Medullary sponge kidney associated with distal renal tubular acidosis in a 5-year-old girl

Introduction Medullary sponge kidney (MSK) is characterized by cystic dilatation of the inner medullary collecting ducts, which causes the kidneys to resemble a sponge.Case report Although distal renal tubular acidosis (dRTA) is commonly observed in patients with MSK, we report a 5-year-old girl with MSK who had features of both dRTA (nephrocalcinosis, hypercalciuria, hypocitraturia) and proximal tubular dysfunction (hyperuricosuria, impaired tubular phosphate reabsorption and proteinuria).Discussion Metabolic acidosis, hypercalciuria, hypocitraturia, tubular phosphate reabsorption and growth retardation in the patient improved with alkali therapy.