The scientific world erupted with outrage and concern Monday after a Chinese scientist claimed he used gene-editing to alter the DNA of a pair of twins who were born recently.

The scientist, He Jiankui of Southern University of Science and Technology in Shenzhen, China, said he used a DNA-editing tool called CRISPR to alter the genes of the twin girls to make them resistant to infection by the AIDS virus HIV. He plans to present more details later this week at a scientific meeting in Hong Kong.

Fertility researchers around the world were quick to denounce both the way He announced his work — with a YouTube video and in an interview with the Associated Press — and the work itself.

Scientists usually present their work in journals, which vet their data and methods and usually also invite other experts in the field to check for errors before it's published.

The idea of permanently altering a baby's DNA so that their own children also carry the change is controversial, if not abhorrent, to much of the world. But some experts also say the furor surrounding the case shows it may be time to legalize such work and create a regulatory framework to ensure it is done safely and ethically.

China’s Southern University said it did not support the experiment. "The research work was carried out outside the school by Associate Professor He Jiankui. He did not report to the school and the department of biology, and the school and the biology department did not know about it," it said in a statement.

The university said it was investigating. Likewise, Rice University in Houston distanced itself from Michael Deem, a bioengineering professor there who said he collaborated with He on the project. “This research raises troubling scientific, legal and ethical questions,” the university said in a statement.

“Rice had no knowledge of this work. To Rice’s knowledge, none of the clinical work was performed in the United States. Regardless of where it was conducted, this work as described in press reports, violates scientific conduct guidelines and is inconsistent with ethical norms of the scientific community and Rice University. We have begun a full investigation of Dr. Deem’s involvement in this research,” it added.

“If true, this experiment is monstrous."

Other experts pointed out that the work was evidently done on healthy human embryos, and not to correct any genetic diseases. They said there is a difference between experimenting to save a life, and experimenting on babies out of scientific curiosity.

“If true, this experiment is monstrous,” said Julian Savulescu, an expert on bioethics at Britain’s Oxford University. “Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer. There are many effective ways to prevent HIV in healthy individuals: for example, protected sex. And there are effective treatments if one does contract it.”

Dr. Robert Winston, a fertility expert at Imperial College London, said the experiment amounted to scientific misconduct.

“It should be condemned,” he said in a statement.

Experts worry that permanently altering the germline — the genes that are passed on to children — can cause unanticipated problems for future generations.

Several European countries ban germline gene editing, while allowing gene therapy to treat disease in a patient without altering DNA likely to be passed along to offspring. The U.S. has a complex system that strongly discourages germline gene-editing in people. Congress has expressly forbidden the Food and Drug Administration to approve germline gene editing treatments involving people and that has had the effect of discouraging the work.

Scientists including MIT's Feng Zhang and Jennifer Doudna of the University of California Berkeley, who developed the CRISPR-cas9 gene editing technique, have called for a moratorium on its use in treating real human patients.

"The work as described to date reinforces the urgent need to confine the use of gene editing in human embryos to cases where a clear unmet medical need exists, and where no other medical approach is a viable option, as recommended by the National Academy of Sciences," Doudna said in a statement.

But several groups said the case showed that such experiments should be encouraged while being strictly regulated.

"We would like to see research in this area be allowed to continue with vigorous oversight," Sean Tipton of the American Society for Reproductive Medicine told NBC News.

“It has potential to eliminate known genetic diseases ... so people could have healthier children," he added. "Our view is that you have got to let the best American scientists pursue this work with the rigorous research oversight system that we have."

The International Society for Stem Cell Research also supports experiments, but not using gene-editing to make live human babies.

“The ISSCR supports laboratory-based research that involves editing of the nuclear genomes of human sperm, eggs, or embryos, but that is only when it is performed under rigorous review and oversight, as suggested in our international guidelines,” ISSCR president Doug Melton, of the Harvard Stem Cell Institute, said in a statement. “We do not support any clinical application of human germline or embryo editing at this time,” he added.

The U.S. National Academies of Sciences, Engineering and Medicine has said gene editing should be acceptable if overseen properly. Organizers of the Hong Kong meeting said it was not yet clear if He’s work met the recommendations.

"We hope that the dialogue at our summit further advances the world's understanding of the issues surrounding human genome editing. Our goal is to help ensure that human genome editing research be pursued responsibly, for the benefit of all society," the National Academies said in a statement.