It is a procedure that could prevent children from inheriting rare, incurable diseases such as stroke, blindness, deafness, kidney failure and heart disease.
"What we're doing here [in the new technique] is a massive number of abnormal things to try and get rid of abnormality… You don't get eggs easily, women have to have their ovaries stimulated and sometimes they suffer as a result of that."
- Josephine Quintavalle, the director of Corethics
Healthy embryos are being created using two women and one man. Scientists are trying to eliminate defects that affect an estimated one in 4,000 children.
But it is stirring the ethics debate.
There are a lot of questions about the morality of having babies with three parents, the implications for the child's descendants, and the prospect of babies-to-order.
The research for the new technique is being conducted at Oregon Health and Science University in the US.
The procedure still needs US federal government approval to be tested on humans.
In 2009, scientists were able to create eggs with DNA transplants from Rhesus monkeys. Four developed into healthy animals.
"Unfortunately it's not going to allow us to eliminate all genetic diseases… One in a 100 of genetic diseases – single-gene defects – arise from mitochondrial DNA mutations, and these are the first category of disorders that we would be able to treat."
- Brian Bigger, a specialist in genetic therapy
The team has now used the same technique to create human embryos, with about half having abnormalities.
But they say some 20 per cent of the eggs did produce embryos that would have been suitable for transfer back into the mother.
So is science creating so-called designer babies? And should scientists be allowed to interfere with nature?
To discuss this on Inside Story with presenter Zami Zeidan are guests: Josephine Quintavalle, the director of Core-ethics, a public interest group focusing on the ethics of human reproduction; Laurie Zoloth, a professor in biotechs and medical humanity at the Feinberg School of Medicine at Northwestern University; and Brian Bigger, a senior research fellow at the University of Manchester and a specialist in genetic therapy who has also worked extensively on gene therapy and neurological disorders.
"Is this [gene therapy] the best way to do that, what other effects does this cloning technique have, and this is the kind of technique that challenges two very serious ethical bright lines that we've erected to regulate this kind of technology."
Laurie Zoloth, a biotechs professor
|New gene-swapping technique:
- A woman's egg cell contains thousands of what are called mitochondria, each with its own DNA.
- And if they are defective they can be passed on from mother to child.
- The egg also has a nucleus, which holds chromosomes. It is these that influence traits such as eye colour and height.
- The new technique involves removing the nucleus from the mother's egg cell which has defective mitochondria and inserting it into a healthy donor egg cell.
- A sperm cell is then injected to fertilise the egg, which is re-implanted into the mother.