HOW TO THINK ABOUT IT
Nuts and bolts. CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeats, or chunks of recurring DNA that defend against viruses. But normally the term CRISPR refers to CRISPR-Cas9. Cas9 is a protein that slices through the DNA, and when that protein is injected into a cell it can snip out specific genes to disable them. Many in the medical community hope this can offer a workable way to fight against gene-based disorders like sickle cell anemia and cystic fibrosis. But editing genes can have unintended consequences — not just for the edited embryo, but also for their descendants, if the edited gene is passed on.
Global game. New experiments — and successes — involving genetic manipulation of human embryos have been happening around the world. The “three-parent” technique, which mixes DNA from three individuals to prevent deadly mutations being passed on, was legalized in the U.K. and first performed in 2016 by American scientists in Mexico. Since then a clinic in Ukraine has duplicated the feat. Meanwhile, Korean and Singaporean officials have granted CRISPR patents, German pharmaceutical companies like Bayer have invested hundreds of millions in potential CRISPR treatments and the French government has launched a project to share research on the technology. Outside of China, though, the technology hasn’t resulted in any live births. Meanwhile, other scientific issues requiring a global regulatory framework, like dealing with pandemics, offer few lessons for creating and enforcing regulations.
Ethical considerations. There’s been near-universal condemnation of gene-editing human embryos outside the scrutiny of regulatory bodies. When news broke about He’s work, more than 100 scientists signed a petition calling for greater oversight. China reiterated that gene-editing of human embryos for reproductive purposes is banned in the country. But some scientists are advancing CRISPR research in what may be more morally palatable ways, like editing adult genes to help alleviate disease. Patients with Hunter syndrome have shown promise after undergoing gene-editing treatment, which allows their livers to produce an enzyme curbed by the disease. Others hope CRISPR will be a valuable weapon in the fight against heritable conditions like diabetes, muscular dystrophy and Huntington’s.
Plants and animals. A great deal of research is going into using CRISPR in ways that don’t have to do with humans. Across the globe, companies are developing uses for CRISPR in agriculture, with edited corn DNA and trimmed animal embryos that they hope will breed healthier livestock. Scientists at the Institute for Sustainable Agriculture in Spain recently used CRISPR to edit wheat to make it safe for people with celiac disease, and last year scientists created a strain of algae using CRISPR technology that produced twice the normal amount of lipid, which can be used as biofuel. Meanwhile, the Bill & Melinda Gates Foundation has backed seven years of research in hopes of eradicating malaria by editing the genome of mosquitoes.