Cystine Capacity Clinical Study (CysCap)

Inclusion Criteria: * Patients with a confirmed laboratory diagnosis of cystinuria will be included in this study. There will be no age barrier to inclusion, but included patients must be able to reliably collect urine for 24 hours. Men and women will be recruited equally and there are no restrictions for racial or ethnic origin in this study. * Patient enrollment will require signing of an informed consent document approved by the Lenox Hill IRB. * For children 8-18 years of age, signing an assent to participate will also be required. Exclusion Criteria: * Patients will be excluded if they cannot sign consent or assent. * Furthermore if the patient cannot reliably collect urine for 24 hours or adhere to study follow up visit requirements.