Links have been posted disputing this claim and those 3% have been found to have something, not Celiac....if Celiac is an autoimmune disease, which it is, there has to be some genetic component present, identified or not.
No one is saying that celiac is not genetic. Just that not all the associated genes are commonly known. In my own family I have seen one person who was diagnosed with positive blood and biopsy and then years later had their genes tested and was told since they didn't have DQ2 or DQ8 that they couldn't have celiac. So now they are back on gluten and suffering the effects. That is what encouraged me to get my genes tested. I have DH and am a firmly GI diagnosed celiac and I don't have either of those two genes. I have a double DQ9. IMHO no one who has positive blood tests should quit or not start the diet just because the gene test is negative.