Which one of the following is true about the genetics of aortopathies?A. Marfan syndrome is an X-linked recessive disorder
Marfan syndrome has dominant inheritance. Having a first-degree relative with the condition is a major criterion in the Ghent nosology for the diagnosis of the condition. Fifty per cent of patients with Turner’s syndrome have congenital cardiovascular disease, including bicuspid aortic valves, coarctation, and dilated ascending thoracic aorta. Routine screening for these pathologies has been advised by the ACC/AHA. Assessing aortic dilatation in patients with Turner’s syndrome is difficult owing to their small stature. However, if the definition of a dilated ascending aorta is taken as a ratio of ascending to descending aortic diameters of >1.5:1, then 33% of patients with Turner’s syndrome have dilated ascending aortas. Only the vascular form or Ehlers–Danlos type IV is associated with aortic aneurysm formation. The disease is caused by defects in the gene that encodes the synthesis of collagen III (COL3A1 gene). It is dominantly inherited, although it can present sporadically, and is characterized by joint hypermobility, lax skin, and tissue friability. 125 spot mutations for the fibrillin gene are known. Matrix metalloproteinase is important in extracellular metabolism and increased expression of the gene encoding this has been seen in patients with thoracic aortic disease.