MedGen

Focal segmental glomerulosclerosis-10 (FSGS10) is an autosomal dominant kidney disease characterized by isolated glomerulopathy without extrarenal manifestations. In particular, affected individuals do not have other signs of NPS. The renal disease is highly variable in severity and pathology, even within the same family. Most patients present in the first decades of life with proteinuria and hematuria, although onset of symptoms can manifest at any age, including late adulthood. Some patients progress to end-stage renal disease, whereas others have a stable disease course. Light microscopic analysis of renal biopsies shows a constellation of glomerular abnormalities, including focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), and, rarely, immune complex nephropathy. Electron microscopy characteristically shows an irregular thickening of the glomerular basement membrane (GBM) with electron-lucent areas containing accumulated bundles of type III collagen fibrils. The collagen deposition usually occurs in endothelial cells of the GBM; partial effacement of podocyte foot processes may also be present. These specific pathologic findings are similar to those observed in NPS patients with nephropathy. However, these findings may not always be present, which may make the diagnosis challenging (summary by Hall et al., 2017, Lei et al., 2020; review by Harita et al., 2017). For a discussion of genetic heterogeneity of FSGS, see FSGS1 (603278). [from OMIM]

Nail-patella syndrome (NPS) (previously referred to as Fong's disease), encompasses the classic clinical tetrad of changes in the nails, knees, and elbows, and the presence of iliac horns. Nail changes are the most constant feature of NPS. Nails may be absent, hypoplastic, or dystrophic; ridged longitudinally or horizontally; pitted; discolored; separated into two halves by a longitudinal cleft or ridge of skin; and thin or (less often) thickened. The patellae may be small, irregularly shaped, or absent. Elbow abnormalities may include limitation of extension, pronation, and supination; cubitus valgus; and antecubital pterygia. Iliac horns are bilateral, conical, bony processes that project posteriorly and laterally from the central part of the iliac bones of the pelvis. Renal involvement, first manifest as proteinuria with or without hematuria, occurs in 30%-50% of affected individuals; end-stage renal disease occurs up to 15% of affected individuals. Primary open-angle glaucoma and ocular hypertension occur at increased frequency and at a younger age than in the general population. [from GeneReviews]