• ASDs are reported to occur in all racial, ethnic, and socioeconomic groups.
• ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252).
• Studies in Asia, Europe, and North America have identified individuals with an ASD with an average prevalence of about 1%. A recent study in South Korea reported a prevalence of 2.6%.
• About 1 in 6 children in the U.S. had a developmental disability in 2006-2008, ranging from mild disabilities such as speech and language impairments to serious developmental disabilities, such as intellectual disabilities, cerebral palsy, and autism

fonte:  

http://www.cdc.gov/media/releases/2012/p0329_autism_disorder.html