**Chinese scientists have successfully manipulated human embryos to repair defective genes, in a world-first breakthrough that could lead to new treatments for genetic diseases.**.
The team, led by researchers from the Guangzhou Institutes of Biomedicine and Health, used a gene-editing technique called CRISPR-Cas9 to correct a genetic defect that causes a rare blood disorder called β-thalassemia..
The study, published in the journal Nature, is the first to show that CRISPR-Cas9 can be used to repair genetic defects in human embryos. The findings could pave the way for new treatments for a wide range of genetic diseases, including cystic fibrosis, sickle cell anemia, and Huntington’s disease..
**CRISPR-Cas9 is a powerful gene-editing tool that allows scientists to make precise changes to DNA.** It is based on a system that bacteria use to defend themselves against viruses. When a virus infects a bacterium, the bacterium uses CRISPR-Cas9 to cut up the virus’s DNA..
Scientists have adapted CRISPR-Cas9 so that it can be used to cut and paste DNA in human cells. This allows them to correct genetic defects or insert new genes into cells..
**In the new study, the Chinese scientists used CRISPR-Cas9 to correct a genetic defect in human embryos that causes β-thalassemia.** β-thalassemia is a blood disorder that is caused by a mutation in the β-globin gene. This mutation prevents the body from producing enough β-globin, which is a protein that is essential for the production of red blood cells..
The scientists used CRISPR-Cas9 to cut out the mutated β-globin gene and replace it with a healthy copy of the gene. They then implanted the edited embryos into mice, where they developed into healthy mice that did not have β-thalassemia..
**The study is a significant breakthrough in the field of gene editing.** It shows that CRISPR-Cas9 can be used to repair genetic defects in human embryos, which could lead to new treatments for a wide range of genetic diseases..
**However, the study also raises ethical concerns.** Some scientists worry that gene editing could be used to create .
