Successful Kidney Transplantation in Dent Disease

Introduction: Dent disease is a rare X-linked recessive condition due to inactivating mutation in CLCN5 or OCRL1 gene resulting in proximal tubular dysfunction that primarily affects young men characterized by low molecular weight (LMW) proteinuria, hypercalciuria, recurrent kidney stones, nephrocalcinosis and progressive kidney failure. Only ∼ 250 families have been identified with these mutations. We present a patient with Dent disease from CLCN5 mutation and kidney failure who underwent successful kidney transplantation from a living donor. Case Description: A 51-year-old male with long-standing proteinuria, recurrent kidney stones, progressive chronic kidney disease (CKD) on peritoneal dialysis for 2 years with kidney biopsy evidence for secondary focal segmental glomerulosclerosis was evaluated for kidney transplantation. His brother also was experiencing recurrent kidney stones and CKD. Genetic test on the patient revealed mutation in CLCN5 gene consistent with Dent disease type 1. Patient was not sensitized, IgG negative for CMV but positive for EBV and underwent living unrelated kidney transplantation from a 4 HLA mismatched donor who was IgG negative for CMV and positive for EBV. Thymoglobulin was used for induction followed by tacrolimus/mycophenolic acid maintenance. Patient received infection prophylaxis with acyclovir, nystatin and trimethoprim-sulfamethoxazole. There was prompt allograft function (figure1). Discussion: Our case illustrates the importance of genetic testing especially in young patients with family history of kidney disease. This will help in arriving at correct diagnosis and to advise genetic screening of immediate family members. Since end-organ damage in Dent disease is renal-limited, kidney transplantation is curative. Female family members are carriers, can have low grade LMW proteinuria and could develop future mild kidney failure. Caution should be used while evaluating female family members as potential living donors.