<<Disclaimer: Verify this information before applying it to your situation.>>
There are no GF beers. Many US beers now used broken rice as an
ingredient instead of wheat. The malt from barley remains an ingredient
in these "rice beers".
Homwbrewers may be interested in the Feb/Mar 94 issue of Brew Review.
The article "Beer Allergy" give somes notes on experiments with GF beer.
I have not seen the article.