Allele frequencies of candidate immune genes were calculated for @ SNPs on @ human chromosomes for their possible involvement in clearance of drug-resistant parasites with the triple mutations of pfcrt@T , pfmdr@Y , and pfmdr@Y ( TY ) and pfdhfr@I , pfdhfr@R , pfdhfr@N , and pfdhps@G ( IRNG ) which were determined by dotblot or PCR-restriction analysis .