Problems with CRISPR: Unintended Brain Enhancement on China’s Gene-edited Twins


Profiled article

A. Regalado, “China’s CRISPR twins might have had their brains inadvertently enhanced”, Feb. 21, 2019. [Online] MIT Technology Review. Available at: [Accessed 24 Feb. 2019].

About the article author

Antonio Regalado is the senior editor for biomedicine for MIT Technology Review. He specializes in stories about how technology is changing medicine and biomedical research.


Three months ago, the world discovered that a team of Chinese scientists, led by He Jiankui of the Southern University of Science and Technology in Shenzhen, used CRISPR technology on a number of Chinese babies. So far two baby girls, Lulu and Nana, have been born. Through the deletion of the gene CCR5, He hoped to make the babies immune to the HIV virus their mother carried. New research shows that people without at least one copy of the CCR5 gene recover more quickly from strokes and have higher intelligence. How exactly the lack of this gene could impact the cognitive function of these babies is impossible to predict.


The actions of He’s team exhibit one of the most blatant ethical breaches in science in recent history. Since the dawn of CRISPR technology, scientists have hypothesized on the pitfalls of experimenting with humans. With the birth of Lulu and Nana, all these hypotheses have come to light as real questions that must be answered. There is so much that scientists do not understand about how genes affect how a human develops. Inadvertent brain enhancement is just the tip of the iceberg.

Even more devastating is the realization that some U.S. scientists knew the experiment was taking place, and even offered guidance when asked.

What should happen to Lulu and Nana? (and the other babies on the way?)
How should CRISPR research be performed in the future?
Is it fair for He to be demonized when numerous US scientists were aware of the research taking place?

Related Links

Timeline on the Chinese CRISPR babies

Initial discovery

Video in which He presents the twins

International outcry over He’s actions

Investigation on US scientists who appear to have supported He

He defends his experiment and admits he acted without informing his university

Chinese authorities order He to suspend his research

Three Stanford University faculty members were aware of the gene-edited babies

American Nobel Prize Winner Craig Mello also knew of the gene-edited babies