LONDON • Britain's fertility regulator gave the green light yesterday for the country to become the first in the world to legally offer "three-parent baby" fertility treatments, reported newswire agency Agence France-Presse (AFP).
British MPs had voted in February to allow the creation of in-vitro fertilisation (IVF) babies with DNA from three people, but clinics needed the approval of the Human Fertilisation and Embryology Authority (HFEA) before introducing the treatment.
The technique would allow women who carry disease-causing mutations in their mitochondrial genes to give birth to genetically related children free of mitochondrial disease.
HFEA chair Sally Cheshire called the decision to let clinics offer mitochondrial gene therapy "historic and important" and "a world first".
"I'm sure patients who might be in line for this treatment will be really pleased by what we've decided today," she said, but added: "We will proceed with caution." She said the decision was "about cautious go- ahead, not gung-ho go-ahead" and there was still a "long way to go".
The technique would allow women who carry disease-causing mutations in their mitochondrial genes to give birth to genetically- related children free of mitochondrial disease.
According to AFP, an independent panel of experts last month said the practice should be "cautiously adopted" to prevent certain genetic diseases from being passed on to future generations.
Mitochondria are structures in cells which generate vital energy and contain their own set of genes called mDNA which is passed through the mother.
Mitochondrial diseases cause symptoms ranging from poor vision to diabetes and muscle wasting. Health officials estimate that an average of 125 babies are born with the mutations in Britain every year.
According to The Independent news site, the procedure is carried out by transferring the parents' genetic material that effectively encodes a baby's identity to a donor egg whose own nuclear DNA has been removed.
In theory, mitochondrial replacement can not only prevent a child from developing inherited diseases, but also protect future generations.
Critics say the technique is not foolproof and small numbers of faulty mitochondria may still be "carried over" into the child, and even replicate in the developing embryo, said The Independent.
Others believe the procedure is tantamount to genetic modification of humans or even "playing God".
Some religious people have qualms about assisted reproductive techniques because they believe that a fertilised egg constitutes a distinct human life, and consider the discarding or destruction of embryos in the process to be unacceptable.
Earlier attempts at using three-parent techniques to treat infertility or genetic disorders in the 1990s were called off for medical reasons, when miscarriages or developmental disabilities arose.
The scientific community was also concerned that the unusual genetic code of a female child with three parents' DNA could be passed down to her own children and subsequent generations.
Earlier this year, a Jordanian couple became the first to produce a healthy baby boy using this procedure, after undergoing the gene therapy in Mexico.