High prevalence of Plasmodium falciparum Pfmdr1 86Y mutant gene in sickle cell disease in Nigeria.

BACKGROUND AND PURPOSE: In areas where malaria is endemic, drug prophylaxis is required for people with sickle cell disease. Chloroquine resistance has been associated with the Plasmodium falciparum multidrug resistance 1 (Pfmdr1) mutant gene. This study tested for the Pfmdr1 86Y mutation in P. falciparum isolates from individuals with sickle cell disease and sickle cell trait, who also underwent hemoglobin genotyping.

METHODS

Blood samples were collected from patients presenting with symptoms of malaria in an endemic region. The subjects were screened for hemoglobin genotype using hemoglobin electrophoresis and P. falciparum Pfmdr1 genotyping was carried out using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

229 subjects, comprising 144 with hemoglobin AA genotype, 57 with hemoglobin AS genotype and 28 with hemoglobin SS genotype, were enrolled in this study. There was no significant difference in the infective rate of malaria in the 3 groups (p>0.05). However, the prevalence of Pfmdr1 86Y was higher in those with hemoglobin SS genotype than in hemoglobin AA and AS subjects (p<0.05).

CONCLUSIONS

Uncontrolled use of chloroquine is a major cause of chloroquine resistance in Nigeria. Chloroquine prophylaxis may be the underlying cause of the high prevalence of Pfmdr1 86Y mutant gene in individuals with hemoglobin SS genotype.