Prospective analysis of single nucleotide polymorphisms of the transforming growth factor beta-1 gene in Peyronie's...

The detection of increased expression of transforming growth factor beta-1 (TGF-beta1) in Peyronie's disease plaques and the possibility of initiating a Peyronie's disease-like condition by intratunical injection of a synthetic heptopeptide with TGF-beta-like activity in an animal model has provided evidence for the central role of this cytokine in the pathogenesis of this entity. Recently 2 defined single nucleotide polymorphisms in the coding region of the TGF-beta1 gene have been described that are associated with different levels of TGF-beta1 production. Based on these data we prospectively investigated the genetic association of distinct TGF-beta1 genotypes with Peyronie's disease.

DNA samples from 111 consecutive patients with idiopathic Peyronie's disease and 100 controls were genotyped for the 2 defined dimorphic single nucleotide polymorphisms T869C and G915C in the coding region of the TGF-beta1 gene using allele specific polymerase chain reaction.

We found an increased frequency of the homozygous genotype of the single nucleotide polymorphism G915C in patients with Peyronie's disease compared with healthy controls (89.2% versus 79%, p = 0.04). However, there were no significant differences in allele frequencies of the single nucleotide polymorphism T869C.

Experimental data from other investigators have shown that TGF-beta1 has an important role in the etiopathology of Peyronie's disease. Our results indicate that the homozygous wild type of the G915C single nucleotide polymorphism in the coding region of the TGF-beta1 gene, which was recently associated with elevated TGF-beta1 production and pulmonary fibrosis, may influence the predisposition to Peyronie's disease. However, it does not represent a major genetic risk factor.