Biology and Diagnostic Applications of Fetal Nucleic Acids in Maternal Plasma

Many traditional methods of prenatal diagnosis are invasive, e.g. amniocentesis, and constitute a finite risk to the fetus. Professor Dennis Lo from The Chinese University of Hong Kong is the first to demonstrate that fetal DNA is present in the plasma of a pregnant woman. This discovery has important implications for the future development of prenatal diagnosis.

Professor Lo has elucidated the fundamental biological parameters of this previously unexplored area of research, including the variation of circulating fetal DNA concentration with gestational age and its clearance after delivery. This work has laid a solid foundation for the subsequent use of circulating fetal DNA for non-invasive prenatal diagnosis, including its application for fetal RhD blood group determination and for the prenatal exclusion of beta-thalassaemia, the latter being an important genetic anaemia in many parts of the world, including China.

In addition to proving the presence of circulating fetal DNA, Professor Lo has demonstrated, for the first time in the world, that the fetus will also release its RNA into the plasma of mother. While DNA is the building block of genes, RNA is only copied from genes which are active. The detection of circulating fetal RNA therefore has an important implication of providing a means to monitor the gene expression profile of an unborn fetus. This discovery has greatly enhanced the diagnostic application of plasma-based molecular diagnostics.

Professor Lo has produced 107 publications in the field of circulating DNA/RNA, with many in high impact international journals. Professor Lo has also obtained or applied for a number of patents or patent applications in this field.