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Background and Objectives: Dent disease is a rare X-linked disorder characterized by low molecular weight proteinuria and often considered a renal tubular disease. However, glomerulosclerosis was recently reported in several patients. Thus, Dent disease renal histopathologic features were characterized and assessed, and their association with kidney function was assessed., Design, Setting, Participants, & Measurements: Clinical renal pathology reports and slides (where available) were collected from 30 boys and men in eight countries who had undergone clinical renal biopsy between 1995 and 2014., Results: Median (25th, 75th percentiles) age at biopsy was 7.5 (5, 19) years with an eGFR of 69 (44, 94) ml/min per 1.73 m 2 and a 24-hour urine protein of 2000 (1325, 2936) mg. A repeat biopsy for steroid-resistant proteinuria was performed in 13% (four of 30) of the patients. Prominent histologic findings included focal global glomerulosclerosis in 83% (25 of 30; affecting 16%±19% glomeruli), mild segmental foot process effacement in 57% (13 of 23), focal interstitial fibrosis in 60% (18 of 30), interstitial lymphocytic infiltration in 53% (16 of 30), and tubular damage in 70% (21 of 30). Higher percentages of globally sclerotic glomeruli, foot process effacement, and interstitial inflammation were associated with lower eGFR at biopsy, whereas foot process effacement was associated with steeper annual eGFR decline., Conclusions: These associations suggest a potential role for glomerular pathology, specifically involving the podocyte, in disease progression, which deserves further study. Furthermore, Dent disease should be suspected in boys and men who have unexplained proteinuria with focal global glomerulosclerosis and segmental foot process effacement on renal biopsy., (Copyright © 2016 by the American Society of Nephrology.)

Familial and genetic forms of focal segmental glomerulosclerosis (FSGS) are associated with six different mutations in genes affecting the podocyte (NPHS2, ACTN4, CD2AP, WT1, TRPC6, and PLCE1). Immunosuppressive agents are often unsuccessful in treating this condition. Data regarding the efficacy of renoprotection through blockage of the renin-angiotensin axis is lacking. We describe three children from two different families with familial FSGS in whom partial to complete remission of proteinuria was attained through early blockade of the renin-angiotensin axis. In addition, there was no deterioration of renal function. We speculate that presymptomatic patients with normal renal function who have genetic or familial FSGS may benefit from early blockade of the renin-angiotensin axis and that this may also prevent progressive renal disease.

Background and Objectives: Dent disease is a hereditary form of progressive renal failure characterized by hypercalciuria and proximal tubular dysfunction. The clinical presentation is often insidious with the majority of patients remaining asymptomatic throughout childhood. Despite the seemingly mild, early course, more than 20% of 32 asymptomatic patients in one study had biopsy evidence of focal glomerulosclerosis. Furthermore, end-stage renal disease often occurs in men in early to middle adulthood., Design, Setting, Participants, & Measurements: This article describes two male patients who presented with asymptomatic proteinuria and were found to have focal glomerulosclerosis. Despite the absence of nephrocalcinosis on renal ultrasound, the diagnosis of Dent disease was considered because of unexplained proteinuria. Subsequent history revealed renal calculi in each maternal family., Results: The clinical diagnosis of Dent disease was established by intermittent hypercalciuria and low molecular weight proteinuria and confirmed through mutational analysis., Conclusions: It is hypothesized that a diagnosis of Dent disease may be unrecognized in patients with unexplained proteinuria and idiopathic focal glomerulosclerosis.