Lulu and Nana: Designer Babies
In a breakthrough experiment, He Jiankui edited an embryo by disabling a gene linked to HIV. This embryo was implanted in the mother’s uterus and led to twins, Lulu and Nana. Studying their genomes, He identified that the only changed gene is the one regarding HIV infections.
The father had HIV and He offered his gene-editing capabilities to ensure that his children don’t inherit it. This experiment seemed to be more of a proof-of-concept than an altruistic endeavor. It was meant to demonstrate the technology and its capabilities. HIV isn’t particularly heritable and there are several post-natal treatments. So, modifying the genes offers a way to prune out genetic illnesses.
Given the lack of robustness of embryonic gene editing and the fact that you have to wait for the birth of the child to exactly verify your findings, there is a risk and ethical push-back in conducting the experiment on a larger scale.
The results are impressive but flawed. The edits to the gene were displayed differently in different cells. Some parts of the twins’ bodies contain the edits and some have no edits at all. He only managed to edit half of Lulu’s CCR5 genes (corresponding to HIV infections), and others were completely normal. So, she still has some genetic predisposition for HIV though the odds of contracting it are reduced because of the editing.
There is also a possibility of off-target edits. He’s experiment aimed to delete a small section of CCR5 to mimic a naturally occurring mutation, delta 32. However, Lulu ended up developing a different mutation and Nana ended up with two mutations. He’s edits were roughly in the same area as where delta 32 would develop but he was presumptuous in asserting that changing the same region would lead to the same outcome. It is difficult to determine exactly the consequences of gene editing.
Similar research is being done by Denis Rebrikov in Moscow. He has worked on an in vitro experiment to repair a gene that causes deafness, GJB2, using CRISPR, a gene editing technology. He was approached by a deaf couple worried about the hereditary nature of hearing impairments.
As gene editing technologies evolve, so, will their consumer demand. Increased safety, precision, and economic demand will help address ethical concerns. I look forward to larger scale studies on customizing children preconception. Combatting genetic illnesses is just the starting point.