Predominance of K1 Allele in Erythrocytic form of Plasmodium falciparum MSP-1 Gene Signifies Severe Malaria in Jos, Nigeria

Abstract

Aim: The study explored the diversity of Plasmodium falciparum Merozoite Surface Protein 1 (msp-1) gene sequence and delineated the K1 allele occurrence and profile. The Plasmodium falciparum msp-1 gene encodes an antigen that is being proposed as a major vaccine candidate against the parasite infections. Study Design:  The design of the study was experimental. Place and Duration of Study: The study was undertaken, between October 2018 and June 2019, in the Department of Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Jos, Nigeria. Methodology: The DNA of Plasmodium falciparum was extracted from 117 blood samples of malaria patients confirmed by microscopy in three different hospitals in Jos. The msp-1 (block 2) allelic family’s genotyping was carried out using PCR and nested PCR techniques. Sequencing and Bioinformatics of the K1 alleles were done to further identify the K1 alleles. Results: Out of the 117 DNA extracted, 13 samples were positive for Plasmodium falciparum and each was genotyped for msp-1. K1 was the most predominant allele (6/13) compared to MAD20 (4/13) and R033 (2/13). The allelic frequency of K1 was calculated to be 46.15%. The 225 bp Plasmodium falciparum K1 allele of the msp-1 gene studied displayed polymorphism. However, the sequence was very similar to those of Plasmodium falciparum already characterized. Conclusion: Predominance of K1 allele is an indication that Jos is endemic to severe Plasmodium falciparum malaria.