Reserachers discover genes that shape the brainPublished On: Sat, Jan 24th, 2015 | Neurobiology | By BioNews
In a significant finding, an international team of scientists has discovered five genetic variants that influence the size of structures within the human brain.
Nearly 300 researchers from ENIGMA consortium (Enhancing Neuro Imaging Genetics through Meta-Analysis) analysed genetic data and magnetic resonance imaging (MRI) scans from 30,717 individuals from around the world.
They used the brain scans to measure the total volume of the brain, as well as the volumes of seven different structures that lie in the middle of the brain, including the hippocampus, known for its role in memory. Each DNA sample was analysed to reveal millions of common genetic variants – specific positions within the genome where a person may carry either of two alternative DNA ‘letters’. The researchers could then check to see if any of the genetic variants was associated with the volume of a particular brain structure. The key to their success was obtaining data from such a large number of people, because this enabled the detection of very small genetic effects that would not have been apparent in a smaller study. By taking a similar approach, future studies should be able to uncover further connections between genetics and brain anatomy.
This is the largest analysis of brain structure and genetics ever done.
“Through a large-scale, international data sharing and data-analysis-sharing effort, we were able to actually successfully identify genetic effects on the hippocampus, putamen and other brain regions that no one had ever successfully identified genetics effects on before,” said Jessica Turner, associate professor of psychology and neuroscience at Georgia State University.
Their goal was to determine how common genetic variants affect the structure of these seven subcortical brain regions, which are associated with memory, movement, learning and motivation.
Changes in these brain areas can lead to abnormal behaviour and predisposition to disease.
Previous research showed that the brain’s structure was strongly shaped by genetic influences. Identifying genetic variants could provide insight into the causes for variation in human brain development and help to determine how dysfunction in the brain occurs.
“Those are brain regions that we know are involved in various psychiatric and neurodegenerative disorders. In trying to figure out the genetics that make them either larger or smaller, it could have great benefits for understanding mechanisms of these disorders,” Turner concluded.
Their findings were published in the journal Nature.
Common genetic variants influence human subcortical brain structures. Nature 2015 DOI: 10.1038/nature14101