Genetics of susceptibility to tuberculosis in humans

There is substantial epidemiological evidence that host genetic factors in part determine susceptibility to mycobacteria, and many approaches have been applied to identify the specific genes involved. These include the study of single genes in 'knockout' mouse models and rare human families in which increased susceptibility to mycobacterial infection segregates as a single gene defect. Several genes have now been studied in many different populations. This review gives an overview of the progress made in the field of genetic susceptibility to tuberculosis and highlights more generally some of the challenges involved in the identification of complex disease genes.