RENAL DYSPLASIA - NEW APPROACHES TO AN OLD PROBLEM

Renal dysplasia is a clinically important consequence of abnormal neph rogenesis, Various forms are encountered in clinical practice; however , renal dysplasia may represent the final common end point of defects in the normal cascade of fetal kidney development. Typical histopathol ogic changes characterize renal dysplasia, including architectural dis tortion, metaplasia, and primitive glomeruli and tubules. Cystic chang es are not universal but can be found in most situations. The advent o f recent molecular techniques, including gene targeting and positional cloning, has expanded our knowledge of the molecular control of norma l mammalian nephrogenesis and with it our understanding of the pathoge nesis of renal dysplasia, A defect in the ability of the branching ure teric duct and the undifferentiated metanephric blastema to communicat e appears to be the basic underlying principle for the formation of dy splasia, Mutation, defective regulation of transcription, and alterati on in spatial or temporal expression of a number of classes of genes, including growth factors, have been implicated in the development of r enal dysplasia, Numerous examples, both experimental and in nature, hi ghlight this point. (C) 1998 by the National Kidney Foundation, Inc.