For the last few years, scientists have been warning us that genetically modified children are just over the horizon. Rumors have been flying around that laboratories are already using a revolutionary new gene-editing technique called CRISPR to try to change the genes of human embryos.
Advanced gene-editing techniques like CRISPR hold great promise for treating or even curing genetic disease in existing patients that need it. But in genetic engineering, it is not just the what, but the when, that matters. Any genetic modifications done at the embryonic stage are considered germ-line modifications, meaning those genetic changes will be incorporated into reproductive cells and will be passed down from generation to generation.
Prominent researchers have called for a voluntary moratorium on using CRISPR technology in human embryos, even for therapeutic purposes, because of the inherent risk to multiple generations. They rightly argue that gene editing in humans should only be attempted in therapeutic cases where any modifications cannot be passed on.
The Catholic Church agrees. In Dignitas Personae, a clear line is drawn between gene therapy that is for a single patient and germ-line modifications that can be inherited. Not only is it unethical to create and manipulate human life in a laboratory, but Dignitas Personae states, in regards to human germ-line modifications, “… it is not morally permissible to act in a way that may cause possible harm to the resulting progeny.”
Unfortunately, the rumors surrounding the use of CRISPR technology to genetically modify human embryos have proven to be true.
Scientists in China have published results of their experiments into editing the genes of leftover in vitro fertilization embryos that were deemed nonviable because of genetic abnormalities. Led by genetics researcher Junjiu Huang, the Chinese attempts were, by all accounts, a failure. Out of 86 embryos that researchers tried to modify, only 71 survived.
Of those that survived, 54 were tested to see if the genetic engineering worked. Only four embryos showed evidence of the intended modification, an editing of the gene responsible for a blood disorder.
Overall, there was evidence of what The New York Times called “collateral damage,” meaning unintended mutations in other parts of the genome caused by the attempted genetic engineering. The Times reported, “The Chinese researchers point out that in their experiment gene editing almost certainly caused more extensive damage than they documented.”
Rebecca Taylor blogs at Mary Meets Dolly