Fragmentation of cell-free fetal DNA in plasma and urine of pregnant women
Fragmentation of cell-free fetal DNA in plasma and urine of pregnant women
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DOI：
10.1002/pd.1213
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发表时间：
2005-07-01
影响因子：
3
通讯作者：
Okai, T
中科院分区：
文献类型：
--
作者：
Koide, K;Sekizawa, A;Okai, T
目的 我们评估冷冻对母体血浆中胎儿DNA片段化的影响以及孕妇血浆和尿液中DNA片段化的差异。方法1.我们准备了七种实时PCR检测方法来扩增针对SRY基因的不同大小的扩增子。对新样本 (n = 10) 和 4 岁样本 (n = 10) 的母体血浆中胎儿 DNA 的碎片进行了比较。 2. 为了研究孕妇血浆和尿液中胎儿 DNA 片段化的差异，我们扩增了 3 个不同大小的扩增子，并比较了血浆和尿液之间的 DNA 片段化 (n = 7)。 结果 1. 107、137、193 和 193 个 PCR 扩增子与新样本中 63 bp 扩增子相比，胎儿 DNA 的相对浓度分别为 53.1、42.0、9.2 和 2.0%（中位数）。分别为 313bp。 4 岁儿童样本中的浓度分别为 70.4%、40.9%、11.9% 和 2.3%。 2. 虽然在尿液中未检测到 SRY 序列的 107-bp 和 137-bp 扩增子的胎儿 DNA，但在 7 例病例中有 5 例检测到使用 63-bp 扩增子的胎儿 DNA (71.4%)。 结论 母体血浆中的无细胞胎儿 DNA 在 -20°C 冷冻保存至少 4 年时保持稳定。母体血浆中大约 60% 的胎儿 DNA 片段化长度小于 100 bp，尿液中的胎儿 DNA 进一步片段化。母体尿液可用于检测胎儿 DNA，尽管较小的目标尺寸对于尿液中胎儿 DNA 的 PCR 扩增比分析孕妇血浆更重要。版权所有 (c) 2005 John Wiley & Sons, Ltd.
Objectives We assessed the effect of freezing on fragmentation of fetal DNA in maternal plasma and differences in DNA fragmentation between plasma and urine from pregnant women.Methods 1. We prepared seven kinds of real-time PCR assays to amplify different-sized amplicons targeting the SRY gene. Fragmentation of fetal DNA in maternal plasma was compared between new (n = 10) and 4-year-old samples (n = 10). 2. To investigate differences in fragmentation of fetal DNA between plasma and urine from pregnant women, we amplified three different-sized amplicons and compared DNA fragmentation between plasma and urine (n = 7).Results 1. Relative concentrations of fetal DNA compared to a 63-bp amplicon in new samples were 53.1, 42.0, 9.2 and 2.0% (median) for PCR amplicons of 107, 137, 193 and 313 bp, respectively. Concentrations in 4-year-old samples were 70.4, 40.9, 11.9 and 2.3%, respectively. 2. Although fetal DNA in urine was not detected for 107- and 137-bp amplicons of the SRY sequence, fetal DNA using a 63-bp amplicon was detectable in five of seven cases (71.4%).Conclusion Cell-free fetal DNA in maternal plasma is stable under cryopreservation at -20 degrees C for at least 4 years. Approximately, 60% of fetal DNA in maternal plasma was fragmented to < 100-bp long, and fetal DNA in urine was further fragmented. Maternal urine may be usable for detection of fetal DNA, although smaller target size is more important for PCR amplification of fetal DNA in urine than in the analysis of plasma from pregnant women. Copyright (c) 2005 John Wiley & Sons, Ltd.