IVF innovation marks promising genetic milestone

Mitochondrial DNA is passed from mother to child through the egg, and in rare instances genetic mutations occur, which can lead to the baby developing mitochondrial disease. This condition affects approximately one in every 5,000 people, making it one of the most common inherited disorders. When the mitochondria, often referred to as the cell’s batteries, fail in various organs, children may experience a wide range of symptoms from muscle weakness to epilepsy, encephalopathy, vision and hearing loss, and diabetes. In the most severe cases, the disease can be fatal at a young age.

Mitochondrial Donation Treatment ("MDT")

MDT is a procedure that seeks to prevent children from inheriting mutated mitochondria by fertilising the mother’s egg with the father’s sperm and then transferring the genetic material from the nucleus into a fertilised healthy donor egg that has had its own nucleus removed. This results in a fertilised egg containing a full set of chromosomes from the parents, but healthy mitochondria from the donor, and the egg is then implanted into the womb to establish a pregnancy.

The development in the UK comes following a change in the law in 2015 that enabled the UK's fertility regulator, the Human Fertilisation and Embryology Authority ("HFEA"), to allow MDT for women at high risk of transmitting serious mitochondrial DNA disease to their children. Notwithstanding criticism questioning its ethics, the UK parliament passed it by a two-thirds majority. Newcastle Fertility Centre, part of Newcastle Hospitals NHS Foundation Trust was granted the first licence to perform clinical mitochondrial donation by pronuclear transfer in 2017. 

Ireland

Many countries do not permit MDT because of concerns over human germline genetic modification, i.e. the modification of DNA to create heritable changes, raising significant ethical, legal, and social concerns. At present, IVF clinics in Ireland are not permitted under law to carry out MDT with the Department of Health calling it “a relatively new and highly complex form of assisted human reproduction technology”.

Further to our recent article (Expanded Access to State-Funded Assisted Human Reproduction Treatments), while not yet commenced, the Health (Assisted Human Reproduction) Act 2024 (the "2024 Act") was signed into law in 2024 and establishes a regulatory framework for fertility clinics and assisted human reproduction ("AHR") treatments in the State, with the aim of ensuring consistency, oversight and ethical standards in AHR practice and research.

However, in light of the recent MDT milestone in the UK, the National Infertility Support and Information Group ("NISIG") said “while work is underway to establish a regulatory authority for Assisted Human Reproduction (AHR) treatment in Ireland as part of this legislation, research like this in the UK highlights just how far behind Ireland still is in comparison to other countries”.

NISIG say it is imperative the Government’s regulatory framework includes an authority that “enables the use of pre-implantation genetic testing (PGT) of embryos; posthumous assisted human reproduction; and embryo and stem cell research”.

This is another aspect of the regulation of fertility treatment that the Assisted Human Reproduction Regulatory Authority will have to grapple with in due course.  At present, Part 6 of the 2024 Act provides for pre-implantation genetic testing, i.e. testing carried out to analyse the DNA of embryos for the purposes of determining genetic disorders or to undertake HLA-matching to determine compatibility for organ and tissue transplantation. Under Part 6, section 48 of the 2024 Act also provides for sex selection for the purpose of ensuring or increasing the probability that an embryo will be of a particular sex only where, in the opinion of a relevant specialist, such treatment is indicated because there is a significant risk of a child being born with a genetic disease that affects only one sex, or affects one sex significantly more than the other. The 2024 Act does not make provision for Mitochondrial Donation Treatment.

With formal drafting of the Health (Assisted Human Reproduction) (Amendment) Bill (the "Amending Bill") to address legal and procedural gaps in the 2024 Act nearing completion and expected to undergo pre-legislative scrutiny in the Autumn, it will become clearer if the legislature intends to address this developing area within the confines of the Amending Bill, once published.

General information on public fertility services and on publicly funded AHR Treatment is available on the HSE website.

The Health (Assisted Human Reproduction) Act 2024 is available here.

General information on MDT is available on the HFEA website.

Written by Zoe Richardson and Dena Keane.