First born daughter «DiePresse.com

According to their own statements, Chinese scientists have for the first time used the CRISPR / Cas9 gene scissors method to modify the human germ line. From the genetic material of the fertilized oocytes of the Lulu and Nana girls, born a few weeks ago, the CCR5 receptor gene had been removed, whereby the AIDS viruses infect the cells. It was the first birth of babies after such an intervention.

"Two healthy little girls, Lulu and Nana, came into the world crying – like all the other babies – Grace, the mother, became pregnant after a normal in vitro fertilization, with one difference: immediately after the sperm we had also added a small protein for "gene surgery" to her husband's egg, "said He Jiankui of YouTube.

Thus, at the level of fertilized ova, the "gate" through which AIDS viruses can enter cells has been removed. CCR5 is what is called a co-receptor for IH viruses (in addition to CD4). If there are no CCR5 structures on the cells, they are resistant to HIV. There is no proof of the scientist's claims yet: there is no verified scientific publication, just an entry in a Chinese register for clinical trials.

Father was HIV positive

The question has a serious background for Chinese scientists. The subjects are couples who want to have children, in which the man is HIV positive. Although the HIV / AIDS clinical trial appears superficial with the CRISPR / Cas9 procedure, it is not a "therapy". Because more and more couples, whose one partner is HIV positive, are getting kids. With modern treatment methods, a pregnancy can be carried out without risk of HIV. The treatment that accompanies it also helps to avoid a risk of infection during childbirth.

Immediately after the announcement of the Chinese scientist's statement, an international criticism is installed. With CRISPR / Cas9 gene scissors, the genes in cells can be modified on purpose. If this occurs in the germ line, affected people pbad the modified genetic material to their children.

"If confirmed, this work breaks with the restrained and transparent approach of the global scientific community of using CRISPR / Cas9 to alter the human germline," said one of the two Hong Kong researchers. , Jennifer Doudna. There is an urgent need to set clear limits on gene manipulation in embryos. It should only be used if there is a clear medical need and no other treatment exists.

Markus Hengstschläger, head of the organizational unit of the Center for Pathobiology and Genetics of the Vienna Institute of Medical Genetics, commented: "In this edition of the genome, the genes are modified or corrected, which represents a huge chance for somatic cells – in the tissues the germ line, the embryo, is rejected for ethical reasons in most states of the world ".

"Intervention in evolution"

Hengstschläger cited several reasons for this: on the one hand, the method does not always work exactly, it could lead to side effects. "In addition, it is an evolving intervention, we are changing people, we will not bring it back." The human genome has slowly evolved over millions of years in the evolution of Homo sapiens as an interaction between genetics and the environment. "But in such experiences, we have no idea what will come out, we can not return it, an badessment of impact is impossible."

In Austria, such interventions would be prohibited, as in most countries of the world, for example in the United States. In addition, the development of methods for the treatment of CRISPR / Cas9 diseases without germinal interference on certain organs or tissues would be permitted.

Critics have also come from China: "Direct attempts against human beings can only be described as crazy," he said in a letter signed Monday by more than 100 Chinese scientists. Children born this year may be healthy for a period of time. "But the risks and potential harm to all humanity that could result from unjustified use of the process in the future are immeasurable." The experiments undermine the global reputation of Chinese science.

(APA)