Bioethics board backs embryo alteration for mitochondrial disease

June 12, 2012

One method of fusing a diseased egg with a healthy one to prevent rare mitochondrial diseases (credit: Human Fertilisation and Embryology Authority)

Reproductive procedures that would save children from inheriting mitochondrial diseases received a provisional thumbs-up from an influential U.K. bioethics body on June 12, Nature News Blog reports.

The London-based Nuffield Council on Bioethics found few ethical qualms with two procedures that involve transferring DNA from an egg cell with defunct mitochondria to another woman’s egg that has been stripped of its nucleus (see UK sets sights on gene therapy in eggs).

In principle, the resulting egg could then develop into a healthy child carrying both the parents’ nuclear genes and mitochondrial DNA from the donor. But the work amounts to genetic modification of embryos — which is currently illegal in the United Kingdom — and also involves destroying fertilized eggs.

The procedures haven’t been tried out on humans, but basic research is underway to determine if they are safe and effective for clinical trials to begin. Meanwhile, movement is afoot to make the procedures legal in the UK (see Nature News recent editorial on the process Fertile Union).

The 100-page Nuffield report considered a number of potential ethical pitfalls of the mitochondria swapping procedures, such as the concept of having three biological parents (two nuclear parents and the mitochondrial donor) and the possibility that endorsing mitochondrial transfers could open the floodgate for other genetic manipulations of embryos.

None of these potential objections were strong enough not to attempt mitochondrial transfers, should they prove safe and effective and if conducted as carefully monitored clinical trials, the working group that put together the reporter concluded. The report emphasized the importance of following the health of the children born through such procedures, and even the health of their children.