KUALA LUMPUR, Feb 23 — The controversial genetic modification of two twin girls born in China to make them immune to HIV may have inadvertently enhanced their brains.
MIT Technology Review reported new research has shown that the deletion of a gene called CCR5 — which was done to the twins Lulu and Nana by a Chinese scientific team using the CRISPR gene editing tool before they were born last year — made mice smarter, improved human brain recovery after stroke, and may be associated with greater success in school.
“The answer is likely yes, it did affect their brains,” University of California neurobiologist Alcino J. Silva was quoted saying.
His lab had reportedly uncovered a great new role for the CCR5 gene in memory and the brain’s ability to create new connections.
“The simplest interpretation is that those mutations will probably have an impact on cognitive function in the twins,” Silva was quoted saying.
The scientist, however, pointed out that the exact effect on the twins’ cognition was unclear and “that is why it should not be done.”
Silva and a team from the United States and Israel reported in the journal Cell that CCR5 suppressed memories and synaptic connections. They found that people who naturally lacked the gene recovered faster from strokes.
People who missed at least one copy of CCR5, they found, also appeared to progress further in school, suggesting a role in intelligence.
“We are the first to report a function of CCR5 in the human brain, and the first to report a higher level of education,” UCLA biologist S. Thomas Carmichael, who led the new study, was quoted saying.
He Jiankui, a scientist from the Southern University of Science and Technology in Shenzhen, China, announced last November that he used the CRISPR technique to edit human embryos that were later used to create pregnancies. Lulu and Nana were born a few weeks before He’s announcement.
He reportedly said the gene-editing was meant to protect the children, whose father is HIV-positive, from HIV by deleting the CCR5 gene that enables the AIDS-causing virus to enter immune system cells. But other scientists have criticised creation of the world’s first genetically modified babies.
Chinese authorities are currently investigating He, Xinhua reported last January, and confirmed there is a second pregnancy with a gene-edited embryo.