What are the mild symptoms of autism and Asperger syndrom?

None are mild. The potential warning symptoms of later trouble are 1. Neonatal jaundice, 2. So-called "colic" and 3. Ear infections that are treated with antibiotics repeatedly. The earliest autism symptoms are a rather sudden change from normal mental development, e.g. Loss of speech, persistence of temper tantrums, hand flapping etc.
Aspergers. Try this video for more information. Check out this video on youtube: http://youtu.Be/xg1ngp1ngds.