A new study has investigated the genetics that underlie brain structure. With more than 36,000 brain scans and a wealth of human genetic data, scientists identified over 4,000 genetic variants that are associated with brain architecture. Until now, little has been known about the genetic influences on the development of the brain, which can very tremendously from one person to another when it comes to the manner and thickness of its folds. The findings have been reported in in Nature Genetics.
In this work, the investigators assessed more than 32,000 MRIs that were taken of adults who also had data in the UK Biobank. Data from more than 4,000 children from a US database were also included. The scientists took measurements of the cortex, the brain's outermost layer, as well as 180 different cortical regions. Then they linked the genetic information to the measurements, revealing the variants that influence structure.
The study also found some new genetic connections between different parts of the brain and confirmed others that have been previously been identified.
The scientists were particularly interested in whether the same genes that are associated with the size of the cortex, in terms of both volume and area, are also associated with how the cortex is folded, said study co-leader Dr. Varun Warrier of the Autism Research Center at the University of Cambridge. "By measuring these different properties of the brain and linking them to genetics, we found that different sets of genes contribute to folding and size of the cortex."
The researchers also determined whether genes that have been associated with clinical conditions in which head sizes are unlike the average are the same genes that were connected to brain size variations in the general populations.
"Many of the genes linked with differences in the brain sizes in the general population overlapped with genes implicated in cephalic conditions. However, we still do not know how exactly these genes lead to changes in brain size," noted co-lead study author Dr. Richard Bethlehem of the University of Cambridge.
"This work shows that how our brain develops is partly genetic," added Warrier. The findings may help show how alterations in brain structure are linked to neurological and psychiatric conditions, which could improve treatment options for those affected.