The first genetically edited babies are reported to have been born in China with the help of He Jiankui, a Chinese researcher, at the Human Genome Editing Conference in Hong Kong. Although nothing has been published in scientific media yet, according to international media twin girls have been born that scientists claim have been genetically edited to be naturally resistant to HIV.
The process that was used is called Crispr-Cas9, a gene editing technique that was named Scientific Breakthrough of the Year 2015. It uses a protein called cas9, derived from the bacteria Streptococcus pyogenes, which acts like a molecular scalpel. The natural functions of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and CRISPR-associated (Cas) genes enable certain organisms, such as Streptococcus pyogenes, to respond to and remove invading genetic material.
In the laboratory we can attach a ribonucleic acid (RNA) sequence to the Cas9 protein that, for example, matches the gene sequence of a faulty or mutated gene that may cause a disease. When the Cas9-RNA combination is placed into the nucleus it will find the corresponding faulty gene sequence and attach to it. A chemical reaction then cuts the mutated strand, which can then be replaced with the correct sequence, allowing the cell to work properly. This technique, developed from a natural biological process, is a precise molecular tool that does have the potential to do great good in eliminating genetically based diseases. Following its initial demonstration in 2012, the CRISPR/Cas9 system has been widely adopted in research to target important genes in many cell lines and organisms, including the human.
Even though we are still awaiting scientific proof that these CRISPR/Cas9 edited babies exist, the possibility has raised many important questions about the use and control of this powerful genetic tool.
The father of these alleged children was HIV positive and the goal of the editing was to confer resistance to HIV by modifying the CCR5 gene (the protein doorway by which HIV enters human cells). What worries me is that the CCR5 gene that was reportedly disabled after Crispr-Cas9 treatment also plays an important role in resistance to disease and it is impossible to predict what effect this will have on the children as they grow up. Questions also are being asked about why the procedure was allegedly used for the CCR5 gene since it is not unusual for HIV positive patients to be treated with conventional IVF procedures quite safely without risk to the children.
The clinical use of the CRISPR/Cas9 technology is illegal in many countries and whether this report is true or not it has created deep concern around the world and even triggered an international summit in Washington to discuss the ethics of genetically engineering the human using Crispr-Cas9.
Are we ready for the consequences of genetically engineering our own evolution? Can individual scientists be allowed to decide the fate of the human genome? What are the potential risks with human genome editing?
One thing is for sure: the future of Crispr-Cas9 technology in the human is going to be very interesting to follow.