There are varying degrees of problems associated with these disorders. Common symptoms of these disorders include problems with communication, and social interaction and repetitive behaviors. Another name for this group of disorders is Autism Spectrum Disorders (ASD).
Expression of symptoms, their severity and manifestations varies greatly. Some individuals with mild problems live independent lives whereas on the other hand individuals with severe problems have to face many problems and need life long care and supervision.
Rett’s syndrome: It is mostly present in girls than boys. There is normal development of the child till six months of life. One important finding in Rett’s syndrome is presence of abnormally small head known as microcephaly. Other symptoms associated with this syndrome are teeth grinding and hand wringing. With advancement of the disease, child will develop other symptoms e.g. seizures.
Childhood disintegrative disorder: This is relatively a rare disorder. This disorder affects boys more as compare to girls. Child shows normal development for the first three or four years. Suddenly they show regression in language skills and avoid social interaction. Repetitive behavior such as flapping of fingers is present.
Asperger’s syndrome: It is a milder form of autism. Children with asperger syndrome show normal development. They face problems in social interaction, communication and exhibit repetitive behavior. Children with asperger syndrome show good academic results but they focus their interest on one area and lose interest in everything else.
The difference between autism and asperger’s syndrome is that in autism delay in communication skills, social interaction and other developmental signs are present before the age of three whereas in asperger’s syndrome such delays occur later in life. Children with asperger’s syndrome have high level of brain functioning.
Pervasive development disorder not otherwise specified: Children with PDDNOS shows mild form of impairment. They face difficulties in interaction with the people or lack in communication skills. Repetitive behavior is more pronounced as compare to asperger’s syndrome.
Some researchers believe that all these disorders are similar to each other in one way or another. No exact cause of these disorders has been discovered yet. Most individuals suffering with these disorders can learn to deal with their problems with appropriate care and to live their life independently.
The National Autistic Society, London, England. "Do children with autism spectrum disorders have a special relationship with Thomas the Tank Engine and, if so, why?" Research undertaken by Aidan Prior Communications. February, 2002.
National Institute of Mental Health, Autism Spectrum Disorders (Pervasive Developmental Disorders) A detailed booklet that describes symptoms, causes, and treatments, with information on getting help and coping. 2004.
www.AmericanAutismSociety.org
http://www.disability-resource.com/Autism/asperger-syndrome.html