The relationship between MDR1 gene polymorphism and long-time survival in children with acute lymphoblastic leukemia

Abstract

Objective To study the frequency distribution patterns of gene polymorphism of multidrug resistance gene MDR1 in children with acute lymphoblastic leukemia(ALL), and their relationship with long-time survival. Methods A case-control study was carried out to compare the distribution of genotype and genetic frequency of MDR1 C3435T, C1236T and G2677T/A in 176 children with ALL by single nucleotide polymorphisms-shot (SNP-shot) method. Results MDR1 C3435T C/C, C/T, T/T took 67, 94 and 15 cases respectively; MDR1 C1236T C/C, C/T, T/T took 23, 82 and 71 cases respectively; G2677T/A G/T, T/T, T/A, G/G, G/A and A/A took 66, 17, 28, 37, 24 and 4 cases respectively. The overall survival rate of 176 children in this group was 77.3 % (136/176). The 5-year event-free survival (EFS) rates in children with MDR1 C3435T C/C, C/T and T/T were 79.57 %, 83.33 % and 33.33 % respectively. The EFS rate in children with T/T genotype was lower than those in C/C and C/T genotypes(χ2=15.301, P=0.002). The 5-year EFS rates in patients with MDR1 C1236T C/C, C/T and T/T were 52 %, 81.71 % and 71.93 % respectively. The EFS rate in patients with C/C genotype was lower than those in C/T and T/T genotypes (χ2=17.800, P=0.001). Conclusions The gene polymorphism of MDR1 is related to the EFS of children with ALL. The survival rates in children with MDR1 C1236T C/C and C3435T T/T genotypes are lower than those in other genotypes. Key words: Leukemia, lymphocyte, acute; Multidrug resistance gene; Gene polymorphism; Event-free survival