The journal Science has published the results of an international investigation that represents an important advance in the degree of knowledge about the genetic map that determines the structure of the key regions of the human cerebral cortex. These advances allow us to advance in knowing how genetic variability marks differences in the brain structure associated with the risk of suffering from some mental illness.
IDIVAL researchers participate in this international study that has been carried out within the ENIGMA consortium and which has been led by Dr. Benedicto Crespo-Facorro of the Virgen del Rocío University Hospital and whose main analysis of the study has been carried out by Dr. Katrine. Grasby from the University of Southern California (USA).
This work is the result of a consortium made up of 900 researchers, 296 research groups from 45 countries, in order to reveal the role of genes on the structure and function of the brain, using genetic and clinical data from 30,000 patients. of all the world.
The cerebral cortex, also known as the “gray matter”, is the external part of the brain where cognitive abilities, the ability to think, process information, memory and attention reside. It is a highly complex and relatively thin, folded layer that can house large numbers of neurons. Variations in the surface and thickness of the cortex influence the psychological, behavioral, and neurological traits of each person, and have been associated with diseases such as schizophrenia, attention deficit hyperactivity disorder, depression, autism, and bipolar disorder. These variations in the cortex can be measured in vivo using Nuclear Magnetic Resonance (NMR).
To date, several genes have been identified that affect the structure of the cerebral cortex of model organisms; however, as of today, very little is known about the genetic variants that affect the structure of the human cerebral cortex. In this context, the objective of the study has been to identify the genetic variants that affect the structure of the human cerebral cortex, both globally and regionally.
To this end, a comprehensive meta-analysis has been carried out that associates genomic data with data on the brain resonances of 51,665 people belonging to 60 cohorts. “A study was carried out that demonstrated the genetic influence on the structure of the brain and also on how we think and behave as human beings”, emphasizes Dr. Crespo-Facorro.
The results have shown both genetic correlations (306 genetic variants) and bidirectional causality between the total surface of the cortex and the cognitive function and educational achievements of people. Furthermore, they have revealed genetic correlations between the total surface of the cortex and Parkinson's disease, but no causal relationship was found in this regard.
Genetic variants associated with having less cortical surface, or less folding thereof, have also been found to contribute to an increased risk of depression, insomnia, and attention deficit hyperactivity disorder. “Using MRI and genetics information, one-third of the differences in cortical structure between individuals with genetic variants can be predicted,” according to Dr. Katrine Grasby.
“These findings represent a milestone on the way to know how genetic variability marks differences in the brain structure that ultimately puts us at risk of suffering from some mental illness,” according to Dr. Benedicto Crespo-Facorro.
Ref. The genetic architecture of the human cerebral cortex.Grasby KL, Jahanshad N, Painter JN, Colodro-Conde L, Bralten J, Hibar DP, Lind PA, et all. Genetics through Meta-Analysis Consortium (ENIGMA)—Genetics working group.Science. 2020 Mar 20;367(6484). pii: eaay6690. doi: 10.1126/science.aay6690.PMID:32193296
