MDR1 C3435T and C1236T polymorphisms: association with high-risk childhood acute lymphoblastic leukemia.

BACKGROUND MDR1, one of the most important drug-transporter genes, encodes P- glycoprotein (P-gp)-a transporter involved in protecting against xenobiotics and multi-drug resistance. The significance of the genetic background in childhood acute lymphoblastic leukemia (ALL) is not well understood. MATERIALS AND METHODS To evaluate whether C3435T and C1236T MDR1 polymorphisms are associated with the occurrence and outcome of ALL, 208 children with ALL (median age 5.0 yr) and 101 healthy Thai children were studied by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) assay. RESULTS C3435T and C1236T MDR1 polymorphism are significantly associated with the high-risk group (OR=2.6, 95%CI=1.164-5.808; P=0.028 and OR=2.231, 95%CI=1.068-4.659; p=0.047, respectively), indicating that both may be candidates for molecular markers in the high-risk group of ALL.