Glomerular basement membrane abnormalities in infants with heavy proteinuria.
Two Indian male children with infantile-onset heavy proteinuria (with nephrotic syndrome in 1) had thickening of the glomerular basement membrane with splitting and basket-weave appearance of lamina densa on electron microscopic evaluation of kidney tissue (like Alport's syndrome), with normal light microscopic findings and negative immunofluorescence. The proteinuria was non-familial and was not associated with microhaematuria in patient 1; transient microhaematuria, perhaps associated with urinary tract infection, was noted in patient 2. There was no neurosensory deafness in the patients or their parents. The nephrotic syndrome remitted totally in one patient over a 7-month period. The proteinuria, as well as the renal disease, was non-progressive in the second patient over a 27-month period. The significance of these basement membrane abnormalities (classically described in Alport's syndrome) in early-onset nephrotic syndrome/heavy proteinuria that is non-familial and non-progressive needs to be evaluated.