Synthetic Biology Ethics
Palmer Fliss shares his ethics & society case study, which he completed as part of our Young Scientist Program.
When one hears the phrase “synthetic biology”, images of clone soldiers, designer babies, cyborgs, and GMOs spring to mind. With the cost of genetic sequencing dropping precipitously thanks to advances in the technology, coupled with the rise of increasingly specific genetic manipulation techniques, synthetic biology has developed from a field only touched upon in science fiction to a real scientific field filled with some of the brightest minds in current biotechnology research. As with all biological organisms on Earth, all of our genetic potential is coded into every cell in our body, a ‘gene’ will code for one function, while all of the genes that make up an individual referred to as its ‘genome’. Every aspect of who you are is encoded in your genome, from your height, to your hair color, to your predisposition for certain diseases. As our capability to understand and alter our genetic blueprints expands, the ethics of such tampering are under question. Recently, a technique utilizing the natural gene editing and repair capability of our cells called CRISPR (for Clustered Regularly Interspaced Short Palindromic Repeats) has vastly improved the ability of scientists to edit sections of genetic code in all biological organisms. At the outset, CRISPR editing was a technique that was utilized in microbial and rodent populations exclusively, and once the ease and efficiency of gene-specific editing was determined, some scientists began to think larger.
With the advent of this technology, one can imagine screening all babies born for specific genetic markers that can be correlated to disease later in life. For a fee, a doctor could utilize CRISPR editing to remove those genes that conferred disease, and splice in genes from healthy individuals with no sign of those diseases. As expected, the advent of this raised ethical concerns from many individuals. There is a steep divide in biology between the understanding of an organism at a gene-by-gene level and the role that those genes play within the entire human body system. It is possible to roughly correlate the presence of a gene within a genome to a function or lack thereof after it has been translated into its functional protein, but oftentimes the web of interaction within a biological system is far more complicated. In April, scientists in China announced in Nature that they had used the CRISPR technique to edit the genomes of non-viable human embryos, attempting to alter the gene responsible for a fatal blood disorder. Despite the demonstrated success of this technique in microbial and rodent populations, only 28 out of the 86 embryos that underwent this editing technique showed signs of successful editing, leading the authors of the study to halt their experiment until the CRISPR technique can be developed further. The researchers, led by Junjiu Huang, found a surprisingly large number of unintended mutations that occurred far away from the intended editing site, and Huang believes that these are only a small subset of the ‘off-target’ mutations that would be present throughout the genome.
It is for this reason that in early 2015, researchers and scientists from around the globe authored two papers in Nature and Science urging their peers to refrain from utilizing these genetic editing techniques to alter the human germline. In these publications, they cite the likelihood of unintentional, heritable defects in the human genome that could persist for generations, potentially outweighing any benefit that could come from individual therapeutic intent.
For now, the CRISPR gene editing system is the most specific technique that exists to remove and insert genetic material in living systems. There are many labs that are fine-tuning it, making it more specific, cheaper, and less likely to fail. It is likely that some time in the next decade, there will be increased opportunity for scientists that have ambitions to remove heritable disease from the human germline. It is difficult to say now if unintended mutations currently seen from CRISPR will be present in future iterations of genetic editing techniques, but at the moment, it appears that the therapeutic benefit that may be gained from specific editing is outweighed by the poorly understood and potentially harmful tangential mutations. These techniques with the capacity for real and potentially irreversible harm to the human germline require additional vetting and consideration by the academic research community and may require additional soul-searching by the human population we seek to alter.