Causes of Autism
- Abnormalities in brain structure
- Biochemical disorders
- Viral Infection
- Yeast/Candida infections
- Allergies and food sensitivities (milk and wheat products)
- Dysfunctional immune system.
The Genetic Component
A study done at the University of
Washington suggested there might be six or more genes that have to come
together in one individual in the right form to lead to autism.
Researchers have identified only one specific genetic connection with
autism - fragile X syndrome, which is also the most common cause of
genetically inherited mental retardation. According to the
National Fragile X Foundation of USA, between 2 and 6 percent of all
children diagnosed with autism have a fragile X gene mutation, and
approximately one-third of all children with fragile X have autism. If
a child with autism also has fragile X, there is one-in-two chance that
boys born to the same parents will have fragile X syndrome. If one
identical twin has autism, there is a 90 percent chance that the other
will have autism as well. Research done at Yale Child Study Centre has
shown that if you have given birth to a child with autism, there is
one-in-twenty chance of giving birth to another child with autism
(Exkorn, Karen Siff. The Autism Sourcebook. New York: Harper Collins
Publishers Inc., 2006 (p.73)).
The Brain Component - The Underconnectivity Theory
There is a disruption of circuitry in brains of children with autism.
Some parts are over-connected; some are under-connected. There are
early developmental cues that point to brain abnormalities; smaller
head size at birth followed by a period of excessive head growth
between 6 months and 2 years of age, where chronic inflammation occurs
in the areas of excessive growth. In the frontal lobes where nerve cells
are responsible for higher order processing like decision-making and
social reasoning, the nerve cells are much smaller than normal.
The Environmental Component
environmental factors include viral infections, exposure to
environmental chemicals such as lead and mercury, environmental toxins
such as PCBs (polychlorinated biphenyls), and metabolic imbalances.
The Immune System Component
with autism seem to have lower levels of cytokines, which are protein
molecules that help mediate the body's immune reponse and influence
both behaviour and mood.
The Immunization Component
had been raised concerning MMR (Mumps, Measles, Rubella) vaccine and
vaccines that contain thimerosol, a mercury preservative found in
immunizations for hepatitis, whooping cough, tetanus, and diphtheria.
However, to date, no scientific study has discovered beyond a doubt
that a link exists between immunization and autism.