Communication abnormalities
Use of gestures is frequently limited.
Body language or nonverbal communication may be awkward and inappropriate.
Facial expressions may be absent or inappropriate.
Pragmatic errors are commonly produced by children with Asperger disorder in response to questions. Children with Asperger disorder often produce irrelevant responses.11
Speech and hearing
Affected children demonstrate several abnormalities in speech and language, including pedantic speech and oddities in pitch, intonation, prosody, and rhythm.
Miscomprehension of language nuance (eg, literal interpretations of figures of speech) is common.
Individuals often exhibit practical speech problems, including an inability to use language in social contexts, a lack of sensitivity about interrupting others, and irrelevant commentary.
Speech may be unusually formal or used in idiosyncratic ways that others do not understand.
Individuals may vocalize their thoughts without censoring. Personal remarks inappropriate to most social environments may be uttered routinely.
The amount of speech may also widely vary and reflect the individual's current emotional state more than the communication requirements of the social setting. Some individuals may be verbose and others taciturn. Furthermore, the same individual may demonstrate excesses and paucity of speech intermittently.
Some individuals may display selective mutism, speaking not at all to most people and excessively to specific people. Some may choose to talk only to people they like. Thus, speech may reflect idiosyncratic interests and preferences of the individual.
The form of language chosen may include metaphors that are meaningful only to the speaker. The message meant by the speaker may not be understood by those who hear it, or the message may be meaningful only to a few people who understand the private language of the speaker.
Children often exhibit auditory discrimination and distortion, particularly when the child encounters 2 or more people speaking simultaneously.
Activities
Children exhibit peculiar and narrow interests, excluding other activities.
These interests may be so important that the children do not develop typical relationships with their family, school, and community.
Sensory sensitivity
Children may show sensitivity to sound, touch, taste, sight, smell, pain, and temperature. For example, a child may demonstrate either extreme or diminished sensitivity to pain.
Children may be particularly sensitive to the texture of foods.
Children may exhibit synesthesia, including a sensory response to an environmental stimulus in a different sensory modality.
Physical
Screening for a theory of mind

Key features of the deficit manifested in people with Asperger syndrome pertain to their inability to understand the thoughts of other people and themselves. A typical child can recognize the thoughts of other children and himself or herself and hypothesize how other people are likely to respond to life occurrences. The lack of this comprehension in a person with Asperger syndrome is termed a deficiency in the formation of a theory of the mind.
[link to emedicine.medscape.com]