For as long as genetic engineering has been possible there has been debate over its potential misuse. In the 1970s, cloning was the hot topic. Bring it forward to 2015, the warnings sound much the same, but now they concern the risks of genetically modified humans.
In 2012, scientists at UC Berkley developed revolutionary genome editing technology known as CRISPR/Cas9. In this method, the protein Cas9 searches through cells genetic material until it finds the sequence that matches its guide RNA (a programmable sequence complementary to DNA). From here Cas9 can open the DNA helix, cut each strand and insert new genetic information. In other words, Cas9 has provided an incredibly fast and easy way to modify genes.
Since its discovery, Cas9 has only been used to alter sequences in animals and cultured tissues generated from stem cells - to test new therapies and identify drug targets for disease, for example. However, this technology could be applied to human germline cells (eggs and sperm) to remove and replace mutations that cause disease, potentially eradicating debilitating genetic disorders.
Nevertheless, there are a vast number of ethical and social implications germline modification could have; from not knowing what impact editing even a single gene could have on development to classic fears surrounding ‘designer babies’ and eugenics.
Last month, a group of prominent scientists and ethicists (including the co-inventor of the technology in question) published a commentary piece in Science discouraging clinical application until there has been more discussion whilst other scientists (Lanphier et al, Nature) and the International Society for Stem Cell Research have called for a voluntary moratorium. Where all are in agreement is that a dialogue is desperately needed before the controversial technology is taken any further.
However, with rumours of soon to be published papers regarding the production of genetically modified embryos, there are some that believe this concern is coming too late.