The innovative fertilization procedure was done in the United Kingdom. The treatment offers parents “with serious inherited mitochondrial conditions the chance to have a healthy child,” British officials said.
A baby fertilized with DNA from three people was born in the United Kingdom, thanks to an innovative procedure aimed at preventing children from inheriting incurable diseases.
Most of the baby’s DNA comes from his biological father and mother, and about 0.2% from a third female donor.
The technique, known as mitochondrial donation treatment (MDT), uses tissue from the eggs of healthy donor women to create In Vitro Fertilization (IVF) embryos free of harmful mutations carried by their mothers and likely to pass them on to their children. Mitochondrial diseases are incurable and can be fatal within days or even hours of birth.
Like anyone else, babies conceived through this method are born from the fertilization of a single sperm and a single egg. The difference lies in the relationship between the nuclear material that houses the vast majority of the genes responsible for building a human being and the small amount of non-nuclear DNA that helps make the cell’s energy units, called mitochondria.
Because embryos combine the sperm and egg of the biological parents with the tiny mitochondrial structures of the donor egg, the resulting baby has DNA from the mother and father, plus a small amount of genetic material (about 37 genes) of the donor, according to information accessed by The Guardian newspaper.
People inherit mitochondria from their mother, so harmful mutations can affect all children. Mitochondria are the small compartments within almost all cells in the body that convert food into usable energy, when defective they do not fuel the body and cause brain damage, muscle atrophy, heart failure and blindness.
For affected women, natural conception is often uncertain, 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.
Around one in 6,000 babies are affected by mitochondrial disorders in the UK. In that country, the Human Fertilization and Embryology Authority (HFEA) is the regulatory agency for the sector and authorizes procedures on a case-by-case basis, and has already given the green light to at least 30.
Research into mitochondrial donation treatment, also known as mitochondrial replacement therapy (MRT), was pioneered in the UK by doctors at the Newcastle Fertility Centre.
The process involves 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’s egg and replaced with that from the couple’s fertilized egg.
The resulting egg has a complete 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.
Progress with MDT led parliament to change the law in 2015 to allow the procedure. Two years later, the Newcastle clinic became the first and only national center licensed to do so, with the first cases approved in 2018.
Following the international disclosure of this case, the British Human Fertilization and Embryology Authority issued a statement in which it stated: “The United Kingdom 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 diseases the possibility of having a healthy child. The HFEA oversees a robust framework that ensures mitochondrial donation is provided safely and ethically. “All requests for treatment are assessed individually against the evidence set out in law and only after independent expert advice,” said Peter Thompson, CEO of HFEA.
Furthermore, doctors at the Newcastle clinic have not published details of births from their MDT programme, for fear of compromising patient confidentiality.
Source: Infobae.
