp和 136bp两条带 ,判断所妊娠胎儿血型为RhD阳性 ;扩增出 136bp一条带 ,判断所妊娠胎儿血型为RhD阴性。 8例RhD阴性孕妇中 ,5例扩增出136bp一条特异性片段 ,3例同时扩增出 136bp和 186bp两条特异性片段 ;12例RhD阳性孕妇血浆标本 ,均同时扩增出 136bp和 186bp两条特异性片段 ,所有RhD PCR扩增结果均得到脐血血清学检测结果的证实。 结论 利用孕妇血浆中游离胎儿DNA对胎儿RhD血型进行诊断 ,是一种简便、快速、特异性较高的产前诊断方法 ,值得临床推广应用。

Objective To establish a method for non-invasive pren atal diagnosis of fetal RhD type.Methods From Feb.1999 to Dec.2001,8 RhD negative and 12 RhD positive pregnant women with single fetus in the Sec ond Hospital of Xi'an Jiaotong University were studi es.DNA was extracted from the 20 maternal plasma sample(between 14～40 weeks) an d amp lified by polymerase chain reaction to detect the RhD gene.RhD types were determined directly by serologic analysis of the cord blood after delivery.Results Both 186 bp and 136 bp amplified suggested to be RhD positi ve.Only 136 bp amplified was RhD negative.Among the 8 RhD negative women,136 bp special fragment was identified in 5 women , 136 bp and 186 bp special fragment was amplified in the other 3 women.Among the 12 RhD positive women,136 bp and 186 bp special fragment was amplified in all of t hem.The RhD-PCR result corresponded to the serologic analysis of cord blood.Conclusion Using fetal DNA in maternal plasma can be a simple,quick,specific and non-i nvasive method for prenatal diagnosis.