The pushback comes amid claims made online by Chinese scientist He Jiankui that twin girls had been born with DNA altered to make them resistant to HIV, a groundbreaking move that is likely to spark significant ethical questions around gene editing and so-called designer babies. If He Jiankui's claims are true, this development would be a profound leap in the field of genetics as well as scientific ethics, points out an AP report. Gene editing on humans is banned in the US, notes the report, because modifying genes and making changes in the DNA could possibly move from one generation to the next and there is an ever-present threat to the health of other genes as well. JK says the goal was not to cure or prevent any diseases that a child might inherit but to try and give it a trait that a small percentage of humans naturally have—the ability to possibly resist future HIV infections. AP has also said that, so far, there is no independent analysis or any confirmation of He and his work, and it is yet to be published in a peer-reviewed journal so that it can be thoroughly vetted by other researchers and experts in the field. “I feel a strong responsibility that it’s not just to make a first, but also make it an example,” He told the Associated Press. It’s a big deal.”

However, one famed geneticist, Harvard University’s George Church, defended attempting gene editing for HIV, which he called “a major and growing public health threat.”

“I think this is justifiable,” Church said of that goal. It can effectively perform operations on the DNA directly and theoretically, one can supply a needed gene to the strands or even disable the one that's causing problems, notes AP. There is no scientific consensus on the ethics of editing genes in human embryos for the purpose of reproduction, but now we may be seeing the world’s first “designer babies.”

According to He Jiankui of the Southern University of Science and Technology in Shenzhen, his team used CRISPR to edit the genes of human embryos that eventually became twin girls Lulu and Nana. He claims that he chose the HIV virus, the infection that can lead to AIDS, because the disease is a growing problem in China. “There are many effective ways to prevent HIV in healthy individuals … In many other places in the world, this would be illegal punishable by imprisonment.”

Scientist He said he used a tool called CRISPR-cas9 to delete a gene called CCR5 that acts as a “doorway” to allow the HIV virus to enter a cell, according to the AP. All of the men in the project had HIV and all of the women did not, but the gene editing was not aimed at preventing the small risk of transmission, Mr He said. He, a professor at Southern University of Science and Technology in Shenzhen, claims that his lab had been editing embryos’ genetic codes for seven couples undergoing in-vitro fertilization (IVF). He's team used CRISPR to edit 16 embryos, and implanted 11 edited embryos into the wombs of women to attempt to create a viable pregnancy before the twin pregnancy was achieved, according to the Associated Press, which first reported He's claims. The twins He said were born after he genetically engineered them as embryos are being referred to as “Lulu” and “Nana.” It appears that one twin had both copies of the CCR5 gene edited while the other twin only had one copy edited, He said. Several scientists reviewed materials that Dr He provided to the AP and said tests so far are insufficient to say the editing worked or to rule out harm. "If this was done to avoid HIV infection, there are alternative ways to prevent infection that are already effective," Doudna says, such as "washing" the sperm of infected men to eliminate HIV. In his YouTube video, He describes the procedure as having “removed the doorway through which HIV enters.”

But the hospital named in He’s ethical approval documents, Shenzhen Harmonicare Women’s and Children’s Hospital, has denied involvement in the procedures.
A Chinese scientist claims to be the first person to edit the genome of a human baby, by targeting an immune-receptor which is used by HIV (CCR5). This has provoked denial from the hospital and international outcry.