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
[{'content': 'Which is false about Hurler syndrome: \nSelect and explain. \nA. X linked, B. Mental retardation, C. Joint stiffness, D. Coarse facial features', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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.', 'role': 'assistant'}]