association of acute lymphoblastic leukemia and mdr1 gene polymorphism in an ethnic iranian population

background: the frequency of the multi-drug resistance 1 (mdr1) gene c3435t polymorphism differs in various ethnical populations such as asian, african, and caucasians populations. a silent c3435t polymorphism in exon 26 of mdr1 has been reported to be associated with a decreased expression of p-gp in tt genotypes carriers compared with cc genotypes carriers. materials and methods: to evaluate the association between mdr1 gene c3435t polymorphism and acute lymphocyte leukemia (all), 126 all patients (72 males and 54 females) with a mean age of 11.42 ± 6.55 and 139 healthy controls (79 males and 60 females) with a mean age of 12.15 ± 7.5 who were referred to dr. sheykh hospital, mashhad, iran, between 2005-2007 were enrolled in our study and their c3435t mdr1 polymorphism was investigated using pcr-rflp. results: the mutant homozygous tt and tc genotypes were found to be associated with the incidence of all (p<0.05). there was no significant difference for t allele frequency between all patients and healthy controls (or=1.08, 95% ci 0.84-1.66, p=0.33). conclusion: tt genotypes carriers are at higher risk of developing all than carriers of other genotypes.