Plasmodium vivax Malaria and G6PD Testing

Abstract

Early malaria investigators were certainly correct in classifying the species falciparum and the species vivax as belonging to the same genus, Plasmodium [...].

Figure 1

Genetics and pharmacogenetics of G6PD deficiency: a triangular relationship. One vertex of the virtual triangle is G6PD deficiency due to a mutation in the human G6PD gene located on the tip of the long arm of the X chromosome (Xq28). Like any other gene, G6PD is susceptible to spontaneous mutations, and some of these entail G6PD deficiency. Another vertex is the malaria parasite; when it infects heterozygotes, in whom G6PD normal red cells (pink) and G6PD deficient red cells (grey) co-exist, this mosaicism is key to protection [28], at least in the case of P. falciparum. As a result, genetically determined G6PD deficiency tends to become prevalent in malaria-endemic areas. The third vertex are 8-aminoquinolines, potent hypnozoitocides that, by producing reactive oxygen species (ROS), kill P. vivax hypnozoites [35]; unfortunately, ROS also cause oxidative injury to G6PD deficient red cells, thus causing acute haemolytic anaemia in G6PD-deficient persons. RBC = red blood cell.