Mitochondria like the two seen here from a mammal's lung tissue could be the key in saving babies for two women.Wikimedia Commons
One of the most controversial proposed fertility treatments of recent years has its first two UK patients. Doctors in the UK were given permission to create "three-person babies" for two women suffering from incurable genetic diseases. The delicate fertility process means that doctors would make embryos for the two women by combining fertilized eggs made via in vitro fertilization (IVF) using DNA from female donors.
It's a process called mitochondrial donation, and while it's been around in theory since the late 1980s, it hasn't been put into practice until recently. The donation works by swapping out 0.1 percent of the baby's DNA (the unhealthy mitochondria) with a donor's mitochondria. The mother's nucleus from the unhealthy egg is then placed into the donor's egg surrounded by healthy mitochondria. This replaces the disease-carrying DNA with a 'clean slate' from the donor. The other genetic codes for elements like hair color and eye color come from the mother and the father's DNA.
The radical process was made legal in the UK in 2015, but no woman has yet to undergo the treatment until now. While few specifics are known about the women due to patient confidentiality and security, official records from the approval committee noted that these women carry Merrf syndrome -- a gene for myoclonic epilepsy with ragged red fibers.
Merrf syndrome is a crippling neurodegenerative disorder that typically results in an early death. The condition affects one in every 100,000 people and is often diagnosed early on in someone's life. Symptoms include loss of muscle control, weakness, dementia, and increasing deafness.
World's first 'three-person baby' was born in the US
This revolutionary procedure would shape policy around fertilization throughout the United Kingdom. However, it's not the first case of the "three person" technique. In 2016, a team of US doctors used the process to make sure a Jordanian mother wouldn't pass down a genetic disease to her son. The mother suffered from Leigh Syndrome and had already suffered four miscarriages as well as losing two children to the disease.
Professor Alison Murdoch was part of the Newcastle team at the time the first child was born using this technique. She said in an interview with the BBC that it's critical to take the process with caution and care.
"The translation of mitochondrial donation to a clinical procedure is not a race but a goal to be achieved with caution to ensure both safety and reproducibility," she said.
Sian Harding serves as the director of the British Heart Foundational Imperial Cardiac Regenerative Medicine Center in London. She said that the process gives women around the world hope for the future.
"It is absolutely fantastic that we have got to this point in such a well-regulated and controlled way," she said in an interview with the Guardian. "It is going to be so important now to follow up and understand whether this is successful and how we can take it forward. If you don’t follow up the children, we just won’t know whether this is the right thing to do."