Autism seems to be inherited, but until now, little has been known about the genetics behind the disorder. In a study at the University of California, San Diego School of Medicine, researchers have linked specific genetic changes with the abnormal early brain growth seen in children with autism. The brain seems to grow too quickly, and then starts to lose connections between brain cells. This is particularly in an area of the brain known as the prefrontal cortex, which is associated with social, communication and cognitive development, which ties in with the symptoms of the syndrome.
By carrying out analyses of the DNA in samples from this area of the brain from children and young people and comparing it with adults with autism syndrome disorder, they found changes in the genes that regulate the number of cells and the patterns of cells in the young people with autism. In the adults with autism, this part of the brain had changes in signaling. Both groups also had lower levels of the genes that coordinate cell repair.
"Our results indicate that gene expression abnormalities change across the lifespan in autism, and that dysregulated processes in the developing brain of autistic patients differ from those detected at adult ages," said Eric Courchesne, Ph.D., director of the Autism Center of Excellence at UCSD. "The dysregulated genetic pathways we found at young ages in autism may underlie the excess of neurons--and early brain overgrowth--associated with this disorder."
Autism seems to be a recurring theme in biomarker research at the moment, with researchers moving closer to blood-based or imaging-based tests for this distressing developmental disorder. Finding the biomarkers, targets and processes underlying autism could help find better ways to identify and treat--or even maybe to prevent--the abnormal brain growth that seems to be a common factor in the disorder.