A little more than a decade after scientists first unraveled the human genome, some researchers are trying to rewrite it. Advances in gene-editing technology have provided relatively inexpensive and easy ways to delete, insert, or replace genes in human cells to correct defects associated with devastating diseases such as cystic fibrosis and sickle cell anemia. Gene-editing tools could also be used to alter plant and animal genomes to boost agricultural yields and food production or to modify insect genomes to reduce the spread of diseases such as malaria.
Not only are gene-editing tools scientifically promising, they also have the potential to be highly lucrative commercially. But with that promise comes worries that gene-editing technology could be used to create designer babies with enhanced traits, such as higher intelligence or greater beauty. Many scientists are also worried that the technology could change the human germ line—the DNA in reproductive cells that is passed on from one generation to the next—in unexpected or dangerous ways.
The ethical implications and risks of human gene editing came to a head in April....