Frequency Distribution Of ABO Alleles In A Malaria-Endemic Area Of Pakistan

Background: Falciparum malaria has exerted adaptive responses in mankind over a period of years for their survival advantage. Red cell disorders like thalassemia, Glucose 6 phosphate dehydrogenase deficiency, sickle cell anemia parallel the endemicity of malaria and are associated with malaria resistance. Distribution of ABO types had been linked to the prevalence of malaria. Pakistan has a huge burden of malaria, and the commonly reported blood phenotype is O. Despite this, no local information is available for allelic frequency of blood types. The study aimed in determining the frequency of ABO blood group alleles in a malaria-endemic area of Pakistan. Methods: : A total of 90 blood samples from healthy blood donors residing in Southern Pakistan were included in this study. Serological testing was performed using gel column agglutination and the conventional tube method. DNA extraction was performed from whole blood using Extra-gene I kit) followed by molecular genotyping by polymerase chain reaction, using sequence-specific primers (SSP-PCR) BAGene ABO kits. Results: : Of 90 samples, O phenotype constituted 33.3% (n=30) of the total ABO types. Twelve genotypes were identified in a combination of 6 common ABO alleles. Allele frequency of ABO*O.01.01 was highest at 0.4944 followed by ABO*B.01 (allelic frequency of 0.2555) and ABO*A1.01 (allelic frequency 0.1666). Conclusion: This study demonstrated the ABO*O.01.01 as the most frequent ABO allele in a malaria-endemic area at Pakistan and may be considered as an adaptive response to malaria. We need large scale studies for determining ABO alleles in different regions of the country depending on variability in malaria transmission.