Duplication of a small segment of human chromosome 7 has been found in some children with autism. Lucy Osborne and her colleagues at the University of Toronto aim to understand the effects of duplication of this region, 7q11.23, on the growth and function of the brain. They plan to study this using a mouse model with a similar duplication.
Osborne and her team have generated mice with duplications of eight genes from the critical region, as well as mice with a duplication of a single, important candidate gene, GTF2I. The researchers plan to test the model mice for behaviors that are relevant to autism in humans, such as abnormal social interaction, impaired communication and repetitive behaviors. They also plan to use magnetic resonance imaging to look at brain structure and examine how neurons from the mice grow and function in culture.
Because brain tissue from individuals with the 7q11.23 duplication is not available, Osborne and her team plan to use a new technique to reprogram human blood cells into stem cells so that in the future they can be grown into neurons in culture. If successful, this technique will allow the researchers to study neurons from people with 7q11.23 duplication syndrome, even without direct access to their brain tissue.
Findings from these experiments will be related to the results of a Simons Foundation Autism Research Initiative project, directed by Carolyn Mervis at the University of Louisville in Kentucky, examining the characteristics of children with 7q11.23 duplication syndrome. Together, these projects could contribute to the growing understanding of the biology of autism and help build a picture of how features in autism arise from genetic alterations.