Autism Spectrum Disorders
The website Reading Rockets (WETA) explains why autism spectrum disorders is not a "learning disability"--we do not know the cause of ASD, and we know that LDs are neurological disorders. "Sometimes the media, the public, and even educators confuse autism with learning disabilities. They are two separate disorders. According to the Autism Society of America, autism is a developmental disability that typically appears during the first three years of life and affects a person's ability to communicate and interact with others. Autism is defined by a specific set of behaviors and is a 'spectrum disorder' affecting individuals differently and to varying degrees. There is no known single cause for autism."
Each of the disorders on the autism spectrum share some or all of the following characteristics, which can vary from mild to severe:
Children with autism or one of the other disorders on the autism spectrum can differ considerably with respect to their abilities, intelligence, and behavior. Some children don't talk at all. Others use language where phrases or conversations are repeated. Children with the most advanced language skills tend to talk about a limited range of topics and to have a hard time understanding abstract concepts. Repetitive play and limited social skills are also evident. Other common symptoms of a disorder on the autism spectrum can include unusual and sometimes uncontrolled reactions to sensory information--for instance, to loud noise, bright lights, and certain textures of food or fabrics.
Above from Reading Rockets, Autism Society, and National Dissemination Center for Children with Disabilities