Scientists in England say that they are just three years away from creating three-parent embryos which would be free from rare mitochondrial diseases. In an article in Nature, researchers from Newcastle University say that they created 80 embryos which grew for six to eight days to reach the blastocyst stage, a ball of around 100 cells. They were then destroyed, in line with UK legislation.

About one in 6,500 children is born with serious diseases caused by malfunctioning mitochondrial DNA, leading to a range of conditions that can include fatal heart problems, liver failure, brain disorders, blindness and muscular weakness. This technique cannot help children who suffer from these conditions. Rather, it genetically engineers an embryo by replacing the defective mitochondria with healthy mitochondria from an egg from a second “mother”.  "What we've done is like changing the battery on a laptop,” said Dr Turnbull. “The energy supply now works properly, but none of the information on the hard drive has been changed."

In their enthusiasm, scientists involved in the experiment tended to gloss over the ethical issues. Alison Murdoch of the Newcastle Fertility Center, whose patients donated the eggs for the research, says that all the characteristics of the baby would come from its two principal parents.

However, Josephine Quintavalle of campaign group Comment on Reproductive Ethics, declared that "No matter how small the contribution from the egg of the donor woman, the fact remains that an attempt is being made to create a three-parent child.” And Peter Saunders, of the Christian Medical Fellowship pointed out that “What is currently happening in Newcastle may be legal in Britain – but it is illegal in almost every other Western country for good public safety and ethical reasons. Britain is regarded by many as a rogue state in all this.”

But other scientists thought the interests of the parents, not the embryos, are paramount. “Is it fair for society to make it impossible for a woman who has a high percentage of mutant mitochondrial issues to have a healthy baby? That’s what I’m confronted with in my clinic,” California geneticist Doug Wallace told Wired magazine. “There’s an ethic of what’s best for the patient.” ~ AP, Apr 14