Experts urge moratorium as Chinese researchers ‘edit’ human embryos

MIAMI, April 24

Global scientists renewed calls to halt controversial research to genetically edit human embryos after a Chinese team published details of a breakthrough attempt in this new frontier in science.
First reported by Nature News on Wednesday, the paper by Junjiu Huang, a gene-function researcher at Sun Yat-sen University in Guangzhou, and colleagues appear in an online journal called Protein and Cell.
In the paper, researchers describe how they changed the genomes of embryos obtained from a fertility clinic. The embryos could not have resulted in a live birth because they had an extra set of chromosomes after being fertilised by two sperms.
Researchers "attempted to modify the gene responsible for beta-thalassemia, a potentially fatal blood disorder, using a gene-editing technique known as CRISPR/Cas9," said the report in Nature News.
The researchers injected 86 embryos and waited 48 hours for the molecules that replace the missing DNA to act. Seventy-one embryos survived and 54 of those were tested. Researchers found that of those only 28 were "successfully spliced and that only a fraction of those contained the replacement genetic material." "If you want to do it in normal embryos, you need to be close to 100%," Huang said, adding: "That's why we stopped. We still think it's too immature." — AFP