The defining characteristic of pediatric research is its concern with human development, the effect of changes that occur over time in the structure and function of biological and psychosocial processes. Thus, research in pediatric nephrology and urology includes developmental studies, and it focuses on diseases that have altered manifestations or therapeutic requirements in the pediatric age group. The diseases and conditions reviewed here are limited to those that fit within these definitions.
Developmental abnormalities are responsible for some of the major clinical problems in pediatric nephrology and urology. Until recently, the general perception of developmental abnormalities was restricted to obvious physical anomalies. This limitation resulted in a severe underestimation of the magnitude and scope of the clinical problems due to aberrant development. It is now recognized that developmental abnormalities at the enzymatic and molecular levels are responsible for many biochemical and physiological disturbances, some of which produce serious