Introduction
Alkaptonuria is a rare autosomal recessive disorder that is reported to affect 1 in 250,000 individuals. 1 This disorder is due to a deficiency of homogentisate 1,2-dioxygenase which leads to an accumulation of homogentisic acid (HGA) and its derivatives within the blood and urine. Once homogentisic acid is oxidized and polymerized, the derivatives deposit into connective tissue, leading to microscopic yellow discoloration and macroscopic black pigmentation of the tissue, leading to ochronosis.2
While the involvement of the connective tissue and genitourinary system have been well documented, and are often regarded as the most common manifestations of alkaptonuria, the cardiovascular system has been shown to be severely affected in many patients with alkaptonuria as well.3 Most cases of ochronotic heart disease have reported involvement of the aortic valve, but manifestations can be extensive and affect the myocardium, coronary vessels, and internal thoracic arteries as well.4