A genetic link discovered between the face and the shape of the brain
An interdisciplinary team led by KU Leuven and Stanford has identified 76 overlapping genetic locations that shape both our face and our brains. What the researchers did not find was evidence that this genetic overlap also predicts a person’s behavioral and cognitive traits or the risk of diseases such as Alzheimer’s sickness. This means that the results help debunk several persistent pseudo-scientific claims about what our faces reveal about us.
There were already indications of a genetic link between the shape of our face and that of our brain, explains Professor Peter Claes of the Genetic Imaging Laboratory at KU Leuven, who is the study’s lead co-author with the Stanford professor Joanna Wysocka. University School of Medicine. âBut our knowledge of this link was based on research of model organisms and clinical knowledge of extremely rare diseases,â Claes continues. âWe set out to map the genetic link between the face and brain shape of individuals in a much broader way and for genetic variations common in the larger, non-clinical population. “
Brain and DNA scanners from UK Biobank
To study the genetic basis of brain shape, the team applied a methodology that Peter Claes and his colleagues had used in the past to identify the genes that determine the shape of our face. Claes: âIn these previous studies, we analyzed 3D images of faces and linked several data points on those faces to genetic information to find correlations. In this way, the researchers were able to identify various genes that shape our face.
For the current study, the team drew on this previously acquired information as well as data available in the UK Biobank, a database from which they used MRI brain scans and genetic information from 20 000 people. Claes: âIn order to be able to analyze the MRI scans, we had to measure the brains shown on the scans. We focused on variations in the folded outer surface of the brain – the typical ânut shapeâ. We then linked the data from the image analyzes to the available genetic information. In this way, we identified 472 genomic locations that impact the shape of our brain. 351 of these locations have never been reported before. To our surprise, we found that up to 76 genomic locations predictive of brain shape had previously been linked to facial shape. This makes the genetic link between the face and the shape of the brain compelling. “
The team also found evidence that genetic signals that influence both brain and facial shape are enriched in regions of the genome that regulate gene activity during embryogenesis, i.e. in facial progenitor cells, either in the developing brain. This makes sense, says Wysocka, because the development of the brain and the face are coordinated. “But we didn’t expect this developmental crosstalk to be so genetically complex and to have such a broad impact on human variation.”
No genetic link to behavioral or neuropsychiatric disorders
What the researchers did not find is at least as important, says Dr Sahin Naqvi of Stanford University School of Medicine, who is the first author of this study. “We have found a clear genetic link between a person’s face and the shape of their brain, but this overlap is almost completely independent of that person’s behavioral and cognitive traits.”
Concretely: even with advanced technologies, it is impossible to predict a person’s behavior based on their facial features. Peter Claes continues: âOur results confirm that there is no genetic evidence for a link between a person’s face and that person’s behavior. Therefore, we explicitly dissociate ourselves from pseudo-scientific claims to the contrary. For example, some people claim that they can detect aggressive tendencies in faces by means of artificial intelligence. Not only are such projects totally unethical, they also lack a scientific basis. “
In their study, the authors also briefly discuss conditions such as Alzheimer’s disease, schizophrenia, and bipolar disorder. Claes: âAs a starting point, we used the results previously published by other teams on the genetic basis of these neuropsychiatric disorders. The possible link with the genes that determine the shape of our face has never been examined before. If you compare the 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.
Reference: âShared Heritability of the Human Face and Brain Shapeâ 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 and Peter Claes, April 5, 2021, Genetics of nature.
DOI: 10.1038 / s41588-021-00827-w