An Interview with our Clinical Pathologist Carol Siu
Born in Hong Kong Carol Siu graduated medical school at the University of Hong Kong, her choice of specialty, chemical pathology. “At the time genetic diagnostics were rapidly emerging” remarks Carol. Her training allowed her to then pursue a fellowship of molecular genetics in the UK where she obtained a PhD in genetics. She was able to do further research and gain exposure with advanced technology at that time such as massive parallel sequencing and microarray (DNA sequencing and genetic testing). She has also been doing two years of obstetrics and gynecology and has worked in hospitals both in New Zealand and Hong Kong. “I am very happy I am now able to work in a service related to clinical care.” says Carol.
Carol brought her power house of training to New Zealand three and a half years ago and is now working in Auckland hospital. “I’m a pathologist with qualifications of chemical pathology and molecular genetics and I now work in the Auckland City Hospital. My main role is chemical pathologist but I also work with molecular genetics which is where non invasive prenatal testing (NIPT) sits.” Carol’s work with Healthscope is focused only on Illumiscreen NIPT. The work with NIPT involves review of the results, consultations from referrers, patient queries and quality assurance.
“I find genetics fascinating and rewarding” enthuses Carol “and the technology has changed so much in the last 10-20 years allowing us to do much more!” The first major scientific discovery found that a baby’s DNA is actually detectable in the mother’s blood. From there a sample of the mother’s blood is taken and stored in a special tube to preserve the delicate plasma DNA which is inside the blood. The sample is then transported to the laboratory, where the plasma is isolated from the blood in a centrifuge, then the DNA can be extracted. Both the DNA from the mother and the DNA baby are found in this plasma. The next part of the process is called “library preparation” where they get the DNA ready for analysis. The DNA is then loaded onto a sequencer, this part of the process is called Massively Parallel Sequencing. This sequencing process takes overnight, so it can be ready for the data to be analysed the next day. The data they gather from this process lets Carol know if there is excess chromosome 13, 18, or 21 outside of the normal range which would indicate that the baby is affected by the trisomy for that particular chromosome. The data collected also includes the XY chromosomes, which determine gender.
NIPT testing was first published in the medical literature in 2008, and was brought to New Zealand through Labtests who are the only laboratory which offer NIPT tests onshore, “Our service has been available since 2016, so we are the first providers in New Zealand.” It has only been in the last 5-10 years that this technology has been available. “When it came into the market, the way they invented it, is like something from Science Fiction.” says Carol “Earlier it was hard to imagine that it could be done like this.The technology behind this is fascinating and better yet, the information gives us power. The aim of NIPT is to give parents the most comprehensive information so they can make the best decision. It supports parents by providing them with early, accurate testing. The early diagnosis for any chromosomal abnormalities allows the parents to know sooner and then decide what to do next, whether or not their pregnancy goes forward or how they can best take care of their baby in the future says Carol.
Carol is also hard at work on quality control, reviewing results and checking the requests of each individual patient. She then decides, after careful inspection, if the results are ready to be released. If they are abnormal the requester is contacted directly to discuss these results. There is also a quarterly review of all positive and negative results to ensure their accuracy. “We also participated in the external quality assurance schemes. The external quality assurance organisation provides us samples to test as an assessment; we have to test them like patient samples and return our results and interpretations to the organisation where they examine our submissions and give us back a report whether we passed or failed. We do this regularly. This is great because it simply validates that our quality meets the international standard.”
NIPT testing can be done so much safer and sooner than ever before, and with a whole team of talented hard working people like this, peace of mind for the health of your baby can be as easy as a blood test.
An interview with molecular scientist Blair Shilton
Blair Shilton is a molecular scientist for Illumiscreen, a husband, a father of 9 month old Harper and on his way to turning his masters degree in science into a PhD. Blair has been working with Labtests for 10 years.. He starts his day early at 3:30am to get ready and care for his daughter before walking in the door of Labtests around 6:30am to begin his day bringing peace of mind to other parents. In fact that is the first job of the day, corresponding with patients and referrers, answering questions and easing minds. Blair then moves on to checking samples and ensuring every sample expected to arrive has been received and that no sample is overdue or missing. Then it is time to get the process started.
Blair admits he gets the most satisfaction from bringing reassurance to patients and says “It’s great being able to give results to the patients that has meaning behind it.” Blair wants to ease the anxiety of parents and if the results are abnormal bring them the safety of time. “It gives them time to make some sort of decision” he asserts. “Rather than finding out when it’s too late to do anything, it can give parents time to consider and prepare for their next steps.” This technology isn’t about pro choice or pro life, it’s about pro information and it’s especially about pro information as early as possible. Illumiscreen want to empower parents with early and accurate information and the sensitivity of these tests are a key part of what NIPT delivers.
Maternal serum screening could only give you chances such as a 1-in-200 or a 1-in-50 chance that something isn’t right. Diagnostic testing such as amniocentesis and chorionic villus sampling can also be invasive and risky to the pregnancy which has a small chance of causing miscarriage. “It’s a small chance,” says Blair “but you really don’t want to take any chances with your child’s life!” An estimated 10-12 pregnancies a year could be saved by not having to use older testing methods. NIPT is safe and accurate as Blair affirms.
The process is “not as flashy as some people would think.” Blair reveals “It’s not all test tubes and beakers and stuff.” The tests are done on a small scale with small volumes. NIPT aren’t mass produced and each sample takes an incredible amount of concentration due to the outcome of what is riding on the results and as Blair assures “we have to make sure that what we report is on the dot.” After the DNA is collected from the blood, the sample is very small but what separates it from other testing is the concentration required for each sample. Most of this process is being done in a biohazard cabinet. For the Illumiscreen team “It is 100% concentration for 8 hours.”
Blair goes on to explain that the price for NIPT can seem a lot. He explains that “It’s about peace of mind.” Blair and his wife chose to take the test during their pregnancy. “Straight away you feel relieved. You know what’s happening with the life growing inside of you.” and when asked if he would do it again he responded with “Absolutely, I believe it’s worth every single cent.”