explains, the technique, which implants the modified fertilised- egg from one couple into the egg of another woman, could be used to prevent, the sometimes fatal, "mitochondrial" diseases which are passed down from mother to child.
The mitochondria provide energy to every cell in the body, but about one in every 200 children is born with faulty mitochondria. Most will be born with few or no symptoms but in the most extreme cases, the cells of the body don't recieve energy which leads to muscular dystrophy, blindness, heart failure and sometimes death.
says the technique would pass along only a small fraction of the DNA from the donor but would prevent future generations from rare and debilitating conditions.
Currently the technique is forbidden but the Human Fertilisation and Embroyology Authority (HFEA)
in Britain has started a public consultation that will be used to make a decision on whether the health benefits outweigh ethical concerns.
The HFEA says it hopes to find out,
"What are the implications of this? Would this be the first step on a slippery slope to genetic modification, perhaps for trivial purposes? Or are such concerns overstated? Will the availability of these techniques create pressure to use them? Or is this no different from existing treatments to help couples have healthy children?"
Lisa Jardine, chair of the Human Fertilisation and Embryology Authority (HFEA), says
, "We find ourselves in unchartered territory, balancing the desire to help families have healthy children with the possible impact on the children themselves and wider society."
the issue of the conception and birth of Louise Brown, the first IVF baby, born in 1978. Jardine says, at the time, many expected the child to be a "monster" and they perceived conception outside the womb as "absolutely appalling," but now IVF has become commonplace.
"Here, we are going that mile further which is a genetic modification of the egg. That is uncharted territory. I feel very strongly that once we have genetic modification we have to be damn sure that we are happy, because this is not about us. This is not about our children. It's not even about our grandchildren. It's about many generations down the line what the consequences might be."
says the technique also raises legal issues and how it would impact a child's sense of identity. It also questions whether the child should be allowed to contact the donor later in life.
The public consultation will run unti December and the conclusions will be presented to government ministers next spring. But even if the procedure is approved, its safety is still being investigated.
Prof Mary Herbert from Newcastle University and one of the pioneers of the procedure, says
"We are now undertaking experiments to test the safety and efficacy of the new techniques. This work may take three to five years to complete."