Three People contribute to a Single Embryo

British scientists claimed to have created human embryos using DNA from two women and one man. Initially, the nucleic acids of a man and a woman were combined and the resulting embryo was then shifted into the egg of another woman.

The woman who received the formed embryo actually had healthier mitochondria – the energy source of the cell— than the other woman.

So the replacement occurring is only in relation to the mitochondria which are contained outside the nucleus in a normal female egg. Faults in the mitochondria's genetic code can result in serious diseases like muscular dystrophy, epilepsy, strokes and mental retardation.

According to researchers, the technique only targets a couple of mitochondria-related diseases and does not affect the DNA of the embryo. In future, they hope, such practice may be used to rid the embryos of inherited diseases.

The research has raised concerns about the possibility of forming genetically modified babies.

"We are not trying to alter genes, we're just trying to swap a small proportion of the bad ones for some good ones," said Patrick Chinnery, a professor of neurogenetics at Newcastle University involved in the research.

While Scientific, legal and ethical reactions continue to come up, one easy catch exists. If an embryo comes from the DNA of three people, does it have three parents?

No, says The Associated Press, citing unnamed experts, "Only trace amounts of a person's genes come from the mitochondria, and experts said it would be incorrect to say that the embryos have three parents."

The research, sponsored by the Muscular Dystrophy Campaign, a British charity, was presented at a scientific conference recently, but it has not yet been published in a scientific journal.