Autism Causes

Posted on Sep 23, 2008 in Autism, Chronic Disease

Date updated: May 31, 2008
Content provided by MayoClinic.com

Autism has no single, known cause. Given the complexity of the disease, the range of autistic disorders and the fact that no two children with autism are alike, it’s probable that there are many causes. These may include:

* Genetic errors. Researchers have discovered a number of genes that appear to be involved in autism. Some may make a child more susceptible to the disorder; others affect brain development or the way brain cells communicate. Still others may determine the severity of symptoms. Each genetic error may account for a small number of cases, but taken together, the influence of genes may be substantial. Some genetic errors seem to be inherited, whereas others occur spontaneously.
* Environmental factors. Many health problems are due to both genetic and environmental factors, and this is likely the case with autism as well. Researchers are currently exploring whether viral infections and air pollutants, for instance, play a role in triggering autism.
* Other causes. Other factors under investigation include problems during labor and delivery and the role of the immune system in autism. Some researchers believe that damage to the amygdala – a portion of the brain that serves as a danger detector – may play a role in autism.

One of the greatest controversies in autism centers on whether a link exists between autism and certain childhood vaccines, particularly the measles-mumps-rubella (MMR) vaccine and vaccines with thimerosal, a preservative that contains a small amount of mercury. Though most children’s vaccines have been free of thimerosal since 2001, the controversy continues.