Eight babies, four boys and four girls, may have been protected from serious hereditary diseases after being born through an innovative in vitro (IVF) technique. The procedure was performed with the three -person DNA, in an intervention that involved the replacement of defective mitochondria of their mothers with healthy mitochondria of a donor.
The results of the procedure were released on Wednesday (16) by the team of researchers at the University of Newcastle, England, and published in the scientific journal (Nejm). The new treatment, known as pronuclear transfer, was effective in reducing the risk of bass that would otherwise be incurable.
According to research, all babies were born healthy, reaching their developmental milestones, and mutation in mitochondrial DNA, causing diseases, from their mothers were undetectable or present at unlikely levels of causing pathologies.
Every year, about one in 5,000 children is born with mutations in Mitochondrial DNA. These changes can cause serious and incurable diseases, as mitochondria produce energy needed for life. Mutations can affect high energy demand tissues such as heart, muscles and brain.
When the mutation in mitochondrial DNA comes from the mother, these diseases can be transmitted to the child. Although men can be affected, they do not transmit the disease. Despite the years of research, there is still no cure for people with diseases in mitochondrial DNA. The new study is an unprecedented advance in this field.
“As parents, all we always wanted was to give our daughter a healthy start. In vitro fertilization with donation of mitochondria made it possible. After years of uncertainty, this treatment gave us hope – and then gave us our baby. We look at them now, full of life and possibilities, and we are flooded with gratitude. Science has given us a chance,” said the mother of one of the babies.
How does the procedure work?
Pronuclear transfer is performed after. The procedure involves nuclear genome transplantation (which contains all genes to individual characteristics such as hair color and height) from a mitochondrial (mother) DNA mutation egg to an egg donated by an unlawful woman whose nuclear genome was removed.
Thus, the resulting embryo inherits the nuclear DNA of its parents, but mitochondrial DNA is inherited predominantly by the donated egg. Therefore, babies born of this procedure receive “three DNAs” instead of two.
According to the researchers, mitochondrial DNA levels causing diseases detected in babies born after pronuclear transfer treatment varied from undetectable to 16% in neonatal blood – a value well below the 80% needed for clinical disease. The presence of mutation in mitochondrial DNA in babies born after treatment results from the transfer of maternal mitochondria that surround nuclear DNA at the time of transplantation.
The transfer of maternal mitochondrial DNA is a known limitation of mitochondrial donation technologies. The team seeks to understand and better address this issue as part of an underlying research program.
“The results give reasons for optimism. However, research to better understand the limitations of mitochondrial donation technologies will be essential to further improve the results of treatment,” says Mary Herbert, the main author of the study.
Nevertheless, all eight babies, including a pair of identical twins, were born healthy and normally developed, five have not had medical problems ever since. In the article, the team notes that three babies have surpassed some early health problems that, according to them, cannot directly attribute to the donation of mitochondria.
“Although long -term monitoring of children born after mitochondria donation is of paramount importance, these initial results are very encouraging. Seeing the joy and relief that these children have brought to their parents is a privilege,” says Bobby McFarland, director of the Highly Specialized Service of the National Health Service (NHS) rare mitochondrial diseases.
