Homocystinuria symptomatology collected through an international patient-report data program as a source for natural history data.

Natural history data for homocystinuria is difficult to accurately obtain due to many factors related specifically to rare disorders. HCU Network America, a non-profit organization for this patient population, utilizes a patient-driven data collection program to support research. Patients and caregivers are asked to complete surveys through the collection program, and findings are provided as deidentified data. This report outlines the symptoms that enrolled participants identified as most impactful. Follow-up surveys were requested in those areas for specific symptomatology. Patients enrolled ranged from 1 to 74 years of age and encompass an international population from 23 countries and 35 US States.