Causes of Autism

The incidence of autism has grown dramatically in the last 10 years. It is now estimated that some form of autism occurs in 1 out of every 150 births⁴. It is the fastest growing developmental disability, more common now than Down Syndrome, childhood cancer, or diabetes. It is not known what causes autism, although research continues to get us closer to answering that question. There is clearly a genetic component to the disorder; having one child with autism greatly increases the chances of having another child with autism. However, genetics is not the only factor involved. This is apparent in studies conducted with identical twins. There are many instances where one identical twin has autism and the other twin does not. As the twins share the same genes, another factor must be contributing to the presence of autism. Experts now believe that a combination of genetics and environmental factors cause autism. Researchers suspect that genes may make a child more susceptible to autism but that an environmental factor may trigger it. What the environmental factors are is unknown at this time. Although questions have been raised about whether vaccinations could be a factor involved in autism, no evidence of this has been found. An Institute of Medicine committee has reviewed existing studies on a possible link between autism and vaccines and has concluded that no linkage exists⁵.

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A website devoted to the issue of genetics and autism. Summary of Institute of Medicine report on possible linkage between autism and vaccines.