Li Ying, Hahn Sinuhe, Holzgreve Wolfgang
Department of Research, University Women's Hospital, Basel, Switzerland.
Ann N Y Acad Sci. 2006 Dec;1092:285-92. doi: 10.1196/annals.1365.024.
The presence of cell-free fetal DNA in maternal plasma allowed noninvasive prenatal diagnosis of fetal loci completely absent from the maternal genome, such as SRY gene and RhD gene. However, the detection of fetal point mutations is hindered by the predominance of maternal DNA sequences. Recent studies have shown that cell-free fetal DNA exists in maternal plasma in small fragments. Thus, cell-free fetal DNA can be enriched by size fractionation, which improves detection of fetal gene mutations. Furthermore, it has been shown that Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) mass spectrometry also permits the detection of fetal SNPs from maternal plasma. These two new developments are discussed.
母体血浆中游离胎儿DNA的存在使得能够对母体基因组中完全不存在的胎儿基因座进行无创产前诊断，例如SRY基因和RhD基因。然而，母体DNA序列占主导地位阻碍了胎儿点突变的检测。最近的研究表明，游离胎儿DNA以小片段形式存在于母体血浆中。因此，可通过大小分级分离来富集游离胎儿DNA，这提高了胎儿基因突变的检测率。此外，已经证明基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱法也能够从母体血浆中检测胎儿单核苷酸多态性（SNP）。本文对这两项新进展进行了讨论。
