Polymorphisms and haplotypes in multidrug resistance 1 gene are not associated with chronic lymphocytic leukemia susceptibility and prognostic parameters of chronic lymphocytic leukemia in Chinese population.

The human multidrug resistance (MDR1, ABCB1) gene encodes P-glycoprotein (P-gp), which affects the pharmacokinetics of many drugs. Here, we investigated whether common MDR1 single nucleotide polymorphisms (SNPs) (C1236T, C3435T, and G2677T/A) affect predisposition to chronic lymphocytic leukemia (CLL). Genotyping was performed in 150 patients with CLL and 117 controls using polymerase chain reaction (PCR)-based assays. Haplotypes were inferred using the PHASE algorithm. We found comparable allele and genotype frequencies among patients with CLL and controls. Moreover, patient and control groups did not differ regarding MDR1 haplotype distribution (p = 0.97). Furthermore, no correlation was shown between the MDR1 1236, 3435, or 2677 genotypes and Binet stage, unmutated immunoglobulin heavy-chain variable region (IGHV) status, CD38 expression, ZAP-70 expression, and p53 deletion. In conclusion, our results do not support a major influence of MDR1 variants on the risk of CLL, and these genomic polymorphisms are not associated with clinical prognostic factors in Chinese patients with CLL.