Electron microscopic studies in a long-term follow-up of a case of congenital nephrotic syndrome.

A boy presenting with a severe congenital nephrotic syndrome diagnosed by histological analysis at the age of 3 weeks was biopsied again 7 years later. The ultrastructural glomerular basement membrane abnormalities depicted in the first biopsy were no longer present in the second one. The number of completely hyalinized glomeruli was not significantly decreased. The GFR remained normal, but a moderate persistent, non-selective proteinuria (800 mg/24 h) was noted without oedema. The patient however developed a progressive perceptive deficit of hearing.