U.S. Researchers Advance Gene-Editing in Embryos, But Challenges Remain
A team of researchers in the United States has made significant progress in the field of gene-editing by using an improved form of CRISPR technology, known as base editing, to modify human embryos. This technique allows for precise changes to be made to DNA with a reduced risk of unwanted mutations. The study, conducted by Dieter Egli and his colleagues at Columbia University, involved editing healthy two-cell embryos donated by parents. The results showed that one of the targeted genetic changes was successfully made in three-quarters of the cells without any unintended alterations. However, the other change was only successful in about half of the cells and often resulted in unwanted changes. Despite these advancements, the issue of mosaicism, where not all cells in an embryo are edited uniformly, remains a significant hurdle. This problem poses a risk that a child born from such an embryo might still develop the disease the editing was intended to prevent. 
