"Neurodevelopmental disorder" refers to the specific medical disease or condition that causes the developmental disability in the first place (e.g. Down Syndrome, PKU, William's Syndrome, Perinatal hypoxia/ischemia). Neurodevelopmental disorders can be either "genetic" or "acquired"(see below). It is important for the physician to establish the precise etiology/syndrome of the neurodevelopmental disorder because knowing the exact cause then directs the physician towards syndrome-associated conditions that will need to be evaluated and monitored (e.g. thyroid dysfunction in Down Syndrome). Regardless of the exact cause, most people with neurodevelopmental disorders will have one or more of four "general" complications, namely: cognitive disability, neuromotor dysfunction, seizures, or abnormal behaviors. The purpose of this site is education regarding neurodevelopmental disorders, their precise diagnosis, and management of their complications. The issue of "disability" (i.e. the functional limitation) that results from the neurodevelopmental disorder, its social ramifications and its multidisciplinary management, while not being the primary focus of this site should nonetheless always be considered by the health care professional who is charged with the responsibility of providing services to an individual with a neurodevelopmental disorder.