Varies. Can be mild to severe. They develop normally and suddenly lose their social/language skills, unusual behaviors, odd repetitive movements-hand wringing, finger twisting, unusual preoccupation, generally do not make friends easily, may seem clumsy or awkward. Some are exceptionally talented or skilled in a particular area eg music or math.
Communication. Generally, substantial difficulties in pragmatic verbal and nonverbal reciprocal communication, stereotyped interests or activities, and sometimes unusual mannerisms - there will be a new system in dsm-v considering autism and aspergers as a continuum: http://cpancf. Com/autismspectrumdisorder. Asp.