It sounds like science fiction. The "three-parent baby". Yet in Britain, a procedure may soon be made legal that would allow children to be born containing the genetic material of one father and two mothers.
It's a procedure that is illegal in Canada, and yet it holds the potential to eliminate a whole range of genetic defects in a single generation if adopted and executed globally. Still, it raises profound questions about human identity and the nature of parenthood.
"There are two ways of looking at it," says Kerry Bowman, a bioethicist at the University of Toronto. "One is that it's simply another form of IVF and no big deal, but the other is that this is a form of genetic altering and we're going down a road we haven't gone down before. There is a line that is being crossed."
The technology is being pioneered by scientists at Newcastle University in the U.K., who are world leaders in this area of study, reports the Daily Telegraph. Public consultations of "three-parent IVF" will begin soon, and could potentially be legalized in the U.K. within five years.
The procedure does not involve the nuclear DNA that is believed to be responsible for most of our individual characteristics, and it will not be used to create "designer babies", with genes altered to improve qualities like intelligence or physical appearance. Rather, the procedure will be used to swap in a very specific type of genetic material known as mitochondrial DNA.
Mitochondria are tiny organelles that power the cell and which, if defective, can cause debilitating conditions like muscular dystrophy. It is the mother's mitochondrial DNA that is passed on to the offspring. By swapping in healthy mitochondria DNA from a donor female, these conditions could potentially be eliminated completely.
The actual procedure would be done in-vitro, and would result in an embryo with nuclear DNA from the mother and father and mitochondrial DNA from another woman.
Scientists say that the child would be genetically the offspring of the two parents, and that the mitochondrial DNA would power the cell's functions, rather than defining the identity of the baby.
Bowman says that while the benefits could be huge — ending the suffering that comes with diseases like muscular dystrophy is no small thing — there is really no way of knowing exactly how the procedure will work until long after it is completed.
"Everything we know indicates that what makes us who we are is in the nuclear DNA," says Bowman, "And yet an element of the genetic code from the third party is inherited and will be passed down. It's possible some unknown effect would not show itself for generations."
Roger Pearson, a fertility specialist at the University of Saskatchewan, voices similar concerns.
"This is a line of inquiry that needs to happen, but it's important to take it slowly and with full cognitive power," says Pearson.
He agrees that the effects of this procedure are unknown and could be far-reaching.
"Once that individual is born, if that person is female and able to reproduce, this is something that will be passed on."
A chimera is an organism that contains the DNA of more than two parents, and the Canadian Assisted Human Reproductive Act states that to "create a chimera, or transplant a chimera into either a human being or a non-human life form" is prohibited.
Yet it is Britain that is leading the world in this type of research and experimentation, and if things go well across the pond, Bowman says it's entirely possible that could change.
"As we understand it right now, it appears that the benefits outweigh the potential harm or risk," says Bowman. "But ultimately, we still don't know what we don't know."