الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
 |  | from | 120 |  |  |
| | | from | 120 | | |
Abstract
Pervasive developmental disorders consist of five disorders: autism,
Asperger’s disorder, childhood disintegrative disorder, Rett disorder and
pervasive developmental disorder. These disorders marked by their onset in
infancy and preschool years. Hallmarks of these disorders include impaired
communication, impaired social interaction as well as stereotypic behaviors,
interests and activities. Autism which is a life long marked impairment in
reciprocal social interaction communication, and restrictive range of activities and
interests present by 3 years of age should be distinguished from other (ASD) like
Asperger’s disorder which is characterized by preservation of language
development, childhood disintegrative disorder which is characterized by
normal pattern of development up to 2 years followed by severe developmental
regression. Rett disorder which is distinguished only in females and has
characteristic pattern of developmental regression after a pattern of relatively
normal development in the first few months associated with deceleration of the
development of head circumference and prominent motor inco-ordination.
The recent surveys suggest that the rate of all pervasive
developmental disorders is about 60 per 10,000; the prevalence of autism today is
estimated as 13 per 10.000. Asperger’s disorder is approximately 3 per] 0000, the
childhood disintegrative disorder is about 0.2 per 10000, but the assessment
process, sample size, and geographic location of studies all have an effect on
prevalence estimates, also many surveys indicate a relationship between autism
and sex, IQ and other medical conditions (Fombonne, 2005).