A research team led by a University of Utah neuroscientist has identified a gene whose expression can be linked to intelligence.
Science has suspected that human intelligence is largely genetic, but how specific genes affect cognitive ability has remained a puzzle, one that Julie Korenberg is hoping to unlock.
She and colleagues at California institutions performed genetic testing on 65 patients with Williams Syndrome, an uncommon congenital developmental disorder that appears in only one in 20,000 births. People with the syndrome are genetically similar to other individuals except they are missing 27 genes.
"Sometimes rare events can illuminate everyday processes. In the case of Williams Syndrome, we know the genetic changes that lets us hone in on less than 1,000th of the genes. We can ask when that gene changes, does that change their IQ?," said Korenberg, a pediatrician who came to the U. two years ago to work with the Utah Science, Technology and Research initiative (USTAR) and the U.'s Brain Institute.
Williams Syndrome patients have IQs around 60. They are verbal and social, but are challenged by numbers, memory and spatial perception.
Korenberg's team studied 10 genes, but the one that jumped out was STX1A, which helps control electrochemical processes at the synapses, the junction between nerve cells. It can account for 15.6 percent of variation in cognitive function, according to findings published Wednesday in the on-line journal PLoS ONE .
"This was an exciting finding because it connects genes and the brain, which is one of the major problems of modern medicine," said Korenberg, the study's senior author. "It could provide new insights into how we think. It could provide the basis for improving the thinking power of people with retardation in children or people who are losing cognitive function."
The gene in question plays a central role in neuro-transmission, particularly in the areas of the brain associated with learning, memory and fear.
"We're talking about a basic utility when we look at STX1A," Korenberg said. "This study shows in part how nature's hand shapes intelligence at the synapse."
Korenberg collaborated with scientists at the University of California, Los Angeles, where she last worked before coming to Utah, and the Cedars-Sinai Medical Center and the Salk Institute.