As first reported by Antonio Regalado at MIT Technology Review, Chinese scientist He Jiankui claims to have made the first crispr-edited babies. “Two beautiful little Chinese girls, Lulu and Nana, came crying into the world as healthy as any other babies a few weeks ago,” He said in the first of five videos, posted yesterday to YouTube. “The girls are home now with their mom, Grace, and dad, Mark.” The claim has yet to be formally verified, but if true, it represents a landmark in the continuing ethical and scientific debate around gene-editing.
Late last year, He reportedly enrolled seven couples in a clinical trial, and used their eggs and sperm to create embryos through in vitro fertilization. His team then used crispr to deactivate a single gene called CCR5 in the embryos, six of which they then implanted into mothers. CCR5 is a protein that the HIV virus uses to gain entry into human cells; by deactivating it, the team could theoretically reduce the risk of infection. Indeed, the fathers in all eight couples were HIV-positive.
Whether the experiment was successful or not, it’s intensely controversial. Scientists have already begun using crispr and other gene-editing technologies to alter human cells, in attempts to treat cancers, genetic disorders, and more. But in these cases, the affected cells stay within a person’s body. Editing an embryo is very different: It changes every cell in the body of the resulting person, including the sperm or eggs that would pass those changes to future generations. Such work is banned in many European countries, and prohibited in the United States. “I understand my work will be controversial but I believe families need this technology and I’m willing to take the criticism for them,” He said.