About one in 500 children are diagnosed with the developmental disability known
as autism and, more recently, the related conditions Asperger Syndrome and
Pervasive Developmental Disorder. However, there is increasing evidence that many highfuncioning individuals may suffer from "shadow syndromes" of these disorders.
A person with some form of autism is affected in four major
ways:
severe difficulties with talking to and understanding other people;
great trouble with friendships, relationships and other social interaction;
unusual behaviour, frequent tantrums and a great need for routine and
sameness;
poorly developed sensory integration: their environment is a confusing
place to be part of.
Subgroups and related disorders
There is no adjective which can be used to describe every type of person with autism because there
are many forms of this disorder. For example, some individuals are anti-social, some are asocial, and
others are social. Some are aggressive toward themselves and/or aggressive toward others.
Approximately half have little or no language, some repeat (or echo) words and/or phrases, and
others may have normal language skills. Since there are no physiological tests at this time to
determine whether a person has autism, the diagnosis of autism is given when an individual displays a
number of characteristic behaviors.
In the last five years, research has shown that many people who engage in autistic behaviors have
related but distinct disorders. These include: Asperger Syndrome, Fragile X Syndrome,
Landau-Kleffner Syndrome, Rett Syndrome, and Williams Syndrome. Asperger Syndrome is
characterized by concrete and literal thinking, obsession with certain topics, excellent memories, and
being 'eccentric.' These individuals are considered high-functioning and are capable of holding a job
and of living independently.
Fragile X Syndrome is a form of mental retardation in which the long arm on the X chromosome is
constricted. Approximately 15% of people with Fragile X Syndrome exhibit autistic behaviors.
These behaviors include: delay in speech/language, hyperactivity, poor eye contact, and
hand-flapping. The majority of these individuals function at a mild to moderate level. As they grow
older, their unique physical facial features may become more prominent (e.g., elongated face and
ears), and they may develop heart problems.
People with Landau-Kleffner Syndrome also exhibit many autistic behaviors, such as social
withdrawal, insistence on sameness, and language problems. These individuals are often thought of
as having 'regressive' autism because they appear to be normal until sometime between ages 3 and 7.
They often have good language skills in early childhood but gradually lose their ability to talk. They
also have abnormal brain wave patterns which can be diagnosed by analyzing their EEG pattern
during an extended sleep period.
Rett Syndrome is a degenerative disorder which affects mostly females and usually develops
between 1/2 to 1 1/2 years of age. Some of their characteristic behaviors include: loss of speech,
repetitive hand-wringing, body rocking, and social withdrawal. Those individuals suffering from this
disorder may be severely to profoundly mentally retarded.
Williams Syndrome is characterized by several autistic behaviors including: developmental and
language delays, sound sensitivity, attention deficits, and social problems. In contrast to many autistic
individuals, those with Williams Syndrome are quite sociable and have heart problems.
Causes
Although there is no known unique cause of autism, there is growing evidence that autism can be
caused by a variety of problems. There is some indication of a genetic influence in autism. For
example, there is a greater likelihood that two monozygotic twins (i.e., identical twins) will have
autism than two dizygotic twins (i.e., fraternal twins). In the case of monozygotic twins, there is a
100% overlap in genes; whereas in dizygotic twins, there is a 50% overlap in genes, the same
overlap as in non-twin siblings. In a survey conducted in Utah, researchers identified 11 families in
which the father had autism. Of the 11 families, there was a total of 44 offspring, 25 of whom were
diagnosed as having autism. Other research has shown that depression and/or dyslexia are quite
common in one or both sides of the family when autism is present.