title: Medullary sponge kidney presenting in a neonate with distal renal tubular acidosis and failure to thrive: a case report.
abstract: BACKGROUND
  Medullary sponge kidney is a congenital anomaly characterized by diffuse ectasy of the collecting tubules of one or both kidneys. It is usually diagnosed in the second or third decade of life.
  
  
  METHODS
  Distal renal tubular acidosis is commonly observed in patients with medullary sponge kidney. We describe here a 50-day-old Egyptian Caucasian girl with medullary sponge kidney who had features of distal renal tubular acidosis, (persistent alkaline urine, hypercalciuria, hypocitraturia) and failure to thrive. Renal ultrasound revealed left renal increased medullary echogenicity and bilateral nephrocalcinosis.
  
  
  CONCLUSIONS
  Early gene(s) expression of medullary sponge kidney disease might be responsible for persistent metabolic acidosis during the neonatal period.
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Sawi
authors.forename: Abdul-Rahman
authors.initials: AR
authors.lastname: Shahein