What is the most likely diagnosis if a urine sample collected for routine testing darkens on standing?
Urine turns dark on standing in alkaptonuria due to the formation of black coloured alkaptone bodies. Ref: Textbook of Biochemistry By DM Vasudevan, 3rd Edition, Page 184 ; Harper's Biochemistry, 25th Edition, Page 332
Phenylketonuria
Alkaptonuria
Maple syrup disease
Tyrosinemia