An international team of researchers has located a gene that determines both brain size and intelligence. The study, published in Nature Genetics , has collected brain images from more than 20,000 people from around the world.
“We had two goals,” says Paul Thompson of the University of California. “On the one hand we were looking for genes that increase the risk of mental illness. And secondly we wanted to find factors that cause atrophy and reduce brain size, which in turn is an indicator of conditions such as schizophrenia, bipolar disorder, depression, Alzheimer’s disease or dementia. “
The analyzes revealed that the smaller brains corresponded to subtle changes in the genetic code. Furthermore, the results were the same for individuals in Europe, Australia, and North America , so the same molecular targets could be used to develop equally effective drugs in all three regions.
The intelligence gene
In addition, researchers have also discovered the gene that explains the differences in intelligence. A simple mutation in the HMGA2 gene affects both brain size and intelligence . People who have a cytosine molecule instead of tyrosine in a specific region of that gene have larger brains and do better on IQ tests.
Since some diseases such as Alzheimer’s, autism or schizophrenia affect brain circuits, the researchers’ next efforts will focus on the search for genes that influence them and thus be able to develop more effective therapies to combat these conditions.
