Topol Predicts Genomic Screening Will Replace Amniocentesis
Eric J. Topol, MD.
November 11, 2013

This is Dr. Eric Topol, Editor-in-Chief of Medscape, commenting on another exciting area in medicine that involves genomics: prenatal genomic screening. I recently had some first-hand experience with this because I have a daughter who is expecting, and she had one of these tests. Four of them are now available. Chromosomal aberration screening could be done between 8 and 10 weeks in the first trimester, to screen for trisomy 13, 18, and 21. It is pretty darn remarkable that there are 4 simple blood tests capitalizing on the cell-free DNA from the fetus in that 1 tube of maternal blood, from which we can determine chromosomal aberrations and gender as well as a whole lot more in terms of sequencing the fetal genome.

This is a very exciting time. Until now, we have completely relied on amniocentesis and chorionic villi sampling, which carry a significant risk, although low. And, of course, expense, all sorts of trepidation, and anxiety are factors. To be able to do this noninvasively with a tube of blood, with accuracy that is as good as amniocentesis, is pretty darn remarkable.

Beyond the fact that this is extraordinary and represents one of the biggest impacts that genomics has had in medical practice today, the question I really want to bring up is, where do we draw the line? Now that we can sequence a fetal genome, when are we going to start doing that and not just screen for big chromosomal aberrations of trisomies and aneuploidy? This is something that will perhaps engender the biggest bioethical issues of the future. What do we say is an appropriate finding from sequencing — whether it is an exome of the fetus or whole genome — that constitutes criteria for early termination of pregnancy?

Watch out for that because it’s coming. It is eminently doable today and it’s scalable as we go forward, just from a single tube of maternal blood. I think it’s amazing. From first-hand experience, I could see how much impact it has on the parent as well as the grandparent. Thanks very much for your attention.

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Raghuthaman

This is also posted in the Pediatric section.