<prompt> Which of the following is false about alkaptonuria?Genitourinary system not involvedHomogentisic acid oxidase deficiencyBlack urineCalcification in vertebral bodies  <response>: a. Genitourinary system not involvedRef: Nelsons 20e p 636-642, Ghai 8e p 653-655Genitourinary 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. 