Normal and Abnormal Development of the Kidney: A Clinician’s Interpretation of Current Knowledge

Abstract

The recent basic science literature is replete with new discoveries in the molecular genetics of renal development. However, little of this information has filtered into urological textbooks and journals. An effort is made herein to integrate these new findings and propose a more sophisticated blueprint of renal development than the one traditionally taught in medical school and residency. To accomplish this goal the author offers simple definitions and interpretations of complicated terms and events, and points out how maldevelopment results when mutations take place. A review of recent advances in the molecular genetics of renal development and maldevelopment was done. Renal metanephric development results from the expression of many genes in the ureteral bud and metanephric blastema with each sending messages to the other to induce organogenesis. Currently an understanding of normal renal organogenesis stems from a study of disease states resulting from perturbations in molecular genetics. In turn, a better understanding of normal renal organogenesis facilitates an understanding of how dysplasia, hypoplasia, cystic disease and tumors develop when molecular genetics go awry. For each form of renal dysgenesis and for most renal tumors 1 or more gene defects are eventually identified. The young urologist based in these new discoveries would be better prepared to make the breakthroughs in the future that are necessary for advancing the prevention and management of these conditions.