Cystic kidney diseases.
The goal of understanding the primary defects that lead to renal cystic diseases has proved to be an elusive one, despite 3 decades of physiologic and genetic investigation. Within the past 2 years the genes responsible for type 1 and type 2 autosomal dominant polycystic kidney disease have been identified. The process of defining the normal distribution and functions of the proteins encoded by these genes as well as the precise pathophysiology of cystogenesis is underway. For other major hereditary cystic kidney diseases, chromosomal localization or gene identification has also been achieved in recent years. Mouse and rat models of renal cystic disease continue to be a rich source of new data on the effect of genetic and environmental modifying factors on disease progression as well as serving as a preliminary testing ground for novel approaches to management such as gene therapy and early dietary modification. Ongoing clinical research continues to better define the renal and extra-renal manifestations of autosomal dominant polycystic and other renal cystic diseases. It is likely that a clearer understanding of the pathophysiology of these diseases will provide important insights into the processes that control tissue development and growth, and cellular differentiation.