引物延伸预扩增后STR分型在鉴定母血中胎儿有核红细胞的应用

Identification of fetal nucleated erythrocytes in maternal blood using short tandem repeat typing after primer extension preamplification

目的探讨一种鉴定母血中胎儿有核红细胞(NRBC)的方法,为无创性产前基因诊断创造必要条件。方法联苯胺染色识别孕妇外周血中 NRBC,经显微操作获取,并以引物延伸预扩增(PEP)对单个 NRBC 进行全基因组扩增后,用短串联重复序列(STR)分析其基因型,与父母基因型比对,确定该细胞的来源。结果 28例轻型β地中海贫血孕妇外周血样本中每例发现 NRBC 4～13个/5ml,经鉴定每例有胎儿 NRBC 2～8个/5ml,约43.6%的 NRBC 来源于胎儿。结论 PEP 后 STR 基因型分析能有效鉴定孕妇外周血中 NRBC 的来源,使应用单个胎儿 NRBC 进行产前基因诊断成为可能。

Objective To develop a method for identifying fetal nucleated erythrocytes （NRBCs） in maternal blood. Methods NRBCs in maternal blood were detected by benzidine staining and collected by micromanipulation. After primer extension preamplification （PEP） of the entire genome from a single NRBC, short tandem repeat （STR） genotype was analysed ＇after further amplification of this gene. Single NRBC was differentiated as fetal or maternal origin by eomparison of STR genotype of NRBC with its corresponding parents, Results NRBCs were found in all of 28 pregnant women in a range of 4 to 13 per 5 ml venous blood. About 43.6% of NRBCs were determined to be fetal origin by STR typing. Conclusion This method provides effective identification of fetal NRBCs and allows non-invasive prenatal genetic diagnosis using single fetal NRBC.