Alkaptonuria in 17-month-old female child: a case report

ABSTRACT

Alkaptonuria is a rare inborn metabolic disorder with Mendelian recessive inheritance characterized by triad of homogentisic aciduria, arthritis and ochronosis. The incidence is one per 0.25 - 1 million persons. A 17-month- old female child of non-consanguineous parents presented with darkening of clothes / diapers moistened with urine when left unwashed for hours. There was no other medical problem in the family. Physical examination including joints revealed a healthy child with normal growth parameters. There was no pigmentation of the sclera, conjunctiva and cornea and ear cartilage. Her urine appeared normal colored on voiding. However, it turned black on standing at room temperature. Regular laboratory investigations were within normal range and skeletal survey showed no degenerative changes. Urine for alkalization and reducing substances was positive. Urine organic acidogram-chromatogram study showed [1137.87%] 2845-fold increase in homogentisic acid and confirmed the diagnosis of alkaptonuria. She was started on Vitamin C [0.5 gm twice a day]. She is now asymptomatic over a 13-month follow-up period