The purpose of this study is to gain a better understanding of alkaptonuria and collect medical data on patients who may later participate in new drug trials for this rare genetic disease. In alkaptonuria, a pigment called homogentisic acid collects in bone and connective tissue, causing arthritis and eventually bone fractures, and also causes discoloration in the ears and whites of the eyes.
Some patients also develop kidney stones and heart valve problems.
Patients with alkaptonuria who are at least one month old may be eligible for this study. Participants will be evaluated at NIH's Clinical Center for 5 to 7 days every 1 to 2 years. They will have a medical history, physical examination, routine blood and urine tests. Blood may also be collected to measure a type of collagen that indicates new bone formation and to analyze DNA for genetic studies. 24-hour urine collections will be done to measure organic acids and homogentisic acid excretion, assess overall kidney function, and evaluate bone metabolism.