First baby born in UK with DNA from three people

A baby fertilized with the DNA of three people has been born in the United Kingdom, after doctors used an innovative procedure with the aim of preventing children from inheriting incurable diseases, the British newspaper The Guardian publishes on Wednesday.

The technique, known as mitochondrial donation treatment (MDT), uses egg tissue from healthy donor women to create In Vitro Fertilization (IVF) embryos free of harmful mutations carried by their mothers that are likely pass them on to their children.

Because embryos combine sperm and egg from the biological parents with tiny battery-like structures called mitochondria from the donor egg, the resulting baby has DNA from the mother and father, plus a small amount of genetic material (about of 37 genes) from the donor.

Although there is DNA from a donor, 99.8% of the newborn's DNA comes from the mother and father, the information adds.

Research on MDT, which is also known as mitochondrial replacement therapy (MRT), was pioneered in the UK by doctors at the Newcastle Fertility Center (North East England).

The Newcastle process consists of several steps. First, the father's sperm is used to fertilize the eggs of the affected mother and a healthy donor.. The nuclear genetic material is then removed from the donor egg and replaced with that of the couple's fertilized egg.

The resulting egg has a full set of chromosomes from both parents, but carries the donor's healthy mitochondria instead of the mother's defective ones.. It is then implanted in the uterus.

The work was aimed at helping women with mutated mitochondria have babies without the risk of passing on genetic disorders, The Guardian has learned.

People inherit mitochondria from their mother, so harmful mutations can affect all children.

One in 6,000 babies affected

For affected women, natural conception is often an uncertainty, as some babies may be born healthy because they inherit only a small proportion of the mutated mitochondria, but others may inherit much more and develop serious, progressive, and often fatal diseases.

Approximately one in 6,000 babies is affected by mitochondrial disorders.

The Guardian says the UK's Human Fertilization and Embryology Authority (HFEA), the industry's regulator, makes it easy to approve the procedure on a case-by-case basis, but has already given at least 30 the green light.

Doctors at the Newcastle clinic have not released details of their MDT program births, for fear of compromising patient confidentiality.

However, the newspaper says it learned of this proceeding from a request under freedom of information laws.