The diagnostic category pervasive developmental disorders, as opposed to specific developmental disorders, refers to a group of five disorders characterized by delays in the development of multiple basic functions including socialization and communication. More at Wikipedia
Specific developmental disorder - Specific developmental disorders categorizes specific learning disabilities and developmental disorders affecting coordination.
Multiple-complex Developmental Disorder - Multiple complex developmental disorder is a research category, proposed to involve symptoms of autism and schizophrenia.
Multisystem Developmental Disorder - Multisystem developmental disorder is a term used by Stanley Greenspan to describe children under age 3 who exhibit signs of impaired communication as in autism, but with strong emotional attach...
Infantile neuroaxonal dystrophy, a rare and severe neurological disorder which shows developmental regression in infants and toddlers