The team from the Guangzhou Medical University published the study in the Journal of Assisted Reproduction and Genetics. The aim was to use a system called CRISPR/Cas to introduce precise genetic modifications in early human embryos that would make them resistant to the Human Immunodeficiency Virus (HIV). The CRISPR gene editing tool has been used on 213 fertilized human eggs taken from 87 subjects, to mutate the CCR5 gene that mediates HIV immunity. However, the Chinese team was only able to modify four embryos in total, and with mixed results. Some of the cells did, in fact, acquire unplanned mutations, showing that the CRISPR system still requires further perfecting before it could be considered viable for this purpose.
A different team of Chinese scientists already edited human genes exactly one year ago, in April 2015. That time, the research team tried to defend their work explaining they used embryos which were unsuitable for life. The human cells obtained from fertility clinics were all affected by thalassemia, a severe blood disorder that would have fatal consequences if the scientists did not remove it from their genetic code. Nonetheless, the CRISPR technique has the potential of doing more than just removing dangerous health conditions. It could be, in fact, employed to enhance secondary traits such as physical appearance and intelligence, coming dangerously close to the dreaded ethical line nobody has ever tried to cross.
A team of leading biologists has already called for a worldwide ban on the use of human DNA-editing techniques. Many do in fact fear that this technology could be used to achieve eugenic purposes. The use of the CRISPR system has been recently approved even by UK regulators to find and remove faulty genes that hamper healthy embryonic growth. To address some of the ethical issues, the Chinese research team destroyed all the embryos after the experiment was done. In their study conclusion, they also advocated to prevent the “application of genome editing on the human germline until after a rigorous and thorough evaluation and discussion are undertaken by the global research and ethics communities.“
