What role does HLA-DQ2 play in Sport?

HLA-DQ2 is a genetic risk marker for celiac disease, an autoimmune condition triggered by gluten. In sports, there is no direct, sport-specific function of HLA-DQ2. However, undiagnosed celiac disease or non-celiac gluten sensitivity in affected athletes can impair performance, cause fatigue, nutrient deficiencies (e.g., iron, vitamin D), and gastrointestinal issues. Carriers of HLA-DQ2 have an increased risk for celiac disease, but most never develop symptoms. A genetic test alone is not diagnostic; if celiac disease is suspected, serological tests (tTG-IgA) and duodenal biopsy are required. For asymptomatic athletes without family history or symptoms, the presence of HLA-DQ2 has no clear clinical consequence. Evidence for a performance-relevant effect in symptom-free carriers is weak. Supplements or diets without medical indication are not recommended. Caveat: Commercial marketing of genetic tests often overstates the importance of HLA-DQ2 for general health and athletic performance.