An innovative technique of assisted fertilization, the mitochondrial donation, has made it possible to circumvent diseases related to the DNA of maternal mitochondria.
A revolutionary assisted fertilization technique allowed to correct a minimal, but significant part of genetic inheritance of eight children, who were born (and grow) healthy thanks to the union of the DNA of three people. In addition to the genetic heritage of the two parents, the embryos from which the little ones originated the healthy mitochondria of a donor, to replace the defective mitochondria of the mothers.
The procedure, known as mitochondrial donationspared very serious children’s children, who would compromise quality and expectation of their lives. The results, the result of decades of research, were published in two articles on New England Journal of Medicine.
Mitochondrial diseases
The mitochondria are organules present in the gelatinous substance within the membrane of our cells, in charge of energy production. Mitochondria have a particularity: contain their own DNAvery small and containing little gene information compared to nuclear DNA, and inherited exclusively by the biological mother. When a high portion of mitochondria contains a harmful mutation, it is very probable that a serious and progressive genetic disease develops, which mainly affects the most “thirsty” organs of energy, such as heart, muscles and nervous system.
Mitochondrial diseases are various pathologies related to the alteration of the functioning of the mitochondria that you cannot avoid with normal pre -implant genetic tests carried out in assisted fertilization techniques. In fact, it is very difficult to obtain oocytes with low levels of anomalous mitochondrial DNA, if this is present at high levels in the patient.
The mitochondrial donation
The 8 children reported by their studies were born thanks to the technique of mitochondrial donation or Pronuclear transfer. It works like this: the egg of the mother and a donor are fertilized with the father’s sperm; Therefore, the nuclear DNA is taken from the maternal egg, which is then transferred to the ovulus of the donator, from which the nuclear DNA was previously removed. The result is An embryo with the nuclear DNA of the mother and father, but having the healthy mitochondria of the donatorinstead of those with harmful mutations of the mother.
The first time with legal support
In 2015 the United Kingdom was the first country to approve the procedure For high risk women to transmit mitochondrial diseases. The Regulatory Authority, the Human Fertilisation and Embryology Authority (HFEA) has allowed the technique to be carried out in a highly disciplined way and only in a clinic, the Newcastle Fertility Center. The two new studies document the research carried out in this institute. Already in 2023 the first 5 children born thanks to mitochondrial donation had been given, but the health conditions of the young were not clear.
In perfect health (but to follow)
In total, 22 women with damaged mitochondrias have faced the pronuclear transfer, and this led to 8 births (two of the infants were twins). A pregnancy is still in progress. The children, from the two years spent to 5 months of age, they were born healthy and are growing normally. Five had no health problems, three others have reported some disorders (muscle shots that have gone away on their own; a urinary infection, and high levels of fat in the blood as well as arrhythmias) which however do not seem to be connected to problems in the mitochondria.
Scientists say they are “cautiously optimistic” on the success of the procedure, even if they must continue to carefully monitor the health conditions of children. In fact, in the transfer of the nuclear DNA of the mother to the egg cell of the donor, some pathogenic mitochondria could inadvertently pass, and with the development of the embryo, amplify to cause diseases. For the moment, even in children who bear the highest percentages of mitigated mitochondria (from 5 to 16%) these percentages are not high enough to cause pathologies.
For now, and according to this small champion, the mitochondrial donation – which is not allowed in Italy – seems to be a safe technique, and a life -saving therapeutic opportunity.
