Which symptoms do autistic children have, say at the age of 2?

PDD: The term "pervasive developmental disorders, " also called pdds, refers to a group of conditions that involve delays in the development of many basic skills. Conditions typically are identified in children around 3 yrs/age, although it begins prior to that age, it's difficult to notice until age of two. A toddler who is not walking, talking or developing as well as other children of the same age.

The M-CHAT screen : (firstsigns.Org) captures qualitative impairments in social reciprocity: joint attention, gaze monitoring, pointing at items to share interest. Atypical social communication may be absent language, words mixed with bizarre jargon (e.g., "digga-digga") or deviant (saying the alphabet before "mama, dada, & bye-bye). Stereotypies, repetitive non-functional movements, may be hard to spot before 3.