Cystinuria may fairly be classed among the rarities of medical practice. Presumably the perversion of metabolism whereby cystin, one of the amino-acid fragments of the protein molecule, is not destroyed in the body as it is in a normal person, is not so uncommon as statistics might lead one to believe. As the metabolic disorder may exist for very long periods without revealing itself by any easily detected symptom other than the presence of the unutilized cystin in the urine, the discovery of the cases becomes more or less fortuitous. Only when urinary concretions arise to direct attention to their cause, or when the presence of cystin is detected by chance in a routine examination of the urine, does the anomaly come to the knowledge of those who are interested in its cause and treatment.
From the point of view of the patient the chief problem in connection with cystinuria
THE TREATMENT OF CYSTINURIA. JAMA. 1914;LXIII(5):407-408. doi:10.1001/jama.1914.02570050043018