The estimated prevalence rate of autistic spectrum disorders, including Asperger syndrome, is 56 per 10,000 people in the U.K.

Autism can be caused by a variety of conditions affecting brain development and which occur before, during or after birth. They include:

• maternal rubella
• tuberous sclerosis
• lack of oxygen at birth
• complications of childhood illnesses (such as whooping cough and measles).

In many instances, genetic traits appear to be important, although the sites of the relevant genes have yet to be identified.

Autism is a pattern of abnormal development that unfolds over time, so diagnosis depends upon obtaining a detailed history of the child's development, and a careful assessment of skills and abilities.

A child with autism will:

• often appear aloof and indifferent to other people, especially other children, although some will enjoy certain forms of active physical contact
  
  
• passively accept social contact and even show some signs of pleasure in this, but will rarely make spontaneous approaches
  
  
• occasionally approach other people but in an odd, inappropriate, repetitive way, paying little or no attention to the responses of those they approach
  
  
• not appreciate the social uses and the pleasure of communication; this is true even of those who have a lot of speech, which they use to talk "at" others and not "with" them
  
  
• not understand language is a tool for conveying information to others; they may be able to ask for their own needs but find it hard to talk about feelings or thoughts and will not understand the emotions, ideas and beliefs of other people
  
  
• be unable to play imaginatively with objects or toys or with other children or adults
  
  
• tend to focus on minor or trivial things around them, for example an earring rather than the person wearing it, or a wheel instead of the whole toy train
  
  
• have a limited range of imaginative activities, possibly copied and pursued rigidly and repetitively
  
  
• miss the point of pursuits that involve words e.g. social conversation, literature, especially fiction and subtle verbal humour
  
  
• always show repetitive activity or behaviour. At a simple level, this might involve repeatedly flicking their fingers, or an object like a piece of string.
  
  
• demonstrate challenging behaviour, such as running away, screaming, biting or kicking other people, grabbing things off counters in shops, socially unacceptable habits, or making naive and embarrassing remarks.
  

About 10% of children with autistic spectrum disorders have some special skill at a much higher level than the rest of their abilities, for example music, art, numerical calculations or jigsaw puzzles. Some have a remarkable memory for dates and things that particularly interest them.

If you suspect that autism is present it is essential that you refer the child for a specialist diagnosis and assessment as early as possible (either your local GP, the Child Development Centre or the Child and Family Guidance Centre), or (if you are a teacher) to your LEA's educational psychologist. In theory, every local authority is supposed to provide such specialist expertise, but in practice this is not always the case.

There are no formal medical tests or blood examinations that can be done to confirm the diagnosis.

As yet there is no cure for autism, but specialised education and structured support can help maximise a child's skills and minimise any behaviour problems.

The right kind of education and care programmes are essential. They make a real difference to the child's life enabling each individual, whatever their level of disability, to achieve as great a degree of independence as possible.