This week, a historic announcement was made by the UK fertility regulator: the first baby with DNA from three people has been born in the UK through a pioneering IVF procedure. This is a major breakthrough for families who are at risk of passing on devastating mitochondrial diseases to their children.
What is mitochondrial donation treatment (MDT)?
Mitochondrial donation treatment (MDT) is a modified form of IVF that replaces faulty mitochondria with healthy ones from a donor egg. Mitochondria are tiny structures inside the cells of all multi-cellular, oxygen-breathing organisms. They serve many useful functions in the cell, the most essential of which is using ATP (adenosine triphosphate-made from glucose by our bodies) to generate energy for the cell. Mitochondria have their own DNA, which is inherited only from the mother. If the mother has mutated mitochondria, she can pass them on to her children, causing serious and often fatal diseases that affect the brain, heart, muscles and liver.
MDT involves extracting the nucleus from one of the mother’s eggs, which contains her own DNA, and transferring it into a donor egg that has healthy mitochondria and whose own nucleus has been removed. The resulting egg has DNA from the mother and father as usual, plus a small amount of DNA from the donor that is only relevant for making effective mitochondria. The egg is then fertilised by the father’s sperm and implanted into the mother’s womb.
What are the benefits of MDT?
MDT offers a chance for women with mitochondrial diseases to have healthy children of their own, without the risk of passing on harmful mutations. It also prevents the transmission of these diseases to future generations. MDT is seen as the only option for some families who have lost multiple children to mitochondrial diseases or who have children with severe disabilities.
MDT also has potential benefits for other areas of medicine and technology. It could help researchers understand more about how mitochondria function and how they affect human health and ageing. It could also pave the way for new treatments for other genetic disorders that involve faulty nuclear DNA.
“Mitochondrial donation treatment offers families with severe inherited mitochondrial illness the possibility of a healthy child”.The U.K. fertility regulator
What are the challenges and risks of MDT?
MDT is a complex and novel technique that requires careful regulation and oversight. The UK was the first country in the world to legalise MDT in 2015, after extensive scientific and ethical reviews. The Human Fertilisation and Embryology Authority (HFEA) is responsible for granting licences and monitoring MDT cases in the UK.
MDT is not without risks and uncertainties. Some experts have raised concerns about the safety and efficacy of MDT, as well as the long-term health effects on the children born through this procedure. There are also ethical and social issues around the use of donor eggs and the creation of children with DNA from three people.
One of the main challenges of MDT is to ensure that no mutated mitochondria are transferred along with the mother’s nucleus into the donor egg. This could result in a mixture of healthy and unhealthy mitochondria in the child, which could still cause disease or affect their development. Another challenge is to prevent any unwanted interactions between the donor’s mitochondrial DNA and the parents’ nuclear DNA, which could affect gene expression or cause immune problems.
“News that a small number of babies with donated mitochondria have now been born in the UK is the next step, in what will probably remain a slow and cautious process of assessing and refining mitochondrial donation”.Sarah Norcross, the director of the Progress Educational Trust
What are the future prospects of MDT?
MDT is still a very new and rare procedure that has been performed only in a handful of cases worldwide. The first baby born through this technique was to a Jordanian family in 2016 who were having treatment in the US. The first UK baby born via this technique was announced this week, but no further details have been released.
The HFEA has said that “less than five” babies have been born through MDT as of 20 April 2023, but it is not giving precise numbers to protect the privacy of the families. The efficacy of MDT in these cases has not been disclosed. Confirmation on whether the babies are free of mitochondrial disease, and if there is any risk of them developing problems later in life has not been made public.
MDT is still an experimental technique that requires more research and evaluation before it can be widely available. It is also an expensive and specialised procedure that may not be accessible or affordable for many families who need it. However, MDT represents a remarkable achievement of science and medicine that could offer hope and relief for many people affected by mitochondrial diseases.
What are some other similar technologies on the horizon?
While MDT is a groundbreaking technique that has attracted attention for its potential to prevent mitochondrial diseases, there are other similar technologies on the horizon that could have a significant impact on human health and wellbeing.
One such technology is CRISPR-Cas9, a powerful gene-editing tool that allows scientists to selectively modify genes in living cells and organisms. CRISPR-Cas9 has the potential to cure genetic diseases, improve food security, and even create new forms of life. However, it also raises ethical concerns about genetic engineering and the unintended consequences of altering the human genome.
Another technology that is gaining traction is gene therapy, which involves delivering healthy copies of genes to replace defective or missing ones. Gene therapy has already been used to treat some rare genetic disorders, such as spinal muscular atrophy and retinal dystrophy, and could potentially be used to cure more common diseases, such as cystic fibrosis and sickle cell anaemia.
Despite the potential benefits of these technologies, there are also concerns about their safety, efficacy, and accessibility. There is a risk that they could be misused or abused, leading to unintended consequences or even harm. Therefore, it is crucial to ensure that these technologies are developed and regulated in a responsible and ethical manner, with appropriate oversight and transparency.
Implications and Challenges of Mitochondrial Donation Technology
The birth of the first baby with DNA from three people in the UK is a significant milestone for reproductive medicine and genetics. It offers hope and relief for families affected by mitochondrial diseases, while also raising important ethical, social, and scientific questions about the use and regulation of new technologies. As MDT and other similar technologies continue to develop, it is essential to balance the potential benefits and risks and ensure that they are used for the greater good of society.