Autism Spectrum Disorder, Biology of

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that affects social communication, involves repetitive interests and behaviors, and impacts sensory functioning. Increases in the rate of ASD since the early 2000s have led to increased efforts to understand the underlying biology and etiology, or causes, of the condition. This entry reviews differences in genetic makeup and in the structure and function of the central and peripheral nervous systems of people with ASD.

Although no specific cause for ASD has been discovered, it is widely agreed to originate with and affect the biology of the individual. An important point to consider, though, is the developmental nature of the condition. ASD is considered “pervasive,” or continuing to be present across the lifespan. However, the symptoms of the ...