DHFR and Plasmodium falciparum malaria: The sulphadoxine/pyrimethamine (SDX/PYR) combination had been chosen to treatuncomplicated falciparum malaria in Malaysia for more than 30 years.Non-silent mutations in dihydrofolate reductase (dhfr) anddihydropteroate synthase (dhps) genes are responsible for theresistance to pyrimethamine and sulphadoxine, respectively.