Emerging roles of obstruction and mutations in renal malformations

Abstract.

In this short review I will highlight some of the ”molecular lesions” that occur in patients with malformations of the urinary tract in terms of: (1) aberrant gene expression in dysplastic and obstructed kidneys and (2) the effects of mutations and genetic polymorphisms on renal growth and response to injury. It is suggested that the prenatal obstruction of urinary flow transduces a signal which elicits a proliferative response in existing metanephric epithelia, with a concomitant block in new nephron formation and apoptosis of precursor cells. Understanding these processes may lead to the therapeutic modulation of disease. Secondly, I will review possible genetic influences in the generation of isolated (non-syndromic) renal malformations. In this respect, primary vesicoureteric reflux represents numerically the most important disorder, and the discovery of disease loci should facilitate early diagnosis and identification of asymptomatic carriers. It is possible that the apparent variable penetrance and expression of some familial renal malformations are the result of the action of modifying genes which act during kidney development or even after the nephrogenic period.