The most important science story you may have never heard of is one you need to know about.
A few months ago, a Chinese scientist announced he had used a powerful gene-editing technique to create the world’s first genetically edited babies. Dr. He Jiankui showed no proof of the twin babies whose genes he said he altered to make them resistant to HIV infection, but it was enough to send the scientific world into a tizzy.
It’s illegal in many countries — including the United States — to deliberately alter human embryos, which raises all kinds of ethical questions. The practice is opposed by many researchers around the world and in China, where He is being investigated.
“It is unethical to do such a thing,” says Dr. Mazhar Adli, a geneticist at the University of Virginia School of Medicine who has done research with the gene-editing technique. “It was reckless.”
The gene editing technique allegedly used by Dr. He is known as CRISPR, short for Clustered Regularly Interspaced Short Palindromic Repeats. Basically, CRISPR is a cluster, or sequence, found in the DNA of bacteria. Using enzymes created by the bacteria, scientists figured out a way to manipulate the genes by cutting out some and substituting others. The applications of the editing system are huge — scientists can actually control which genes get expressed in plants, animals and yes, even humans.
For example, CRISPR could be used to take out a gene that causes a particular disease — say, cystic fibrosis — and replace it with a good gene that won’t cause the disease. It could be used on crops to make them more hardy or nutritious or on dairy cows so they won’t have horns.
The technique appears to have worked on every organism it’s been tried on. Some researchers have reporting using CRISPR to fix a gene mutation that causes the heart disorder hypertrophic cardiomyopathy; others say they were able to reduce genetic deafness in mice.
“It’s one of the most exciting developments in the history of molecular biology,” says Adli, whose lab is utilizing and developing CRISPR-based technologies. Last year his research group at UVa’s Department of Biochemistry and Molecular Genetics came up with a safer and more efficient way to use the system to silence genes. He provided the technique to scientists around the world.
But while CRISPR is exciting, it has so far only been used in labs. The science still isn’t quite there to begin clinical trials on humans. For one thing, researchers still don’t completely know all the potential side effects, Adli says. And then there’s the big issue of ethics. If scientists can pick and choose which genes to take out and put back in, what about genes besides those that affect disease? Could CRISPR be used to make so-called designed babies — changing hair or eye color, or increasing athleticism, or bumping up IQ? We already know the disastrous effects of eugenics experiments in the past.
“Who has the right to make one person more desirable than others?” questions Adli.
In 2017, an advisory group formed by the National Academy of Sciences and the National Academy of Medicine endorsed gene editing in principle, but with the caveat that it be used only to deal with “serious diseases and disability” and only when no “reasonable alternative” exists.
Still, Marcy Darnovsky, executive director of the Center for Genetics and Society in Berkeley, Calif., told The New York Times that any policy discussions surrounding gene editing needs to go even further, including more voices than just scientists.
“There are ethical parts that we as scientists can’t decide,” agrees Adli.
We need more effective ways to involve the public in the discussion on CRISPR and to come up with the plan on how to move forward.”
He’s announcement about the twin babies left many researchers scratching their heads, because there was no medical need to change the genes that he did. He claimed he altered a gene in the embryos before they were implanted in the mother’s womb that would make the babies resistant to infection with HIV, the virus that causes AIDS. The father in the case had HIV.
The thing is, there are other ways doctors could have made the embryos resistant to HIV. And while He claims that the editing technique was performed safely, Adli says there’s no sure way to know. Some studies have shown that CRISPR-edited cells can inadvertently trigger cancer.
Whatever was done to the twins’ genes will not only affect them, but also their children and for generations to come. The genes that the CRISPR technique uses are involved in the immune system — could that have an effect somewhere in the future?
“The technology is not perfect,” says Adli, who says research is done with CRISPR on a daily basis to make it safer. “It’s still very, very young technology. There’s tremendous progress, but it’s not perfect yet.”
Adli does believe that CRISPR will eventually have huge benefits in how we treat diseases, and he says he believes it should be used to help in cases like cystic fibrosis, or sickle cell anemia. There are about 6,000 known genetic diseases in the world — for those diseases considered monogenic, meaning that just one gene causes the disease, being able to correct that single gene could be huge.
Even now, there are companies developing CRISPR technologies. Monsanto (since acquired by Bayer) and DuPont have already licensed technologies for agricultural use. And work continues in labs around the world — at the most basic level, CRISPR is making it easier for scientists to figure out what different genes in different organisms actually do. Better knowing the function of the genes in the human genome can only help genetics research.
If there’s a positive to come out of the Chinese baby announcement, it’s that more people — beyond just doctors and researchers — are learning what CRISPR is, Adli says. That’s important as discussions continue.
“Now that the Pandora’s Box is open, we’ll see more and more applications of this technology,” he says. “It has wide applications, which is why it is so powerful. And as with any powerful tool, it should come with great responsibility.”
