Association of urokinase gene 3'-UTR T/C polymorphism with calcium oxalate urolithiasis in children

Abstract

Introduction and objectives: Urokinase is synthesized by various cells such as kidney, pneumocytes, and phagocytes. It cleaves plasminogen to plasmin and hence stimulates fibrinolysis. Urokinase breaks down the matrix protein within the stone and thus prevents stone formation and growth. Urokinase concentrations are lower and urokinase gene 3'-UTR T/C polymorphism is higher in patients with recurrent stones. Our aim was to investigate the role of urokinase gene 3'-UTR T/C polymorphism in childhood recurrent stone disease.

Material and methods: A control group of 40 healthy children having no history of stone formation (group 1) (mean age 10.5+/-4.2 years), 40 children (mean age 10.5+/-4.33 years) who had calcium oxalate stones for the first time (group 2), and 40 patients (mean age 11.2+/-3.8 years) with recurrent calcium oxalate stone disease (group 3) were included in the study. The groups were compared with respect to age, gender and urokinase gene 3'-UTR T/C polymorphism. Polymerase chain reaction-based restriction analysis was used to identify C/T polymorphism of the urokinase gene.

Results: No significant difference was observed between the three groups with respect to age and gender, while urokinase gene 3'-UTR T/C gene polymorphism was observed in four patients (10%) from group 3. In groups 1 and 2 there was no patient with T/C polymorphism.

Conclusions: Urokinase 3'-UTR T/C gene polymorphism seems to appear more commonly in children with recurrent calcium oxalate stone disease than in healthy children and in those with stones for the first time. These results suggest that the urokinase gene might play a role in childhood recurrent calcium oxalate stone disease.