Networks of Genes Altered in Autism Brains

Two networks of genes are abnormally expressed in the brains of people with autism, according to a study published today in Nature.Analyzing postmortem brain tissue, the researchers discovered that, compared with controls, genes involved in cell connectivity tend to be expressed at lower levels in autism brains, and genes related to immune cells at higher levels.Autism is known for its diversity in symptoms and in the genes that might cause it. "[But] there is a remarkable consistency in the molecular changes that are occurring in the brain," notes lead investigator Daniel Geschwind, distinguished professor of neurology, psychiatry and human genetics at the University of California, Los Angeles.The study turned up several unexpected findings. For example, the frontal lobe and temporal lobe in healthy controls show significant differences in gene expression, reflecting their distinct cell types and functions. But in the autism brains, "those differences are essentially wiped out," Geschwind says. Many of these genes are first turned on during embryonic development, he says, suggesting that the abnormal trajectory of autism brains begins early.Read more at...SFARI, May 2011.