Celiac disease (CD) is a genetic disorder associated with HLA-DQ α/β heterodimers. This study shows that the DR3DQw2 haplotype is strongly associated with CD. The DQ α chain of DR3DQw2 is identical to that of DR5DQw7, while the DQ β chain is similar to that of DR7DQw2. The pairing of α and β chains is determined by amino acid residues in the first domain. Individuals who are DR5DQw7/DR7DQw2 heterozygous may express the same DQ α/β heterodimers as those formed by the DR3DQw2 haplotype. Using allele-specific oligonucleotide probes, the study found that 98.9% of CD patients carry DQA1 and DQB1 genes that may encode the same DQ α/β heterodimer. This suggests that most CD patients share a particular cis- or trans-encoded DQ α/β heterodimer. The study also found that DR3 is the most common HLA allele associated with CD, while DR5/7 is associated with CD in combination with DR3 or DR5. The results support the idea that the DQ α/β heterodimer plays a critical role in CD susceptibility. The study also suggests that the DQ α/β heterodimer may interact with gluten peptides, contributing to the pathogenesis of CD. The findings indicate that the DQ α/β heterodimer is a key factor in CD susceptibility.Celiac disease (CD) is a genetic disorder associated with HLA-DQ α/β heterodimers. This study shows that the DR3DQw2 haplotype is strongly associated with CD. The DQ α chain of DR3DQw2 is identical to that of DR5DQw7, while the DQ β chain is similar to that of DR7DQw2. The pairing of α and β chains is determined by amino acid residues in the first domain. Individuals who are DR5DQw7/DR7DQw2 heterozygous may express the same DQ α/β heterodimers as those formed by the DR3DQw2 haplotype. Using allele-specific oligonucleotide probes, the study found that 98.9% of CD patients carry DQA1 and DQB1 genes that may encode the same DQ α/β heterodimer. This suggests that most CD patients share a particular cis- or trans-encoded DQ α/β heterodimer. The study also found that DR3 is the most common HLA allele associated with CD, while DR5/7 is associated with CD in combination with DR3 or DR5. The results support the idea that the DQ α/β heterodimer plays a critical role in CD susceptibility. The study also suggests that the DQ α/β heterodimer may interact with gluten peptides, contributing to the pathogenesis of CD. The findings indicate that the DQ α/β heterodimer is a key factor in CD susceptibility.