Carl Zimmer Hosts “Ask Me Anything” Session On Reddit, Tackles Heredity, Genetics, DTC Testing

By Bio-IT World Staff

June 1, 2018 | To celebrate the recent publication of his book She Has Her Mother’s Laugh, New York Times science columnist Carl Zimmer hosted an “Ask Me Anything” (AMA) session yesterday on Reddit.

In She Has Her Mother’s Laugh, Zimmer traces the history of our understanding of heredity from Hippocrates, who believed both men and women produced semen and new life was formed when the two were mixed, through the innumerable twists and turns that expanded our understanding of how we come to be: from the Habsburg’s royal bloodline to Carl Linnaeus, Jean-Baptiste Lamarck, Charles Darwin, Gregor Mendel, Hugo de Vries, eugenics in America, genome sequencing, CRISPR, and gene drives.

Questions during the AMA covered a wide range of topics from consumer genetic testing and how genomic information should be integrated into healthcare, to heredity and where Zimmer stands on genetic cloning.

Here are some highlights from the AMA session:

Q: Do you think that interest in consumer genetic testing is going to keep growing over the next 3-5 years or is it going to plateau soon?

Carl Zimmer: The latest growth charts I've seen for Ancestry.com and 23andMe.com are downright exponential, in a rocket-like way. I can't imagine it stopping in the next few years. But it's an open question just how big the demand for this kind of testing will turn out to be. I remember ebooks exploding in the same way, and we writers imagined that in a few years, printed books would disappear. But then all the ebook folks joined the market, and it topped out around 30 percent. Maybe that's what will happen in the direct-to-consumer testing world.

Just yesterday, I was chatting about this with a scientist visiting from Germany. He said that these ancestry tests are nowhere near as popular in Germany. I asked him if he could guess why, and he said, "We know where we came from." I think he may be on to something there. We Americans have been using genealogy to trace back our transoceanic roots for centuries.

Q: Aside from data privacy protection (which has been discussed a lot!), what do you think are some other big concerns that customers face about [Direct-To-Consumer] genetic testing, and how can companies like 23andMe and AncestryDNA address these concerns?

CZ: One concern I have is that these findings can seem definitive. Partly that's because we're dealing with DNA, which we think of as our essence, and partly because the designs of these web sites are so snappy. It looks like you're getting a blood pressure or temperature reading. But there's a lot of ambiguity to these tests. If you go to different companies for your ancestry, you may get different percentages. That's not because they're fundamentally wrong, but because they're using different samples of people and different population-genetic models to estimate your ancestry. Likewise, if you find out from a company that you don't have a cancer-causing BRCA1 cancer mutation, it's still possible that you have one that the company doesn't yet test for. So you can't take that information as a definitive diagnosis that you're free and clear.

Q: Do you think that in the near future, sequencing from Oxford Nanopore Technology is going to replace the current short reads from Illumina (and competitors) for clinical testing and human genetics?

CZ: I wouldn't make bets on particular companies, but there are certainly a number of technologies rising up to challenge the current standard of short reads (breaking DNA up into tiny fragments, making lots of copies, and then piecing the copies back together to determine a genome sequence). Long-read technology like Pac Bio is becoming pretty common in the labs of scientists I talk to regularly.

Q: How will/should genomic information be integrated into ordinary healthcare, and when should that start? Does it make sense to sequence children's genomes?

CZ: Right now, some big health-care providers are scaling up their DNA sequencing on a tremendous scale. They're not just screening for a few genes here or there--they're trying to gather up whole genome sequences for lots of their patients. For now, it looks like a lot of the interest is in research--finding genes linked to diseases. For a lot of people, it's still an open question whether actually having your genome sequenced matter to your health. That being said, genome sequencing is becoming a regular part of diagnosis. In some neonatal intensive units, lots of the babies are having their genomes sequenced so that doctors can search quickly for hereditary disorders, including ones new to science. In some cases, that knowledge can lead to immediate interventions that can help the children.

Q: Where do you stand on genetic cloning? Should businesses be allowed to clone organic cells/ organs/organisms for profit, assuming they have the technical capability and/or consent? Is there an ethical line that should not be crossed?

CZ:  I think the most important ethical issues when it comes to any biomedical advance are well-being, suffering, and autonomy. If cloning causes suffering (deformities due to epigenetic disruptions in the cloning process, for example), then that is a serious concern, not just for humans but for animals. I don't think we should be quite as hung up on whether clones are "natural" or not. Identical twins are in effect clones, but their genetic identity doesn't make them less human. Nor do we think of them as having indistinguishable existences, because life is more than DNA. That being said, it would be very cruel and creepy for some rich person to clone himself or herself, and raise a child on the expectation of carrying on his or her legacy/existence.