How many people are affected by Asperger syndrome ?
The prevalence of Asperger syndrome is not well established. Estimates range from 1 in 250 to 1 in 5,000 children. Three to four times as many males are affected than females.  Because of changes in the way developmental disorders are classified, Asperger syndrome was not often diagnosed in adults until recently, and the prevalence is often perceived to be rising as more people are recognized to have features of the condition. Many mildly affected individuals likely continue to be undiagnosed.