A unique familial lobular glomerulopathy.

Five members of a family (four brothers and their father) were found to have proteinuria and microhematuria. One of the affected brothers developed chronic renal failure. Although a renal biopsy was never performed, this brother has subsequently received a renal transplant from a clinically unaffected sister. Renal biopsy was performed on four of the siblings (three brothers and the sister). Renal tissue from all three brothers who underwent biopsy showed similar glomerular lesions, characterized by striking cloverleaf expansion of glomerular lobules by an acellular hyaline material and segmental mesangial cell proliferation. Electron microscopy showed massive mesangial and subendothelial deposits and occasional areas of glomerular basement membrane splitting with round inclusions. The renal biopsy specimen of the sister was normal on light and electron microscopy and negative for immunoglobulins and complement on immunofluorescent staining. Immunofluorescence microscopy on one of the male siblings was negative for immunoglobulins and complement. No other physical or serologic abnormalities could be established. To our knowledge, this is a unique form of familial glomerulopathy that has not been previously described.