Some bacteria have an enzyme that can cut the DNA of invading viruses as a defense mechanism. Scientists realized they could use this enzyme to edit human DNA.
Programs to screen the genomes of healthy adults to identify genes that may put them at risk for disease later in life need to be implemented with care so that they do not do more harm than good, says an expert panel.
CRISPR was used to introduce mutations into cells that see what effects these mutations have on the cell.
Preimplantation genetic testing is widely used to increase the chance of having a healthy baby. Whether it should be performed at all, however, is hotly debated.