The UK fertility regulator has confirmed the birth of a baby using the DNA of three individuals in a groundbreaking technique aimed at preventing devastating mitochondrial diseases. The majority of the baby’s DNA comes from their two parents, while approximately 0.1% is derived from a third donor woman. Although fewer than five such babies have been born, no further details have been disclosed.
Mitochondrial diseases are incurable and can be fatal within hours or days of birth, leading to severe health complications. Families affected by these diseases, who have often lost multiple children, view this technique as their only hope for having a healthy child.
Mitochondria, the energy-converting compartments present in nearly every cell of the body, contain their own genetic information or DNA. As such, mitochondrial donation treatment, a modified form of IVF, involves using mitochondria from a healthy donor egg. There are two techniques for performing mitochondrial donation: one takes place after fertilization of the mother’s egg by the father’s sperm, and the other occurs before fertilization.
It should be noted that the donor DNA is solely responsible for producing functional mitochondria and does not impact other traits, such as appearance. Consequently, it does not constitute a “third parent.” However, this alteration represents a permanent change that will be inherited by future generations.
The technique was pioneered in Newcastle, and UK laws permitting the creation of babies through this method were introduced in 2015. However, the UK did not immediately proceed with the implementation. The first baby born using this technique was from a Jordanian family receiving treatment in the US in 2016.
The Human Fertilisation and Embryology Authority (HFEA) has confirmed that as of April 20, 2023, “less than five” babies have been born through this technique, withholding precise numbers to protect the families’ identities. These limited details emerged after a Freedom of Information request by The Guardian newspaper.
Sarah Norcross, the director of the Progress Educational Trust, stated that the news of a small number of babies with donated mitochondria being born in the UK marks the next step in the cautious and gradual process of assessing and refining mitochondrial donation.
The success of the technique and the absence of mitochondrial disease in the babies remain uncertain, as there has been no official communication from the teams in Newcastle. Professor Robin Lovell-Badge from the Francis Crick Research Institute expressed interest in evaluating the practical effectiveness of the mitochondrial replacement therapy technique, as well as the long-term risk of any potential health problems.
While there is a slight risk of “reversion,” where defective mitochondria could increase in number and still lead to disease, this groundbreaking technique opens the door for potential advancements in treating mitochondrial disorders. The estimated possibility of up to 150 such babies being born each year in the UK highlights the potential impact of this pioneering method in preventing the transmission of devastating mitochondrial diseases.