The aim of the procedure is to prevent the mother from passing defective mitochondrial genes to her child.

A new breakthrough in medical science has been achieved in the UK as a result of a mitochondrial donation treatment (MDT), which has allowed for the birth of a “three-parent baby”.

The revolutionary procedure is designed to prevent inherited diseases by replacing the defective genes in the mitochondria of the mother with healthy ones from a third party.

The nuclear DNA, which contains crucial information such as personality traits and eye colour, is still provided by the mother and father.

How it works

The revolutionary technique aims to prevent newborns from inheriting severe mitochondrial diseases by incorporating healthy mitochondrial DNA from a third person, which makes up about 0.1% of the child’s overall DNA.

However, the vast majority of the child’s DNA comes from their biological parents.This method has resulted in the birth of fewer than five babies, with no further information released to the public.

Mitochondrial diseases are incurable and can be fatal, causing severe brain damage, muscle wasting, heart failure, and blindness. Defective mitochondria are only passed down by the mother, and this technique offers hope for families who have lost multiple children to these diseases.

The technique involves using healthy mitochondrial DNA from a donor egg, which accounts for only around 0.1% of the resulting child’s DNA. The nuclear DNA, which contains crucial information such as personality traits and eye colour, is still provided by the mother and father.

“Mitochondrial donation treatment offers families with severe inherited mitochondrial illness the possibility of a healthy child,” Peter Thompson, chief executive of the HFEA, told Sky News.

“The UK was the first country in the world to allow mitochondrial donation treatment within a regulatory environment.”

The procedure was pioneered in Newcastle, and the UK introduced laws to allow the creation of such babies in 2015.

In 2016, a New York-based team helped to create the world’s first baby using DNA from three parents, who was born in Mexico. The mother carried genes for Leigh syndrome, which is a deadly condition that impacts the nervous system during development.

The Human Fertilisation and Embryology Authority has not given precise figures on the number of babies born through this technique to protect the families’ identities.

The Guardian was the first to report on the MDT birth after submitting a freedom of information request to the HFEA, revealing that the pandemic had affected donors and couples hoping to undergo the therapy.

The Newcastle clinic’s procedure involves transferring the genetic material responsible for encoding the baby’s identity to a donor egg that has had its own nuclear DNA removed, creating an embryo with healthy mitochondria from the donor and nuclear DNA from the baby’s mother and father.