The various factors that have been found to influence parasite densities are the age of the subjects,27 host immune status,35 transmission intensity,19,24 disease phenotypes30 and Hb Variants.19,24,29,34 In the present study, the variables like age of the subjects, transmission intensity and disease phenotypes were similar in the three groups because all the subjects with severe malaria were of similar age group, and came from the same geographical area with similar transmission pattern. The gene discussed is GSTM1; the disease is malaria.