Figure 2. Renal histology of patient A131 II-4.

Morphologic changes are characteristic for NPHP and include (a) thickening, splitting, and attenuation of tubular basement membranes in tubules with disorganized epithelium (thick arrows); (b) atrophic tubules that contain protein casts (thin arrows); (c) dilated collecting ducts (cd), which are lined by exceptionally tall epithelium; and (d) a mild degree of interstitial fibrosis. Most glomeruli appeared normal, but there were a few scattered obsolescent glomeruli (not shown). Scale bar: 30 μm.