The genetics of synaesthesia
Julian Asher, Donnie Johnson, Carrie Allison, Allen Chan, Simon Fisher, and Simon Baron-Cohen
The ARC developed the Test of Genuineness of Synaesthesia, and conducted the first neuroimaging study of synaesthesia using PET and later using MRI. It also published the first genetic study of synaesthesia. In collaboration with Professor Anthony Monaco’s group at the Wellcome Trust Centre for Human Genetics in Oxford, our work identified four genetic regions linked with susceptibility to synaesthesia.
The study of the genetics of synaesthesia is in its infancy, and we are in the first stages of unravelling the genetic substrates underlying the condition. Although there is strong evidence that synaesthesia has a genetic component, we do not yet know which genes cause synaesthesia or how they contribute to the development of the condition.
While there is no evidence that synaesthetes are more likely to have autism-spectrum disorders than people in the general population, it is notable that the region with the most significant linkage is to a region which has been previously linked to autism. This of particular interest as sensory abnormalities are common in autism spectrum conditions and the extreme memory and recall capabilities of at least one numerical savant appear to be driven by his synaesthesia. This discovery spurred the development of our work on synaesthsia and autism.
Working in collaboration with Simon Fisher at the Max Planck Institute for Psycholinguistics in Nijmegan in the Netherlands we aim to identify and characterise genes that may make people more susceptible to developing synaesthesia.