Newly Discovered Gene Networks Impact Intelligence
Scientists at Imperial College London have identified two networks of genes in the human brain that appear to govern memory, attention, processing speed and reasoning—the cognitive functions that combine in intelligence.
Complex traits such as intelligence are influenced by large groups of genes working together, according to Dr. Michael Johnson, a neurologist at Imperial College, rather “like a football team made up of players in different positions.” Dr. Johnson is deputy head of the Centre for Clinical Translation in the college’s Division of Brain Sciences. In a paper published in the journal Nature Neuroscience, he and an international team of scientists describe the gene clusters they discovered. A story on the Imperial College website describes the discovery as the first of its kind, and one that could lead to treatment and amelioration of neurodevelopmental disorders and the cognitive impairments associated with them.
The newly identified gene networks, called MI and M3, appear to be under the control of master regulator switches. The researchers hope to identify the switches and explore whether they can be therapeutically manipulated. The M1 network has more than 1,100 genes, according to a story in sci-news.com, and the M3 network has more than 150 genes. An NIH paper explains that at least a third of the approximately 20,000 different genes that make up the human genome are expressed, or turned on, in the brain. The brain has a higher proportion of expressed genes than any other part of the body.
“What’s exciting about this is that the genes we have found are likely to share a common regulator, which means that potentially we can manipulate a whole set of genes whose activity is linked to human intelligence,” Dr. Johnson said published interviews. “Our research suggests it might be possible to work with these genes to modify intelligence, but that is only a theoretical possibility at the moment. We have just taken a first step along that road.”
The researchers examined samples of human brains from patients who had undergone neurosurgery for epilepsy. They looked at thousands of genes expressed in the brain, and combined the those observations with genetic information from healthy people who had taken IQ tests, and information from people who had such neurological conditions as autism spectrum disorders and cognitive disabilities. Using multiple computational analyses they were able to identify the gene networks that influence healthy cognitive abilities and begin to get some clues about how the genes interact.
Interestingly, Dr. Johnson reported the researchers found that some genes can be both helpful and harmful: Some of the genes that influence working intelligence in healthy people are the same genes that cause seizure disorders and cognitive impairments when they are mutated. The researchers believe use of large genomic datasets can be used to help uncover new aspects of human brain function in both health and disease or disorder, and new treatment possibilities