About Lulu and Nana: Twin Girls Born Healthy After Gene Surgery As Single Cell Embryos

Two Chinese girls, who we ll call Lulu and Nana to protect their privacy, were born healthy a few weeks ago. Their mother Grace started her pregnancy by regular IVF with one difference: right after sending her husband s sperm into her eggs, an embryologist also sent in CRISPR, Cas9 protein and instructions to perform a gene surgery intended to protect the girls from future HIV infection. The surgery reproduces a natural genetic variation shared by more than 100 million people of primarily European origin tha