Savant synrome, sometimes abbreviated as savantism, is not a recognized medical diagnosis, but researcher Darold Treffert defines it as a rare condition in which persons with developmental disorders (including autism spectrum disorders) have one or more areas of expertise, ability or brilliance that are in contrast with the individual's overall limitations. Treffert says the condition can be genetic, but can also be acquired, and coexists with other developmental disabilities "such as mental retardation or brain injury or disease that occurs before (pre-natal) during (peri-natal) or after birth (post-natal), or even later in childhood or adult life."