[Genetic susceptibility to infectious diseases: immunogenetical approaches to mycobacterial infections and subacute sclerosing panencephalitis].

Genetic susceptibility to infectious diseases can be explained by nucleotide alteration (mutation, polymorphism, etc.) of genes encoding molecules involved in the entry of or the immune response to microorganisms. We have conducted studies on host genetic factors for the development of mycobacterial infections and subacute sclerosing panencephalitis (SSPE) in the past decade. First, we identified autosomal dominant IFN-gamma receptor deficiency as a predominant genetic basis of patients with bacille Calmette-Guérin osteomyelitis in Japan. Second, by gene-based association analysis of 21 candidate genes, it was suggested that genetic variants of IL-12 receptor beta1 gene (IL12RB1) confer genetic susceptibility to tuberculosis, and are associated with the progression of the disease in Japanese. Third, we demonstrated that variants of several genes encoding molecules associated with innate immunity (MxA and TLR3 genes) and acquired immunity (IL4 and programmed cell death 1 [PD1] genes) were associated with the development of SSPE. Immunogenetical approaches to infectious diseases would help us to evaluate the risk for disease development and progression, individualize prevention and treatment strategies, and create new therapies.