The range of Autism Spectrum Disorders 

The range of disorders on the Spectrum includes:

• Kanner Autism
  People with Kanner Autism are at the lower functioning end of the Spectrum and may act totally detached from the world. Most people with Kanner Autism will have some degree of learning disability.
  
  
• Asperger Syndrome (AS)
  People with Asperger Syndrome are at the higher functioning end of the Spectrum and may be able to lead independent lives, even though they experience difficulty in their social interactions. People with AS have average to above average intelligence.
  
  
• Childhood Disintegrative Disorder
  Also known as Heller's Syndrome, this is a rare Pervasive Developmental Disorder (PDD).  PDD's are a spectrum of behavioural problems associated with Autism and may also be referred to as Autistic Spectrum Disorders (ASD).  Childhood Disintegrative Disorder differs from Autism in that it occurs in children who have previously had normal development but who then appear to regress. 
  http://www.patient.co.uk/
  
  
• Rett Syndrome
  This is a complex neurological disorder which mainly affects girls.  Most people with Rett Syndrome are profoundly and multiply disabled. 
  http://www.patient.co.uk/ 
  
  
• Dyspraxia
  Developmental dyspraxia is an impairment or immaturity of the organisation of movement.  Individuals also have impairments with social interactions and language problems. 
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• Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS)
  This term refers to people who have difficulties in more than one developmental area but who do not fulfil the diagnostic criteria for Autism or Asperger Syndrome.
  http://www.nas.org.uk/
  
  
• Sematic Pragmatic Disorder
  There has been much debate over the years as to whether this is a separate disorder from Autism and whether it's a language problem that many people with ASD have.  Semantic refers to the use of words and pragmatic refers to the understanding of words.  The current way of thinking by most professionals appears to be that it should be viewed as part of the Autistic Spectrum rather than a developmental language disorder.
  http://www.nas.org.uk/
  
  
• High Functioning Autism (HFA)
  There continues to be a debate over the differences between HFA and Asperger Syndrome.  The general agreement amongst professionals appears to be that if an individual with Autism has an IQ in the normal range (or above), they are said to have HFA.  If an individual meets all the criteria for HFA except communicative abnormality or history of language delay, they are said to have Asperger Syndrome.
  http://www.nas.org.uk/
  
  

More about ASD

• The Triad of Impairments
• Some facts about ASD