The experiment was just an exercise in science - the embryos were not allowed to develop for more than a few days and were never meant to be implanted into a womb, according to MIT Technology Review, which first reported the news.
Scientists have even questioned the ethics of genetically editing human embryos, saying that gene-editing technology could be used to create designer babies with enhanced traits, such as higher intelligence or greater beauty.
Results of the peer-reviewed study are expected to be published soon in a scientific journal, according to OHSU spokesman Eric Robinson.
The earlier Chinese publications, although limited in scope, found CRISPR caused editing errors and that the desired DNA changes were taken up not by all the cells of an embryo, only some. It involves using molecular "scissors" to remove undesirable elements of gene sequencing and replace them with new DNA elements.
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 can not reveal any information about the research.
By altering the DNA code of human embryos, Technology Review explained, scientists hope to eradicate or correct genes that cause hereditary conditions, such as blood disease beta-thalassemia.
Last year, Britain said some of its scientists could edit embryo genes to better understand human development.
In December 2015, ethicists and scientists convened at the National Academy of Sciences (NAS) in Washington, and discussed how it is "irresponsible" to use gene editing in human embryos to correct genetic diseases, until such time that safety and effectivity can be fully established.
"It is proof of principle that it can work", the researcher said. It is thought to be the first such work in the USA; previous experiments like this have been reported from China. They significantly reduced mosaicism.
The news follows a report earlier this year by the National Academy of Sciences and the National Academy of Medicine, which essentially gave a green light to researchers to use gene editing to treat or prevent inherited disease. With gene editing, these so-called "germline" changes are permanent and would be passed down to any offspring. It's unclear what illnesses were involved exactly, but they used sperm donated by subjects with various inheritable diseases.