TEMPEST IN A GENE-EDITING TEST TUBE
CHINESE EXPERIMENT SPARKS FIRESTORM
AChinese scientist has rocked the world of genetics with claims Monday that he used gene-editing technology to alter the DNA of embryos that have now produced twin girls. The experiment to try to make the babies resistant to HIV infection has been widely condemned as unethical, and underlines the controversy surrounding this cutting-edge science. Here’s a primer on what all the fuss is about.
WHAT IS GENE EDITING, ANYWAY?
This is technology that — as the name suggests — can change the genetic building blocks of life by adding or subtracting material at various locations in the genome. The development of a new editing tool — CRISPR-Cas9 — has made the process easier, more precise and cheaper, generating much scientific excitement. But you’re wondering, what does that acronym stand for (assuming it has nothing to do with fried chicken)? Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9. You asked!
WHY THE EXCITEMENT?
The enthusiasm stems from gene editing’s potential to help better understand diseases, and to prevent or treat certain illnesses. Studies have focused on genetic ailments like cystic fibrosis, hemophilia and sickle-cell anemia, but it might also have application to more complex illness like cancer, heart disease and HIV. In fact, treatments involving some diseases are now in clinical trials. In simple terms, the idea is to change the genetic content of cells so a disease in a living person is halted or prevented, or so it is not passed on to future generations.
WHY IS IT CONTROVERSIAL?
Much of the research is focused around laboratory and animal testing, since the safety of gene editing on human beings has not been confirmed. The main thrust of human study is addressing disease in “somatic” cells, those that cannot be inherited. Altering the genes in germ cells — like those in sperm and eggs — is what raises major ethical questions. One fear is that the technology could be used to produce enhanced, designer human beings, by programming facial appearance, height or intelligence levels, though some scientists doubt that is technically possible.
IS IT SAFE?
Another concern is about possible harmful side effects from gene editing, such as “off-target” errors where the edits occur in the wrong place, or “mosaicism,” where some cells have the edit but not others. Some experts argue that until those safety issues are resolved, the potential harms outweigh the benefits of altering the genome of an embryo — a future human — as opposed to someone who already has or will have a serious disease. That is at the core of why the Chinese project — which purports to have changed genes to prevent the resulting person from ever getting HIV — is being condemned. “If true, this experiment is monstrous,” Oxford University ethics professor Julian Savulescu told the Guardian newspaper.
A SECURITY DANGER?
The U.S. intelligence community’s official threat assessment has raised the prospect of unregulated gene editing being used to produce harmful biological agents. “Its deliberate or unintentional misuse might lead to far-reaching economic and national security implications,” said the community’s 2016 report to Congress.
WHAT IS THE LAW AROUND GENE EDITING?
About 40 countries have some kind of law or regulation at least discouraging the type of experiments done in China, where gene-edited embryos are actually implanted in mothers. Canada has one of the most stringent laws, making it a crime — with punishment up to a $500,000 fine and 10 years in prison — to do any gene editing on germ cells, even if they will not actually be used to create a new life.
Does everyone agree on strict legal bans?
Some Canadian researchers and ethicists are calling for Canada to loosen its rules, so basic research on germ cells can take place here. “Our policy has simply shut down discussion,” McGill University health-policy expert Bartha Knoppers said at a conference last year of Canada’s Stem Cell Network.