Alkaptonuria is a rare metabolic disease in which homogentisic acid (HGA), an intermediary metabolite in tyrosine catabolism, accumulates due to deficiency of the enzyme homogentisic acid oxidase. Patients with alkaptonuria exhibit homogentisic aciduria and ochronosis, or dark pigmentation of
Alkaptonuria is a rare autosomal recessive disorder in which homogentisic acid accumulates and destroys connective tissue and bone, creating a condition called ochronosis. Symptoms generally begin in the third or fourth decade and progress to incapacitating spondylosis, arthropathy, and fractures by