With the improvement of genetic technologies, there are many genes now being identified that result in increased risk for autism. In people with a mutation in an area of chromosome 15, known as “dup15q”, almost 80 % are diagnosed with ASD. Between 1-3% of all autism cases may involve this or similar alterations of chromosome 15. Therefore, understanding the brains of people with this genetic form of autism may provide important insights into the causes of autism spectrum disorder more generally.
Because of the strong commitment by the Dup15 Alliance, many scientific discoveries have been made using brain tissue of those with dup15q. This knowledge is critical to moving forward with specific and targeted interventions for those with this mutation.
As shown by the lab of Dr. Jerzy Wegiel at Institute of Basic Research in NY (pictured right), neurons in brains from individuals with dup15q show pronounced and persistent changes in cell size in brain regions known to be associated with autism. As the brain regions involved include the hippocampus and other areas of the limbic system, this may contribute to the high rate of seizures and epilepsy in those with this mutation. This group also has been investigating expression of amyloid-beta protein in individuals with autism and dup15q.
By focusing on individuals with specific genetic mutations, a better understanding of how genes and the environment interact is possible. For example, Janine LaSalle at the University of California, Davis (left) found that PCB levels (an environmental toxin) were very high in brain tissue of individuals with dup15q and autism. The amounts were much higher than what would be expected and indicate that the mutation may alter clearance of these environmental contaminants. Dr. LaSalle is actively pursuing these gene/environment interactions in mouse models, thanks to this discovery in human brain tissue.
We thank all the members of the Dup15 Alliance community for their participation in this research.
We encourage families that are part of the Chromosome 15 community to register for Autism BrainNet. Please feel free to contact Autism BrainNet personnel at any time by calling (877) 333-0999 or emailing us at info(at)autismbrainnet.org.