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Consultations & reviews of policy

Mitochondrial donation


The regulations on mitochondrial donation, which prevents mitochondrial disease being passed on from mother to child, have now come into force. This page provides an overview of what mitochondrial donation involves, and links to the various expert reviews and consultations that led up to the Parliamentary vote in February 2015.

If you are a patient considering mitochondrial donation treatment and want to know what to do next, you can find some useful information on our patient pages.

If you work at a clinic and would like to know more about the application process, you will find all the necessary forms and guidance on our clinic pages.

What are mitochondria?

Mitochondria are present in almost all human cells, including eggs. They generate the majority of a cell’s energy supply which power every part of our body. Mitochondria carry just a few genes. These genes are involved in energy production. For any cell to function, the mitochondrial genes need to work properly. Mitochondria with gene abnormalities can cause severe medical disorders known as mitochondrial disease.

What does mitochondrial donation treatment involve?

Two techniques for mitochondrial donation have been developed and approved by Parliament: maternal spindle transfer (MST) and pronuclear transfer (PNT).

MST and PNT are both techniques of mitochondrial donation allowing eggs or embryos to be created for patients containing their nuclear genetic material (the genes which make you who you are) and donated mitochondria.

In MST, a patient’s nuclear genetic material will be removed from their eggs and transferred into donated eggs once their nuclear genetic material has been removed.

The eggs containing the patient’s nuclear genetic material and the donor’s healthy mitochondria will be fertilised with the intended father’s (or a donor’s) sperm to create embryos.

In PNT, the patient’s eggs will be fertilised with the intended father’s (or a donor’s) sperm in a laboratory to create embryos. The nuclear genetic material within each embryo will then be transferred into embryos created using donated eggs and sperm from the sperm provider, once the nuclear genetic material has been removed.

In both MST and PNT, the resulting embryos containing the patient’s and partner’s (or sperm donor’s) genetic material and the mitochondria donor’s healthy mitochondria will be transferred to the patient’s womb and hopefully implant and develop into a baby.

What’s happened so far?

In February 2015, both houses of Parliament voted to pass regulations that permit the use of mitochondrial donation treatment for mothers likely to pass on serious mitochondrial diseases to their children. The regulations do not permit the use of mitochondrial donation for fertility treatment, but only for the purpose of avoiding the inheritance of serious mitochondrial diseases.

The regulations came into force on the 29 October 2015. However, before the first application can be received, the outstanding safety and efficacy tests, as set out in the third review by an expert panel convened by us will need to be considered by the panel and then by the HFEA Authority. There is presently no definite timeline for completion of the outstanding tests and so the timeframe for the first application remains uncertain at this time.

Page last updated: 29 October 2015