Kwan Dong University College of Medicine, Seoul, Korea.
FASEB J. 2012 Jan;26(1):250-8. doi: 10.1096/fj.11-191429. Epub 2011 Sep 30.
The aim of this study was to develop a simple and effective method for noninvasively detecting fetal sex using circulating fetal DNA from first-trimester maternal plasma. A study was conducted with maternal plasma collected from 203 women between 5 and 12 wk of gestation. The presence of circulating fetal DNA was confirmed by a quantitative methylation-specific polymerase chain reaction of the unmethylated-PDE9A gene (U-PDE9A). Multiplex real-time PCR was used to simultaneously quantify the amount of DYS14 and GAPDH in maternal plasma. The results were confirmed by phenotype at birth. Pregnancy outcomes and U-PDE9A concentrations were obtained in all cases, including 99 male-bearing and 104 female-bearing participants. At equivalent specificity (100%), the false-negative rate was 9.1% for DYS14 quantification cycle, 7.1% for DYS14 concentration, and 0.0% for the concentration ratio of DYS14/GAPDH, respectively. In male-bearing participants, DYS14, U-PDE9A, and GAPDH concentrations were significantly lower in the false-negative case than in correct case (P<0.001 in all). Moreover, DYS14, U-PDE9A, and GAPDH concentrations showed significantly positive associations with each other (P≤0.001 in all). The ratio of DYS14/GAPDH in maternal plasma was an effective biomarker for noninvasive fetal sex detection during the first trimester, indicating that it could be useful for clinical application.
本研究旨在开发一种简单有效的方法，通过从妊娠早期母体血浆中循环胎儿 DNA 无创性检测胎儿性别。对 203 名妊娠 5-12 周的女性进行了研究，通过非甲基化-PDE9A 基因（U-PDE9A）的定量甲基化特异性聚合酶链反应（qMSP）证实了循环胎儿 DNA 的存在。采用多重实时 PCR 同时定量母体血浆中 DYS14 和 GAPDH 的含量。结果通过出生时的表型确认。所有情况下均获得妊娠结局和 U-PDE9A 浓度，包括 99 名男性胎儿和 104 名女性胎儿。在同等特异性（100%）下，DYS14 定量循环的假阴性率为 9.1%，DYS14 浓度的假阴性率为 7.1%，DYS14/GAPDH 浓度比的假阴性率为 0.0%。在男性胎儿中，DYS14、U-PDE9A 和 GAPDH 的浓度在假阴性病例中明显低于正确病例（均 P<0.001）。此外，DYS14、U-PDE9A 和 GAPDH 浓度之间存在显著的正相关（均 P≤0.001）。母体血浆中 DYS14/GAPDH 的比值是一种有效的非侵入性早期胎儿性别检测的生物标志物，表明其可能对临床应用有用。
