Abstract

 Background and Objectives

 The important reason of drug resistance is ATP dependent pumps such as MDR1 that extrudes drugs from the cell. MDR1 is highly polymorphic. It seems that polymorphisms influence the gene expression and response to treatment. The aim of this study was to investigate G2677T/A polymorphism of the MDR1 gene and its association with the response of treatment in childhood acute lymphoblastic leukemia. 

 Materials and Methods

 In this descriptive study, G2677T/A polymorphism of MDR1 was investigated in 44 children with acute lymphoblastic leukemia and 40 healthy individuals by the ARMS-PCR technique. The association of this polymorphism with response to treatment was also investigated .

 Results

 In the patient group, the frequencies of genotypes were 36.4% for TT, 41% for GT, 13.6% for GG,4.5% for AG, 2.25% for AT and 2.25 % for AA whereas in the control group the frequencies were 35%, 37.5% , 10%, 7.5%, 5% , and 5% for TT, GT, GG, AG, AT, and AA, respectively . There was no significant difference in the frequencies of G2677T/A polymorphism between patients and the healthy group. Neither was there any significant difference between the frequency rates of G2677T/A polymorphism of MDR1 in the responder and the non responder .

 Conclusions

 It seems that there is no correlation between G2677T/A polymorphism of MDR1 gene and response to treatment. So the role of G2677T/A polymorphism in the gene expression of MDR1 in childhood acute lymphoblastic leukemia and response to treatment is still controversial.