Duffy Antigen Receptor for Chemokines (DARC) Polymorphisms and Susceptibility to Plasmodium Vivax Malaria in Sudan: a Case - Control Study.

Abstract

Background: Duffy-negative individuals were long considered resistant to Plasmodium vivax, yet emerging infections challenge this assumption, underscoring the need to examine Duffy antigen receptor for chemokines (DARC) gene polymorphisms and clarify evolving susceptibility patterns.

Objective: This study investigated the association between DARC genetic variants and susceptibility to P. vivax infection to elucidate transmission patterns and explain the rising incidence of P. vivax infection in Sudan.

Methods: A total of 405 participants were recruited for the study, including 202 patients with a confirmed diagnosis of P. vivax malaria and 203 blood donors serving as the control group. DNA was extracted from the peripheral blood, and DARC polymorphic variants were analyzed using polymerase chain reaction- sequence specific primer (PCR-SSP).

Results: The study showed that the Duffy-negative homozygous genotype FYBES/FYBES was present in both P. vivax-infected patients and the control group; however, it was significantly more frequent in healthy blood donors. The frequencies of the homozygous FYB/FYB genotype and the two heterozygous genotypes FYB/FYA and FYB/FYBES were substantially higher among the patients with P. vivax malaria than in the control group. The homozygous genotype FYA/FYA was more frequent among P. vivax malaria patients, while the heterozygous genotype FYA/FYBES was more common in the control group; however, the differences were not statistically significant. The FYAES allele was not detected in either group.

Conclusion: There was a potential association between FYA and FYB alleles and susceptibility to P. vivax infection. The FYBES allele confers partial resistance to P. vivax malaria, as some infected individuals were found to carry the homozygous Duffy-negative genotype (FYBES/ FYBES).