Cystinuria is an inherited metabolic disorder characterized by abnormal transport of certain amino acids in the intestinal epithelium and proximal renal tubule. Due to the accumulation of
high concentrations of cystine in the urine and its poor solubility in water, it percipitates out and can form cystine stones. The urinary stones, that cause clinical symptoms, can occur at the age of 4-6 months. This can lead to life-threatening closure of the urinary tract.