Evidence check: HLA-DQ2 in the context of allergy

HLA-DQ2 is a genetic variant strongly linked to celiac disease, an autoimmune condition, not a typical allergy. In allergy diagnostics, HLA-DQ2 has no established role. Evidence for celiac disease is human-strong (large GWAS, clinical guidelines), but for allergy it is unclear or marketing-driven. Some direct-to-consumer tests misleadingly present HLA-DQ2 as an 'allergy gene'. A positive result warrants medical follow-up for celiac disease if symptoms are present (e.g., diarrhea, fatigue, rash). However, many carriers remain healthy. Caveat: Do not self-treat; allergy testing (IgE) and celiac serology (tTG-IgA) are the appropriate tools. Genetic tests have limited utility for allergy prediction overall.