2 Feb 2015

Risks and potential rewards of ‘three-parent embryos’

The idea is simple. Fix devastating mitochondrial disease by taking a parent’s DNA out of a sickly embryo and sticking it into a healthy donor cell.

The techniques involved are not much more complicated than those used every day in IVF clinics and should, according those developing them, be no more harmful than established fertility techniques.

So why does licensing “mitochondrial donation”, as it’s known by its backers, require a vote from parliament tomorrow – one they fear may not go their way?

Well, partly because of the other name the technique has been given: “three-parent embryos”.

The thing is, mitochondria – the small organelles in the cell which are being swapped out using the technique – contain their own DNA. That DNA is largely involved in making the mitochondria work, generating the cell’s power – but it’s DNA nonetheless.

Birmingham Women's Hospital Offers Technological Advances In Its Care

Each of us inherits our mitochondria from our mother and has done, probably, since multicellular life evolved 3 billion years ago. For that reason many people object ethically to the idea of unhitching parental DNA from its mitochondria with which it has resided for aeons.

Others object for scientific reasons. Even the New Scientist magazine, typically a champion for progress in all areas of research, warned of lack of understanding about the links between mitochondria and nuclear DNA.

Others object to the fact that steps taken during the technique (removing “pro-nuclei” containing parent’s DNA and transplanting it) are untried in humans and cause miscarriages or other developmental problems later in a child’s life.

Against that backdrop, however, there has been nearly eight years of consultation and review and three separate studies by the Human Fertilisation and Embryology Authority. It has concluded that the procedure is “not unsafe” and that, subject to further experiments to prove it is efficient, could be awarded a licence by them.

Tomorrow’s vote is not to allow the technique to happen – but it would allow those developing it the chance to do more experiments to demonstrate it could yield a clinically useful technique.

Some doubt they ever will, but the team themselves are confident. Supporting them are many of the 2,500 women in the UK who are carriers of mitochondrial disease, for whom this technique could spare their children a lifetime of suffering – but also all the generations of children to come.

Follow @TomClarkeC4 on Twitter