[Glomerular nephropathy in the Bardet-Biedl syndrome].

A case of Bardet-Biedl syndrome (BBS) with kidney involvement and renal failure is reported. Light microscopy demonstrates fibrosis of 40% of glomeruli, altered tubules and interstitial fibrosis; no cystic formation is present and immunofluorescence studies are negative. In electron microscopy, the glomerular basement membrane (GBM) looks twisted and uniformly thickened with segmental effacement of the trilaminar architecture; fibrillary material is accumulated close to the inner layer of the GBM. Intermittent peritoneal dialysis is initiated 2 years later; death occurs, after one year of dialysis, due to a bleeding duodenal ulcer. Chronic renal failure seems to be the most frequent cause of death in BBS and several mechanisms are involved. Tubulo-interstitial lesions and renal cysts have been well documented. Glomerular damage with early ultrastructural changes of the GBM may be implicated in the occurrence of renal failure. Further studies are needed to define the incidence and the specificity of the GBM abnormalities in BBS.