Abstract: Objective To investigate whether polymorphism in MDR1 gene is associated with gingival hyperplasia induced by calcium channel blockers in end-stage renal disease (ESRD) patients. Methods We studied 183 ESRD patients with hypertension from the Haikou Xiangya Hospital of Central South University. Patients were classified into 3 groups based on calcium channel blocker (CCB) agent used. The patients were genotyped for C3435T polymorphism in MDR1 gene. Results The distribution of C3435T genotype in MDR1 gene was in Hardy-Weinberg equilibrium (CC=28.3%, CT=50.7% and TT=21%; χ2=0.032, P=0.985). No statistically significant difference was found in the ratio of CCB-induced gingival hyperplasia among the 3 genotypes (χ2=3.690, P=0.158). Conclusions MDR1 C3435T polymorphism was not associated with the CCB- induced gingival hyperplasia in ESRD patients with hypertension. Further study with larger samples
may be required.

Key words: MDR1, gingival hyperplasia, calcium channel blocker