孕妇血浆游离DNA高通量测序用于胎儿性染色体非整倍体检测的初步探讨

Detection of fetal sex chromosomal aneuploidies by massively parallel sequencing of cell-free DNA in maternal plasma

目的初步探讨孕妇血浆游离DNA高通量测序用于产前胎儿性染色体非整倍体检测的效果及临床可行性。方法2011年至2012年收集早、中孕期单胎孕妇5 540例,在知情同意的原则下采集外周血血浆进行游离DNA的高通量测序检测,通过生物信息学分析,获得测序结果;对测序检出的性染色体非整倍体患者行羊水穿刺,进行染色体G显带分析。结果5 540例样本中测序方法共检出10例性染色体非整倍体,其中6例与G带核型分析结果一致,包括3例45,X,1例47,XXY,2例47,XYY,其余4例G带核型正常。结论孕母血浆游离DNA高通量测序可对性染色体非整倍体胎儿进行无创性产前检测,但存在假阳性,还需进一步完善实验方案以提高检测效果。

Objective To explore the clinical efficacy and practical feasibility of massively parallel sequencing （MPS） of cell-free DNA from maternal plasma for detection of sex chromosomal aneuploidies in prenatal diagnosis. Methods A total of 5 540 maternal plasma samples from singleton pregnancy in the first or second trimester of pregnancy were collected from August 2011 to December 2012, and detected by using MPS. The sequencing data were compared with the human reference gene-database and statistically analyzed by informatics. The positive cases of sex chromosomal aneuploidies were advised to accept prenatal fetal chromosomal karyotype analysis of amniotic fluid cells using G-banding technique. Results In 10 of 5 540 pregnant women MPS revealed sex chromosomal aneuploidies. Using the results of fetal chromosomal karyotyping as golden standard, 6 of lO cases were validated by prenatal karyotyping, including 3 cases of 45,X, 1 cases of 47, XXY and 2 case of 47, XYY, while the other 4 cases were confirmed to be euploid karyotype. Conclusion MPS based on maternal plasma DNA to detect fetal sex chromosomal aneuploidies should be feasible, but there can be false positive results. The MPS technology should still be improved for detecting sex chromosomal aneuploidies.