基于染色体短串联重复序列的荧光定量PCR技术在产前诊断中的实际应用

Application of Quantitative Fluorescent PCR Technique Based on Chromosomal Short Tandem Repeat Sequences in Prenatal Diagnosis

目的本研究旨在探讨基于染色体短串联重复序列(short tandem repeat,STR)的荧光定量PCR(quantitative fluorescence PCR,QF-PCR)在产前诊断中的应用潜力及其价值。方法通过基于STR的QF-PCR技术结合染色体核型分析技术和染色体微阵列分析技术(chromosomal microarray analysis,CMA),我们对635例产前筛查异常的羊水样本进行了筛查,从而有效地排除了母源细胞污染(maternal cell contamination,MCC)(>20%),为后续的产前检测提供了可靠的依据。此外,为了快速诊断胎儿及其相应的孕妇样本,我们检测了包括13、18、21、X、Y在内的五条染色体,并将其与核型分析的结果进行比较。结果通过QF-PCR检测,在635例样本中,发现了3例母源污染,1例三倍体,1例与母亲的亲缘关系不符,12例21三体,6例18三体,1例13三体。除此之外,还有10例性染色体异常和1例21三体嵌合。与CMA结果比较,QF-PCR检测结果均符合试剂盒的检测范围。值得一提的是,QF-PCR检测还额外的发现了5例母亲的性染色体异常,同时若在试剂盒检测范围内发现了三体还可以结合亲本的STR分型结果分析额外染色体的亲本来源并且推测异常染色体减数分裂不分离发生时期。结论基于STR位点的QF-PCR技术是一种快速检测方法,不仅适用于非整倍体倍型的检测,还可用于母源细胞污染检测、亲缘溯源检测以及染色体嵌合体的检测,同时还可以检测染色体三体的亲本来源。QF-PCR技术在产前诊断中具有广泛的应用前景,可以为医生和家庭提供更准确、更可靠的诊断结果。

Objective To explore the potential application and value of QF-PCR technology in prenatal diagnosis.Methods By combining fluorescent quantitative polymerase chain reaction(QF-PCR)with chromosome karyotype analysis and CMA technology,we screened 635 amniotic fluid samples with prenatal screening abnormalities,effectively excluding maternal cell contamination(>20%)and providing a reliable basis for subsequent prenatal testing.In addition,to quickly diagnose fetal and corresponding maternal samples,we tested five chromosomes including 13,18,21,X,and Y,and compared the results with karyotype analysis.Results Through QF-PCR detection,among the 635 samples,3 cases of maternal blood contamination,1 case of triploidy,1 case of inconsistency with the mother's kinship,12 cases of trisomy 21,6 cases of trisomy 18,and 1 case of trisomy 13 were found.In addition,there were 10 cases of sex chromosome abnormalities and 1 case of 21 trisomy mosaic.Compared with the CMA results,the QF-PCR detection results were within the detection range of the kit.It is worth mentioning that QF-PCR detection also identified 5 additional cases of maternal sex chromosome abnormalities,and if trisomy is found within the detection range of the kit,the origin of the additional chromosome can be analyzed based on the STR genotype of the parents,and the time of abnormal chromosome meiosis separation can be inferred.Conclusion QF-PCR technology based on STR loci is a fast detection method,which is not only suitable for detecting non-triploid genotypes,but also for detecting maternal cell contamination,genetic traceability testing,and chromosome mosaic.QF-PCR technology has a wide range of applications in prenatal diagnosis and can provide more accurate and reliable diagnostic results for doctors and families.