RESUMO
Objective:To explore the association of its polymorphism of TFRC with the susceptibility, clinical and pathologic phenotypes of IgA nephropathy. Methods: A total of 380 patients with IgA nephropathy and 250 normal controls were enrolled in the study. The regions with 424G/A and -5184C/T polymorphism sites of TFRC were amplified by PCR from genomic DNA and then the PCR-RFLP were performed by restriction enzymes, BanⅠ and BsmA Ⅰ, respectively. The genetic association of genotypes with the clinical and pathologic phenotypes was analyzed. Results: The distribution of frequency in TFRC was consistent with Hardy-Weinberg equilibrium; however, we found no significant difference in genotypes distribution between patients and controls. There were no differences between genotypes in age, blood pressure, 24 h urine protein excretion, serum creatinine, creatinine clearance and serum IgA. 424G/A and -5184C/T polymorphisms were associated with immunofluorescent intensity of IgA deposit in mesangial area, though there was no difference in pathological lesions evaluated by HAAS grade. Conclusion: The polymorphisms of TFRC in 424G/A and -5184C/T sites were not associated with susceptibility to IgA nephropathy, but associated with density of immunofluorescence of IgA in mesangium in our large population based Chinese patients. The association of IgA nephropathy and other polymorphism sites, as well as interaction between TFRC polymorphism and other genes' polymorphisms, neededs to be further investigated.