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 affect brain shape, 76 of which are also linked to face shape; these loci do not affect cognitive ability, and further convince that intelligence can be judged on facial features.
Naqvi et al. has recently developed a data-driven approach to the phenotyping of complex, multidimensional properties; this multivariate approach, when applied to facial surface images, has revealed numerous genomic loci, with no previously known role in human face shape variation; in the new study, the team implemented this approach to discover associations between common genetic variants and brain shape, using MRI data from middle-aged participants in the UK Biobank. Image credit: Gerd Altmann.
“To study the genetic underpinnings of brain shape, we have applied a methodology that we have used in the past to identify genes that determine the shape of our face,” said Professor Peter Claes, a researcher in the Laboratory of Image Genetics. to KU Leuven, said.
“In these previous studies, we analyzed 3D images of faces and linked multiple data points on these faces to genetic information to find correlations.”
“In this way, we were able to identify different genes that shape our face.”
In the current study, the scientists used information stored in the British Biobank to study the brain structure – obtained by magnetic resonance imaging (MRI) – of 19,644 healthy people.
“To be able to analyze the MRI scans, we had to measure the brains on the scans,” Professor Claes said.
“Our specific focus was on variations in the folded outer surface of the brain – the typical ‘walnut shape’.”
“Then we linked the data from the image analyzes to the available genetic information.”
The authors found 472 loci in the genome that affect the shape of the brain. It has previously been shown that 76 affects the facial structure.
‘In this way, we have identified 472 genomic regions that have an impact on the shape of our brain. “351 of these locations have never been reported before,” he said.
‘To our surprise, we’ve found that up to 76 genomic locations predictable for the brain shape have been linked to the face shape before. This makes the genetic link between face and brain convincing. ”
They also found evidence that genetic signals that affect the shape of the brain as well as the face are enriched in the regions of the genome that regulate gene activity during embryogenesis, either in facial paternal cells or in the developing brain.
“It makes sense because the development of the brain and face is coordinated,” said Professor Joanna Wysocka, a researcher at Stanford University School of Medicine.
“But we did not expect this cross-talk in evolution to be so genetically complex and to have such a huge 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 previously published by other teams on the genetic basis of such neuropsychiatric disorders,” Professor Claes said.
“The possible link with the genes that determine the shape of our face has never been investigated before.”
‘If you compare existing findings with our new one, you compare 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. not. ”
“In other words, our risk of developing a neuropsychiatric disorder is not on our face either.”
“We were amazed to find 76 genetic regions that affect face and brain shape in the human population,” Professor Wysocka added.
‘It’s an incredible amount of overlap, and it shows how closely these two structures influence each other during development. However, nothing in our data suggests that it is possible to predict behavior, cognitive functions or neuropsychiatric disorders such as schizophrenia or ADHD by simply looking at the person’s face. ”
The results appear in the journal Natural genetics.
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S. Naqvi et al. Shared heredity of human face and brain shape. Nat Genet, Published April 5, 2021 online; doi: 10.1038 / s41588-021-00827-w