Rewriting Our Genes Is Easier Than Ever. That Doesn't Mean We Should Do It.

Gene-editing technologies have huge potential to alleviate human suffering. But, like all very powerful technologies, they also carry enormous risks if used improperly.

In November 2018, a team of scientists in China led by Dr. He Jiankui revealed shocking news at a conference: he’d used CRISPR-Cas9 (often referred to as just CRISPR) to edit the genes of three embryos. Two of the embryos were successfully implanted in a surrogate, resulting in twin girls. Now known only as Nana and Lulu — their identities protected in scientific version of the witness protection program — Dr. He said he’d used CRISPR to immunize the embryos to HIV. But he’d acted against worldwide guidelines and regulations to do so. Those regulations prohibited “germline” edits, or genetic edits that are heritable to the edited organism’s future offspring. (Dr. He and his collaborators were recently sentenced by a court in Shenzhen to three years in prison for conducting "illegal medical practices.")

Let’s back up.

Gene editing is what it sounds like: modifying an organism’s genes. The technology has a massive range of applications, and those...