Introduction to Part 1.

Autism spectrum disorder (ASD) is one of the most challenging neurodevelopmental disorders of our era that the Centers for Disease Control and Prevention estimates the prevalence to be about 1 in 59 children in the United States. Over the last two decades, research focusing on ASD has increased, particularly in areas focusing on physiological disruptions such as mitochondrial and redox metabolism abnormalities, immune system dysfunction and environmental health, although research focusing on genetics and behavior still predominate the field. Drug treatment trials have provided few "home runs" with many failures and some promising, but preliminary, results. A series of two issues of Seminars in Pediatric Neurology will provide articles representing the cutting edge of research and clinical care for children with ASD. The first issue will contain three articles on Advances in Diagnostic Methodology and three articles on Cutting Edge Method for Studying Outcomes. The second issue will contain articles on Advances in Early Screening and Diagnosis on the Front Lines and Novel and Cutting-Edge Therapies. I believe the two issues will provide significant insight into new and exciting developments in the field as well as provide a framework for understanding the challenges ahead.