Alkaptonuria: Case report

Alkaptonuria is a rare autosomal recessive condition arising as a result of a genetic deficiency of the enzyme homogentisic acid oxidase which has a role in the metabolism of tyrosine and phenylalanine. Blue-black discoloration which developes from excessive accumulation of homogentisic acid in various tissues such as connective tissue and cartilage due to deficiency of homogentisic acid oxidase enzyme, called ochronosis. The most important causes of morbidity are ochronotic arthropathy and cardiovascular involvement seen in fourth and sixth decades. There is no definitive treatment and treatment options generally are intended to prevent complications. Herein we report a 66-year-old woman diagnosed with alkaptonuria who presented with blue discoloration in auricle and nails. Alkaptonuria is a progressive systemic disease and it should be considered in the presence of appropriate clinical findings.