Genetic testing involves looking for the (human leukocyte antigen) HLA-DQ2 and/or DQ8 haplotypes (I have HLA-DQ8 0302). Without DQ2 or DQ8 there is only a rare chance that they have celiac; they could have gluten intolerance or some other complication. About 1% of the world's population has celiac (mostly undiagnosed, and some areas with higher percentages). More than 30% of the US population has HLA DQ2 and/or DQ8 and several percent of those folk develop celiac. Doctors tend not to believe you have celiac unless you have positive celiac panel bloodwork and preferably small intestine biopsy. Irksome that genetics and symptoms are not enough for some doctors. https://www.sciencedirect.com/topics/nursing-and-health-professions/hla-dq2-antigen https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9331400/