Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Saturday, December 1, 2018

CRISPR babies

One of my problems with resolving ethical questions is that I so often have a hard time deciding the difference between moral, ethical, reasonable, and justifiable, and figuring out where an issue lies on the spectrum thereof.

I've always had this problem.  There are things that in my view are always wrong -- harming or endangering a child comes to mind -- but the vast majority of issues lie in that immense field of gray areas.

Which is why I'm having a hard time deciding what to make of the bombshell announcement last week that a Chinese geneticist, He Jiankui, claims to have genetically altered a pair of human embryos -- and it resulted in the birth of twin girls who, if the gene editing was successful, will be resistant to HIV.

The technique involved was CRISPR-Cas9, a protein complex that allows for what amounts to cut-and-paste for your DNA.  What He did was to use CRISPR-Cas9 to selectively delete a gene for a  receptor called CCR5 that allows HIV to attach to cells.  Without that receptor -- He hopes -- the children will be genetically immune.

[Image is in the Public Domain]

When He made his announcement, the scientific community had a collective meltdown.  "The underlying purpose of doing the experiment was obviously to show that they could do gene editing on an embryo, but the purpose for the party involved does not make any sense," said Anthony Fauci, an HIV/AIDS researcher and head of the U.S. National Institute of Allergy and Infectious Diseases in Bethesda, Maryland.  "There are so many ways to adequately, efficiently, and definitively protect yourself against HIV that the thought of editing the genes of an embryo to get to an effect that you could easily do in so many other ways in my mind is unethical."

Okay, I'm not defending He.  The real issue here, in my opinion, is risk.  "Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer," said Julian Savulescu, an ethicist at the Oxford University.  "This experiment exposes healthy normal children to risks of gene editing for no real necessary benefit."

But the problem is that at some point, scientists were going to have to take the leap and do something like this.  Ever since Jennifer Doudna of UC-Berkeley developed CRISPR-Cas9 as a gene editing protocol in 2012, it's only been a matter of time.  Once a technique like this becomes possible, it becomes inevitable.

So sooner or later, someone was going to have to accept the risk of trying it on human embryos.  Animal models only get you so far.  The potential for eradicating genetic diseases is nothing short of astonishing; think of a world without cystic fibrosis, Huntington's disease, Tay-Sachs disease, sickle-cell anemia, hemophilia.  All of that is well within the realm of possibility now.

But.  Once you've started down that road, what's to stop people from altering other traits?  Appearance, personality, behavior... for me, this gets out onto some very thin ice.  When this Pandora's box is opened, there's no telling what dubiously ethical practices will escape.

There's also the problem that if such a technique really becomes capable of (relatively) risk-free editing out of deleterious genes, it's almost certain that it would be available only to the rich, further widening the gap between the privileged and the non-privileged.  The brilliant (and prescient) 1997 film Gattaca dealt with this very issue -- how genetic engineering of children could result in a new lower class, people conceived the old-fashioned way who didn't have the same opportunities for jobs, education, health care, and health insurance as the smarter, stronger, healthier "Valids."

So I'm of two, or more, minds about all of this.  First, the potential of the therapy is mind-boggling.  And the idea that once developed, researchers were going to hold off trying it out on human embryos, is naively optimistic about human nature.

But it comes back once again to the quote from scientist Alan Grant in Jurassic Park -- "You were so busy trying to figure out if you could, you never gave any thought to whether you should."  The thorny ethical issues this technique brings up go way beyond the potential risk to two baby girls in China.

All of which makes me glad that I'm not on the scientific regulatory boards who are wrestling with how to respond to He's announcement.


Ever wonder why we evolved to have muscles that can only pull, not push?  How about why the proportions of an animals' legs change as you look at progressively larger and larger species -- why, in other words, insects can get by with skinny little legs, while elephants need the equivalent of Grecian marble columns?  Why there are dozens of different takes on locomotion in the animal world, but no animal has ever evolved wheels?

If so, you need to read Steven Vogel's brilliant book Cats' Paws and Catapults.  Vogel is a bioengineer -- he looks at the mechanical engineering of animals, analyzing how things move, support their weight, and resist such catastrophes as cracking, buckling, crumbling, or breaking.  It's a delightful read, only skirting some of the more technical details (almost no math needed to understand his main points), and will give you a new perspective on the various solutions that natural selection has happened upon in the 4-billion-odd years life's been around on planet Earth.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

1 comment:

  1. This seems like the sort of thing that might originally be very expensive, but we're talking a time span of generations here in a very fast-moving field. It wouldn't remain expensive for long in those terms, and editing out common diseases will probably become routine -- after all, it's an overall cost savings compared to dealing with the symptoms of the illness.

    As regards attributes that aren't as clear-cut whether they're favorable or not, I don't trust parents to make good decisions. Look at the risk they put their kids to by not vaccinating them, to avoid an imaginary risk of autism. And autism is really a disability mainly because the world is set up to accommodate the neurotypical, not for the benefit of those whose brains operate a little differently.

    But then, parents make a lot of decisions for their children that might be sub-optimal. I think we can only limit the extremes.