Background: Nephropathic cystinosis is an autosomal recessively
inherited metabolic disorder presenting with metabolic acidosis,
Fanconi syndrome and renal failure. Case Presentation: We present a
6-year-old girl with severe growth failure, hyponatremia and
hypokalemia. Her parents were 4th degree relatives. Two relatives were
diagnosed as end stage renal failure. She also had persistant
hypokalemic hypochloremic metabolic alkalosis. Her renal function was
normal at presentation. She was thought to have Bartter syndrome with
supporting findings of elevated levels of renin and aldosterone with
normal blood pressure, and hyperplasia of juxtaglomerular apparatus.
Her metabolic alkalosis did not resolve despite supportive treatment.
At 6th month of follow-up proteinuria, glucosuria and deterioration of
renal function developed. Diagnosis of cystinosis was made with slit
lamp examination and leukocyte cystine levels. At 12th month of
follow-up her metabolic alkalosis has converted to metabolic acidosis.
Conclusion: In children presenting with persistant metabolic alkalosis,
with family history of renal failure, and parental consanguinity,
cystinosis should always be kept in mind as this disease is an
important cause of end stage renal failure which may have features
mimmicking Bartter syndrome