Alport's syndrome: experience at Hôpital Necker

We review the characteristic morphologic features identifiable by electron microscopy that have been described in patients presenting with Alport's syndrome. They are diffuse thickening and splitting of the glomerular basement membrane (GBM), which are either isolated or associated with thinning. In occasional cases, only diffuse thinning can be seen. Our study of 100 families followed in Necker's hospital, of which 60 patients have had electron microscopic examination of their renal parenchyma, demonstrates that these GBM changes are highly suggestive of Alport's syndrome. All the patients included in the study fulfilled the following clinical criteria: familial incidence, nerve deafness in the propositus or in another member of the family, renal disease with progression to renal failure in the proband or in another member of the kindred. Although a failure in the proband or in another member of the kindred. Although a normal GBM was found in five patients, the GBM changes should be one of the criteria for the definition of the syndrome. Results dealing with a few other problems raised by this syndrome are reported. They concern the antigenicity and the biochemical composition of the GBM, the incidence of macular and perimacular changes, and the genetic transmission of the disease. It is concluded that Alport's syndrome is genetically heterogeneous and that the GBM ultrastructural changes are observed in most patients whatever the type of genetic transmission.