Imagine a world where genes that cause serious, debilitating diseases could be deleted from your genome just as easily as you delete a typo using Microsoft Word. With the invention of clustered regularly interspaced short palindromic repeats (CRISPR), scientists could soon remove and replace defunct genes in somatic cells. This may be a reality sooner than people think: a team of Chinese scientists recently used CRISPR to introduce HIV-resistant genes into non-viable human embryos. One would assume these experiments with CRISPR represent a good thing-- after all, if an individual lives a healthy life devoid of debilitating genetic illnesses, everyone benefits! But opponents worry that using CRISPR technology could lead to the revival of modern day eugenics or wreak unintended havoc on the individuals with the modified genes. Some scientists claim the uncertainties of CRISPR are powerful enough that we should stop all research into this technology. I disagree.
The strongest argument against CRISPR research involves the permanence of the changes CRISPR makes to the genome. Any modifications made to the human genome will be passed along to every subsequent generation in a process known as 'crossing the germ line.' In over 40 countries--including most of continental Europe--human germ line modification has been declared illegal. In the US, no outright ban exists on such technologies, but the American scientific community hesitates to tackle the jungle of regulations around CRISPR research. This patchwork of various state and federal laws meld with national and international regulations to hinder American exploration of human somatic cell engineering.
The genome itself represents the largest area of uncertainty: scientists currently do not have a deep understanding of which genes influence what traits. Scientists may believe they have removed a gene for a severe genetic disease, when they may actually have removed one piece of a larger network that causes the trait and will have no effect on it. Or because genes work together to influence normal traits, removing one "bad" gene may set off a chain reaction that negatively affects the individual. Sickle cell anemia has been put forth as one example. While this condition causes a range of health deficiencies, sickle cell anemia also protects its host from malaria. Would removing sickle cell anemia from the population cause more harm than good? We simply don't know.
Scientists also worry that if such modifications become commonplace, we set ourselves up for increased genetic weaknesses as we stamp out the diversity within our species. Just as genetically modified corn can be wiped out by a single blight, genetically modified humans might be destroyed by a similar disaster. However, the negatives pale in comparison to the potential benefits of CRISPR, which stretch as far as the human imagination. Couples with genetic abnormalities could have could create healthy offspring without fear of passing on debilitating or fatal genetic illnesses. Children would be spared preventable pain and suffering. And society would avoid the costs of caring for children whose diseases never materialized. In addition, CRISPR could create genetically modified foods that resist global warming and other biological diseases, or further research into cancer and other human illnesses. If we can use CRISPR for so much good, we must explore its practical uses before we ban it. Once we have more information, perhaps in a decade or two, scientists and the public can make a more permanent decision about its inherent benefits or burdens. But until then, banning research on CRISPR is shortsighted.