A-to-I RNA editing in autism spectrum disorder

Significant recent progress has been made in deciphering the genetic basis of autism spectrum disorder (ASD), revealing a key role for synaptic gene mutations. However, relevant mechanisms for Gene-Environment interactions and their contribution to the ASD phenotype remain largely unknown. RNA is emerging as a central substrate for encoding environmental exposures at the molecular level, especially in the nervous system. One effective mechanism for regulating gene function and dosage in response to the changing environment is RNA editing. Recently, we showed that Adenosine-To-Inosine (A-to-I) RNA editing of synaptic genes is altered in postmortem brains of individuals with ASD, suggesting that this epigenetic mechanism could play a role in ASD. Here we review our current understanding of RNA editing at the molecular level, describe the behavioral phenotypes associated with altered A-to-I editing in animal models, discuss recent discoveries in human A-to-I editing, and speculate about the diagnostic and prognostic potential of A-to-I editing changes in ASD.