China’s CRISPR twins suffered ‘impact on cognitive function’ from gene editing Jeff ParsonsFriday 22 Feb 2019 2:52 pm

A pair of twins born in China after having their genes edited using the CRISPR editing tool will have suffered brain enhancements as a result. The goal of the experiment was to make sisters Lulu and Nana immune to HIV. As such, a particular gene called CCR5 was removed from their system before birth. Removing it has been shown to make mice smarter and it will almost certainly have an effect on the girls’ brains as well. ‘The answer is likely yes, it did affect their brains,’ Alcino J. Silva, a neurobiologist at the University of California, Los Angeles, told the MIT Technology Review. Chinese scientist He Jiankui defends his work during a panel discussion at the Second International Summit on Human Genome Editing, at the University of Hong Kong in Hong Kong, China (EPA) ‘The simplest interpretation is that those mutations will probably have an impact on cognitive function in the twins,’ said Silva, whose lab uncovered a major new role for the CCR5 gene in memory and the brain’s ability to form new connections. The HIV virus requires the CCR5 gene in order to enter human blood cells. But one of the reasons this kind of editing shouldn’t be carried out, Silva argues, is because of the uncertainty over how this will affect the girls’ brains over time. The gene editing experiment has been widely condemned (iStockphoto) It’s unclear whether or not He Jiankui, who led the CRISPR experiment last year intended to try and affect the intelligence of the babies. He, from the Southern University of Science and Technology in Shenzhen (which denied knowing about the work) defended the experiment despite condemnation from the wider scientific community. Nobel laureate David Baltimore said professor He’s work would ‘be considered irresponsible’ because it did not meet criteria many scientists agreed on several years ago before gene editing could be considered. Baltimore said he didn’t think that was medically necessary. He said the case showed ‘there has been a failure of self-regulation by the scientific community’ and said the conference committee would meet and issue a statement on Thursday about the future of the field. A screen shows information of genomic data from He Jiankui’s experiment (AP) The National Health Commission has ordered local officials in Guangdong province to investigate He’s actions, and his employer, Southern University of Science and Technology, is investigating as well. The Chinese researcher said he practiced editing mice, monkey and human embryos in the lab for several years and has applied for patents on his methods. He said he chose embryo gene editing for HIV because these infections are a big problem in China. Either way, it will be a long time before we know for sure what the cerebral impacts of the experiment turn out to be. Genetic engineering is still in its infancy (Science Photo Library) ‘Could it be conceivable that at one point in the future we could increase the average IQ of the population? I would not be a scientist if I said no,’ Silva concludes. ‘The work in mice demonstrates the answer may be yes,’ he said. ‘But mice are not people. We simply don’t know what the consequences will be in mucking around. We are not ready for it yet.’