Congenital hypernephronic nephromegaly with tubular dysgenesis: a distinctive inherited renal anomaly

This paper describes a distinct, apparently inherited renal disorder we call congenital hypernephronic nephromegaly with tubular dysgenesis. The disorder is characterized by oligohydramnios, the Potter phenotype, and enlarged nonfunctional kidneys. Light microscopy demonstrates increased numbers of glomeruli, undifferentiated tubules, and interstitial fibrosis. Microdissection reveals short, immature nephrons that lack proximal convolutions, and abnormal vascularization of the glomerulus. Morphometric analysis demonstrates increased glomerular mass, primarily in the region of the corticomedullary junction, increased interstitial mass, and decreased tubular mass. The parameters that define this anomaly are presented, and the possible mechanisms of pathogenesis are discussed in relation to pathologic observations and current concepts concerning renal embryogenesis and differentiation. The recurrence of this anomaly in the male children of a consanguineous couple suggests an X-linked recessive mode of inheritance, although an autosomal-recessive mode of inheritance cannot be ruled out. This condition indicates that not all cases of the Potter phenotype can be considered to be sporadic.