Parents can observe the symptoms in their child in the first year. The baby shows uncoordinated motor skills such as clumsy way of crawling or walking.
They don't like any change in their daily routine or lifestyle.
They are bad at social skills such as starting a conversation and maintaining it, knowing about others' body language, etc.
The child will be poor in understanding a joke or a sarcastic comment.
They lack tone, pitch and accent, so their speech is hard to understand.
They can't make an eye contact with other person.
They talk a lot on a particular subject and are interested in one sided conversation.
They are very sensitive and gets distracted by light and loud noise.
If the child shows a combination of the above symptoms and if he or she has a significant trouble with social situations, then the child can have asperger syndrome.  

The asperger syndrome symptoms during teen years are:

Some of the symptoms of childhood persists through the teen years.
They inculcate a feeling that they are different from others.
They are immature when compared with others of the same age.
They are socially isolated, which leads to depression, as per the website NINDS.

Asperger syndrome treatment mainly aims at the treatment of the main symptoms of the disorder, which include poor communication skills, repetitive routines and clumsiness in physical activities. The treatment needs a combined effort of parents, teachers and the doctor. Asperger syndrome treatment strategies include:
Education and training provided by the parents.
Specialized educational strategies used by the teachers.
Language therapy.
Sensory integration training, which makes them to desensitize to the stimuli, to which they are overly sensitized.
Psychotherapy and behavioral therapy.