Hypothesis: Dent disease is an underrecognized cause of focal glomerulosclerosis.

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.