Forty-eight Turkish patients with FMF treated with colchicine were genotyped for 3435C>T, (-)1A>G, 61A>G, 1199G>A, 1236C>T, 2677G>A, 2677G>T polymorphisms in the P-gp/MDR1 gene and 3435C>T, 1B(-392A>G), 2(15713T>C), 3(23171T>C), 12(21896C>T), 17(15615T>C) polymorphisms in the CYP3A4 gene.
MDR1 gene C3435T polymorphism enacts an important role on colchicine response in FMF; good response to colchicine treatment was related to the C allele, whereas poor response was related to the T allele in FMF.
The CT genotype frequency of the C3435T polymorphism (p = 0.003), the CT-GT-CT (C1236T-G2677T/A-C3435T) triple genotype (p = 0.001) and the C-G (C1236T-G2677T/A) haplotype (p = 0.030) were more common in the FMF patients.
Our results indicate that C3435T polymorphism in exon 26 of MDR1 gene is associated with colchicine resistance in nonresponder FMF patients during the common therapy protocol.