Objective: To summarize the clinical features and genetic analysis results of 10 children with Dent disease. Methods: The clinical data and gene test results of 10 boys aged from 8 months to 12 years with Dent disease diagnosed in Children's Hospital of Nanjing Medical University from January 2014 to July 2017 were analyzed retrospectively. Results: All patients had insidious onset, 5 cases were found to have proteinuria on routine urine examination after hospitalization duo to other diseases, 4 cases were admitted to hospital because increased foams in the urine, and 1 case was found to have proteinuria on health checkup. All cases presented with low molecular weight proteinuria, urine protein electrophoresis showed that the proportion of low molecular weight protein was greater than 50%, 7 cases had nephrotic-range proteinuria, but none had hypoproteinemia. Six cases had hypercalciuria, 3 cases had nephrocalcinosis, 1 case had nephrolithiasis, 2 cases had glomerular microscopic hematuria, in 1 case urine glucose wa weakly positive but blood glucose was normal. All patients had normal renal function, normal serum calcium, no hypophosphoremia and none had rickets. Genetic analysis results showed that 7 patients with variants in the CLCN5 gene, including 2 nonsense variants (p.R637X, p.Y143X), 3 missense variants (p.A540D, p.G135E, p.G703V), 1 deletion variant (exons 9, 10, 11, 12, 13, 1 missing), and 1 frameshift variant (p.T260Tfs*10). Three cases had missense variants of OCRL gene (p.I274T, p.I371T, p.F399S). Except for p.R637X and p.I274T, the other 8 cases had newly discovered variants. Five patients underwent a renal biopsy, the biopsy revealed focal global glomerulosclerosis in 3 patients, mild mesangial proliferative glomerulonephritis in 1 patient and renal minimal change in 1 patient. Mild focal tubular atrophy and interstitial fibrosis were noted in three cases. Mild segmental foot process effacement was noted under electron microscope in all five cases. Conclusions All the children with Dent disease had insidious onset, low molecular weight proteinuria is the main clinical manifestation, most cases presented with nephrotic-range proteinuria, but there was no hypoalbuminemia, some cases were not associated with hypercalciuria. The pathogenic genes in most cases were CLCN5 and a few were OCRL. The types of genetic variation include missense variant, nonsense variant, deletion variant and frameshift variant. Although Dent disease is a renal tubular disease, renal biopsy suggests that most cases are associated with glomerular lesions.

Objective To analyze the clinical diagnosis and treatment data of 20 children with hypophosphatemic rickets (HR) in order to improve the clinical diagnosis and treatment of HR.Methods The retrospective analysis of clinical data of 20 cases with HR who were hospitalized at Children's Hospital of Nanjing Medical University from May,2010 to April,2016 was performed to summarize the clinical characteristics.All patients were analyzed for the phosphate regulating gene with homologies to endopeptidase on the X chromosome(PHEX) gene by direct sequencing.If no mutations were detected,multiplex ligation-dependent probe amplification analysis was performed.Results All of the 20 cases with HR showed different degrees of growth retardation and typical X-ray rickets.After treatment,the clinical features were improved.Height standard deviation score (HSDS) was improved significantly with longer treatment time,and the difference was statistically significant(P =0.027).There was a correlation between the blood phosphorus fluctuation and secondary hyperparathyroidism(P ＜ 0.05).Nineteen cases had PHEX gene mutations.Truncating mutations was the most frequent mutation type,and 4 new mutations were found.Conclusions Clinical characteristics,laboratory test results and X-ray examination are important clinical index for the diagnosis of HR,and PHEX gene test can be used as an important auxiliary diagnostic tool.Early diagnosis and treatment can significantly improve the clinical manifestations of the patients.