This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Keratoconus is seen in: March 2010 
Select and explain. 
A. Patau syndrome, B. Down syndrome, C. Turner syndrome, D. Weber syndrome
B: Down syndrome
Answer: B: Down syndrome 
Explanation: Ans. B: Down syndrome