In 2018, He Jiankui used then-novel CRISPR/Cas9 technology to genetically engineer a fetus for implantation into a donor mother. The aim of the genetic edit was to produce a mutation of the CCR5 gene allegedly conferring resistance against HIV-AIDS. The pregnancy led to the birth of two twin girls, known by the pseudonyms Lulu and Nana.
He and the experiment were the subject of near universal condemnation. He failed to recreate the intended CCR5 mutation, and instead produced an unprecedented CCR5 variant as well as other off-target mutations in Lulu and Nana's genome. The physiological effects of such mutations are unknown. The ordeal was also shrouded in numerous ethical violations, including ill-informed consent of the donor parents, financial fraud, and secrecy. In response, the World Health Organization (WHO) set up the Human Genome Editing (HGE) Registry to track scientific trials on human genome editing.
He was found guilty of fraud and scientific misconduct in 2019 and was sent to 3 years in prison; he was let out of prison in 2022. As of February 2023, He claims both girls are safe and normal.