Scientists have genetically engineered human embryos for the first time in the United States, according to a report in the MIT Technology Review.
The effort, led by Shoukhrat Mitalipov of Oregon Health and Science University, involved changing the DNA of a large number of one-cell embryos with the gene-editing technique CRISPR, the report which was released Wednesday said.
Ma Hong, a staff scientist at Mitalipov's lab, told Xinhua on Thursday that their paper is about to be published and that, for the moment, she cannot reveal any information about the research.
"Although none of the embryos were allowed to develop for more than a few days -- and there was never any intention of implanting them into a womb -- the experiments are a milestone on what may prove to be an inevitable journey toward the birth of the first genetically modified humans," said the report in the MIT Technology Review, a magazine published by the Massachusetts Institute of Technology.
"To date, three previous reports of editing human embryos were all published by scientists in China," it said.
Scientists like Mitalipov believe they can eradicate or correct genes that cause inherited disease and even cancer by altering the DNA of human embryos.
Critics, however, said that it could open the door to the world of "designer babies," where people choose the traits they want in a child.
According to the report, the earlier Chinese publications have found CRISPR caused editing errors that lent weight to arguments that the technique "would be an unsafe way to create a person."
Currently, any effort to turn an edited human embryo into a baby in the United States is banned by Congress.
But in February, a report from the U.S. National Academy of Sciences and the U.S. National Academy of Medicine said that clinical trials for gene editing of human reproductive cells "could be permitted in the future, but only for serious conditions under stringent oversight."
Frances Flinter, professor of clinical genetics at Guy's and St. Thomas' NHS Foundation Trust in Britain, who was not involved in the study, said it's impossible to comment on a reported scientific development that has not been peer-reviewed and published in a reputable scientific journal.
"While it might be tempting to consider a technology that potentially offers the prospect of curing serious genetic diseases at such an early stage of development, there are major risks, both of technical failure and unanticipated adverse consequences, which could affect generations to come," Flinter said.
"Couples who wish to avoid passing on serious inherited conditions may consider well established alternatives, such as prenatal diagnosis and pre-implantation genetic diagnosis," he added.