Many genes including HLA, KIR, and
MICA genes, as well as polymorphisms in
cytokines have been investigated for their role in
infectious disease. HLA alleles may influence not only susceptibility or resistance to
leprosy, but also the course of the disease. Some combinations of HLA and KIR may result in negative as well as positive interactions between NK cells and infected host cells with M. leprae, resulting in activation or inhibition of NK cells and, consequently, in death of bacillus. In addition, studies have demonstrated the influence of
MICA genes in the pathogenesis of
leprosy. Specifically, they may play a role in the interaction between NK cells and infected cells. Finally, pro- and anti-inflammatory
cytokines have been influencing the
clinical course of
leprosy. Data from a wide variety of sources support the existence of genetic factors influencing the
leprosy pathogenesis. These sources include twin studies, segregation analyses, family-based linkage and association studies, candidate gene association studies, and, most recently, genome-wide association studies (GWAS). The purpose of this brief review was to highlight the importance of some immune response genes and their correlation with the clinical forms of
leprosy, as well as their implications for
disease resistance and susceptibility.