An international research effort has identified 254 genetic variants that influence the volume of key brain regions, offering new insights into neurological and psychiatric disorders.
Summary: A genome-wide association study of nearly 75,000 individuals has revealed hundreds of genetic variants that shape subcortical brain structures, with potential implications for understanding Parkinson’s disease and ADHD.
Estimated reading time: 5 minutes
In one of the largest studies of its kind, researchers have uncovered a wealth of genetic information related to brain structure. The study, published in Nature Genetics, identified 254 genetic variants associated with the volume of critical subcortical brain regions.
Led by scientists from the University of Southern California (USC) and the Queensland Institute of Medical Research (QIMR Berghofer) in Australia, this research represents a significant step forward in understanding the genetic basis of brain development and related disorders.
Mapping the “Deep Brain”
The study focused on key structures in the “deep brain,” including the brainstem, hippocampus, amygdala, and thalamus. These regions play crucial roles in memory, emotion, movement, and sensory processing.
Dr. Paul M. Thompson, associate director of the USC Mark and Mary Stevens Neuroimaging and Informatics Institute and principal investigator for the ENIGMA consortium, explained the significance of the research:
“A lot of brain diseases are known to be partially genetic, but from a scientific point of view, we want to find the specific changes in the genetic code that cause these. By conducting this research all over the world, we’re beginning to home in on what has been called ‘the genetic essence of humanity.'”
The study analyzed DNA samples and brain scans from 74,898 participants, using genome-wide association studies (GWAS) to identify genetic variations linked to brain volume. Some of these variations were associated with a higher risk for Parkinson’s disease and attention-deficit/hyperactivity disorder (ADHD).
Implications for Neurological Disorders
Dr. Miguel Rentería, an associate professor at QIMR Berghofer and principal investigator of the study, highlighted the potential impact on understanding and treating neurological conditions:
“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. Our findings suggest that genetic influences that underpin individual differences in brain structure may be fundamental to understanding the underlying causes of brain-related disorders.”
The genetic variants identified in the study explained up to 10% of the observed differences in brain volume across participants. While this may seem modest, it represents a significant advancement in our understanding of brain genetics.
A Roadmap for Future Research
Dr. Thompson emphasized the precision of the new findings:
“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.”
However, the researchers caution that the study is correlational, and more investigation is needed before genes can be causally linked with various diseases.
The study’s findings could have far-reaching implications for neuroscience and medicine. By identifying specific genetic variants associated with brain structure, researchers may be able to:
- Develop more targeted treatments for neurological and psychiatric disorders
- Improve early detection and risk assessment for conditions like Parkinson’s and ADHD
- Enhance our understanding of normal brain development and aging
Collaborative Effort and Data Sharing
This research was made possible by the Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) consortium, an international collaboration uniting over 1,000 research labs across 45 countries.
The study also utilized data from other large-scale projects, including the UK Biobank and the Adolescent Brain Cognitive Development (ABCD) study. To promote further research, the team has made their summary statistics available for download through the ENIGMA consortium.
As we continue to unravel the complex relationship between genetics and brain structure, studies like this pave the way for a deeper understanding of human cognition and the biological underpinnings of neurological disorders.
Quiz: Test Your Knowledge
- How many genetic variants associated with brain volume were identified in the study? a) 100 b) 174 c) 254 d) 354
- What percentage of observed differences in brain volume did the identified genetic variants explain? a) Up to 5% b) Up to 10% c) Up to 25% d) Up to 50%
- Which two specific disorders were mentioned as potentially benefiting from this research? a) Alzheimer’s and depression b) Schizophrenia and bipolar disorder c) Parkinson’s and ADHD d) Epilepsy and autism
Answer key:
- c
- b
- c
Glossary of Terms
- Genome-wide association study (GWAS): An approach to identify genetic variations associated with particular traits or diseases.
- Subcortical brain structures: Regions located deep within the brain, beneath the cerebral cortex.
- ENIGMA consortium: Enhancing Neuro Imaging Genetics through Meta-Analysis, an international collaboration studying brain structure, function, and disease.
- Polygenic scores: Estimates of an individual’s genetic predisposition to a trait or disease based on multiple genetic variants.
- Neuroimaging: Techniques used to produce images of the brain’s structure or function.
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