The UK government has passed new regulations which allow IVF clinics to be licensed to carry out techniques designed to eradicate the transmission of serious mitochondrial disease from mother to child.

Background

Mitochondrial diseases include diabetes mellitus, deafness and some heart and liver conditions. These are caused by genetic faults in mitochondrial DNA (which, unlike nuclear DNA, is inherited only from our mothers). Mitochondrial donation techniques, such as maternal spindle transfer (“MST”) and pro-nuclear transfer (“PNT”), have been developed for use in IVF in order to allow mothers to avoid passing on genetically inherited mitochondrial diseases to children who otherwise carry their parents’ DNA. These techniques are the source of considerable controversy in the field of bioethics, with the children born as a result of these techniques dubbed “three-parent children”.

In common with many other countries worldwide, the UK generally prohibits genetic modifications to the “germ line”, which governs the inheritability of genetic defects. In particular, section 3A of the Human Fertilisation and Embryology Act 1990 (“the Act”), as amended in 2008, prohibits the implantation of any embryo in which the mitochondrial or nuclear DNA has been altered (which would be the case with PNT), or which is derived from an egg in which the mitochondrial or nuclear DNA has been altered (which would be the case with MST).

However, a carve-out was introduced in 2008 in section 3ZA, allowing the UK government to introduce regulations permitting the implantation of an egg or embryo which has had applied to it “in prescribed circumstances a prescribed process designed to prevent the transmission of serious mitochondrial disease.” The Act requires Parliamentary approval for any such regulations.

The UK government has now made use of this carve-out, by way of the Human Fertilisation and Embryology (Mitochondrial Donation) Regulations 2015 (“the Regulations”), which received Parliamentary approval by a large majority in both Houses in February 2015.

The Regulations

Under Regulation 5, the Human Fertilisation and Embryology Authority (“HFEA”), an independent regulator overseeing the use of gametes and embryos in fertility treatment and research, is authorised in future to issue a specific licence to carry out this treatment where is has determined that:

  • there is a particular risk that any egg extracted from the ovaries of a woman named in the determination may have mitochondrial abnormalities caused by mitochondrial DNA; and
  • there is a significant risk that a person with those abnormalities will have or develop serious mitochondrial disease.

The Regulations also set out a similar process and circumstances applying to embryos.

Comment

The UK is the first country in the world to permit such techniques to be carried out in the course of IVF treatment.

It should be noted that although the EU Tissues and Cells Directives have been incorporated into UK law, they do not cover the issue of mitochondrial donation and it appears that EU member states are free to pass their own rules.

Opponents of mitochondrial donation techniques argued that the Regulations are incompatible with EU law, in particular Article 9(6) of the EU Clinical Trials Directive (2001/20/EC), which prohibits gene therapy trials resulting in “modifications to the subject’s germ line genetic identity.” Supporters of the Regulations say that there is no conflict as the subject’s nuclear DNA remains unchanged, and the techniques do not amount in any event to a “clinical trial”. So far there has been no formal legal challenge to the validity of the Regulations.

Next steps

The Regulations will come into force on 29 October 2015. It is now up to the HFEA to assess the competency of any clinic proposing to offer mitochondrial donation, and that each case of treatment is appropriate based on the particular facts and in accordance with scientific advice.