My son started having signs of autism awhile back. It was hard to accept, but I know it is from my amalgam filings and his shots. My daughter has some of the same symptoms, but not to the extreme of my son. Why some children? I don't know. Why do some people have problems with metal fillings and not others? Or does everyone really have problems, and they just don't know what the signs are. I guess some people just have "something" in them, that makes them more susceptible, and I guess that's the hundred thousand dollar question, what that is.:(