1st Babies Born in UK to ‘3 Parents’

An embryologist works on a petri dish at the Create Health fertility clinic in south London, on Aug. 14, 2013. Sang Tan/AP Photo

Babies have been born using DNA from three parents for the first time in the United Kingdom, the country’s fertility regulator has confirmed.

The babies were born using the pioneering mitochondrial donation treatment (MDT), which is used by individuals with severe mitochondrial disease to avoid passing the condition on to their children, the Human Fertilisation and Embryology Authority (HFEA) said.

Mitochondria are the tiny parts of almost every cell in your body and act like the powerhouse of cells, converting sugar and oxygen into energy that the cells need to function properly, according to the U.S. Centers for Disease Control and Prevention (CDC).

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However, in individuals who have mitochondrial diseases, the mitochondria cannot efficiently turn sugar and oxygen into energy, meaning that various parts of the body such as the kidneys, muscles, heart, eyes, ears, and others, are not able to function properly.

The condition can be both mild or serious, according to the CDC.

HFEA confirmed to The Guardian, following a Freedom of Information request, that a “small number of babies” have been born in the UK using mitochondrial donation transfer.

The independent regulator, which oversees the use of gametes and embryos in fertility treatment and research, said that as of April 2023, “less than five” babies have been born using the treatment.

Mitochondrial Diseases Explained

It declined to give the exact number of births via the treatment, noting that doing so “could lead to the identification of a person to whom the HFEA owes a duty of confidentiality.”

The condition of the babies is not known.

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Mitochondrial diseases are passed down by the parents. Under MDT—essentially a modified version of in vitro fertilization—eggs or embryos are created using nuclear genetic material, or DNA, and mitochondria donated from the healthy egg of a second woman, preventing the child from inheriting the incurable condition.

While the babies will have the majority of their DNA from their two parents, 0.1 percent of its DNA, or roughly 37 genes, will come from the healthy egg provided by the second woman, according to the UK’s Department of Health (pdf), hence the term “three-parent babies.”

In a separate statement on Twitter, HFEA Chief Executive Peter Thompson said, “The UK was the first country in the world to allow mitochondrial donation treatment within a regulatory environment.”

“Mitochondrial donation treatment offers families with severe inherited mitochondrial illness the possibility of a healthy child. The HFEA oversees a robust framework which ensures that mitochondrial donation is provided in a safe and ethical manner,” Thompson continued. “All applications for treatment are assessed on an individual basis against the tests set out in the law and only after independent advice from experts.”

‘Still Early Days’

“These are still early days for mitochondrial donation treatment and the HFEA continues to review clinical and scientific developments,” he added.

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According to the CDC, symptoms of mitochondrial diseases are not always visible, although they typically appear during toddler and preschool years.

Children with mitochondrial diseases display symptoms or signs of autism and epilepsy or have problems with muscle tone, as well as movement disorders such as difficulty with walking or eating.

Currently, there is no cure for mitochondrial diseases, and scientists have warned that vaccines could worsen the condition, saying more research is needed to determine if rare cases of the diseases are triggered by anything related to vaccines, according to the CDC.

However, there are a number of treatments available to help manage mitochondrial disease, such as vitamins and supplements and exercises, according to the Cleveland Clinic.

Potential Problems With MDT

Between one in 6,000 and one in 8,000 babies are affected by mitochondrial diseases, according to Boston’s Children’s Hospital, making them almost as common as childhood cancer.

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In 2016, the first-ever baby born using MDT was welcomed by a Jordanian family who were treated by a U.S.-based team in Mexico, according to the New Scientist.

However, the condition of the child is not known.

Britain became one of the first countries in the world to be formally granted permission to use mitochondrial replacement therapy in 2017.

Professor Robin Lovell-Badge, the senior group leader and head of the Laboratory of Stem Cell Biology and Developmental Genetics at the Francis Crick Institute, London, told The Telegraph that he is eager to see how well the technique worked at “a practical level, whether the babies are free of mitochondrial disease, and whether there is any risk of them developing problems later in life. Or, if female, if their offspring are at risk of having the disease.”

“Such problems might arise if there is ‘reversion,' where the initially small amounts of the mother’s mitochondrial DNA, with the disease-causing variant gene, that are carried over with her nuclear DNA, are amplified,” he noted.

However, Lovell-Badge noted that without MDT, “the risks of the children having mitochondrial disease would be very high.”