Hereditary Tubulopathy in the Practice of a Pediatrician: A Clinical Case of Type 2 Dent’s Disease in Members of the Same Family

Dent’s disease type 2 is a rare X-linked inherited tubulopathy caused by mutations in the OCRL gene. The disease is characterized by dysfunction of the proximal renal tubules and presents with low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, disturbances in phosphate metabolism, renal osteopathy, and progressive decline in kidney function. Clinical manifestations vary depending on age at onset and severity of tubular dysfunction. In some cases, extrarenal symptoms similar to those observed in Lowe syndrome may occur. Early diagnosis plays a crucial role in timely initiation of therapy and slowing disease progression. Molecular genetic testing is essential for confirming the diagnosis, identifying the specific mutation, and providing accurate genetic counseling for the family. This article presents clinical cases of two brothers aged 9 and 7 years diagnosed with Dent’s disease type 2. Both children were followed by a pediatric nephrologist due to persistent proteinuria and hypercalciuria. Molecular genetic analysis revealed a pathogenic mutation in the OCRL gene, confirming the diagnosis. The patients are currently receiving nephroprotective therapy. These cases illustrate the diagnostic challenges associated with Dent’s disease in the absence of specific clinical signs and highlight the importance of a multidisciplinary approach. Special attention should be paid to children presenting with unexplained proteinuria and disturbances in mineral metabolism in order to promptly suspect Dent’s disease and initiate appropriate diagnostic evaluation.