Autism Spectrum Disorder—“Autism” means a developmental disability significantly affecting communication, social interaction, sensory processing and causes significant variation in the rates and sequences of development causing an adverse impact on a child’s educational performance. A child must demonstrate characteristics in all four of these areas to meet eligibility criteria. Other characteristics that may be associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. Essential features are typically but not necessarily manifested before age three. Autism may include autism spectrum disorders such as but not limited to autistic disorder, pervasive developmental disorder—not otherwise specified, and Asperger’s syndrome. The term doesn't not apply if a child’s educational performance is adversely affected primarily because the child has an emotional disturbance. However, a child who qualifies for special education under the category of autism may also have an emotional disturbance as a secondary disability if the child meets the criteria under emotional disturbance.