Limitations in social communication and social interaction including:

• Challenges  in the to and fro of social-emotional exchanges
• Restricted awareness and integration of non-verbal communication
• Difficulty in initiating, developing and maintaining relationships

At least two areas of restricted, repetitive patterns of behaviour from:

• Stereotyped or repetitive speech
• Excessive dependence upon routine and rituals resulting in excessive resistance to change;
• Intense and restrictive special interests
• Sensory sensitivities

Although symptoms may not be fully developed they are present in early childhood and limit day to day functioning.

Link: DSM-V Autism Spectrum Fact Sheet

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, VA, American Psychiatric Association, 2013.