Cystinosis presenting with features suggesting Bartter syndrome. Case report and literature review.

Features suggestive of Bartter syndrome (hypokalemia, hypochloremic metabolic alkalosis, and normal blood pressure despite hyperreninemia and hyperaldosteronism) were found in a 5-year-old black child with cystinosis and Fanconi syndrome. Review of his medical records revealed that these abnormalities had probably been present when he first became clinically ill at 2 years of age. Sodium and potassium chloride supplementation lead to improved growth and strength, partial correction of his electrolyte abnormalities, and a decrease in markedly elevated plasma renin activity. Literature review disclosed a similar presentation in four Caucasian children with cystinosis. Biochemical findings compatible with Bartter syndrome can occur together with evidence of generalized proximal renal tubular dysfunction (Fanconi syndrome) in nephropathic cystinosis.