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