A new study found that the changes in the babies’ DNA make them more vulnerable to certain viruses.
When Chinese scientist He Jiankui announced last fall that he had altered the DNA of twin embryos to protect them from the AIDS virus, he was met with condemnation from scientists and bioethicists who warned of the dangers of gene editing.
“We’re not even sure that it’s safe,” Fr. Nicanor Austriaco, O.P., professor of biology and theology at Providence College in Rhode Island, said in an interview with Aleteia’s John Burger following news of He’s gene-editing. “This scientist was allowed to do experiments with children, using technology that had not yet been deemed safe,” he added.
Now those dangers are more than just hypothetical.
He, who heads the Southern University of Science and Technology in Shenzhen, China, said that he used the CRISPR-Cas9 during an in vitro fertilization procedure that resulted in the birth of twin girls in November of 2018. The procedure aimed to produce a mutation in the gene CCR5 that has been shown to prevent HIV infections.
A study released on Monday in Nature Medicine, found that the specific genetic variation He tried to recreate might significantly shorten the lives of the twin babies by making them more vulnerable to the West Nile and influenza viruses.
After analyzing more than the 4,000 participants in the study, researchers discovered that those with a mutation of the gene known as CCR5 – the same variation He said he replicated in the twin embryos—were about 21% less likely to live until age 75, reported NPR.
“What we found is that they had significantly increased mortality,” said Rasmus Nielsen, a professor of integrative biology at the University of California, Berkeley, who led the study.
“It’s rather substantial. We were quite surprised the effect was this large,” said Nielsen, who called it a “cautionary tale,” according to the NPR report.
According to an AP report, while researchers were not able to find the cause of death of those who died prematurely, increased vulnerability to the flu may have played a major role.
In March a group of 62 doctors, scientists and bioethicists called for a moratorium on experiments that alter human genes which can be passed on to future generations.
“Although we recognize the great scientific advancement represented by gene editing technologies and their potential value for an improved understanding and possible treatment of human disease, we strongly believe the editing of human embryos that results in births carries serious problems for which there are no scientific, ethical, or societal consensuses,” the letter from the American Society of Gene and Cell Therapy read.