What is the future of mitochondrial disease treatment?

A pioneer in mitochondrial research, Sir Doug Turnbull has spent decades with families affected by these rare but devastating disorders. Now, with the UK leading the way in mitochondrial donation, he joins us to explain why this moment matters - not just for parents hoping for healthy children, but for the future of mitochondrial science…

Doug - It's been a long time coming. It started 25 years ago. And to get to this stage and to have eight healthy babies is truly wonderful and great news for the families.

James - It's fantastic that there were undetectable levels of mutated mitochondrial DNA in the vast majority of the babies in this latest trial, but two babies have been born with some small amounts of mutated mitochondrial DNA. I presume what's next is keeping an eye on that and working out why and working out whether this could be passed on to future generations.

Doug - Trying to limit that is going to be important. It's also important to realise that the level of carryover of mitochondrial DNA is well below the level that we would expect to cause disease. So I think it is important to try and limit that transmission, but also to be aware that the risks of disease in those children is very, very low indeed if non-existent. About transmission to the next generation, clearly if they're a male it won't be transmitted. For females, yes, we have to be concerned about that and thinking about that in the future.

James - This particular research was funded by the Wellcome Trust and the NHS, the National Health Service in this country, was involved in offering it to eligible parents. How do you anticipate this procedure might be offered in the future in the healthcare system?

Doug - The clinical trial was funded by Wellcome with the NHS picking up the excess treatment costs. It's very important to appreciate that for mitochondrial disease there is an NHS highly specialised service which was designated a specialised service back in 2007 and it transformed the care of patients with mitochondrial disease. It means that there are three highly specialised centres around the UK and it allows us to provide what I believe is a world-class service for patients with mitochondrial disease. One would hope that if the success of the trial continues that this will be something that we will be able to offer on the NHS, hopefully as part of our NHS highly specialised service. The publicity that's come along with this trial will make patients more aware, make physicians more aware and I would expect that we'll see a greater number of referrals. It is absolutely fundamental to the way in which I think medicine should be practised that this is available to all that suffer from the disease and I hope that that will be able to be continued.

James - Such an exciting development. What else is it in the field of mitochondrial research that you're particularly excited about? Where do you see us going next?

Doug - Mitochondrial research has come a long way, a very long way. It's gone through different phases. There was a phase where we were looking very much at the clinical aspects and then the diagnostic aspects and that's obviously been transformed with the next generation sequencing. Then hopefully we're at the stage where we can say we're preventing transmission of mitochondrial disease. We've made major steps in that way. We still have patients and we will still get patients who've got mitochondrial DNA mutations. It is critical I think that we look to try and get better treatment for those patients and I think that a great deal of effort has gone into preventing the transmission. A lot more effort is going ahead with trying to cure these diseases and I think that should be a major goal of those of us working within mitochondrial DNA diseases.