Gene HLA-A
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Also known as
major histocompatibility complex class I A, HLAA, MHC class I antigen AOverview
HLA-A (Human Leukocyte Antigen A) encodes a major histocompatibility complex (MHC) class I protein that presents peptide antigens to CD8+ cytotoxic T cells. This gene is one of the most polymorphic in the human genome, with thousands of known alleles. HLA-A proteins display fragments of intracellular proteins on the cell surface, enabling immune surveillance for infected or malignant cells.Specific HLA-A alleles are strongly associated with drug hypersensitivity reactions. HLA-A*31:01 increases risk of carbamazepine-induced severe cutaneous reactions, while HLA-A*33:03 is associated with ticlopidine-induced liver injury. These associations have led to pharmacogenomic testing recommendations before prescribing certain medications, particularly in populations with higher allele frequencies.
Understanding your HLA-A genetic status provides insights into immune function, disease susceptibility, and drug response. This information is particularly important for predicting adverse drug reactions and understanding autoimmune disease risk, organ transplant compatibility, and immune responses to infections.