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
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? 
Select and explain. 
A. Ehlers-Danlos syndrome, B. Werner's syndrome, C. Laurence-Moon-Biedl syndrome, D. Marfan syndrome
D: Marfan syndrome
Answer: D: Marfan syndrome 
Explanation: The presentation in the question is of a patient with Marfan syndrome.
• Marfan syndrome is caused by a mutation in a single allele of the fibrillin gene (FBN1).
• The gene product is a major component of elastin-associated microfibrils. Long, thin extremities; ectopia lentis, and aortic aneurysms are the classical triad.
• Mutations in the FBN2 gene can also cause Marfan syndrome, but without aneurysms