Mitochondria Replacement Would Forever Alter the Human Germline. Do You Want a Say?

The Center for Genetics and Society has sent a letter strongly recommending against changing the United Kingdom law that – like those in dozens of other countries – prohibits procedures that would alter the genes we pass on to our children. Please consider adding your voice to this effort here.

A research team at the United Kingdom’s Newcastle University is working on techniques that produce human eggs containing genetic material from two women, and using them to create human embryos – and potentially children – with DNA from three parents. Children born after such “mitochondrial replacement” procedures would pass these genetic changes to their children and all subsequent generations.

Testing the procedure in humans is currently illegal in the UK because it would constitute inheritable genetic modification – that is, it would irreversibly alter the human germline. Over 40 countries prohibit human germline engineering because of its profound social and ethical consequences, but the Newcastle researchers are eager to change the UK law so that they can bring their technique to clinical trial.

Mitochondrial replacement would not alter genes in the nucleus. But the prohibition against human germline engineering represents a critical line in the sand. If the Newcastle proposal to alter mitochondrial genes is approved, we will have crossed that line; it will be harder to argue against other inheritable genetic modifications in the future.

Like the research team from Oregon Health and Science University whose research was recently in the headlines, the Newcastle scientists stress that their procedures are worthwhile because they would enable women with unhealthy mitochondria to have a (mostly) genetically related child without mitochondrial disease. Inherited disease caused by mitochondrial DNA is relatively rare, affecting about 1 in 5,000-10,000 births. Women at risk of having an affected child have several other (far less experimental) options available to them, so these extreme procedures would be considered only in a very small number of cases. Because mitochondrial DNA and nuclear DNA interact with each other consistently and in complex ways that are imperfectly understood, the health risks to any future children created using these procedures would be very large. And these future children would obviously be unable to give their consent.

The Human Fertilization and Embryology Authority (HFEA) ruled last year that a minimum number of further tests would be required before the safety of mitochondrial replacement in humans could be assessed (section 5.4). Even though these tests have not yet been completed, the HFEA is moving forward in an effort to gauge the public’s point of view on the controversial technology. They have launched a public consultation to debate the ethical and social implications of the two novel technologies under discussion: pronuclear transfer (PNT) and maternal spindle transfer (MST).

HFEA’s consultation website has information on the science behind the new techniques being proposed and on various ethical concerns. The results of the consultation will be passed on to the Secretary of State for Health in the UK who will make the next decision as to whether these technologies can move to clinical trial in humans.

Please voice your thoughts or concerns on these issues by submitting them to the HFEA’s public consultation by December 7. For more information on the many social and ethical implications of mitochondrial transfer, please see the letter the Center for Genetics and Society has submitted to the Chair of the HFEA and to the Secretary of State for Health in the UK here. Please also check back for updated information on our website.

Previously on Biopolitical Times:

•    Advocating Human Germline Interventions
•    Proposed New Gene Manipulation Technique in IVF: Is it Safe? Needed? A Precedent to Designer Babies?
•    Of Yeast Genes and Tinker Toys