Savant syndrome , sometimes referred to as savantism, is a rare condition in which people with developmental disorders have one or more areas of expertise, ability, or brilliance that are in contrast with the individual's overall limitations. Although not a recognized medical diagnosis, researcher Darold Treffert says the condition may be either genetic or acquired.
According to Treffert, about half of all people with savant syndrome have autistic disorder, while the other half have another developmental disability, mental retardation, brain injury or disease. He says, "... not all autistic people have savant syndrome and not all people with savant syndrome have autistic disorder". Other researchers state that autistic traits and savant skills may be linked, or have challenged some earlier conclusions about savant syndrome as "hearsay, uncorroborated by independent scrutiny".
Though it is even more rare than the savant condition itself, some savants have no apparent abnormalities other than their unique abilities. This does not mean that these abilities weren't triggered by a brain dysfunction of some sort but does temper the theory that all savants are disabled and that some sort of trade-off is required.