Are and Gene Mutations Associated with Chloroquine-Resistant Parasites?

(1) Background: Malaria remains a significant global public health issue. Since parasites quickly became resistant to most of the available antimalarial drugs, treatment effectiveness must be constantly monitored. In Brazil, up to 10% of cases of vivax malaria resistant to chloroquine (CQ) have been registered. Unlike , there are no definitive molecular markers for the chemoresistance of to CQ. This work aimed to investigate whether polymorphisms in the and genes could be used as markers for assessing its resistance to CQ. (2) Methods: A total of 130 samples from malaria cases with no clinical and/or parasitological evidence of CQ resistance were studied through polymerase chain reaction for gene amplification followed by target DNA sequencing. (3) Results: In the exons, the K10 insert was present in 14% of the isolates. Regarding , T958 and F1076 haplotypes showed frequencies of 95% and 3%, respectively, while the SNP Y976 was not detected. (4) Conclusions: Since K10- and F1076/T958- polymorphisms were detected in samples from patients who responded well to CQ treatment, it can be concluded that mutations in these genes do not seem to have a potential for association with the phenotype of CQ resistance.