获取母血中纯化胎儿有核红细胞行产前基因分析

Isolation of Fetal Nucleated Red Blood Cells from Maternal Blood for Prenatal Prediction of Fetal Sex

目的 探讨获取母血中纯化胎儿细胞的有效方法。方法 对 6 0名孕龄 7～ 40周、年龄 2 1～ 30岁的孕妇外周血进行不连续密度梯度离心 ,将分离后的细胞进行制片 ,显微镜下行显微操作分离胎儿有核红细胞 ,进行 Y染色体特异性DYZ1基因的聚合酶链反应 (PCR)。结果 (1)早孕期母血中胎儿 NRBC检出率为 2 0 % ,中孕期母血中胎儿 NRBC检出率为 71.4% ,晚孕期母血中胎儿 NRBC检出率为 6 .6 5 % ,三者之间有显著性差异 (P <0 .0 5 ) ;(2 )用显微操作技术获得的胎儿细胞数量已满足 PCR扩增所需的模板量 ,对胎儿性别进行预测 ,男胎符合率为 11/ 13(84.6 % ) ,性别符合率为 2 6 / 2 8(92 .9% )。结论 不连续密度梯度离心合并显微操作技术对于无创性早期产前基因诊断意义重大。

Objective To study the effective methods of isolating fetal nucleated red blood cells(NRBCs) Methods We studied 60 women of 7~40 weeks' gestation at age of 21~30 Fetal cells were isolated from maternal blood with discontinuous density gradient centrifugation.NRBCs were found and retrieved using a micromanipulator under a microscope To determine whether the origin of the NRBCs was maternal or fetal, the NRBCs were analysed by polymerase chain reaction(PCR) amplification to determine the presense of a Y-chromosome-specific repeat seqence in mothers carrying male fetuses Results (1)The ratios of NRBC detection in first,second and third trimester were 20%、71 4% and 6 65% respectively, showing significant difference among the three trimesters(P<0 05) (2)The amount of isolated fetal cells was enough for prenatal genetic diagnosis Male pregnancy was correctly predicted in 11/13(84 6%) No Y-specific DNA sequence was detected in 15 women had female babies The overall agreement of the diagnosis was 26/28(92 9%) Conclusion Isolating fetal nucleated red blood cells(NRBCs) using discontinuous density gradient centrifugation and a micromanipulator for prenatal diagnosis are of great value