27 February 2014
The UK government has released a new consultation on proposed new regulation of the mitochondrial replacement technique.
Also known as cytoplasmic transfer, the technique is a modification of cloning procedures that enables the creation of IVF embryos without diseased mitochondria from an affected mother (see previous news). As they involve the use of egg cells from a healthy donor, they have also been called three-parent embryos, since the embryo contains a very small amount of mitochondrial DNA.
A lot of ground-breaking scientific research on the technique has taken place in the UK and the government is now keen to see it move into human subjects. It is currently illegal, since it involves manipulation that creates permanent and heritable genetic changes; however, proposed new regulations would make it possible for the UK regulator the Human Fertilisation and Embryology Authority (HFEA) to permit its use in selected circumstances.
The stated effect of the planned policy change is ‘to reduce the incidence of severe mitochondrial disease in newborn children, whilst ensuring the child has a strong genetic link to both the mother and father’ as well as encouraging ‘inflows of foreign direct investment into the industry in the UK’.
The proposed regulations, which are now available for inspection, are intended:
Responses are sought to a series of questions including whether HFEA authorisation ought to be required; whether it is appropriate for the HFEA to regulate use of the technique; and whether egg donors for mitochondrial transfer should have an anonymous status similar to that of tissue or organ donors, rather than those who donate eggs or sperm for normal fertility treatment
The consultation document notes that the technique would only be used for the most severe cases of mitochondrial disease ‘in the first instance’, an estimated ten couples per year, with scope for expansion over time; mitochondrial disease is estimated to affect one in 6,500 births in the UK. Mitochondrial defects are also associated with adult onset and ageing-related conditions including female infertility, but the most severe forms take effect from birth.
Affected families and research funders such as the Wellcome Trust are keen to see the regulatory changes put in place to allow the first human trials. Critics are concerned by the lack of robust evidence to support the long-term safety of the technique, as well as a potential expansion of scope to permit human germ-line modification for less severe diseases. However, the consultation relates not to the decision to permit the technique, which has already been made, but on the regulatory proposals, which are generally sensible.