U.K. Agency Cautiously Endorses Mitochondria Replacement

20 March 2013 3:00 pm

Nicolle Rager, National Science Foundation

A mitochondrium.

There is broad public support in the United Kingdom for allowing a new type of IVF treatment that could prevent mitochondrial diseases, the country's Human Fertilization and Embryology Authority (HFEA) announced today. The techniques would introduce new DNA into an embryo, and so it has raised thorny ethical questions. At the same time, the authority advised the government that several safeguards should be included in any proposals for new regulations that would permit clinics to perform the technique.

Mitochondria are organelles that provide cells with energy. They carry their own DNA, called mtDNA, and mutations in those genes can cause mitochondrial diseases. These have a range of symptoms and can differ in severity, but they can cause blindness, heart failure, muscular dystrophy, and dementia. The mtDNA is primarily inherited from the mother; although sperm do have mitochondria, most decay after fertilization.

Scientists have been experimenting with possible ways to replace the unhealthy mitochondria in an affected woman's egg or in early embryos. The research is ongoing, and it's not yet considered ready to try in humans. Current U.K. law prohibits the technique and any others that would place an embryo with altered DNA into a woman's body. But recent expert opinions have called for allowing the technique as an option for families who are at risk for having children with mitochondrial disease. In January 2012, the U.K. government asked HFEA, which oversees and regulates the use of gametes and embryos in fertility treatments and research, to conduct a public consultation on the techniques and provide advice on the safety and efficacy of the treatment.

In a public meeting this morning, HFEA experts reviewed the results of the consultation, which conducted workshops, focus groups, and surveys involving nearly 3000 participants. The consultation found widespread support among workshop and focus group participants for allowing the techniques for families who are at risk of having children with mitochondrial disease. A majority of the 1836 open survey respondents opposed changing the law to allow the technique, however. Most of those opposed said they had ethical concerns about the technique's potential destruction of embryos and the precedent of allowing genetic changes to embryos.

HFEA advised that if the government decides to introduce new rules, they should include a number of safeguards, including HFEA review and approval of each use of the technique. They also said that clinics should ensure that follow-up research be conducted on any children born. Mitochondrial donors should be seen as tissue donors, with the option to stay anonymous, they recommended, although the issue was debated at today's meeting, with some members saying that donors' identities should be accessible to any resulting children. Finally, they said, a further assessment of the safety and efficacy should be conducted before any clinics are allowed to start using the procedure.

The U.K. Health Department must now decide whether to draft regulations to allow the procedure, which would then need the approval of both houses of Parliament.

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