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
Oochronosis is found in: 
Select and explain. 
A. Alkaptonuria, B. Tyrosinemia, C. Phenylketonuria, D. Homocystinuria
A: Alkaptonuria
Answer: A: Alkaptonuria 
Explanation: a. Alkaptonuria(Ref: Nelson's 20/e p 636, Ghai 8/e p 652)Ochronosis (dark spot on sclera/ear cartilage) is seen in Alkaptonuria which is an autosomal recessive disorder due to deficiency of enzyme homogentisic acid oxidase.