BackgroundCeliac disease is a multifactorial disorder of the proximal small intestine associated with a permanent intolerance to gluten. The HLA-DQ(&agr;1*0501, &bgr;1*02) heterodimer is strongly associated with this disease.Materials and MethodsThe authors studied a sample of 354 unrelated Caucasoid individuals: 118 patients with celiac disease and 236 control subjects. All patients and controls subjects were born in Gran Canaria (Canary Islands) at least two generations ago.The authors typed the HLA-DQA1 and DQB1 genes by DNA methods. The positive and negative predictive values of the test were studied.ResultsThe mean age at diagnosis was 25.4 months, with a statistically significant proportion of females (64.4%,P< 0.002). For DQB1 gene, the susceptibility allele found was DQB1*02 (relative risk [RR] = 7.60, confidence interval [CI]: 5.35–10.78), whereas for the DQA1 gene, the susceptibility alleles found were DQA1*0501 (RR = 2.99, CI: 2.16–4.14) and DQA1*0201 (RR = 1.88, CI: 1.25–2.82). The presence of the DQ(&agr;1*0501, &bgr;1*02) heterodimer was strongly associated with the disease (92.4% in the patients group vs. 21.6% in control subjects). HLA-DQ8 heterodimer was absent in the authors' patients. DQB1*02 homozygous subjects presented a higher relative risk for celiac disease. There was no correlation of DQB1*02 dosage with age at onset below 12 years of age or with gender distribution. Sensitivity, specificity, and the positive and negative predictive values of the test were 92.4%, 78.4%, 68.1%, and 95.4%, respectively.ConclusionsThe presence of the DQ2 (DQA1*0501/DQB1*02) heterodimer is strongly associated with celiac disease in the population studied by the authors. The value of this test derives from its ability to exclude disease when a negative result occurs.