Quote: ...hopes of tackling mitochondrial disease will be raised in a few weeks when the government announces regulations that will permit the use of an IVF technique that should rid affected families of the disorder. If these plans are approved by parliament, Britain will become the first nation to permit germ-line gene therapy, which will change the DNA of future generations in order to eradicate the condition.
The technique involves taking an egg with healthy mitochondria from a donor female. Its main set of nuclear genes is then scooped out and replaced with those of a woman affected by mitochondrial disease but whose basic nuclear DNA is healthy. The egg is then fertilised using her partner's sperm. In this way an embryo is created that has the central genes of the two parents but no longer carries the mutated mitochondrial DNA once carried by the mother. The technique is known as mitochondrial replacement. It has never been tried on humans, but has worked in animal studies.
Most scientists and doctors, particularly those who work with families touched by mitochondrial disease, support the introduction of the technique. However, some groups vociferously oppose its use. "The social benefits for a relatively small number of women … do not come near to justifying the potential health risks from these techniques to the child and the risks to global society that stem from human genetic engineering," said the campaign group Human Genetics Alert.
Anti-abortion groups also oppose mitochondrial replacement, while some tabloid newspapers have described the creation of embryos using the nuclear DNA of two parents and the mitochondrial DNA of a third-party donor as "three-parent babies" and have claimed that this represents a slippery slope to a "Frankenstein future".
This last claim particularly infuriates researchers. "It is wrong to say this produces three-parent babies," said Turnbull. "More than 99.9% of DNA is nuclear DNA and that will not be affected. Mitochondrial DNA accounts for around 0.1% of our total DNA. We are changing only mitochondrial DNA. We are not changing a person's hair or height or eye colour." |