Summary: Researchers have identified 76 overlapping genetic locations that determine the shapes of our faces and our brains. The genetic signals that influence face and brain shape are enriched by regions of the genome that regulate gene activity during embryogenesis.
Source: KU Leuven
An interdisciplinary team led by KU Leuven and Stanford has identified 76 overlapping genetic locations that shape both our face and our brain. What the researchers didn’t find is evidence that this genetic overlap also predicts someone’s behavioural-cognitive traits or risk of conditions such as Alzheimer’s disease. This means that the findings help to debunk several persistent pseudoscientific claims about what our face reveals about us.
There were already indications of a genetic link between the shape of our face and that of our brain, says Professor Peter Claes from the Laboratory for Imaging Genetics at KU Leuven, who is the joint senior author of the study with Professor Joanna Wysocka from the Stanford University School of Medicine. “
But our knowledge on this link was based on model organism research and clinical knowledge of extremely rare conditions,” Claes continues. “We set out to map the genetic link between individuals’ face and brain shape much more broadly, and for commonly occurring genetic variation in the larger, non-clinical population.”
Brain scans and DNA from the UK Biobank
To study genetic underpinnings of brain shape, the team applied a methodology that Peter Claes and his colleagues had already used in the past to identify genes that determine the shape of our face.
Claes said, “In these previous studies, we analysed 3D images of faces and linked several data points on these faces to genetic information to find correlations.” This way, the researchers were able to identify various genes that shape our face.
For the current study, the team relied on these previously acquired insights as well as the data available in the UK Biobank, a database from which they used the MRI brain scans and genetic information of 20,000 individuals.
Claes said, “To be able to analyse the MRI scans, we had to measure the brains shown on the scans. Our specific focus was on variations in the folded external surface of the brain – the typical ‘walnut shape’. We then went on to link the data from the image analyses to the available genetic information. This way, we identified 472 genomic locations that have an impact on the shape of our brain. 351 of these locations have never been reported before. To our surprise, we found that as many as 76 genomic locations predictive of the brain shape had previously already been found to be linked to the face shape. This makes the genetic link between face and brain shape a convincing one.”
The team also found evidence that genetic signals that influence both brain and face shape are enriched in the regions of the genome that regulate gene activity during embryogenesis, either in facial progenitor cells or in the developing brain.
This makes sense, Wysocka explains, as the development of the brain and the face are coordinated. “But we did not expect that this developmental cross-talk would be so genetically complex and would have such a broad impact on human variation.”
No genetic link with behaviour or neuropsychiatric disorders
At least as important is what the researchers did not find, says Dr Sahin Naqvi from the Stanford University School of Medicine, who is the first author of this study.
“We found a clear genetic link between someone’s face and their brain shape, but this overlap is almost completely unrelated to that individual’s behavioural-cognitive traits.”
Concretely: even with advanced technologies, it is impossible to predict someone’s behaviour based on their facial features. Peter Claes continues, “Our results confirm that there is no genetic evidence for a link between someone’s face and that individual’s behaviour. Therefore, we explicitly dissociate ourselves from pseudoscientific claims to the contrary. For instance, some people claim that they can detect aggressive tendencies in faces by means of artificial intelligence. Not only are such projects completely unethical, they also lack a scientific foundation.”
In their study, the authors also briefly address conditions such as Alzheimer’s, schizophrenia, and bipolar disorder.
Claes said, “As a starting point, we used the results that were previously published by other teams about the genetic basis of such neuropsychiatric disorders. The possible link with the genes that determine the shape of our face had never been examined before. If you compare existing findings with our new ones, you see a relatively large overlap between the genetic variants that contribute to specific neuropsychiatric disorders and those that play a role in the shape of our brain, but not for those that contribute to our face.”
In other words: our risk of developing a neuropsychiatric disorder is not written on our face either.
This research is a collaboration between KU Leuven, Stanford University School of Medicine, University of Pittsburgh, Pennsylvania State University, Indiana University Purdue University Indianapolis, Cardiff University, and George Mason University.
About this genetics research news
Source: KU Leuven
Contact: Peter Claes – KU Leuven
Image: The image is in the public domain
Original Research: Closed access.
“Shared heritability of human face and brain shape” by Sahin Naqvi, Yoeri Sleyp, Hanne Hoskens, Karlijne Indencleef, Jeffrey P. Spence, Rose Bruffaerts, Ahmed Radwan, Ryan J. Eller, Stephen Richmond, Mark D. Shriver, John R. Shaffer, Seth M. Weinberg, Susan Walsh, James Thompson, Jonathan K. Pritchard, Stefan Sunaert, Hilde Peeters, Joanna Wysocka & Peter Claes. Nature Genetics
Shared heritability of human face and brain shape
Evidence from model organisms and clinical genetics suggests coordination between the developing brain and face, but the role of this link in common genetic variation remains unknown.
We performed a multivariate genome-wide association study of cortical surface morphology in 19,644 individuals of European ancestry, identifying 472 genomic loci influencing brain shape, of which 76 are also linked to face shape. Shared loci include transcription factors involved in craniofacial development, as well as members of signaling pathways implicated in brain–face cross-talk.
Brain shape heritability is equivalently enriched near regulatory regions active in either forebrain organoids or facial progenitors. However, we do not detect significant overlap between shared brain–face genome-wide association study signals and variants affecting behavioral–cognitive traits.
These results suggest that early in embryogenesis, the face and brain mutually shape each other through both structural effects and paracrine signaling, but this interplay may not impact later brain development associated with cognitive function.