Alkaptonuria

Researchers are studying alkaptonuria, a rare genetic disorder where a pigment called homogentisic acid builds up in bones and connective tissue. This causes arthritis, bone fractures, and discoloration in the ears and eyes. Some patients also develop kidney stones and heart valve problems. The study aims to gather detailed medical information about alkaptonuria using modern technology to better understand the disease and prepare for future drug trials. Participants with alkaptonuria who are at least two years old will be evaluated every 2 to 3 years during 3 to 5 day visits at the NIH Clinical Center. During visits, patients undergo medical history review, physical exams, blood and urine tests, including 24-hour urine collections to measure homogentisic acid and assess kidney and bone health. Additional tests may include X-rays, ultrasounds, CT and MRI scans, heart and lung function tests, and hearing assessments. Consultations with specialists like dentistry, ophthalmology, cardiology, and others occur as needed. Throughout the study, researchers collect photographs and perform genetic studies to analyze DNA and collagen markers. The goal is to define clinical and laboratory features of alkaptonuria, track disease progression, and identify useful outcome measures for future research. This long-term observational study helps doctors better advise patients and supports the development of new treatments. Participation involves periodic comprehensive evaluations over several years.