The techniques of assisted fertilization advance without brake. Through the use of a new and controversial method, was born the first baby using DNA of three parents: his mom, his dad, and a woman who donated eggs for the boy, who is called Abrahim Hassan, were healthy. Is that the mother has a genetic mutation that causes their babies to be born sick and had already suffered the death of two children.
The history and the scientific advancement of this new technique were published yesterday in New Scientist magazine. The baby, now five months, has the DNA of his mother and his father, plus a small portion of genetic material from a donor. This technique allows parents with rare genetic mutations have healthy babies, but can be controversial because some say that it is "designing babies". In the united States, for example, is prohibited, while the United Kingdom legalized last year.
The baby’s parents are from Jordan and loaded it with a sad family history: first pregnancy, lost it. In the second, in 2005, was born a babe that died at six years of age. There they discovered that he had Leigh syndrome, which affects the brain, the muscles and the nervous system. Then was born another baby, a boy, but he had the same disease and died at eight months.
The couple wanted to try again and spoke to John Zhang and his team of New Hope Fertility Center in New York, although the treatment was done in Mexico, where there is no legislation regulating the cloning or assisted reproduction. In the united States the technique is prohibited. Is that by 2000 began to be used in the transfer technique, cytoplasmic, which also involved three genetic parents. Mixed eggs of young women with those of women who wanted to have children but their eggs were of poor quality. There were several births, but some babies were sick and the FDA lowered the thumb.
This case is different because the donated egg is removed the nucleus and replaces it with that of the mother. So, what is donated is the material mitochondrial achieves that the baby is born without the genetic disease of the mother. These genes are in the DNA of the mitochondria, the "engine" of the cell, which has 37 genes that are inherited from the mother to the baby. In this case, the 25% of the mitochondria of the mother of the baby has the mutation that causes the disease.
Zhang removed the nucleus of an egg cell of the mother and inserted it into the egg of a donor, to which he had extracted its own core. The egg produced was fertilized with the sperm of the father. Zhang had five embryos but only one is developed in the normal way, and that was implanted in the mother. The specialist told the magazine New Scientist that "in order to save lives this is the decision ethically correct."
"mitochondrial diseases are complicated, many are deadly. These women have the option to adopt or resort to egg donation. With this technique, despite being a donated egg, she equally contributes its genes, because most genetic information is in the kernel, which is healthy. Your child will have mitochondria from the donor and will not have the disease", explains grupo Clarín Sergio Pasqualini, of the Institute Halitus.
"What is relevant is that there are three genomes. The nuclear DNA of the father, the nuclear DNA of the mother and the DNA of the mitochondria of the donor. This prevents the disease and at the same time do not have as much weight genetic, so that all physical characteristics will be his mother," says Sergio Papier, to the front of the Cegyr.
The specialists explained that the legal vacuum in Argentina would allow this technique, but it is handled with a code of ethics of the Argentine Society of Reproductive Medicine and is still missing there are more cases and to see its evolution for the technique to be supported.
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