This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inborn Errors of Metabolism, Subject name: Pediatrics
Which of the following is false about alkaptonuria? 
Select and explain. 
A. Genitourinary system not involved, B. Homogentisic acid oxidase deficiency, C. Black urine, D. Calcification in vertebral bodies
A: Genitourinary system not involved
Answer: A: Genitourinary system not involved 
Explanation: a. Genitourinary system not involved(Ref: Nelson's 20/e p 636-642, Ghai 8/e p 653-655)Genitourinary system is also involved in Alkaptonuria, as this enzyme is expressed only in liver and kidneys; darkening of urine on standing is an important feature of Alkaptonuria.