Prenatal diagnosis of pregnant womencan effectively avoid genetic disorders in newborns. For example, Down’s syndrome is a common genetic disorder, which is due to the presence of an extra copy of Chromosome 21 in a human embryonic cell, and is associated with delayed physical growth and intellectual disability. Down’s syndrome can be diagnosed and avoided by prenatal diagnosis. However, conventional prenatal diagnosis for Down’s syndrome and other genetic disorders is based on biopsy of amniotic fluid for DNA analyses, hence invasive for the embryo and subject to high risk of terminating pregnancy. 

Scientists have been trying for a long time to develop non-invasive prenatal diagnosis for detecting genetic abnormalities in fetuses. While fetal nucleated cells could enter maternal blood, these cells are very rare and not adequate for diagnosis. In contract, Prof. Lo discovered in his seminal work in 1997 and 1998 that cell-free fetal DNA exists in maternal blood [1-3]. Based on these early discoveries Professor Lo performed a series of pioneering work investigating the circulating fetal cell-free DNA and demonstrated the feasibility and practical utility of using itfor diagnosis of genetic disorders [4]. These efforts culminated in the method to quantify fetal DNA using next generation sequencing, resulting in a widely utilized approach for Down syndrome detection [5,6]. Such noninvasive prenatal test (NIPT) has been used in over 90 countries. Over a million of such tests are performed annually in China alone. This revolutionary approach has allowed countless parents around the world to benefit from noninvasive prenatal diagnosis.

[1] Lancet 350: 485(1997).

[2] Am J Hum Genet62: 768 (1998).

[3] N Engl J Med339: 1734 (1998).

[4] Proc. Natl. Acad. Sci. USA104: 13116 (2007).

[5] Proc. Natl. Acad. Sci. USA105: 20458 (2008).

[6] Proc. Natl. Acad. Sci.USA 105: 16266 (2008).

Dennis Lo, born in Hong Kong , Ph.D. from Oxford. Director of the Li Ka Shing Institute of Health Sciences, the Li Ka Shing Professor of Medicine and Professor of Chemical Pathology of The Chinese University of Hong Kong (CUHK).