Gene editing used in wide range of research

WASHINGTON Gene editing is getting fresh attention thanks to a successful lab experiment with human embryos. But for all the angst over possibly altering reproduction years from now, this technology already is used by scientists every day in fields ranging from agriculture to drug development. A look at the science. _____ WHAT IS GENE EDITING While scientists have long been able to find defective genes, fixing them has been so cumbersome that it’s slowed development of genetic therapies. There are several gene editing methods, but a tool called CRISPR-Cas9 has sparked a boom in research as laboratories worldwide adopted it over the past five years because it’s faster, cheaper, simple to use with minimal training and allows manipulation of multiple genes at the same time. _____ HOW IT WORKS Pieces of RNA are engineered to be a guide that homes in on the targeted stretch of genetic material. The Cas9 is an enzyme that acts like molecular scissors to snip that spot. That allows scientists to delete, repair, or replace a particular gene. _____ MEDICAL RESEARCH The fresh attention comes from research involving human embryos. In laboratory experiments, a team lead by Oregon researchers used CRISPR to successfully repair a heart-damaging gene in human embryos, marking a step toward one day being able to prevent inherited diseases from being passed on to the next generation. But there’s wide agreement that more research is needed before ever testing the technique in pregnancy. __ THE BIGGEST HURDLE Safety is a key question because gene editing isn’t always precise enough; there’s the possibility of accidentally cutting DNA that's similar to the real target. Researchers have improved precision in recent years, but outof-body treatments like using cells as drugs get around the fear of fixing one problem only to spark another. ____ THE ETHICS CONTROVERSY Altering genes in sperm, eggs or embryos can spread those changes to future generations, so-called “germline” engineering. But it’s ethically charged because future generations couldn’t consent, any long-term negative effects might not become apparent for years, and there’s concern about babies designed with enhanced traits rather than to prevent disease. _____ IS THAT LEGAL? Where you live determines if, or what kind of, research can be performed on human embryos. Some countries, especially in Europe, ban germline research. Britain allows basic lab research only.

In the U.S., scientists can perform laboratory embryo research only with private funding, as the Oregon team did.