Autism Study Focuses on Epigenetics.

• Position: THE BRAIN

Scientists long have tried to pin down the causes of autism spectrum disorder. Recent studies have expanded the search for genetic links from identifying genes toward epigenetics, the study of factors that control gene expression and looks at chemical modifications of DNA and the proteins associated with it. The challenge is knowing where to look, given that our genome is comprised of more than 3,000,000,000 nucleotides, or building blocks, of DNA.

A study published in Science Signaling has brought focus to the search for epigenetic mechanisms related to autism. The work identifies more than 2,000 regulatory regions--DNA regions that control gene expression --involved in learning that strongly are associated with autism. Further study within one of those regions revealed a genetic mutation that is associated with increased risk of developing autism.

"Our proof-of-concept study demonstrates the feasibility of going after genetic components of autism that are outside of genes and may eventually lead to improvements in the diagnosis and treatment of autism," says study coauthor Lucia Peixoto, assistant professor in the College of Medicine at Washington State University, Spokane.

She indicates that the majority of human disease-causing mutations are thought to be outside of genes, which make up...