A Patient with Cystinosis Presenting Like Bartter Syndrome and Review of Literature

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 4(th) 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 6(th) 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 12(th) 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.