Distribution of erythrocyte binding antigen 175 (EBA-175) gene dimorphic alleles in Plasmodium falciparum field isolates from Sudan

BACKGROUND The Erythrocyte Binding Antigen (EBA) 175 has been considered as one of the most important Plasmodium falciparum (P. falciparum) merozoite ligands that mediate invasion of the erythrocytes through their sialated receptor: Glycophorin A (GPA). The effect of the EBA 175 dimorphic alleles (F and C) on the severity of the disease is not yet fully understood. Therefore this study was designed to assess the distribution of the divergent dimorphic alleles of P. falciparum EBA-175 (F and C) in three different geographical areas in Sudan and the possible association of this dimorphism with the severity of the disease. METHODS A sum of 339 field isolates of P. falciparum obtained from patients in three different geographical areas in Sudan were screened for the dimorphic alleles (F, C) of the EBA-175 using nested PCR. RESULTS The percentage of F, C, and mixed F/C alleles were; 41%, 51%, and 8% respectively. F and C alleles showed significantly different distributions in the various geographic areas (p = 0.00). There was no significant association between malaria clinical manifestation and P. falciparum EBA-175 F and C alleles frequencies. CONCLUSIONS This study showed a significant differential distribution of F and C alleles in different geographical malaria endemic areas. No significant association was observed between F and C alleles and different malaria phenotypes.