The baby crisperer
A Chinese scientist claims to have edited the genomes of two babies
Humanity’s power to control the four-letter code of life has advanced by leaps and bounds. A new gene-editing technology called CRISPR-Cas9, which was not discovered until 2012, has been the subject of particular excitement. It allows DNA to be edited easily, raising hopes that it could eventually be used to relieve human suffering. This week, however, CRISPR has caused more unease than optimism, because of claims by a Chinese scientist that he edited the genomes of twin girls when they were embryos, as part of IVF treatment.
He Jiankui, of the Southern University of Science and Technology, in Shenzhen—which was not involved in the work—says he edited a gene, CCR5, that allows HIV to infect human cell. Mr He claims to have created one baby resistant to HIV infection, and a twin who is not. (Another woman is apparently carrying an edited embryo.) If reproductive cells were affected, any such modifications will be passed on to subsequent generations. There is still uncertainty over what Mr He has done. But it is just a matter of time before someone, somewhere, edits human embryos that are grown into babies. Governments and regulators need to pay heed.
Presume that Mr He’s assertions are truthful. One day it may make sense to edit an embryo—to cure genetic diseases, say. That day has not arrived. The technology is so new that the risks to human subjects cannot possibly justify the benefits. Scientists do not fully understand the scope of the unintended damage CRISPR does to DNA elsewhere in the genome or how deactivating CCR5 might leave you vulnerable to other diseases (it may, for instance, make death from flu more likely).
Mr He’s work appears to have had the scantiest oversight and a vice-minister says it violates regulations. Mr He told delegates at a gene-editing conference in Hong Kong this week that he had run the idea for the trial past four people. It seems likely that Mr He himself was largely responsible for deciding whether his human experiment was worth the risks. It is not clear that the babies’ parents gave their informed consent.