This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mendelian Disorders: Single-Gene Defects, Subject name: Pathology
Which is false about Hurler syndrome: 
Select and explain. 
A. X linked, B. Mental retardation, C. Joint stiffness, D. Coarse facial features
A: X linked
Answer: A: X linked 
Explanation: Ans. (a) X linkedRef: Robbiris pathology 9th ed. /155* HURLER syndrome is autosomal recessive while HUNTER SYNDROME is X linked recessive* HURLER syndrome is marked by progressive deterioration, hepatosplenomegaly, dwarfism and unique facial features. There is a progressive mental retardation, with death frequently occurring by the age of 10 years* Hurler is due to defective IDUA gene, which has been mapped to the 4pl6.3 site on chromosome 4. The gene is named IDUA because of its iduronidase enzyme protein product.