What is Cystinuria?
Cystinuria is an inherited metabolic disorder characterized by the abnormal movement (transport) in the intestines and kidneys, of certain organic chemical compounds (amino acids). These include cystine, lysine, arginine, and ornithine. Excessive amounts of undissolved cystine in the urine (cystinuria) cause the formation of stones (calculi) in the kidney, bladder, and/or ureter. One of the peculiar things about cystinuria is that the amount of cystine excreted by the kidneys is not always related to the number and size of the stones formed. Some people with very high cystine levels form very few, if any stones. Others with comparatively low cystine levels are prolific stone formers. Diagnostic tests for cystinuria include a 24 hour urine collection to determine the levels of cystine in the urine and a one off urine sample to detect higher than normal levels of cystine in the urine. In recent years advances in genetic research have led to more information on the different types of cyst
