Some research is to seek information about symptoms to aid in the diagnostic process. Other research is to identify a cause, although much of this research is still done on isolated symptoms. Many studies have exposed base differences in areas such as brain structure. To what end is currently unknown; research is ongoing, however.
Peter Szatmari suggests that AS was promoted as a diagnosis to spark more research into the syndrome: "It was introduced into the official classification systems in 1994 and has grown in popularity as a diagnosis, even though its validity has not been clearly established. It is interesting to note that it was introduced not so much as an indication of its status as a 'true' disorder, but more to stimulate research ... its validity is very much in question."
The direct cause(s) of AS is unknown. Even though no consensus exists for the cause(s) of AS, it is widely accepted that AS has a hereditary factor. It is suspected that multiple genes play a part in causing AS, since the number and severity of symptoms vary widely among individuals. Studies regarding the mirror neurons in the inferior parietal cortex have revealed differences which may underlie certain cognitive anomalies such as some of those which AS exhibits (e.g., understanding actions, learning through imitation, and the simulation of other people's behavior). Non-neurological factors such as poverty, lack of sleep, substance abuse by the mother during pregnancy, discrimination, trauma during early childhood, and abuse may also contribute.
Other possible causative mechanisms include a serotonin dysfunction and cerebellar dysfunction. Simon Baron-Cohen proposes a model for autism based on his empathising-systemising (E-S) theory.[52] The E-S theory holds that the female brain is predominantly hard-wired for empathy, while the male brain is predominantly hard-wired for understanding and building systems, and that AS is an extreme of the male brain.
Some genetic studies point to involvement of neuroligins in AS. Neuroligins are a family of proteins thought to mediate cell-to-cell interactions between neurons. Neuroligins function as ligands for the neurexin family of cell surface receptors. Mutations in two X-linked genes encoding neuroligins NLGN3 and NLGN4 have been reported. These mutations affect cell-adhesion molecules localized at the synapse and suggest that a defect of synaptogenesis may predispose to autism.