Vartdal F
Institute of Immunology, Rikshospitalet, The National Hospital, University of Oslo, Norway.
Acta Odontol Scand. 2001 Aug;59(4):212-5. doi: 10.1080/00016350152509229.
Gene variants (alleles) involved in the immune response are most likely selected during evolution. The allelic polymorphisms that may be advantageous in fighting harmful agents may be susceptibility genes in immune-mediated diseases. Identification of susceptibility genes is important because these genes encode proteins, which are most probably involved in the disease process. Hence, the identification of susceptibility genes may lead to an improved understanding of the pathogenesis and may therefore help the development of preventive and therapeutic measures. Susceptibility genes may be identified by analyzing genes known to be involved in immune responses (candidate gene search) or by analyzing gene markers evenly distributed over the genome (genome-wide scan). However, since several genes jointly contribute to disease susceptibility, the frequencies of single susceptibility genes may be quite high in the normal population. Moreover, different set of genes may predispose to the same clinical disease. It may therefore be very difficult to identify susceptibility genes, apart from the major histocompatibility complex (MHC) genes, which have now been shown to predispose to several immune-mediated diseases.
参与免疫反应的基因变体（等位基因）很可能是在进化过程中被选择出来的。那些在对抗有害因子时可能具有优势的等位基因多态性，在免疫介导疾病中可能是易感基因。确定易感基因很重要，因为这些基因编码的蛋白质极有可能参与疾病进程。因此，确定易感基因可能有助于增进对发病机制的理解，进而有助于预防和治疗措施的开发。可以通过分析已知参与免疫反应的基因（候选基因搜寻）或通过分析均匀分布于基因组的基因标记（全基因组扫描）来确定易感基因。然而，由于多种基因共同导致疾病易感性，单个易感基因在正常人群中的频率可能相当高。此外，不同的基因组合可能导致相同的临床疾病。因此，除了现已证明会导致多种免疫介导疾病的主要组织相容性复合体（MHC）基因外，确定易感基因可能非常困难。
