Marfan Syndrome Essay

Marfan syndrome is a multisystem disorder resulting with clinical manifestations typically involving the skeletal, ocular, and cardiovascular systems. Skeletal abnormalities of Marfan syndrome include disproportionate overgrowth of the long bones, anterior chest deformity due to overgrowth of the ribs, and overgrowth of the fingers. A reduced upper-segment to lower-segment ratio to arm span to height ratio of greater than 1.05 due to the overgrowth of the arms and leg is also a major criterion for Marfan syndrome (Judge& Dietz, 2005). A major criterion for clinical manifestations in the ocular system is ectopia lentis (dislocation of the ocular lens). Although this condition is not unique to Marfan syndrome, ectopia lentis have been reported to be present in around 60% of patients with the disorder. Therefore, individuals with Marfan syndrome maybe at risk of retinal detachment and are predisposed for early cataracts or glaucoma. (Judge& Dietz, 2005). According to Otto (2013) typical clinical manifestations in the cardiovascular system include dilation, aneurysm formation and rupture of the peripheral arteries, multivalvular prolapse (especially mitral valve prolapse), and
dilation and dissection of the aorta. For the clinical cardiovascular manifestations, echocardiography may be used to confirm or exclude suspicions of the diagnosis of Marfan syndrome in patients. Furthermore, since Marfan syndrome is a heritable disorder, echocardiography may also be used to screen first-degree relatives of an affected individual (Otto, 2013). Classic echocardiographic findings include dilation of the aortic annulus, aortic root, sinuses of Valsalva, and ascending aorta, with a loss or undefined sinotubular junction (Otto, 2013). According to Armstrong and Ryan (2010), dilation and weakening of the aorta maybe a result of cystic medial necrosis, which is a degeneration of the medial layer of the aorta. The most common site of dilation are the sinuses of Valsalva, however, patients with Marfan syndrome are at risk of aneurysm formation at any point in the aorta. Therefore, echocardiographic evaluation of the proximal aorta should be done symmetrically with additional measurements made at the level of the annulus, sinuses, sinotubular junction, and proximal ascending aorta (Armstrong & Ryan, 2010). The dilation or enlargement of the aorta at the sinuses of Valsalva with normal aortic dimensions above the sinotubular junction is called annuloaortic ectasia or effacement (Reynolds, 2013). Since the aortic cusps insert at the level of the sinotubular junction, effacement or dilation of the sinotubular junction would cause malcoaptation of the cusps resulting in aortic regurgitation (Armstrong & Ryan, 2010). The full spectrum of echocardiographic findings also includes the presence of mitral valve prolapse, which is commonly found in Marfan syndrome.
According to Keane and Pyeritz (2008), the prevalence of mitral valve prolapse associated with Marfan syndrome is far higher than that of isolated mitral valve prolapse found the general public. The mitral valve leaflets typically appear diffusely thickened and buckling behind the mitral annulus. As a result, mitral regurgitation is not uncommon to appear. However, mitral regurgitation may not be visualized in occasions where there is predominant aortic regurgitation, which causes a volume overload and dilation of the left ventricle, reducing the anatomic appearance of mitral valve prolapse and presence of mitral regurgitation (Armstrong & Ryan,
2010).