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: Pathology
[{'content': "A 22-year-old man has features of arm span greater than height, subluxated lenses, flattened and dilation of the aortic most likely diagnosis is? \nSelect and explain. \nA. Ehlers-Danlos syndrome, B. Werner's syndrome, C. Laurence-Moon-Biedl syndrome, D. Marfan syndrome", 'role': 'user'}, {'content': 'Answer: D \nExplanation: The presentation in the question is of a patient with Marfan syndrome.\n• Marfan syndrome is caused by a mutation in a single allele of the fibrillin gene (FBN1).\n• The gene product is a major component of elastin-associated microfibrils. Long, thin extremities; ectopia lentis,\xa0and aortic aneurysms are the classical triad.\n• Mutations in the FBN2 gene can also cause Marfan syndrome, but without aneurysms', 'role': 'assistant'}]