Marfan Syndrome

Description

• Marfan syndrome (MFS) is an inherited disorder of connective tissue.
• Because many features of MFS appear in the general population, diagnostic criteria (Ghent nosology) are useful for diagnosis including features with major and minor criteria (1).
• System(s) affected: musculoskeletal, cardiovascular, ocular, pulmonary, skin/integument, connective tissue (dura)

Pediatric Considerations
Early surgical intervention may reduce the degree of scoliosis. Pectus excavatum deformities can worsen during adolescent growth and may require surgical evaluation for symptomatic or cosmetic concerns.

Pregnancy Considerations

• Consider pregnancy in MFS high risk and consult with a cardiologist; screening transthoracic echocardiogram with serial monitoring
• Consider β-blockers in all pregnancies to minimize risk of aortic dilation.
• Consider elective surgery before pregnancy if aortic root diameter is >47 mm.
  • Type A aortic dissection may require urgent surgical repair; Type B aortic dissection may require medical management over surgical intervention, but treatment should be individualized.
  • Prepartum aortic root diameter 40 to 45 mm may remain stable during pregnancy (2).
• Avoid spinal anesthesia due to risk of dural ectasia.

Epidemiology

• Congenital; although clinical manifestations may be apparent in infancy, affected individuals may not present until adolescence or young adulthood.
• No gender, ethnic, or racial predilection; with advanced paternal age, a slightly increased risk of de novo mutation resulting in MFS in offspring

Incidence
1/5,000 to 1/10,000 live births

Etiology and Pathophysiology

Genetic abnormality; mutations of the fibrillin-1 (FBN1) gene.

Genetics

• MFS is an autosomal dominant condition with complete penetrance and variable expressivity.
• FBN1 mutations have been identified in 92% of patients with MFS.
• Each child of an affected parent has a 50% chance of inheriting MFS and may be more or less severely affected. 25% of cases result from de novo mutation, most of which result from de novo FBN1 mutation.

Risk Factors

Hypertension and increased BMI may increase risk of acute aortic dissection.

General Prevention

Prenatal diagnosis in families with a known mutation

Commonly Associated Conditions

• Ligamentous laxity, crowded teeth, cataracts, glaucoma, mitral valve prolapse (MVP), aortic regurgitation, and palpitations
• High prevalence of migraines, obstructive sleep apnea in MFS; may be a risk factor for aortic root dilatation