Neonatal renal failure and glomerular immaturity.

A case of acute renal failure in a neonate was observed in which there were no obvious predisposing factors. Renal biopsy showed marked glomerular immaturity with otherwise normal renal architecture. Light and ultramicroscopic abnormalities noted suggest that the glomerular immaturity caused an abnormally low glomerular ultrafiltration coefficient (Kf). An inadequate rate of glomerular filtration secondary to the low Kf could have precipitated the acute renal failure. The finding of isolated glomerular maturational arrest is a previously undescribed cause of neonatal renal failure.