Genome editing, also called gene editing, is a group of technologies that give scientists the ability to change an organism’s DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome. Ever since scientists realized that changes in DNA cause cancer, they have been searching for an easy way to correct those changes by manipulating DNA.
Several methods of gene editing have been developed over the years, but none offered quick, easy, and cheap gene editing. In 2013, researchers showed that a gene editing tool called CRISPR could alter the DNA of human cells like a very precise and easy to use pair of scissors. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a technology that research scientists use to selectively modify the DNA of living organisms.
The gene editing tool CRISPR/Cas9 has revolutionized biomedical research. It edits genes by precisely cutting DNA and then letting natural DNA repair processes take over. The system consists of the Cas9 enzyme and a guide RNA. The discovery of the CRISPR-Cas microbial adaptive immune system and its ongoing development into a genome editing tool represents the work of many scientists from around the world, dating back to 1993.
CRISPR is now moving out of lab dishes and into trials of people with cancer. It is completely customizable and can edit virtually any segment of DNA within the three billion letters of the human genome. With all of its advantages over other gene editing tools, CRISPR has become a go-to for scientists studying cancer. It allows researchers to alter and repair genes in virtually every living thing, including humans, plants, and animals. CRISPR has had great success fighting genetic afflictions like sickle cell disease and could be a helpful ally in the fight against climate change.
However, CRISPR sometimes cuts DNA outside of the target gene, or what’s known as ‘off target’ editing. Some scientists are worried that such unintended edits could be harmful and turn cells cancerous. Genetic manipulation also raises serious ethical questions. It paves the way to profoundly alter humans, other species or even ecosystems. The challenge, many scientists agree, is using this technology properly.
Genetic modification to human embryos and reproductive cells such as eggs and sperms are called germline editing. These types of changes can be passed to the next generation, and that raises serious ethical questions in terms of creating ‘designer babies’ with enhanced physical traits and characteristics. Many countries have an outright ban on germline editing. The United States is ‘testing the waters’ by considering exemptions in cases of hereditary disorders such as muscular dystrophy, cystic fibrosis and Huntington’s disease.
Currently, genome editing is being used in cells and animal models in research labs to understand diseases. It is being explored in research and clinical trials for a wide variety of diseases, including single-gene disorders such as cystic fibrosis, hemophilia, and sickle cell disease. The possibility exists that CRISPR could be used for the treatment and prevention of more complex diseases, such as diabetes, cancer, heart disease, mental illness, and HIV.
This technology is extremely accessible, both technically and intellectually, and while that is helpful it also creates the potential for danger. Amateur scientists or activists called biohackers can experiment with biotechnology outside of conventional institutions and laboratories. CRISPR technology creates the kind of scientific breakthrough that could change human evolution, even creating a world where parents could choose their child’s eye color. CRISPR technology has been mentioned in potentially creating ‘super soldiers’ in China. If this is possible, then there may be no limits to what CRISPR technology could lead to if it is not fiercely regulated and controlled.
Going forward, the immediate question is who governs the limits of genetic science? Stringent regulations and guidelines as well as worldwide debate and awareness are required to ensure responsible and wise use of CRISPR mediated genome editing technology. There is a need for an extensive dialogue among scientists, ethicists, industrialists and policy makers on the societal implications involved.