**5. Marfan's syndrome**

Marfan's syndrome is a disorder of the connective tissue with multisystem involvement, particularly of the musculoskeletal, ocular, and cardiovascular systems [25, 26]. Mutations of the fibrillin-1 gene are believed to be responsible for this syndrome. The overall prevalence is one in 10,000 to 20,000 individuals [27]. The inheritance pattern is autosomal dominant with variable expression. In approximately 15% of cases, it may manifest sporadically [25]. Several reviews of SCD in young athletes disclosed aortic rupture in Marfan's syndrome patients (2 to 3%) as a causative factor [1, 5–7, 26, 28].

Clinical manifestations of Marfan's syndrome are tall stature with arm span >105% of the height, scoliosis, arachnodactyly, pectus deformity, hyper-extensible joints, and dislocation of the lens. They may also have glaucoma and retinal detachment. Some of the clinical features are illustrated in **Figure 18**. Cardiovascular abnormalities include mitral valve prolapse (**Figure 19**) in almost 100% of patients, some with mitral regurgitation (**Figure 19**), and aortic root dilatation (**Figures 20** and **21**) in a high percentage of patients [26, 29]. The mitral prolapse and mitral regurgitation may be appreciated on careful auscultation and confirmed by echocardiography. However, echocardiography is necessary to detect aortic root dilatation [29]; the measurements are compared with normal subjects, and *Z* scores are determined. The diagnosis of Marfan's syndrome is largely on the basis of Ghent nosology criteria [27, 30] using a mixture of major and minor clinical features and the family history. In the absence of

**Figure 18.** *A summary of clinical features of Marfan's syndrome.*

#### **Figure 19.**

*Selected video frames from apical four-chamber views demonstrating mitral valve prolapse (MP) and mitral regurgitation jet (MRJ) in a patient clinically diagnosed as Marfan's syndrome. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.*

#### **Figure 20***.*

*Selected video frame from parasternal long-axis view demonstrating measurements of the dilated aortic root in a patient clinically diagnosed as Marfan's syndrome. Note the measurements are listed at the left bottom. The* Z *scores of the dilated aortic root varied between 2.9 and 3.8.*

these criteria, a scoring system is utilized [31] for the diagnosis. Spontaneous aortic dissection has been observed. To prevent such catastrophes, surgery to replace the aortic root is suggested if the aortic diameter exceeds 5.0 cm or if the rate of growth of the aorta is more than 0.5–1.0 cm/year [30]. Beta-blocking drugs, angiotensin converting enzyme (ACE) inhibiting medications and more recently, losartan (to attenuate TGFß signaling) have been used to decrease the rate of growth of the aorta. In an attempt to prevent aortic dissection and SCD, restriction from participation from sports is generally recommended [31].

#### **Figure 21.**

*Selected video frames from parasternal long-axis view demonstrating measurements of the dilated aortic root in a patient clinically diagnosed as Marfan's syndrome. The measurements are listed at the left bottom in both 'A' and 'B'. while the Z score of the aortic valve (AV) annulus was within normal limits, the Z score of the dilated aortic sinus was +5.5.*
