Lmx1b-associated disease presented with prominent asymptomatic proteinuria

Objective:To analyze clinical data of 3 children with LMX1B-associated disease characterized by asymptomatic glomerular proteinuria, thus improving the recognition of asymptomatic proteinuria with genetic causes. Methods:Three patients with LMX1B-associated disease presented with prominent asymptomatic proteinuria diagnosed by the next-generation sequencing in Department of Pediatrics, Peking University First Hospital from April 2014 to October 2017 were included in this study.Clinical data, including renal and extrarenal manifestations, renal biopsy, and family history, were collected and retrospectively analyzed. Results:All 3 children were girls, the age of onset were 2 years, 1 year, and 4 years, respectively, and the diagnosis age were 11 years, 5 years and 6 years, respectively.All of them had glomerular proteinuria, and nephrotic-level proteinuria occurred in one patient.Microscopic hematuria was found in 2 patients.All of them had normal renal function.Only one patient underwent renal biopsy.Electron microscopy of the first time of biopsy revealed segmental thinning of the glomerular basement membrane.Re-biopsy 4 years later showed irregular thickening of the glomerular basement membrane, moth-eaten appearance and collagen fibrillar material deposition.No abnormalities of nails, limbs and joints were observed by physical examination.Two patients had a family history of renal disease.Conclusions:Genetic factors should be considered in children with obscure onset asymptomatic proteinuria without definite clinical causes.Genetic testing can help diagnose and guide treatment as early as possible.