Radiologic manifestations in alcaptonuria.

Alcaptonuria is a rare, hereditary disorder of amino acid metabolism, secondary to lack of homogentisic acid oxydase . As a consequence, there is an accumulation of homogentisic acid, which is excreted in the urine and deposited in the connective tissues. This deposition results in ochronotic pigmentation and arthropathy, of which some characteristic radiological findings are demonstrated.