The pathogenesis of Balkan endemic nephropathy (BEN) is unknown, however, the pathway to terminal renal insufficiency shows a tubulointerstitial disorder. The reduction of renal excretory function of BEN kidneys is associated with tubular atrophy and renal interstitial fibro­sis. Cytokine transforming grow factor b1 (TGFb1) gene was shown to be a pro-fibrogenic factor. Polymorphisms in the TGFb1 gene were reported to be associated with an enhanced renal fibrotic process. In order to study their role in BEN occurrence and progression, we developed a pro­cedure for genotyping one of the known polymorphisms Thr263Ile in TGFb1, using real-time polymerase chain reaction (PCR) and a melting curve analysis. The presence of Thr263Ile was determined in 95 patients with BEN and 112 healthy individuals (controls). We found a higher prevalence of Thr263Ile in the controls (frequency: 0.07) compared to BEN patients (0.02). The established allele frequencies differed significantly between groups (p = 0.047). Further data on the distribution of other known polymorphisms in BEN patients and in the healthy popula­tion are needed, before the final role of TGFb1 for BEN development can be evaluated.

Key words: Real-time polymerase chain reaction (PCR); Balkan endemic nephropathy; transforming grow factor b1 (TGFb1) polymorphism.