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Breaking news reports of the first genome-edited babies. If true, these are the first humans to be born with a deliberately edited germline (the inherited genome). They will be able to pass on these edited genes to their children. This is practice is outlawed in many countries.
Lots of focus on CRISPR "off-target effects" (when the target gene is edited, some other DNA might also be accidentally modified). This suggests that once this tech works without errors, we should go full steam ahead. Let me explain: bad tech is not why this is controversial. 2/n
It is entirely likely that in a matter of years we'll be able to edit precisely the genes we want to, and leave the rest of the genome intact. Should we then go ahead with human germline modification?
Well, how do you decide WHICH genes to modify, and HOW to modify them? 3/n
Well, how do you decide WHICH genes to modify, and HOW to modify them? 3/n
Except for single-gene (Mendelian) and few-gene traits, we have no clear idea how what's written in our DNA influences our traits. Yes, there are rare single-gene diseases that can be fixed with this tech; but even in those cases, there could be many cascading effects. 4/n
7,300 years ago a child was born with a unique mutation. In single copy it protected against malaria; in two copies, it caused sickle-cell disease. Had the mutation been "corrected", malaria would have decimated human populations. Who makes the choice? nytimes.com/2018/03/08/hea… 5/n
It's not just environmental factors like pathogens. Each gene in our genome has an "environment" determined by all the other genes. Genes "interact" in complex ways, only a few of which we understand. So changing ONE gene could modify the environment of some other gene. 6/n
None of this means we stop helping people with diseases, by modifying genes in various cells. But what was reportedly done here is a modification of the entire embryo. This INCLUDES the germline, the eggs and sperm. This is a permanent change to our species' genetic heritage. 7/n
I think it's quite UNcontroversial to say we don't understand all the consequences of modifying a single gene. Anyone who says differently is either fooling you, or fooling themselves. John Cleese makes the point here better than anybody else could: . 8/n
So there we are. We have unprecedented power to modify genomes, but little knowledge of the consequences of those modifications. This isn't my gut feeling, it's the present status of the science. This is a recipe for misuse, by individuals, by corporations, by governments. 9/n
This is why there is a broad moratorium on germline modifications. The idea is that the human gene pool continues to evolve through natural processes, while gene modifications may be used to treat disorders in individuals (en.unesco.org/news/unesco-pa…, nytimes.com/2015/12/04/sci…).
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The risk is that today, in 2018, with so much still unknown, we start to decide which gene variants are allowed to persist in the human gene pool. A thousand years from now this will look insane, an unprecedented and unnecessary culling of human genetic diversity. 11/11
Follow @EricTopol thread for more on this:
Current recommendations about human germline editing:
A roundup of coverage on this still-unfolding story. Here's some of the background on He Jiankui's ambition to make the first gene-edited babies: apnews.com/13303d99c4f849….
The rogue scientist's "needless" and "reckless" actions have shocked scientists in China and across the world: nytimes.com/2018/11/27/opi…
Surveys in the US show there is public support for research on gene editing to combat serious diseases. But scientists are now worried this episode may trigger a backlash: nature.com/articles/d4158…. (Survey results: americanscientist.org/article/the-ge…)
Jiankui He has just defended his work at the Human Genome Editing Summit in Hong Kong. Here's the summary slide, you can find more on @antonioregalado's timeline.
In this whole mess there's been little attention given to the two baby girls, who never asked for this, and who will spend their childhood as scientific specimens: blogs.sciencemag.org/pipeline/archi…. It's a deep and irreversible human tragedy. 
He Jiankui is directly involved in multiple gene editing companies, but never disclosed this conflict. He authored a paper on, get this, *the ethics of gene editing*. That paper was published just hours after news of the gene-edited babies broke. wired.com/story/he-jiank…
The most abhorrent part: these babies had a perfectly normal version of the gene, one most of us have. What need to mess with it? The parents were told it was for the girls' health, but that was a lie. No, they were just lab specimens to He. /End of thread sciencemag.org/news/2018/11/i…
It is now clear that many people knew of He's plans to gene edit babies, months or years before his bombshell announcement in November 2018. This NYT article makes for chilling reading. nytimes.com/2019/01/23/hea…
The CRISPR baby fallout continues. Stanford has opened an investigation (conducted by a third party) to probe whether members of its own faculty had any role in He's gene-editing plans.
technologyreview.com/s/612892/crisp…
technologyreview.com/s/612892/crisp…
Could the rogue scientist have been held in check by the broader scientific community? There appear to have been many missed opportunities. Here's a behind-the-scenes account of the lead-up to the CRISPR baby bombshell: dev.biologists.org/content/146/3/….
