Marfan’s Syndrome

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Tall stature with disproportionately long limbs

• Ectopia lentis

• Aortic aneurysms, dissection, and aortic regurgitation

• Mitral valve prolapse with regurgitation

GENERAL CONSIDERATIONS

• Autosomal dominant disorder (1 per 5000–10,000) with multisystem involvement

• Affects the skeleton (long thin extremities), eye (ectopia lentis), and cardiovascular system (aortic aneurysms) from mutation in a gene on chromosome 15 that encodes fibrillin

• Mitral valve prolapse secondary to redundancy of the leaflets and the chordae (in 60–80%)

• Severe mitral regurgitation in 25% of patients

• Aortic root dilatation and aortic regurgitation

• Ascending aorta occurs with increasing frequency at a diameter of 50 mm

• Pregnancy increases the risk of dissection, particularly in the third trimester

  • – Low risk if root diameter is < 40 mm

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Chest pain, back pain

• Dyspnea, fatigue

• Palpitations

PHYSICAL EXAM FINDINGS

• Diastolic murmur of aortic regurgitation

• Midsystolic click and late systolic murmur of mitral valve prolapse

• Tall stature, limbs disproportionately long, arm span > height

• Pectus carinatum and scoliosis

• Arachnodactyly

• Ratio of upper body height to lower body height < 0.93 (divided at symphysis pubis)

• High, arched palate

• Ectopia lentis

DIFFERENTIAL DIAGNOSIS

• Loeys-Dietz syndrome

• Ehlers-Danlos syndrome

• Shprintzen-Goldberg syndrome

• Familial aortic aneurysm

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Presence of an FNB1 gene mutation (fibrillin gene)

ELECTROCARDIOGRAPHY

• Signs of left heart chamber enlargement

IMAGING STUDIES

• Echocardiographic findings that may be seen:

  • – Aortic root dilation involving the sinuses of Valsalva

  • – Aortic dissection

  • – Mitral valve prolapse

  • – Calcified mitral annulus

  • – Dilated main pulmonary artery

  • – Aortic regurgitation

• MRI or CT: ideal for imaging aortic aneurysms and dissection

DIAGNOSTIC PROCEDURES

• Slit-lamp exam of the eyes for lens dislocation

TREATMENT

CARDIOLOGY REFERRAL

• Suspected cardiovascular involvement

• Pregnancy

• Aortic dissection

HOSPITALIZATION CRITERIA

• Aortic dissection

• Heart failure

• Significant arrhythmias

MEDICATIONS

• Beta blockers to prevent or delay aortic root dilatation (recommended but efficacy not established)

• Angiotensin receptor blockers to prevent aortic root dilatation have shown promise, but there are no clear guidelines at this point.

SURGERY

• Surgical replacement of aorta with preservation of native aortic valve (either prophylactic at aortic root diameter of > 50 mm or treatment for dissection)

• Mitral valve surgery if mitral regurgitation is severe and patient has symptoms

MONITORING

• ECG monitoring in hospital as appropriate