The Dark Side of the Heart: Cardiovascular Manifestation of Ochronosis.

Alkaptonuria is rare genetic disorder of tyrosine metabolism manifesting with signs of tissue pigmentation, dark urine, and ochronotic arthropathies. Commonly undiscovered by late adulthood, alkaptonuria can manifest as cardiac ochronosis with cardiovascular disorders such as valvulopathies, but rarely coronary artery disease. This case report describes 2 patients with aortic stenosis and coronary artery disease in whom alkaptonuria was diagnosed during open heart surgery.