CRISPR twins’ brains may have been unintentionally ‘enhanced’

22 Feb 2019

Image: © jalisko/

The fallout from the birth of a set of twins using CRISPR continues as research suggests their brains may have superior cognition and memory abilities.

The Chinese twins named Lulu and Nana have caught the attention of much of the scientific community following researcher He Jiankui’s decision to go rogue and modify their genes prior to birth to make them immune to HIV.

Since He announced the births last year, the scientist has become persona non grata both among his peers worldwide and the Chinese government, even more so now given that a second woman has been confirmed as pregnant with her own CRISPR child.

Now, according to MIT Technology Review, the deletion of the gene CCR5 in the twins using CRISPR has likely had another consequence, that being the potential for enhanced cognition and memory. New research published to Cell revealed that the removal of this gene in mice made them ‘smarter’, while also improving human brain recovery after a stroke.

“The answer is likely yes, it did affect their brains,” said Alcino J Silva, a neurobiologist at the University of California, Los Angeles (UCLA) involved in this latest research. “The simplest interpretation is that those mutations will probably have an impact on cognitive function in the twins.”

However, he added that it is impossible to know how their brains will develop in the years to come and “that is why it should not be done”.

Silva said that before the news of the twins’ birth became public knowledge in November 2018, he had occasional interactions with figures in Silicon Valley who expressed a serious, unhealthy interest in the creation of designer babies with enhanced cognitive function. Following the news, Silva feared He may have set out to achieve this.

“I suddenly realised, oh, holy shit, they are really serious about this bullshit. My reaction was visceral repulsion and sadness,” he said.

As for the recent study, the research led by UCLA’s S Thomas Carmichael showed that those who lack the CCR5 gene recover quicker from strokes, and that those missing at least one copy of the gene more often than not progress further in school.

While describing the results as “tantalising”, Carmichael said that further study is needed to confirm the beneficial features.

Colm Gorey was a senior journalist with Silicon Republic