DNA Editing of Human Embryos Alarms Scientists

A call by scientists to halt to precision gene-editing of DNA in human embryos would allow time to work out safety and ethical issues

Sperm cell fertilizing an egg. Credit: Wikimedia Commons

Amid rumors that precision gene-editing techniques have been used to modify the DNA of human embryos, researchers have called for a moratorium on the use of the technology in reproductive cells.

In a Comment published on March 12 inNature, Edward Lanphier, chairman of the Alliance for Regenerative Medicine in Washington DC, and four co-authors call on scientists to agree not to modify human embryos even for research.

Such research could be exploited for non-therapeutic modifications. We are concerned that a public outcry about such an ethical breach could hinder a promising area of therapeutic development, write Lanphier and his colleagues, who include Fyodor Urnov, a pioneer in gene-editing techniques and scientist at Sangamo BioSciences in Richmond, California. Many groups, including Urnov's company, are already using gene-editing tools to develop therapies that correct genetic defects in people (such as by editing white blood cells). They fear that attempts to produce designer babies by applying the methods to embryos will create a backlash against all use of the technology.

Known as germline modification, edits to embryos, eggs or sperm are of particular concern because a person created using such cells would have had their genetic make-up changed without consent, and would permanently pass down that change to future generations.

We need a halt on anything that approaches germline editing in human embryos, Lanphier, who is also chief executive of Sangamo, toldNatures news team.

But other scientists disagree with that stance. Although there needs to be a wide discussion of the safety and ethics of editing embryos and reproductive cells, they say, the potential to eliminate inherited diseases means that scientists should pursue research.

Related trials Geneticist Xingxu Huang of ShanghaiTech University in China, for example, is currently seeking permission from his institutions ethics committee to try genetically modifying discarded human embryos. In February 2014, he reportedusing a gene-editing technique to modify embryos that developed into live monkeys. Human embryos would not be allowed to develop to full term in his experiments, but the technique gives lots of potential for its application in humans, he says.

Besides Huangs work, gene-editing techniques are also being used by Juan Carlos Izpisua Belmonte, a developmental biologist at the Salk Institute for Biological Studies in La Jolla, California, to eliminate disease-causing mutations from mitochondria, the cell's energy-processing structures. Belmonte's work is on unfertilized eggs; human eggs with such modified mitochondria could one day be used inin vitrofertilization (IVF) procedures to prevent a woman's offspring from inheriting mitochondrial disease.

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DNA Editing of Human Embryos Alarms Scientists