Some prominent scientists in the US have called for a moratorium or ban on the genetic modification of children and future generations, after major developments in genetic engineering and synthetic biology, which, they say, could potentially have irreversible and monumental effects on humanity.

The Center for Genetics and Society (CGS), a key US-based organisation that encourages “responsible and effective” uses of biomedical technologies, issued a statement pushing for the moratorium on Monday.

The release of the statement, endorsed by more than 150 advocates and scholars, came a day before the US National Academies of Sciences and Medicine holds the International Summit on Human Gene Editing in Washington DC.

On Monday, the CGS also published a report in collaboration with Friends of the Earth, an international environmental group, on the potential dangers of technology that could alter the DNA of humans and animals, and modify entire ecosystems.

Some scientists advocate for the use of genetic modification as a way of preventing a range of diseases, but they have been met with stiff opposition from many of their peers.

Pete Shanks, a CGS consulting researcher and author on human genetic engineering, said: “Genetic modification of children was recently the stuff of science fiction…But now, with new technology, the fantasy could become reality. Once the process begins, there will be no going back. This is a line we must not cross.”

Earlier this year, researchers at Sun Yat-sen University in China reportedly used gene editing techniques to alter human embryos for the first time in history. Although the embryos were “non-viable”, it was an unprecedented development.

Marcy Darnovsky, the executive director for CGS, told Al Jazeera that although there may be some benefits from the use of the powerful new gene editing tools, they should not be used to create genetically-altered humans.

“Genetic modification has been exploding in the scientific scene,” she said.

“The Gene drive (practice of stimulating genes to alter entire populations of species) could for example be used to prevent mosquitos from spreading malaria, but could also affect the entire ecosystem,” she added, warning that the impact could be “irreversible”.

‘Designer babies’

Eric Landers, the founding director of the Broad Institute of MIT and Harvard, who has devoted his career to realising the promise of the human genome for medicine, said in an article published in July that the technology “raises a more troubling possibility: creating children carrying permanent, heritable changes to the human germline DNA”.

“The press has dubbed such brave new progeny ‘designer babies’ or ‘genetically modified humans’, he added.

Landers explained that the technology is not needed to prevent children from inheriting genetic diseases since conventional techniques are sufficient.

A group of biotech scientists also published a report in March saying although it could be used to tackle many human diseases, “genome editing in human embryos using current technologies could have unpredictable effects on future generations”.

“This makes it dangerous and ethically unacceptable,” the report concluded.

There are laws in scores of countries against the genetic modification of humans, but the US and China are among those without.