MDR1 gene single nucleotide polymorphism and haplotype in Chongqing Han populations

AIM:To investigate the genetic variability of multiple drug resistance 1(MDR1)gene C1236T,G2677T/A and C3435T polymorphism and haplotype structure in Chongqing Han populations.METHODS:Genotypes of the MDR1 C1236T,G2677T/A and C3435T were determined in 196 unrelated Chongqing Han healthy populations(112 males,84 females)usingpolymerase chain reaction followed by restriction fragment length polymorphism analysis(PCR-RELP).Frequency of haplotypes and linkage disequilibrium of MDR1 gene were analyzed by SHEsis programs.RESULTS:For C1236T polymorphism the frequencyof 1236C allele is 33.7%,1236T allele is 66.3%;for G2677T/A polymorphism the frequency of 2677G allele is 44.4%,2677T alleleis 43.1% and 2677A allele is 12.5%;for C3435T polymorphism the frequency of 3435C allele is 56.4%,3435T alleleis 43.6%;Three major haplotypes(defined as more than 10% occurrencefor each)of 1236T-2677T-3435T,1236T-2677G-3435C and 1236C-2677G-3435C were observed in Chongqing Han populations,the frequency of TTT is 31.1%,TGC is 21.7% and CGC is 15.5%.CONCLUSION:This is the first study to show the C1236T,G2677T/A and C3435T polymorphism of MDR1 in Chongqing Han populations.The genotype and haplotype analysis from these data may be used as a basis for studies on the relationship between MDR1 genotypes and drug efficacy,drug toxicity,disease susceptibility in Chongqing Han populations.