Mitochondrial Donation

The technique involves replacing the unhealthy mitochondria in a woman who carries the disease, with the healthy mitochondria from a donor woman during IVF.

Nuclear DNA which is involved in determining all your traits and characteristics is simply transferred from one egg to another but remains completely intact and unchanged during the technique.

The resulting baby has 100% nuclear DNA from its Mum and Dad (and all their characteristics) but with healthy mitochondria from a donor to give it energy to grow and function normally.

A mother may carry a faulty mitochondrial gene at a low level so that she herself may only have mild symptoms (if any), however she will pass this faulty gene to all her children in varying proportions from 1% to 100%. 

The degree to which an unborn child might be affected is incredibly difficult to predict. A severely affected infant may die in the first few weeks of life and any child born with a proportion of faulty mitochondria is likely to experience some symptoms which may come on at any stage of life.

Both techniques have been tested in animals and resulted in many generations of healthy offspring.

Successful results have also been seen in human cells in the laboratory, however until the 4th March 2015 legal restrictions meant these treated embryos could not been implanted to form a pregnancy. Based on animal models doctors have no reason to believe human pregnancy will not result in a healthy child.

The baby would have <0.1% of their total DNA from a 3rd person and this would be mitochondrial DNA (mtDNA) in the donated mitochondria which enables normal energy production.

The overwhelming majority of the DNA 99.9% (all the nuclear DNA that determines human characteristics) would only come from their mother and father.

No. This will not be possible.

Human characteristics and traits are controlled by nuclear DNA and this technique does not modify nuclear DNA at all. The resulting child will have 100% of its parents nuclear DNA and therefore will be the same unique blend of their characteristics as they would have been in a normal pregnancy.

The ban on altering nuclear DNA will remain in place and there is no intention to change this.

As these techniques involve changes to a person’s mitochondria they will be passed down from mother to child through the mitochondrial DNA to the next generation. If the child is female, that same change will be passed to their child and so on. 

As a result these techniques are considered a form of germ-line therapy.

However, we believe this is one of the great benefits of this technique as it means that future generations will be born free of Mitochondrial Disease.

No, this technique will only work for families whose Mitochondrial Disease is passed down from mother to child (also called maternally inherited). This happens when the error lies in the mitochondrial DNA - known as mitochondrial DNA disease (mtDNA disease).

Mitochondrial Disease can also be caused by changes to nuclear DNA. As this treatment does not alter the nuclear DNA at all, it cannot help families with this kind of Mitochondrial Disease.

• The story starts in 2000  - The Chief Medical Officer’s Expert Group Report, Stem Cell Research: Medical Progress with Responsibility considered and recognised the future potential use of the technique in treatment

• May 2004 - Newcastle University apply for a research licence to use PNT to avoid transmission of Mitochondrial Disease

• In September 2005 the HFEA research licence granted on appeal

• The  Human Fertilisation and Embryology Act passed in 2008, allowing researchers to develop techniques to prevent transmission of maternally inherited Mitochondrial Disease.

• In 2010 Researchers at Newcastle University develop techniques to prevent diseased mitochondria being passed from mother to child

• February 2011 Human Fertilisation and Embryology Authority (HFEA) convened 3 Independent  Expert Scientific Review panels to assess effectiveness and safety of mitochondrial donation. The expert panel met 4 times between 2011 and 2013.  All 3 deemed the techniques both safe and effective

• Nuffield Council on Bioethics publishes "Novel techniques for the prevention of mitochondrial DNA disorders: an ethical review" and deemed it ethical

• September - December 2012 - HFEA held two Public Consultations

• March 2013 - Reports from these showed general support for permitting Mitochondrial Donation, providing it was safely regulated and ethical concerns were outweighed by benefits of preventing disease

• Between Febraury and May 2014 the Draft Regulations published for public consultation

• On the 3rd February 2015 the regulations were debated in the House of Commons and MPs given a free vote. Overwhelming cross party support resulted in a vote of 382 Ayes and 128 Noes.

• On the 24th February 2015 members of the Lords discussed the details of the regulations. A motion attempting to block their approval, went to a vote with 48 for and 280 against, so the draft regulations were agreed. 

• On the 4th March 2015, Jane Ellison signed the Mitochondrial Donation Regulations with the UK being the first to legislate

• On 29 October 2015, the HEFA published the licencing conditions for Mitochondrial Donation and these regulations came into force. The HFEA is now authorised to license and regulate Mitochondrial Donation. 

• Mitochondrial Donation in the UK is now a reality. It can be taken out of the laboratory and offered to families that can benefit. Specialist centres will be allowed to apply to the HFEA for licenses on a case by case basis to offer this technique to severely affected families as a reproductive choice. 

• On 9th June 2016 the results of a study using the ‘pronuclear transfer’ technique in human embryos to prevent the transmission of mitochondrial DNA disorders was published in the journal Nature. The study was carried out by researchers at the Wellcome Trust Centre for Mitochondrial Disease at Newcastle University, and involved over 500 eggs from 64 donor women. Results of the study suggest that the technique will lead to normal pregnancies whilst also reducing the risk of babies having mitochondrial disease. The results of the study will now be considered by the Human Fertilisation and Embryology Authority (HFEA), who will decide whether to issue the first licence to a clinic for the technique to be used in treatment.

• On 30th November 2016 the HFEA expert scientific panel agreed that there was sufficient evidence on mitochondrial donation to take the next step and proceed cautiously with offering this to families at high risk of passing mitochondrial disease onto their child. This was subject to final HFEA approval in December 2016.

• On 15th December 2016, the HFEA gave their final approval to mitochondrial donation. Clinics can now apply for licences on a case by case basis to treat families at high risk of passing on mitochondrial disease. 

  NHS England will fund the first treatment trial for women who meet the HFEA criteria, so long as they agree to long term follow up of children after they are born.

• On 16th March 2017 Newcastle-upon-tyne NHS Foundation Trust & Newcastle University were the first site worldwide to be approved by the HFEA as an authorised site to undertake mitochondrial donation.

• In March 2017 the first treatment application for Mitochondrial Donation was submitted to the HFEA for approval.

• In April 2017 a new 'reproduce choices service' was set up in Newcastle to look after families with mitochondrial disease wishing to explore mitochondrial donation and other reproductive options.
• February 2018: HFEA grants first patient licence for mitochondrial donation to Wellcome Centre for Mitochondrial Research in Newcastle. UK becomes the first country to legally offer the procedure to a patient. 

If you carry maternally inherited mitochondrial DNA disease and are looking at starting or extending your family, there are a number of reproductive choices available that might be suitable for you. 

The NHS Highly Specialised Service for Rare Mitochondrial Disorders and the Newcastle Fertility Clinic at Life (Newcastle Hospitals NHS Foundation Trust), are now able to offer a comprehensive pathway of care for women of reproductive age with a personal or family history of mitochondrial DNA disease. 

Upon receipt of a clinical referral, an appointment will be made to attend the Mitochondrial Reproductive Advice Clinic, undertaken by Dr Gráinne Gorman (Consultant in Mitochondrial Medicine) & Catherine Feeney (Nurse Consultant in Mitochondrial Medicine) at the Royal Victoria Infirmary, Newcastle. This clinic will review and confirm the genetic diagnosis, assess fitness for pregnancy from a mitochondrial disease perspective and offer psychological support and advice regarding reproductive options for IVF- based techniques, including pre-implantation genetic diagnosis (PGD) and mitochondrial donation. Once assessed in this clinic, and if considered appropriate, couples will be referred to the Mitochondrial Assisted Reproductive Technologies (Mito-ART) Clinic at Newcastle Fertility Clinic at Life.

Please contact your own clinician who can discuss the possibility of a referral.

General enquiries can be made via:

Bernadette Caygill ([email protected])                             

Direct Dial:  0191 2824876                                                                  

Fax:  0191 282 4373