Autists have problems with other parts of the gluten and casien proteins, just google reichelt gluten or gliadin I think.
Those tiny parts of gluten act like morphine in the body.

In celiac and neurological problems from gluten, the DQ2 and DQ8 gene, or half the DQ2 gene, or sometimes the DQ7 and 9 gene which only differ from DQ8 by one amino acid, present the gliadin part to the immune system. (DQ6 celiacs have also been found, and DQ5, and some have been mistyped, and often the alpha chain has not been typed so they could just have been half the DQ2, namely 0501 i the alpha chain, and the beta chain anything else than DQ4)

These two things are different issues.

nora