Freeing Us from Our Cells: Avoiding Inherited Mitochondrial Disease

Progress Educational Trust
Oliver Thompson Lecture Theatre, Tait Building, City University London, Northampton Square, London EC1V 0HB
25th September 2012
This public event was organised by the Progress Educational Trust (PET) in partnership with City University London's Science Journalism course, and was supported by the Wellcome Trust.
Mitochondria are energy-generating structures in our cells that contain a small portion of their own DNA (mitochondrial DNA, or mtDNA). Problems with mtDNA - which is always inherited from our mother - can cause early infant death, or lead to a range of possible diseases in those who survive. Such diseases can affect major organs such as the brain and heart, or other parts of the body such as the bone marrow and muscles.
Techniques are being developed that use IVF to avoid the transmission of mitochondrial disease, by exchanging a mother's mitochondria with the mitochondria of a donor. A change in the law is needed, before such techniques can be used either in a clinical trial or in treatment within the UK. The Nuffield Council on Bioethics this year published an ethical review of the techniques, while the UK Government has asked the Human Fertilisation and Embryology Authority (HFEA) to seek the public's views on the issue, and an HFEA consultation is due to launch in September.
The mitochondrial exchange techniques currently being developed are pronuclear transfer (PNT) and maternal spindle transfer (MST). They involve taking either a partially fertilised egg (in the case of PNT) or an unfertilised egg (in the case of MST) from a woman whose mitochondrial DNA is damaged, and transferring some of the egg's contents into the egg of a donor who has healthy mitochondria. The intended result is a child who inherits healthy mtDNA from the donor, and all other DNA from their parents. If the resulting child is female, then their healthy mtDNA (inherited from the donor) will in turn be inherited by anyone the child goes on to conceive later in life.
What are the comparative advantages and disadvantages of PNT and MST, in terms of efficacy, safety and ethics?
Should we be concerned that by using techniques which influence the genetic makeup of future generations, scientists are changing the germline?
Is it problematic for the media to refer to such techniques as 'three-parent IVF' or the creation of 'three-parent babies'? If so, for whom is this problematic?
Is the origin of our mtDNA - which doesn't have anything to do with individually distinguishing characteristics, but is often used in the tracing of familial ancestry - of any great importance, beyond the fact that it functions properly?
Will people conceived from three people's genetic material have concerns about their identity, or is mtDNA so distinctive from other DNA that the question doesn't (or shouldn't) apply?
A synopsis of the event proceedings (by Sophie Pryor) can be found on PET's BioNews publication here.

Liz Curtis and Alison Maguire
Chief Executive and Research Executive respectively at the Lily Foundation for Research into Mitochondrial Disease and Other Metabolic Disorders
Mary Herbert
Professor of Reproductive Biology at Newcastle University's Institute for Ageing and Health
Martin Richards
Emeritus Professor of Family Research at the University of Cambridge's Centre for Family Research
Jackie Leach Scully
Professor of Social Ethics and Bioethics at Newcastle University
John Wyatt
Emeritus Professor of Ethics and Perinatology at University College London's Centre for Philosophy, Justice and Health

Professor Sir Mark Walport
Outgoing Director of the Wellcome Trust and Incoming Chief Scientific Adviser to the UK Government

Partners and supporters:
City University London
Wellcome Trust