Alkaptonuria in an adolescent boy.

Abstract

Alkaptonuria is a rare genetic disorder resulting in abnormality of tyrosine metabolism. It is one of the Garrod's tetrad of 'inborn errors of metabolism' proposed to have Mendelian recessive inheritance. The disorder is characterised by deposition of homogentisic acid leading to ochronosis and ochronotic osteoarthropathy; however, blackish discoloration of urine is the only childhood manifestation. Other manifestations present only after third decade. A 13-year-old boy presented to paediatric nephrology clinic with blackish discolouration of urine since infancy. Examination revealed bluish black discolouration of bilateral sclera and ear cartilage; however, he had no symptoms of ochronotic osteoarthropathy. Genetic test pointed towards alkaptonuria. Currently, he is on regular follow-up and is being treated with vitamin C to delay the progression of the disease. Early diagnosis with appropriate intervention delays the onset of complications and preserves the quality of life of the patient.

• Authors: Geminiganesan Sangeetha, Senthil Chandran, Swathi Ganesan, Jaippreetha Jayaraj
• Journal: BMJ case reports (BMJ Case Rep) Vol. 14 Issue 2 (Feb 04 2021) ISSN: 1757-790X [Electronic] England
• PMID: 33541951 (Publication Type: Case Reports, Journal Article)
• Copyright: © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.

Chemical References

• Antioxidants
• Ascorbic Acid

Topics

• Adolescent
• Alkaptonuria (diagnosis, genetics)
• Antioxidants (administration & dosage)
• Ascorbic Acid (administration & dosage)
• Disease Progression
• Early Diagnosis
• Humans
• Male
• Ochronosis (complications)
• Sclera