immunogenetics

Immunogenetics is a branch of medical genetics and immunology that studies the genetic basis of the immune system and how genetic variation influences immune responses. It encompasses the identification of genes involved in immune function, the consequences of their variation for susceptibility to infection, autoimmunity, allergy, immunodeficiency, and responses to vaccines and therapies.

Key genetic elements include the major histocompatibility complex in humans, the HLA genes, which encode cell-surface molecules essential for antigen presentation. HLA class I (A, B, C) and class II (DR, DQ, DP) alleles show extensive polymorphism associated with disease risk and transplant compatibility. Other important components are genes for antigen receptors generated by somatic rearrangements (T cell receptor and immunoglobulin genes), natural killer cell receptors such as KIRs, cytokines and cytokine receptors, and components of the complement and Toll-like receptor pathways.

Comparative and population genetics and modern high-throughput methods enable mapping of immune traits. Researchers use linkage analysis, association studies (GWAS), sequencing, and functional assays to identify variants affecting immune cell development, signaling, and effector functions.

Clinical and translational aspects include matching organs and tissues for transplantation based on HLA typing, predicting vaccine responses, and understanding individual risk for autoimmune diseases (for example, HLA-B27 with ankylosing spondylitis; HLA-B*57:01 and drug hypersensitivity) and infectious disease outcomes. Immunogenetics also informs the development of immunotherapies and personalized medicine, and it is central to studies of primary immunodeficiencies and vaccine design.

Ethical considerations include privacy and equitable access to genetic information and therapies. The field continues to integrate genomics with immunology to understand basic biology and to improve diagnosis, prevention, and treatment of immune-related diseases.