Genome Editing: It’s Not Really About Designer Babies

Genome Editing

We’re about four years into an age of genetic editing where advances are showing up in biology and medical research, but that’s not how it appears in public discussion. Instead, when people hear about editing the genome –the complete set of genes of an organism– they freak out about the prospect of designer babies.

Whoa…hold on. When you found out that you were pregnant, did they ask you to select features like they did when you bought a new car? They didn’t, yet the number of articles devoted to this possibility has been substantial since 2013. That was the year when scientists figured out and explained how a system called CRISPR-Cas9 could be harnessed for genome editing. Let’s back up and discuss what this means.

CRISPR-Cas9 (CRISPR for short, pronounced krisper) is an acronym for a long scientific term. It’s a kind of immune system from microorganisms to protect them from viruses that could destroy them. It works by remembering what the viral DNA looks like, the sequences of the virus’ genes, in order to cut them up. Since the system can cut viral genes, scientists reasoned that it could be hijacked to cut any genes, including those of mice, worms, plants, or humans. Like the cut feature on your word processing app, this capability is the key to editing. In short, the sequence of genes can be edited similar to the sequences of letters that form words.

The natural reaction to hearing about this has been for writers to say that the age of designer babies is upon us. If genomes could be edited, genetic letter by genetic letter, they have reasoned that soon you’ll be able to go to your obstetrician and order up your baby, gene by gene. Want a brown-eyed baby, but you and your partner both have blue eyes? No problem and the same could be said for height, the shape of the nose, or the color of hair. With CRISPR editing, you could make hair blond, or black, or even blue.

Is this possible? The answer is yes, but don’t start ordering, because the technology actually is not there. It may be there many decades into the future, but it’s not around the corner, so when it comes to genome editing, designer babies really should not be the first scenario that comes to mind.

With this in mind, I tell you some ways in which CRISPR actually is being applied currently, and how it’s going to be applied very soon. It’s being used for medical research, for instance to create laboratory mice whose tissues behave like those of humans. This significantly reduces the need to use large animals such as dogs and pigs to acquire new medical knowledge. It has been applied to grow a mouse pancreas inside a rat and a rat pancreas inside a mouse. In either case, the pancreas can be transplanted from the animal that grew it into the animal that matches it and the organ is not rejected. Currently, scientists are trying to do the same but using CRISPR to grow a human pancreas inside a pig. If this works, it will cure diabetes and the same approach could be used to grow replacement kidneys, livers, even hearts.  CRISPR is also being used on the species of mosquitoes that normally spreads malaria but to make them resist malaria instead –and to spread that resistance to other mosquitoes. The list goes on an on with all sorts of applications that could save your life and the life of your child, and all of this could happen before anyone orders up a designer baby.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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