The observation that the HbC trait protects selectively from
cerebral malaria may also partly explain the focal distribution of
HbC in distinct regions of West Africa, with notably mesoendemic
to hyperendemic malaria endemicity and, therefore, a high incidence
of cerebral malaria.2,50 Accordingly, a significant survival
advantage can only be expected in these areas with high risk of
cerebral malaria. The HbS trait, on the other hand, with a general
protection against malarial infection25 should create a survival
advantage in all endemic areas. The high prevalence of HbC in our
holoendemic study area is at least partly the result of strong
migration from northern Ghana.