Gene HLA-DQA1
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Also known as
major histocompatibility complex class II DQ alpha 1, HLA-DQA, MHC class II DQ alpha chainOverview
HLA-DQA1 (HLA Class II Histocompatibility Antigen DQ Alpha 1) encodes the alpha chain of the HLA-DQ heterodimer, an MHC class II molecule essential for presenting extracellular antigens to helper T cells. HLA-DQ molecules are particularly important in autoimmune disease pathogenesis. The alpha chain encoded by HLA-DQA1 pairs with the beta chain from HLA-DQB1 to form functional antigen-presenting complexes.Specific HLA-DQA1 alleles, particularly in combination with HLA-DQB1 variants, are the strongest genetic risk factors for celiac disease. The DQ2.5 haplotype (DQA1*05:01/DQB1*02:01) and DQ8 haplotype are required for celiac disease development. These HLA-DQ molecules efficiently present gluten-derived peptides to T cells, triggering the autoimmune response. Nearly all celiac patients carry one of these risk haplotypes.
Understanding your HLA-DQA1 genetic status provides crucial information about celiac disease risk and other autoimmune conditions. Genetic testing for HLA-DQ2/DQ8 has high negative predictive value for celiac disease, meaning absence of these variants essentially excludes the diagnosis.