Around this time last November, Chinese scientist He Jiankui stunned the world when he revealed the birth of the first known gene-edited babies. Working in relative secrecy, he had used CRISPR to modify human embryos in the lab and then established pregnancies with those embryos. Twin girls with edited genomes were born as a result.
The scientific community’s condemnation of He was harsh and swift. He had edited the germline, making a heritable genetic change. There were safety questions about the effects on the twins, and he had not meant to fix a genetic defect to prevent a heritable disease. Instead, he tweaked a gene in an attempt to bestow an uncommon, protective genetic trait: resistance to HIV.
In the aftermath, leading scientists and ethicists published an open letter in the journal Nature calling for a temporary moratorium on human germline gene editing — that is, editing eggs, sperm, or embryos — to make genetically modified children. But it’s been a year, and there is still no unified set of rules to dictate whether or how scientists should conduct this research. Some scientists have rejected a blanket moratorium in favor of self-regulating, believing that they can chart a path toward responsible germline editing to prevent a number of inherited diseases.
But how to do so remains a point of contention.
Meanwhile, at least one scientist is already planning more gene-edited children. In June, Russian molecular biologist Denis Rebrikov said he wanted to use CRISPR to create more HIV-resistant babies, but in a more ethical way than He’s experiment. His plans have since shifted to editing embryos of couples with inherited deafness in an attempt to make hearing babies.
“The horse has already left the barn,” Jennifer Doudna, one of CRISPR’s inventors, tells OneZero.
The need for regulation in germline editing is urgent because the consequences may fundamentally change the human genome and be passed down through generations. And putting CRISPR directly into the human body, including…