HOST GENETICS AND INFECTIOUS-DISEASE

Recent work on the inheritance of susceptibility to malaria suggests t hat, over what may have been a relatively short evolutionary period, a remarkably diverse series of gene families have been modified in resp onse to the selective drive of this single infection. The phenotype co nsequences are not confined to the red cell, but involve the immune sy stem, cytokines and many other systems. It seems likely that the mecha nisms of variation in genetic susceptibility to other infective agents will reflect at least a similar degree of complexity and, if the sele ctive pressures have been present for longer periods of our evolutiona ry history, may be even more diverse. This may have important implicat ions for work directed at trying to define susceptibility loci for cur rent infectious and non-infectious diseases.