Most children with autism are diagnosed at or before age three. There
are times when it is obvious that there might be a problem, and other
times things can go unnoticed. Children with classic autism have
signs and symptoms that are rather obvious. However, those with
higher functioning forms like Asperger's may not show signs that are
not so easy to pick up on. No matter why type of function these
children have, there are some things that are used in diagnosing
autism that will be noticed in all children. Parents with concerns
should see a doctor for proper diagnosis.
Parents are the first step in diagnosis, but doctors may notice
problems before a parent. There are many signs they can see as early
as age one. A child with autism will be slow to speak or communicate,
if they do so at all. They may be over stimulated or under stimulated
by noises and actions. They may play alone, and they may also use
repetitive motions. Some children might also be super sensitive to
touch, and may cry out when held. Others may have tantrums that seem
to come from things that other children handle well. Sometimes the
smallest change in daily routine can trigger a tantrum. They might
also ignore others, and cannot seem to maintain eye contact with
anyone they don't know. Many have problems with delayed motor skills,
and might appear to be very clumsy....

http://groups.yahoo.com/group/autismnvc