Alkaptonuria is a rare disease in which a deficiency in the homogentisate 1, 2-dioxygenase enzyme results in a buildup of homogentisic acid. Ochronosis, the deposition of excess homogentisic acid in connective tissue, causes brownish-black pigmentation and weakening of the tissue ultimately resulting in chronic inflammation, degeneration, and osteoarthritis. There is currently no definitive cur...