摘要目的:通过荧光定量PCR(quantitative fluorescence PCR, QF-PCR)、染色体微阵列分析(chromosomal microarray analysis, CMA)和G显带核型分析对1例21部分三体胎儿进行产前诊断。方法:对受试孕妇行羊膜腔穿刺术收集羊水，部分羊水细胞提取胎儿DNA后行QF-PCR和CMA，部分羊水细胞和孕妇外周血细胞接种培养，后续行G显带核型分析。结果:QF-PCR结果显示样本在D21S1445位点、D21S1412位点和D21S1411位点为双峰峰型，峰面积比在0.8～1.4正常范围内；在21q11.2位点、D21S1414位点和D21S1433位点为三体峰型(双峰，峰面积比在0.45～0.65或1.8～2.4；三峰，最大峰与最小峰面积比为1.0～1.4)，提示为21部分三体。CMA结果显示该样本在10q23.32-q26.3处发生长度约为41.86 Mb的重复，在21q11.2-q21.3处发生长度约为14.2 Mb的重复。G显带核型结果为47，XN，＋21，der(21)t(10；21)(q23.3；q21.3)mat。结论:本研究应用QF-PCR等方法对1例21部分三体胎儿进行产前诊断，为QF-PCR应用于目标染色体部分三体的产前诊断提供了临床实践资料。21部分三体具有较大的临床异质性，在临床实践中应联合应用多种方法进行检测。

abstractsObjective:To prenatally diagnose a fetus with partial trisomy of chromosome 21 via quantitative fluorescence PCR (QF-PCR), chromosomal microarray analysis (CMA) and karyotype analysis.Methods:Amniocentesis was carried out for the pregnant woman who had presented at Jinan Maternal and Child Health Hospital. QF-PCR and CMA were performed after fetal DNA extraction, and karyotype analysis was performed after cell culture.Results:QF-PCR results showed that the markers D21S1445, D21S1412 and D21S1411 exhibited two peaks with a normal peak area ratio (0.8~1.4); the markers D21S1414 and D21S1433 exhibited two peaks with abnormal peak area ratios (0.45~0.65 or 1.8~2.4); the marker 21q11.2 illustrated a trisomic pattern. CMA revealed a duplication of about 41.86 Mb at 10q23.32-q26.3 and a duplication of about 14.2 Mb at 21q11.2-q21.3. Karyotype analysis showed 47, XN, + 21, der(21)t(10; 21)(q23.3; q21.3)mat.Conclusion:In this study, QF-PCR was carried out for prenatal diagnosis of a fetus with partial trisomy of chromosome 21, which provided clinical practice data for the application of QF-PCR in prenatal diagnosis of partial trisomy. Due to the great clinical heterogeneity, multiple methods should be performed to detect the partial trisomy of chromosome 21.