Histopathological Assessment of the Kidney Biopsies
(A and B) Light microscopy, (C and D) immunohistochemical, and (E and F) electron microscopy findings in biopsied affected individuals from families A and B are shown. The first and second columns are related to individual IV-2 in family A and individual IV-2 in family B, respectively. (A) One of the segmentally sclerosed glomeruli. The sclerosed segment is depicted by an asterisk (hematoxylin and eosin staining [H&E], 500×). (C) Podocytes showed strong staining with monoclonal antibody against PTPRO (immunohistochemistry, anti-GLEPP1 Ab, 500×). (E) Generalized foot process fusion (arrows) and widespread thinning of glomerular basement membranes, with smooth outer and inner contours (electron microscopy, lead citrate and uranyl acetate staining, 15000×). Bar indicates 1 μm. (B) Essentially normal glomeruli with open capillary lumina light microscopically (H&E, 100×). (D) Complete lack of PTPRO (immunohistochemistry, anti-GLEPP1 Ab, 100×). (F) Diffuse foot process effacement (arrows) and extensive microvillus transformation of podocytes (electron microscopy, lead citrate and uranyl acetate staining, 8000×). The scale bar indicates 2 μm.