This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Mental retardation is not a feature of one of the following Mucopolysaccharidosis? 
Select and explain. 
A. Hurler MPS-I, B. Hunter MPS -II, C. Sanfillipo MPS -III, D. Morquio MPS --IV
D: Morquio MPS --IV
Answer: D: Morquio MPS --IV 
Explanation: Features of Morquio MPS-IV:HepatosplenomegalySkeletal dysplasia, odontoid hypoplasiaCorneal cloudingGranulated neutrophilsAoic valve diseaseNo mental retardation(Ref: Harrison's 18/e p2452, table 355-1)