I have a theory that I want to share with anyone who will listen. I do believe that a gluten free diet would benefit children on the spectrum. Gluten is a toxic protein for everyone. We cannot digest it properly and thus chaos erupts! I cannot tell you how many people I have met that have children on the spectrum and also have celiac disease. I believe there is a connection. My own son has spectrum issues.
I believe 30% of all Americans carry these celiac genes. Wouldn't it be something if we could find out what specific genes these children on the spectrum have in common! I also believe that the genes are triggered by the vaccination schedules. I am not against vaccinations, however, I would suggest that you develop your own schedule and ask the doctors to separate them (especially the MMR). They can do this, but this is inconvenient for the doctor. Do what you know your GUT is telling you! (No pun intended)
Many parents say that the GF diet doesn't work for their children. If you cheat once in a while and give them a gluten-filled snack, it won't work. Also, you may not be aware of the hidden gluten-containing ingredients in everyday foods- Rice Krispy treats have malt flavoring (malt is made from barley and that contains gluten!)
You may be toasting their GF bread in the same toaster that you toast your Wonder bread. This is a cross-contamination issue. Crumbs can contaminate the GF bread etc...
If you are going to try a GF diet for your child on the spectrum, you need to educate yourself on the hidden gluten containing ingredients, why you can not cheat, and possible cross contamination issues in your kitchen.
I have not mention casein free (CF) information because I do not know enough about this to share. Please visit http://www.gfcfdiet.com/