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: Unknown
[{'content': 'The FMR1 protein \nSelect and explain. \nA. Is expressed in fragile X-associated mental retardation, B. Is normally found in brain and ovaries, C. When defective, is not sufficient to cause the fragile X-associated mental retardation syndrome, D. Is coded by the FMR1 gene which has the (5′-CGG-3′) n repeat segments', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The family mental retardation (FMR1) protein is normally expressed in brain and testes. It is encoded by the FMR1 gene. Amplification of the CGG region to a repeat number greater than 200 causes methylation of the CpG is land and prevents the FMR1 protein from being expressed. This defect is sufficient to cause the fragile X-associated mental retardation syndrome.', 'role': 'assistant'}]