Sometimes, the blood test is borderline, and the biopsy is ambiguous. That’s when they check your genes—specifically HLA-DQ2 and HLA-DQ8. Almost every celiac has one of these. But here’s the kicker: 30% of the general population has these genes too, and most never develop celiac. So a positive gene test doesn’t guarantee you have it, but a negative test basically rules it out.
Think of it as the tiebreaker in a confusing game. If you have the genes and the symptoms, the puzzle pieces fit. If you don’t have them, your doctor will start looking for other culprits—like IBS or a wheat allergy.
