Darkening of urine on standing is associated with:: (A) Alkaptonuria, (B) Cystinuria, (C) Fabry's disease, (D) Tyrosinemia
Answer is A. a. Alkaptonuria(Ref: Nelson's 20/e p 636-642, Ghai 8/e p 653-655)Darkening of urine on standing is associated with Alkaptonuria, due to Homogentisic acid oxidase deficiency.