pervasive developmental disorder

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several disorders, such as autism and Asperger's syndrome, characterized by severe deficits in many areas of development, including social interaction and communication, or by the presence of repetitive, stereotyped behaviors. Such disorders are usually evident in the first years of life and are often associated with some degree of mental retardation.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A group of five disorders characterized by delays in the development of multiple basic functions including socialization and communication.