First 'three-parent-baby' born in the UK after IVF procedure developed to prevent children inheriting incurable diseases

10 May 2023, 09:09

A new IVF treatment has been developed to prevent babies developing incurable diseases
A new IVF treatment has been developed to prevent babies developing incurable diseases. Picture: Getty

By Jenny Medlicott

A baby has been born using the DNA of three people for the first time in the UK after years of clinical development, the fertility regulator has said.

Doctors performed an IVF procedure that aims to prevent passing down incurable diseases from parents to their children by introducing DNA from a 'third parent' for the first time in the UK.

The technique is known as mitochondrial donation treatment. It aims to to prevent children inheriting mitochondrial diseases, which are incurable and can be fatal within days, sometimes hours, of a child's birth if inherited.

Mitochondria are the tiny compartments inside almost every cell in the body, and they convert food into useable energy.

But defective mitochondria fails to make these conversions – leading to brain damage, muscle wasting, blindness and heart failure.

Roughly one in 6,000 babies are affected by these disorders.

The defective mitochondria is only passed down by the mother, which is why the “three-parent-baby” uses two mothers and a father.

Less than five children have been born using the method so far, but this is the first time one was born in the UK.

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Babies still inherit about 99.8% of genes from the mother and father.
Babies still inherit about 99.8% of genes from the mother and father. Picture: Getty

The technique uses tissue from the egg of a healthy female donor to create an IVF embryo that is free from incurable mutations carried by a mother and is likely to be inherited by children.

A baby born using this method would have the usual DNA of its mother and father, plus a small portion of genetic material from a female donor – about 37 genes.

This tiny segment of genes from the donor then becomes a permanent change that is passed down through generations.

The modified form of IVF has been labelled by many a “three-parent-baby”.

However as the method does not affect characteristics such as appearance, and 99.8% of the genes still come from the mother and father, the donor could not actually be classified a third parent.

It was only in 2015 that the work required to develop this technique was permitted, as a law was passed to enable a clinic in Newcastle to begin developing it.

The first baby ever born using this technique was to a Jordanian family in the US in 2016.

It is uncertain whether the technique for the UK-born baby was successful in eliminating the defective genes, as the Newcastle team have yet to comment.

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The technique aims to eliminate defective mitochondria from the embryo.
The technique aims to eliminate defective mitochondria from the embryo. Picture: Getty

There is a risk of “reversion” in babies who are born using this technique, which means the defective mitochondria could still be carried over and eventually increase in number – resulting in the disease still developing.

The Human Fertilisation and Embryology Authority (the HFEA) said as of April 20 2023, “less than five babies” have been born using the technique.

Sarah Norcross, the director of the Progress Educational Trust said: “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.”

“It is also very important that we respect the privacy of children with donated mitochondria, and their parents, not least because these parents are likely to have had prior experience of illness and bereavement in their family,” she added.

Prof Robin Lovell-Badge, from the Francis Crick Research Institute, said: "It will be interesting to know how well the mitochondrial replacement therapy 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."

If the method is successful up to 150 babies could eventually be born a year via the technique, estimates suggest.