Ochronotic Arthropathy and Alkaptonuria (Ochronosis): Case Report

Abstract

Alkaptonuria (AKU) is a rare genetic condition resulting from a deficiency in the homogentisic acid oxidase enzyme, which is produced by the liver and kidneys, that interferes with the metabolism of the amino acids phenylalanine and tyrosine. Although it may not cause symptoms, AKU can lead to ochronosis, the abnormal accumulation in body tissues of a pigment called alkapton. Over time, this pigment accumulation in the joints may result in secondary osteoarthritis known as ochronotic arthropathy, the most debilitating form of the disease. Since this is a rare condition, not widely discussed, we herein report a case to describe a diagnosis of ochronotic arthropathy of the knee only identified during surgery. Given the rarity of this condition, especially in Brazil, case descriptions will help understand the national epidemiology and disseminate more information about alkaptonuria and its clinical manifestations, particularly those of osteoarticular nature.

Keywords

alkaptonuria - arthropathy - ochronosis

Financial Support

The authors declare that the present research did not receive any specific funding from agencies in the public, commercial, or not-for-profit sectors.

Work carried out at the Universidade Federal Rural do Semi-Árido (Ufersa), Mossoró, RN, Brazil.

Publication History

Received: 26 February 2023

Accepted: 29 May 2023

Article published online:
23 April 2024

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