What about this theory: If your siblings and you are all of the same gender and you're the oldest or among the oldest, you're likely to have AS. If most of your siblings are of the opposite gender and you're the youngest or among the younger, you're also very likely to have AS.
Of course peaguy had to be an exception.
Bear in mind that there are those that suffer from some form of brain damage which makes them display autistic-like symptoms. For all I know, my difficulties could be caused by evironmental influences, not necessarily genetic.
The hereditary theory seems to be a popular theory, but it isn't really accurate, as far as I know. Autism is still an enigma to human society.
And for the record, I don't think I'm AS in any sense of the word.