alkaptonuria in a middle-aged female

background: alkaptonuria (aku) or ochronosis is a rare progressive degenerative arthropathy that results from deficiency of enzyme homogentisate 1,2 dioxygenase (hgd). the features include arthritis of the spine and in larger peripheral joints, with chondrocalcinosis. in this paper, we present a case of alkaptonuria in a 54 year old woman in tehran, iran. case presentation: a 54 year old woman with pain and limitation of motion in hip and lumbar spine was admitted in firoozgar hospital, tehran. the problem began about 12 years ago with a history of darkening of urine and discoloration of sclera and ears. in imaging studies, there were degenerative changes in spine. in urine examination, the darkening of urine after exposure to air or bicarbonate found. alkaptouria was confirmed by demonstrating an increased homogentisic acid (hga) in urine. her sister had back pain for a long period of time without response to therapy. she was subsequently diagnosed with alkaptonuria. conclusion: alkaptonuria must be considered in the evaluation of low back pain of patients especially with having a positive family history and bluish discoloration of cartilage tissues.