The theories of Boyd Haley, former chair of the chem dept at the U of KY, are interesting on this subject, including the possible role of the so called "alzheimer's gene".

http://www.stelior.ee/Boyd_Haley_Medical_Veritas_AD_paper_final.pdf


He also addresses it in this long and somewhat technical presentation.
http://www.myspace.com/video/vid/7383821


This theory then gets applied to autism. A woman who has had exposure to heavy metals (HMs) and has bad detox genes passes on some of her HMs to her child during pregnancy. She also may pass on her bad detox genes to the child. At some point the child receives a dose of HMs (maybe from a vaccine, or later in life from Amalgam filling dental work, or occupational exposure) that is the straw that breaks the camel's back. The body's detox systems can no longer handle the detox process. Some of us, including me and Dr. Mark Hyman who does health programs on PBS, started our downward slide after some illness such as Lyme. Hg also affects the immune system.

One of mercury's effects is on the body's detox system. Levels of other toxins then start to rise as well. These can affect many parts of the body. It is one reason why people who have a mercury problem have such a strange and long list of symptoms.

There is much more that could be said but don't expect to hear it from a doctor who has been injecting people with vaccines that contain mercury as a preservative or from dentists who have been putting silver-mercury Amalgam in your mouth!

Joe