Human TB gene identified
20 June 2006
Researchers have found that a specific gene could determine West Africans'
susceptibility to tuberculosis. They say this could help explain why only a
small fraction of people exposed to the bacteria develop serious disease.
Tuberculosis (TB) infects almost a third of the world's population but only 10
per cent of affected people develop symptoms.
Previous studies have shown that a single gene controls resistance and
susceptibility to TB in mice. Now, a team led by Adrian Hill of the UK-based
Wellcome Trust has studied the corresponding human gene, SP110. They
investigated whether it is associated with TB symptoms in populations from West
The team collected DNA from family members of over 400 TB patients from The
Gambia, Guinea-Conakry and Guinea-Bissau.
Different ethnic groups have subtly different versions of the gene, so using
family members of TB patients minimised these differences making it easier to
show an association between SP110 and the disease.
Of the 27 genetic variations found, three versions of SP110 were associated
with TB symptoms.
The gene's precise function in the disease is unknown but it is thought to
control the death of infected cells.
The new research was published yesterday (19 June) in the journal Proceedings
of the National Academy of Sciences. Hill says the work could provide important
clues on how to design new therapies and ways to prevent TB.
Reference: Proceedings of the National Academy of Sciences doi: