The discipline of medical genetics is rapidly transforming the face of
nephrology. A number of important advances have been made during the
past year in the identification of the molecular basis of renal diseas
es. This article will summarize how these new findings have expanded o
ur understanding of whether diseases are homogeneous or heterogeneous
entities (Bartter's syndrome versus Gitelman's syndrome), the medical
basis of certain diseases of unclear etiology (enuresis), and the natu
re of risk factors for disease occurrence or progression (IgA nephropa
thy, chronic renal failure, and hemolytic uremic syndrome). It is anti
cipated that these exciting discoveries will become routine in the nea
r future as medical genetics is fully incorporated into the practice o
f clinical nephrology.