What is the epidemiology of Asperger's Disorder?

• In a total population study of children between ages 7-16 in Goteborg, Sweden, minimum prevalence of Asperger's Disorder was 36/10,000 (55/10,000 of all boys, and 15/10,000 of all girls), and the male/female ratio was 4:1. 
• The prevalence of autism has traditionally been estimated around 4-5/10,000.  A recent study from United Kingdom found the prevalence of autism at 17/10,000, and the prevalence of all Autistic Spectrum Disorders (including autism) at 63/10,000.

What is Asperger's Disorder?

Asperger's Disorder is a milder variant of Autistic Disorder.   Both Asperger's Disorder and Autistic Disorder are in fact subgroups of a larger diagnostic category.  This larger category is called either Autistic Spectrum Disorders, mostly in European countries, or Pervasive Developmental Disorders ("PDD"), in the United States.  In Asperger's Disorder, affected individuals are characterized by social isolation and eccentric behavior in childhood. There are impairments in two-sided social interaction and non-verbal communication. Though grammatical, their speech may sound peculiar due to abnormalities of inflection and a repetitive pattern. Clumsiness may be prominent both in their articulation and gross motor behavior. They usually have a circumscribed area of interest which usually leaves no space for more age appropriate, common interests. Some examples are cars, trains, French Literature, door knobs, hinges, cappucino, meteorology, astronomy or history.  The name "Asperger" comes from Hans Asperger, an Austrian physician who first described the syndrome in 1944.