In the past, pregnant women may need to receive amniocentesis (taking amniotic fluid from the womb) to test the risk of fetal Down’s syndrome and other fetal genetic diseasese, which may lead to fetal injury or miscarriages. Professor Dennis Yuk Ming Lo, Associate Dean (Research), Faculty of Medicine of the Chinese University, achieved a breakthrough in prenatal examination technology with his research published in 1997. He found high concentrations of fetal DNA in the plasma of pregnant women and subsequently invented non-invasive prenatal testing (NIPT).
NIPT can examine the possibility of fetal Down syndrome and genetic diseases by analysing blood samples taken from pregnant women. Since its introduction to clinical practice in 2011, NIPT has been adopted by more than 90 countries and helped more than 10 million pregnant women every year.
At that time, he was studying medicine at Oxford University and did a clinical rotation in the obstetrics and gynaecology department. As a result, he had a chance to learn about invasive prenatal examination e.g. amniocentesis. Under ultrasound guidance, doctors insert a needle through the abdomen of a pregnant mother to extract amniotic fluid from the uterus for testing. However, this method may cause fetal injury or a miscarriage.
It prompted a question in his mind: Is there a safer way to check whether the fetus is normal?
Although fetal cells were found in the blood of pregnant women, it was not possible to detect whether the fetus was normal since there were too few fetal cells. Hence, a safe and reliable method to test the fetus was still not available.
After graduating from Oxford University, Lo became a houseman. However, the research was always in his mind. He had a sense of mission that he should complete the study as he had started this. After working as a doctor for a year, he returned to Oxford University to pursue a doctorate and engaged in full-time research. However, the road of scientific research had not been smooth. He spent eight years and countless hours on his research but to no avail.
The method sounded crude and unscientific but he still gave it a try.
He went back to the laboratory, where the plasma from a pregnant woman was boiled and then a few drops were tested. He couldn’t believe his eyes - more than a tenth of the pregnant women’s plasma was fetal DNA, the concentration of which was 100,000 times stronger than what could be found in blood cells!
When examining blood cells, the first thing one does is to remove and throw away plasma. It turned out that he had been looking in the wrong place for the past eight years.
The result was simply unbelievable.
In early 1997, he returned to Hong Kong and started teaching at The Chinese University of Hong Kong. He also published the research paper, “Presence of fetal DNA in maternal plasma and serum”, and invented non-invasive prenatal testing (NIPT). Only the maternal blood would be required to test the sex of the fetus and it can also help identify whether a given fetus has Down syndrome by testing chromosome 21 of the fetal DNA.
After three years of trials, this ground-breaking technology was introduced to clinical practice in 2011. The accuracy rate of this technology is as high as 99.7%. It can also eliminate the risk of fetal injury or miscarriage.
Lo is now fondly referred as “the father of non-invasive prenatal testing” around the world and is regarded as a scientist from Hong Kong with the potential to win major international prizes in science.
In order to further expand the application of the research, Lo hoped to draw a complete genome map of the fetus. He had been trying to come up with a formula to solve the problem but he struggled.
Unexpectedly, a Harry Potter movie helped him capture the magic needed to solve the problem!
In 2009, when Lo and his wife were watching a 3D version of one of the Harry Potter movies, he was struck by the letter H that floated in front of him on the screen, the shape of which looked like a pair of chromosomes. Since the two chromosomes of the fetus came separately from the father and the mother, he realised that two equations should be used to analyse the two chromosomes instead of one equation.
As a result, he achieved another significant breakthrough. In 2010, his team produced the first complete genetic map of a fetus in maternal plasma. By extracting blood from pregnant women, any fetus with a single gene disease can now be detected.
The non-invasive prenatal testing for fetal Down syndrome was successfully introduced for clinical application in 2011, with an accuracy rate of 99.7%. Pregnant women can have a non-invasive, safe and accurate prenatal examination in the early stage of pregnancy (e.g. 10 weeks).
The research team has successfully applied DNA sequencing technology to cancer detection. More than 50 kinds of cancer can be detected with only one blood sample. This technology has been launched in the USA in the middle of 2021.
More than 90 countries and regions provide non-invasive prenatal testing services and more than 10 million pregnant women worldwide use this technology every year. This technology has been endorsed by multiple international professional associations.
The global market for NIPT has been estimated to be approximately US$4 billion in 2019.
In 2019, the research team provided the technology for free to the Hospital Authority so that pregnant women in needs can have unobstructed access to this technology.
Through this work, Professor Dennis Lo has received numerous awards, including his election as a Fellow of the Royal Society (2011), his election as a Foreign Associate of the US National Academy of Sciences (2013), a Thomson-Reuters Citation Laureate in Chemistry (2016) (well-known as a metric for predicting future Nobel Prize winners),and he was awarded the inaugural Future Science Prize (2017) (regarded as the equivalent of a Nobel Prize in China) as well as the Breakthrough Prize in Life Sciences (2021)(known as the “Oscar of Science”). He was named the world’s “Top 20 Translational Researchers” for consecutive years. Furthermore, Professor Lo is the first Chinese Scientist ever to receive the Royal Medal for Outstanding Achievements in biological sciences category. The Royal Medal is one of the most prestigious awards of the Royal Society. Two Royal Medals are awarded annually for the most important contributions to the advancement of "natural knowledge” in the physical and biological sciences, respectively. There are 400-some awardees in history, including Charles Darwin who proposed the theory of evolution and John Dalton who developed the atomic theory.
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