Doctors from the Jiménez Diaz Foundation have successfully carried out the pregnancy and birth of a healthy and histocompatible baby with her older brother, affected by sickle cell anemia, who will therefore be able to help his treatment for its corresponding cure.
“The milestone achieved, birth is not only a joy for its parents in itself because he does not have the same disease as his brother, but he is also going to ensure that his sick brother can receive his donated bone marrow, is very rarely accomplished; hence its importance and the progress it represents for the prevention and treatment of these diseases, “states the Carmen Ayuso, Head of the Genetics Department of the Madrid hospital.
And it is that “the chances of success of obtaining healthy and histocompatible embryos in this type of situation are not high, being reached in less than 20 percent of cases,” he adds. Corazón Hernández, head of the Assisted Reproduction Unit of the Fundación Jiménez Díaz, who considered Laura and her husband’s commitment to expand their family with this dual purpose as a real “challenge”, despite being a long road and not without potential difficulties.
Once achieved, the youngest of the family, born in early May, will be able to convert from the 2 years old in bone marrow donor for his older brother, who is now 4 years old and who, diagnosed as soon as he was born of this serious and hereditary disease that deforms and reduces red blood cells, hinders blood circulation and causes from chronic anemia to vascular obstructions and microinfarctions in different organs, he only had this option as a therapeutic alternative effective.
«This success has been the result of the effort and coordination of a multidisciplinary team made up of geneticists, hematologists, embryologists, gynecologists, obstetricians and neonatologists, among other specialists, but above all the ideal conditions for the couple to approach the treatment, mainly the youth of the mother, who is 28 years old“Explains Hernández, stressing that, although” preimplantation genetic diagnosis (PGD) is the highest expression of preventive medicine, the sooner this type of treatment is demanded, the easier it is to achieve the objective, as has been the case ».
The Genetics Service of the Jiménez Díaz Foundation is among the few in the National Health System that offer DGP, technique aimed at avoiding the implantation of embryos, and the consequent birth of individuals, with serious genetic diseases, without effective treatment and who compromise the quality of life of those who suffer them, and whose existence is already known in the family.
“Basically,” Ayuso explains, “DGP is focused on rare diseases, which currently have very few therapeutic options, one of which is precisely its prevention through this technique.”
Additionally, there is a specific type of PGD that is the diagnosis and identification of histocompatible embryos, potential bone marrow donors, with the dual purpose that “a couple beget a healthy and, at the same time, histocompatible child, so that they can solve the problem, through the bone marrow donation of a brother conceived for this purpose, of another brother who has already been born with a rare disease and exists in the same family, “says Isabel Lorda, of the Jiménez Díaz Foundation
“The process began when the couple went to the Genetics Service of the Madrid hospital looking for healthy and histocompatible offspring with their oldest son,” recalls Ana Bustamante, a specialist in this department, explaining that this type of embryonic selection requires a prior genetic study -and that the disease being studied is perfectly identified, as was the case of sickle cell anemia, the causative mutation of which is known and identifiable – and a search for genome markers to study and select two regions within it: that related to the disease and the one related to histocompatibility in order to be a donor to his brother.
After detecting the markers to be used and confirming that the study was feasible, the couple went to the Assisted Reproduction Unit where, as the Luz RodríguezAs a specialist in this, controlled ovarian stimulation allowed obtaining numerous oocytes, which were inseminated and converted into a significant number of embryos.
“After three days of cultivation, they were biopsied to carry out the aforementioned genetic study, and those identified as disease-free and histocompatible were selected as suitable for possible uterine transfer, “he adds. One of these transferred embryos resulted in a pregnancy.
Thus, recalls Ester Arango, a specialist in the Obstetrics and Gynecology Service, “Laura lived a low-risk pregnancy, since she had no conditions that contraindicated it, but very closely followed to anticipate any complications that might arise, which did not occur ». Delivery, term and natural, and in which the collection of the cord blood sample to perform the directed donation It was perfectly coordinated by the entire medical team, “it was very emotional because it was a highly desired pregnancy, and a milestone,” he adds.
“Once the baby was born, the hospital’s Genetics Service verified the absence of disease, and the Community of Madrid Transfusion Center endorsed his histocompatibility with his older brother, thus confirming that the process had been correct,” points out his Maria José Trujillo-Tiebas, associate head of the service, leaves.