Wiktionary
n. The range of conditions classified as pervasive developmental disorders, generally held to include autistic disorder, Asperger syndrome, and pervasive developmental disorder - not otherwise specified (PDD-NOS). Also includes childhood disintegrative disorder and Rett syndrome.
Wikipedia
Autism spectrum or autistic spectrum describes a range of conditions classified as neurodevelopmental disorders in the fifth and most recent revision of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders ( DSM-5) published in 2013.
The DSM-5 redefined the autism spectrum to encompass the previous ( DSM-IV-TR) diagnoses of autism, Asperger syndrome, pervasive developmental disorder not otherwise specified (PDD-NOS), and childhood disintegrative disorder.
Features of these disorders include social deficits and communication difficulties, stereotyped or repetitive behaviors and interests, sensory issues, and in some cases, cognitive delays.
Usage examples of "autism spectrum".
All of this unusual behavior was the result of Asperger's syndrome, a rare disorder at the less severe end of the autism spectrum.
A small, rotund man who walked awkwardly, as if he had never really learned how to move his legs, Marty had Asperger's Syndrome, a rare disorder at the less severe end of the autism spectrum.