RENAL-DISEASE IN MARFAN-SYNDROME

We encountered 4 individuals with Marfan syndrome who presented with m icrohematuria and proteinuria. In 2 of them, a renal biopsy was perfor med. The predominant glomerular change by light microscopy was a focal segmental increase in mesangial matrix with early sclerotic lesions. Ultrastructurally, there was variable subendothelial widening containi ng haphazardly arranged microfibrils, 10-13 nm in diameter. Changes in small arteries present in the biopsies were mild in case 1 and more s triking in case 2 which consisted of elastolysis and fragmentation and focal disruption of internal elastic lamina, and focal degenerative c hanges in the media. In light of observations on the abnormalities of microfibrillar protein (fibrillin) in the microfibrillar-fiber system and the presence of abnormal type IV collagen in the connective tissue s in Marfan syndrome, the glomerular basement membrane alterations may be related to these defects and lead to microhematuria and proteinuri a.