I've certainly been reading a lot more about Autism Spectrum Disorders that I ever thought I would be. DD's primary delays are in the realm of "expressive and receptive language". The team diagnosed other symptoms to a mild degree, but I have yet to be convinced whether any of those are part of her ASD, or are a result of her primary challenge, or are just normal individual variation. That's one of the things that has struck me about ASD -- the large number of symptom-groups and how much individual kids vary in which ones they have and to what degree. Bobby might have severe delay in A & B and a milder difficulty with D, while Billy has a lot of trouble with C and some issues with B & E.
The other thing that's struck me is the wide range of treatments and the fact that nothing's definitely effective in all cases. While my own science background is not in biology, the studies I've read and the widely varying anectodal evidence strongly suggests that there is not just one cause of ASD. There are likely multiple causes and therefore different kids will have different results for a given treatment. For DD, a glutin-free casein-free diet has definitely made a difference. This suggests that an opiate reaction may be part of what's causing her symptoms. Again, however, I don't believe there is necessarily a single cause for ASD. So while she will be starting Applied Behavior Analysis (ABA) therapy soon, we will also be pushing for more tests to be done where appropriate.