Scientists believe that the "CRISPR twins," who had their genes edited last year before birth, will now have an easier time learning and memorizing. Apparently, the gene alteration, which was meant to make the girls immune to HIV, also altered their brains.

According to Technology Review:

Now, new research shows that the same alteration introduced into the girls' DNA, to a gene called CCR5, not only makes mice smarter but also improves human brain recovery after stroke, and could be linked to greater success in school.

"The answer is likely yes, it did affect their brains," says Alcino J. Silva, a neurobiologist at the University of California, Los Angeles, whose lab has been uncovering a major new role for the CCR5 gene in memory and the brain's ability to form new connections.

"The simplest interpretation is that those mutations will probably have an impact on cognitive function in the twins," says Silva. He says the exact effect on the girls' cognition is impossible to predict, and "that is why it should not be done."