<prompt> A 22-year-old man has features of arm span greater than height, subluxed lenses, flattened and dilation of the aortic most likely diagnosis is?Ehlers-Danlos syndromeMarfan syndromeWerners syndromeLaurence-Moon-Biedl syndrome  <response>: Ans. b Marfan syndromeRef: Robbins pathology 9th ed. 144 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; ectopial entis; and aortic aneurysms are the classical triad. Mutations in the FBN2 gene can also cause Marfan syndrome, but without aneurysms. 