Ion Torrent PGM^(TM)系统检测孕妇血浆中胎儿游离DNA

Application of Ion Torrent PGM^(TM) System in Detection of Fetal DNA in Maternal Plasma

目的探讨Ion Torrent PGMTM系统用于孕妇外周血血浆中胎儿游离DNA的Y-STR检测的可行性。方法采集8例孕晚期(38周)和8例孕中期(12周)的无关孕妇外周血血浆,提取胎儿游离DNA,对DYS390、DYS391、DYS393、DYS438、DYS437、DYS456、DYS635共7个基因座进行复合扩增,在Ion Torrent PGM^(TM)系统进行Y-STR测序分析和毛细管电泳分析,并将两者结果进行比较。结果在分娩男性胎儿的孕晚期及中期孕妇血浆中均检测到Y-STR片段,测序检测得出的基因座比毛细管电泳检测得出的多,且与分娩胎儿的Y-STR基因型相一致。结论 Ion Torrent PGMTM系统用于孕妇外周血血浆胎儿游离DNA的Y-STR检测,具有高灵敏度、高通量的特点,且有较好的法医学应用价值。

Objective To explore the feasibility of detecting of Y-STR of fetal DNA in maternal plasma using Ion Torrent PGM^（TM） System.Methods A total of 16 fetal DNA samples from maternal plasmas（8 cases from 38 weeks gestational age and 8 ones from 12 weeks） were prepared and a multiplex assay with 7 STR loci（DYS390,DYS391,DYS393,DYS438,DYS437,DYS456,DYS635） was designed for multiplex-PCR amplification.Using Ion Torrent PGM^（TM） System,the results of Y-STR sequences and capillary electrophoresis were obtained and compared.Results Y-STR specific alleles were detected in the maternal plasma of all the pregnant women having male babies of second and third trimester,which were higher than that detected by capillary electrophoresis.Consistent Y-STR genotypes were observed between fetal DNA from maternal plasma and genomic DNA from the newborn babies.Conclusion Based on Ion Torrent PGM^（TM） System,the prenatal Y-STR detection method may provide a high-sensitive and high-throughput choice for prenatal STR detection in forensic testing.