Recent reports have described the occurrence of the nephrotic syndrome in newborn infants.1-4,15,16 This condition has been called "congenital nephrosis," and seems to represent a clinically distinct entity, with a striking familial incidence. The microscopic changes in the disease have been well described.1-3,15,16 These changes include abnormalities in the renal tubules, alteration of the glomerular epithelial foot processes as seen with electron microscopy, and, in some cases, glomerular basement membrane thickening and glomerular destruction.
Two siblings have been studied by us, who clinically showed the typical features of this syndrome. They demonstrate an unusual microscopic feature which has not been stressed in previous reports. In both children, the small renal arteries and arterioles showed marked muscular hypertrophy without fibrinoid change. This change was apparent even when taking into consideration the fact that these vessels are normally prominent in this age group.5 Tubular and glomerular alterations, similar to