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“Nuclear genome transfer” would mean uncontrolled human experimentation on future children and their offspring.

Proposals to move toward clinical trials of techniques for “nuclear genome transfer” and “mitochondrial replacement” should be rejected by policy makers, said the Center for Genetics and Society. These techniques pose safety risks for future children and generations that cannot be accurately assessed, and they run counter to widespread international opposition to inheritable genetic modification.

Several recent studies, including one released today by scientists associated with the New York Stem Cell Foundation (NYSCF) and Columbia University Medical Center, propose the use of risky genome-swapping techniques as a means for a very small number of women with mitochondrial diseases – estimates put the number at about 1 in 5000-10,000 – to attempt to have genetically related children who would have a lower risk of inheriting those diseases.

“We take seriously parents’ desires to have children who are healthy and genetically related to them,” said Marcy Darnovsky, PhD, the Center's associate executive director. “But these parents can have children using a number of methods that don’t involve inheritable genetic modification. Changing the genes we pass on to our children is widely considered a bright ethical line that’s not to be crossed – and it has been observed by scientists around the world, adopted as law by more than 40 countries, and incorporated in several international treaties.”

Mitochondrial diseases are not well understood; some are linked to genes in the nucleus rather than to those in mitochondria. The ailments of many people with mitochondrial dysfunction may not be caused solely or primarily by problems in mitochondrial DNA, and the techniques being developed would therefore not be applicable to them.

The procedures described in the paper by Egli et al., and related ones developed by researchers at the Oregon Health and Science University (OHSU) and at Newcastle University in the United Kingdom, involve combining the nuclear genes of one woman's eggs with the mitochondria of another woman's eggs to produce human embryos – and potentially children – with genetic material from three individuals. Girls born after such procedures would pass these genetic changes to their children and all subsequent generations.

The authors of the OHSU paper, as well as researchers and policy makers in the UK, explicitly acknowledge that using mitochondrial replacement techniques would constitute inheritable genetic modification, also known as germline modification. The paper by Egli et al. does not mention this, but the procedure they describe also constitutes germline modification. The US Food and Drug Administration (FDA) disallowed clinical trials of a similar procedure in 2002, and the OHSU and NYSCF researchers are reportedly discussing their respective proposals with the agency.

“We urge the FDA to reject any procedures involving human inheritable genetic modification,” Darnovsky said. “No single country should presume to begin irreversibly modifying the human genome, especially when international treaties and more than 40 countries have already prohibited it. The suggestion by scientists that these global agreements be disregarded is extremely disappointing.”

“Opposition to inheritable genetic modification is so strong and widespread for two important reasons,” she continued. “First, such changes would be highly risky, they are permanent and irreversible, and those at risk – future children – obviously can’t give their consent, which is the very foundation of ethical medical practice. Attempting such procedures would amount to unethical experimentation on human beings. Second, allowing the genes of future generations to be manipulated would open the door to additional germline modifications, and could lead to new forms of eugenics, which claimed that scientific control of human reproduction would improve the world but led to horrific abuses.”

“Despite the tiny number of people who would be candidates for these techniques, several research teams seem to be competing to develop them,” Darnovsky said. “Considering the availability of other ways for such people to have children, and the profound risks involved, there is no compelling reason even to develop these techniques. There is certainly no convincing reason for using them to open a back door to inheritable genetic alteration.”

The Center for Genetics and Society is a non-profit public affairs and policy advocacy organization working to encourage responsible uses and effective societal governance of human genetic and reproductive biotechnologies. CGS operates BioPolicyWiki, a wiki-style compendium of country-level policies and binding international agreements governing reproductive and genetic technologies and practices.

Contact:
Marcy Darnovsky
510-625-0819 x305
510-913-7714
mdarnovsky[AT]geneticsandsociety[DOT]org