TB and leprosy resistance gene link
A new gene variant that increases resistance to diseases such as tuberculosis (TB) and leprosy, has been identified from studies on zebrafish and humans.
Both diseases are caused by rod shaped bacteria named mycobacterium. Human contact with the bacteria can result in a range of outcomes. Some people are resistant to the bacteria, but others will harbour it and in some cases infection can result in life threatening symptoms.
These differences led a team of scientists to set out to discover why some people develop resistance when others do not. They studied the action of a mycobacterium (M. marinum) in zebrafish which had not yet acquired an adapted immunity to infection. Early research showed that some zebrafish were more susceptible to the bacterium than others due to the presence of the gene Lta4h. The human equivalent of this gene is LTA4H, so subsequent research focussed on this gene in humans.
Comparing healthy volunteers to those already infected with the disease showed LTA4H to be common in people who were resistant to TB and leprosy in high risk areas. Therefore the gene may be a contributing factor in the natural resistance to both diseases.