Genotype and allele frequencies of MDR1 gene C3435T and C1236T polymorphisms in an Iranian population

Human P-glycoprotein (P-gp) is encoded by the MDR1 gene, which is located on chromosomal region 7q21 and consists of 28 exons. To date, over 50 single nucleotide polymorphisms (SNPs) have been reported for the MDR1 gene this gene is very polymorphic and is known that these polymorphisms not only may affect the expression level of this gene but also may alter the pharmacokinetics of substrate drugs. We aim to analyze the MDR1 gene C3435T and C1236T polymorphisms in Iranian population. The genotyping was performed by the ARMS and RFLP methods in 120 Iranian individuals and we use Real time RT-PCR to measure the expression level of MDR1 gene. The frequencies of the wild-type C3435 and mutant T3435 alleles were 43 and 57%, respectively and the distributions of CC, CT, and TT genotypes were35, 44 and 21%, respectively. For C1236T polymorphism C and T alleles frequencies were 44 and 56% respectively and CC, CT and TT genotypes frequencies were 13, 63 and 24%. There was no considerable association between MDR1 expression level and 3435T or C1236T polymorphism in our results. Our study provides a framework for future studies concerning the role of polymorphic variants of MDR1 gene in the drug responses in various diseases.