Autism

What is…
Is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is threeyears old. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize; how this occurs is not well understood. It is one of three recognizeddisorders in the autism spectrum (ASDs), the other two being Asperger syndrome, which lacks delays in cognitive development and language, and Pervasive Developmental Disorder-Not Otherwise Specified(commonly abbreviated as PDD-NOS), which is diagnosed when the full set of criteria for autism or Asperger syndrome are not met.

Characteristics …
Autism is a highly variable neurodevelopmentaldisorder that first appears during infancy or childhood, and generally follows a steady course without remission. Overt symptoms gradually begin after the age of six months, become established by agetwo or three years, and tend to continue through adulthood, although often in more muted form. It is distinguished not by a single symptom, but by a characteristic triad of symptoms: impairments insocial interaction; impairments in communication; and restricted interests and repetitive behavior. Other aspects, such as atypical eating, are also common but are not essential for diagnosis. Autism'sindividual symptoms occur in the general population and appear not to associate highly, without a sharp line separating pathologically severe from common traits

Causes…
It has long been presumedthat there is a common cause at the genetic, cognitive, and neural levels for autism's characteristic triad of symptoms.[61] However, there is increasing suspicion that autism is instead a complexdisorder whose core aspects have distinct causes that often co-occur.
Deletion (1), duplication (2) and inversion (3) are all chromosome abnormalities that have been implicated in autism.
Autism has a...