A varied kind of disorders may be brought under the broad umbrella of autism. Therefore, this disorder is also called as autistic spectrum disorder (ASD). One such is pervasive developmental disorder not otherwise specified (PDDNOD) in which children demonstrate similar but not all symptoms to autism. A minor form of autistic disorder is called Asperger syndrome. Other forms of the autistic disorders are those that mostly affect girls such as Rett Syndrome, where the child may suddenly withdraw from all social contacts. Another very rare form of the disease is childhood disintegrative disorder (CDD) in which the child rapidly loses all learned communications and regresses into a socially isolated individual.