In a genome-wide association study involving 19,644 individuals of European descent, an international team of researchers identified 472 genomic regions, or loci, that influence brain shape, of which 76 are also linked to brain shape. face; These loci do not influence cognitive ability, further debunking beliefs that intelligence can be assessed by facial features.
“To study the genetic foundations of the shape of the brain, we applied a methodology that we had already used in the past to identify genes that determine the shape of our face,” said Professor Peter Claes, a researcher at the Laboratory of Imaging Genetics at KU Leuven. .
“In these previous studies, we analyzed 3D images of faces and linked various data points on these faces with genetic information to find correlations.”
“In this way, we were able to identify various genes that shape our face.”
In the current study, the scientists used information stored in the UK Biobank to study the structure of the brain, obtained through magnetic resonance imaging (MRI), of 19,644 healthy people.
“To be able to analyze the MRI images, we had to measure the brains that are shown in the images,” said Professor Claes.
“Our specific focus was on variations in the folded outer surface of the brain, the typical ‘walnut shape.’
“Then we went on to link the data from the image analyzes with the available genetic information.”
The authors found 472 loci in the genome that affect the shape of the brain. Of these, 76 were previously shown to influence facial structure.
“In this way, we identified 472 genomic regions that have an impact on the shape of our brain. 351 of these places had never been reported before, ”he said.
“To our surprise, we discovered that up to 76 brain shape predictive genomic locations had previously been found to be linked to face shape. This makes the genetic link between the shape of the face and the brain compelling. “
They also found evidence that genetic signals that influence both the brain and the shape of the face 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 since the development of the brain and the face is coordinated,” said Professor Joanna Wysocka, a researcher at Stanford University School of Medicine.
“But we didn’t expect this crossover developmental conversation to be so genetically complex and have such a broad impact on human variation.”
In the study, the team also briefly addressed conditions such as Alzheimer’s disease, schizophrenia, and bipolar disorder.
“As a starting point, we used the results that were previously published by other teams on the genetic basis of such neuropsychiatric disorders,” said Professor Claes.
“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 the 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 those that contribute to our face. “
“In other words, our risk of developing a neuropsychiatric disorder is not written on our faces either.”
“We were surprised to find 76 genetic regions that affect both the shape of the face and the brain in the human population,” added Professor Wysocka.
“That’s an amazing degree of overlap and it shows how closely these two structures affect each other during development. However, nothing in our data suggests that it is possible to predict behavior, cognitive function, or neuropsychiatric disorders such as schizophrenia or ADHD simply by looking at a person’s face. “
The results appear in the journal Genetics of nature.
S. Naqvi et al. Shared heritability of the human face and the shape of the brain. Nat Genet, published online April 5, 2021; doi: 10.1038 / s41588-021-00827-w