Samardzic et al. Journal of Medical Case Reports 2011, 5:400 http://www.jmedicalcasereports.com/content/5/1/400 C A S E R E P O R T Effect of growth hormone replacement therapy in a boy with Dent’s disease: a case report Mira Samardzic1*, Snezana Pavicevic1, Michael Ludwig2 and Radovan Bogdanovic3 Abstract Introduction: Dent’s disease is an X-linked recessive proximal tubulopathy characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and progressive renal failure. To the best of our knowledge, this is only the third report on the use of growth hormone therapy in a child with poor growth associated with Dent’s disease. Case presentation: We report on a 7-year-old Montenegrin boy with proteinuria, hypercalciuria, nephrocalcinosis, rickets and short stature with unimpaired growth hormone secretion. A molecular genetic analysis showed S244L substitution on the CLCN5 gene. After two years of conventional treatment with hydrochlorothiazide, laboratory tests revealed more prominent proteinuria, mild hypophosphatemia, increased values of alkaline phosphatase and features of rickets. Phosphate salts, calcitriol, potassium citrate and growth hormone were included in the therapy. After three years of therapy, his adjusted parental stature was 1.53 standard deviations higher than at the initiation of growth hormone therapy. His global kidney functions and levels of proteinuria and calciuria remained relatively stable. In spite of the growth hormone therapy, his tubular reabsorption of phosphate deteriorated. Conclusion: Treatment with recombinant human growth hormone may have a positive effect on final height in poorly growing children with Dent’s disease and hypophosphatemic rickets. However, it is not possible to reach definite conclusions due to the small sample within the literature and the brief duration of the therapy. JOURNAL OF MEDICAL CASE REPORTS Open Access Introduction Dent’s disease is an X-linked recessive proximal tubulo- pathy characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, and slowly progressive renal failure in affected males. Renal acidification abnormalities are only rarely seen in Dent’s disease, whereas the hypokalemic metabolic alkalosis associated with hyperreninemic hyperaldosteronism (Bartter-like syndrome) has been reported in a few patients [1]. Clinical characteristics of Dent’s disease include familial tubular syndromes such as X-linked recessive nephrolithiasis, X-linked recessive hypopho- sphatemic rickets and low-molecular weight proteinuria with hypercalciuria and nephrocalcinosis in Japanese children [2]. Dent’s disease is caused by mutations in the CLCN5 gene, which is located on the short arm of the × chromosome (Xp11.22). The CLCN5 gene * Correspondence: samardzic@t-com.me 1Institute for Sick Children, Department of Endocrinology and Nephrology, Ljubljanska bb, 20 000 Podgorica, Montenegro Full list of author information is available at the end of the article encodes for the 746 amino-acid CLC-5 chloride channel that belongs to the voltage-gated chloride channel family (CLC-7, CLC-Ka and CLC-Kb) implicated in membrane excitability, transepithelial transport and possibly the regulation of cell volume [3]. The mechanism by which CLC-5 dysfunction results in hypercalciuria and the other features of Dent’s disease remains unclear. The different clinical features of Dent’s disease makes treatment complex, and it requires simultaneous moni- toring of the effects of therapy. There is still no clear strategy for the management of patients with this condi- tion. Thiazide diuretics have been used to reduce urin- ary calcium excretion, and to prevent the recurrence of nephrolithiasis [4]. A high citrate diet preserved the renal function and delayed the progression of renal dis- ease in CLC-5 knockout mice [5]. Rickets was a promi- nent feature in about one third of patients reported with Dent’s disease. The recommended treatment is based on oral phosphate salts and calcitriol [6]. © 2011 Samardzic et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.