Summary: A large-scale study identified 254 genetic variations that shape the amount of essential brain areas responsible for memory, motor power, and behavior. Researchers analyzed DNA and mental images from almost 75, 000 individuals, uncovering links between these variants and problems like ADHD and Parkinson’s disease.
The research provides important insight into how genetics affect mental composition, which could lead to more efficient treatment for brain disorders. This study represents a major step in the development of a better understanding of the genetic basis for brain function and difficulties.
Important Information:
- Head volume in important subcortical regions was the subject of 254 biological variants.
- Findings link mental amount differences to conditions like Parkinson’s and ADHD.
- A study provides a framework for understanding how mental issues are influenced by genetics.
Origin: USC
In one of the largest-ever studies of DNA and head size, researchers have identified 254 genetic variants that form important structures in the “deep mind”, including those that control memory, motor skills, compulsive behaviors and more.
The results were simply published in the journal , Nature Genetics.
The study is powered by the , Enhancing Neuro Imaging Genetics through Meta-Analysis ( ENIGMA ) consortium, an international effort based at the Keck School of Medicine of USC, which unites more than 1, 000 research labs across 45 countries to hunt for genetic variations that affect the brain’s structure and function.
” A lot of mental diseases are known to be partly hereditary, but from a medical point of view, we want to find the specific changes in the genetic code that produce these”, said , Paul M. Thompson, PhD, interact director of the , USC Mark and Mary Stevens Neuroimaging and Informatics Institute , and main analyst for ENIGMA.
” By conducting this research all over the world, we’re beginning to home in on what has been called’ the genetic essence of humanity,'” he said.
In some groups ( for example, those with a particular brain disease ), finding brain regions that are larger or smaller than others can aid scientists in discovering what causes brain dysfunction.
Finding the genes that control those brain regions’ development provides a new insight into how to act.
A team of 189 researchers from around the world collected DNA samples and magnetic resonance imaging brain scans from 74, 898 participants in the current study, which was partially funded by the National Institutes of Health. The researchers measured volume in key subcortical regions, also known as the “deep brain.”
They then performed genome-wide association studies, or GWAS, an approach that can identify genetic variations linked to various traits or diseases, finding some gene-brain volume associations that carried a higher risk for Parkinson’s disease and attention-deficit/hyperactivity disorder ( ADHD).
” There is strong evidence that ADHD and Parkinson’s have a biological basis, and this research is a necessary step to understanding and eventually treating these conditions more effectively”, said Miguel , Rentería, PhD, an associate professor of computational neurogenomics at the , Queensland Institute of Medical Research ( QIMR Berghofer ) in Australia and principal investigator of the Nature Genetics study.
Our findings point to the possibility that genetic factors that govern individual brain structure may be essential to better understanding the causes of brain-related disorders, he said.
Studying the deep brain
The researchers analyzed brain volume in key subcortical structures, including the brainstem, hippocampus, amygdala, thalamus, nucleus accumbens, putamen, caudate nucleus, globus pallidus and , ventral diencephalon.
These regions are critical for forming memories, regulating emotions, controlling movement, processing sensory data from the outside world, and responding to reward and punishment.
Up to 10 % of the observed differences in brain volume between study participants are explained by the 254 genetic variants that are linked to brain volume across those regions.
The new study uncovers which gene variants shape brain volume more precisely, in contrast to previous research that had established a direct correlation between disease, such as the basal ganglia and Parkinson’s disease.
” This paper, for the first time, pinpoints exactly where these genes act in the brain”, providing the beginnings of a roadmap for where to intervene said Thompson, who is also a professor of ophthalmology, pediatrics, neurology, psychiatry and the behavioral sciences, radiology, biomedical engineering and electrical engineering at the , Keck School of Medicine.  ,
The study is correlational, so more research is required before genes can be linked to various diseases, according to the researchers.
From Rentería’s group, doctoral candidate , Luis García-Marín and postdoctoral researcher Adrian Campos, PhD, were the study’s first authors. The researchers used data from , Cohorts for Heart and Aging Research in Genomic Epidemiology ( CHARGE ), the UK Biobank, and the Adolescent Brain Cognitive Development ( ABCD ) study in addition to those from ENIGMA.  , Summary statistics are available for researchers to download from the , ENIGMA consortium.
About this research
Other authors in the study who are USC include Neda Jahanshad and Sophia I. Thomopoulos from the , USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, and others. A full list of authors and their affiliations can be found in the , online publication.
Funding: This work was supported by federal and private agencies across the world, including the National Institutes of Health, under grants R01AG058854, U01AG068057, R01NS107513 and R01MH116147. A full list of funders can be , found in the , online publication.
About this research in neurology and genetics
Author: Laura LeBlanc
Source: USC
Contact: Laura LeBlanc – USC
Image: The image is credited to Neuroscience News
Original Research: Closed access.
By Paul M. Thompson and colleagues,” Genomic analysis of intracranial and subcortical brain volumes in up to 74, 898 individuals yields polygenic scores that account for brain variation across ancestries.” Nature Genetics
Abstract
Up to 74, 898 people’s genomes were analysed for intracranial and subcortical brain volumes, which revealed polygenic scores that account for brain variation across ancestries.
Subcortical brain structures are involved in developmental, psychiatric and neurological disorders.
Here we performed genome-wide association studies meta-analyses of intracranial and nine subcortical brain volumes ( brainstem, caudate nucleus, putamen, hippocampus, globus pallidus, thalamus, nucleus accumbens, amygdala and the ventral diencephalon ) in 74, 898 participants of European ancestry.
We identified 254 independent loci associated with these brain volumes, explaining up to 35 % of phenotypic variance. We observed gene expression in a number of different types of neural cells, including those involved in intracellular signaling and brain aging-related processes.
When compared to people of various ancestries, polygenic scores for brain volumes demonstrated predictive ability. We observed causal genetic effects of brain volumes with Parkinson’s disease and attention-deficit/hyperactivity disorder.
Findings point to a brain substrate and region of action for risk genes implicated in brain diseases and reveal specific gene expression patterns in brain development and genetic variants in comorbid neuropsychiatric disorders.
