Effect of growth hormone replacement therapy in a boy with Dent's disease: a case report

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.