Chinese Scientists create First Genetically Modified human Embryos

Chinese scientists have admitted to genetically modifying human embryos, sparking an ethical debate about the dangers of "designer babies."

While scientists often experiment with human adult cells and animal embryos, it's the first time a team has openly discussed working with human embryos.

Sun Yat-Sen University researchers said they tried to eradicate the genes for a blood disorder called Beta Thalassemia in embryos that would have otherwise been discarded, according to their Protein & Cell journal article, published Saturday.

Using 86 embryos with extra sets of chromosomes that had been created for in vitro fertilization, the scientists in Guangzhou cut into DNA and either replaced or rewrote problematic genetic sequences.

As the embryos developed over two stages — they could not go to full term — only a portion did not have unintended genetic mutations.

"If you want to do it in normal embryos, you need to be close to 100%," researcher Junjiu Huang told Nature. "That's why we stopped. We still think (the technology) is too immature."

The human embryos developed more mutations than genetically modified animal ones or adult cells do, Huang said, noting "it would be impossible to predict genetic outcomes" using his team's method, called the CRISPR/Cas9 system.

Two journals rejected his team's article because of the ethical implications, Huang said.

George Daley, a stem-cell biologist at Harvard Medical School, told Nature the "landmark" study is also a "cautionary tale."

"Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes."

Scientists are concerned about genetic problems that could arise from altering DNA, especially because those defects could be passed on.

"Genome alterations are permanent and heritable, so very, very careful consideration needs to be taken in advance of such applications," geneticist Dana Carroll told a January science conference.

The paper also does not detail the ethics behind the experiment, nor is there a standard practice for working with human embryos, NYU School of Medicine bioethicist Arthur L. Caplan told Io9.

"There’s enough controversy in the world about the use of human embryos for any reasons, much less (eradicating disease),” Caplan said.

Some scientists worry that creating "designer babies" could create societal problems, similar to those in the 1997 sci-fi movie "Gattaca," in which parents choose the genetic characteristics of their children. In the Ethan Hawke and Uma Thurman film, a hierarchy forms based on genetic superiority.