The Bcg host-resistance gene.

In the mouse, resistance and susceptibility to intracellular growth of mycobacteria in macrophages is controlled by the Bcg (Nramp1) gene, which has been cloned and shown to encode a macrophage phagosomal membrane protein with a putative transporter function. In the homologous human NRAMP1 gene, a total of 11 polymorphisms have been identified, which are being used to test for the linkage of NRAMP1 alleles with human responses to mycobacteria, including susceptibility to tuberculosis and leprosy, as well as BCG immunotherapy in bladder cancer.