Semin Respir Crit Care Med 2010; 31: 380-389DOI: 10.1055/s-0030-1262206ABSTRACTSarcoidosis develops in genetically predisposed individuals that are exposed to unknown antigens. There is a statistically significant increased risk for the disease among family members of sarcoidosis patients, and the disease differs in different ethnic groups. It is a genetically complex disease, with many genes contributing, both as risk factors but also with an influence on the disease course. The strongest genetic associations with sarcoidosis are found within the major histocompatibility complex (MHC) [human leukocyte antigen (HLA) in humans]—region on chromosome six. This region includes, besides the HLA-class I and class-II genes, a large number of genes important for the immune response and infla… Source: MedWorm: Sarcoidosis