Marfan Syndrome

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Basics

Description

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

Pediatric Considerations
Careful monitoring, as described. Early surgical intervention may reduce the degree of scoliosis.

Pregnancy Considerations

  • Manage pregnancy in MFS as high risk with a cardiologist; prepregnancy evaluation: screening transthoracic echocardiogram for aortic root dilation
  • Consider β-blockers in all pregnancies to minimize risk of aortic dilation throughout the pregnancy.
  • 1% complication rate if aortic root diameter <40 mm; 10% if >40 mm. Consider elective surgery before pregnancy if >47 mm.
  • 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 FBN1 (fibrillin) gene. Fibrillin is an extracellular matrix protein widely distributed in elastic and nonelastic connective tissue.

Genetics

  • >1,000 mutations have been identified in the FBN1 gene on chromosome 15q21.1 OMIM 154700 (2).
  • MFS is an autosomal dominant condition with complete penetrance and variable expressivity. Apparent nonpenetrance may be due to lack of recognition of MFS in a mildly affected individual.
  • FBN1 mutations have been identified in 92% of patients with MFS (3).
  • 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.

General Prevention

Prenatal diagnosis in families with a known mutation

Commonly Associated Conditions

  • High prevalence of obstructive sleep apnea in MFS; may be a risk factor for aortic root dilatation
  • Increased prevalence of migraine in MFS

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Basics

Description

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

Pediatric Considerations
Careful monitoring, as described. Early surgical intervention may reduce the degree of scoliosis.

Pregnancy Considerations

  • Manage pregnancy in MFS as high risk with a cardiologist; prepregnancy evaluation: screening transthoracic echocardiogram for aortic root dilation
  • Consider β-blockers in all pregnancies to minimize risk of aortic dilation throughout the pregnancy.
  • 1% complication rate if aortic root diameter <40 mm; 10% if >40 mm. Consider elective surgery before pregnancy if >47 mm.
  • 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 FBN1 (fibrillin) gene. Fibrillin is an extracellular matrix protein widely distributed in elastic and nonelastic connective tissue.

Genetics

  • >1,000 mutations have been identified in the FBN1 gene on chromosome 15q21.1 OMIM 154700 (2).
  • MFS is an autosomal dominant condition with complete penetrance and variable expressivity. Apparent nonpenetrance may be due to lack of recognition of MFS in a mildly affected individual.
  • FBN1 mutations have been identified in 92% of patients with MFS (3).
  • 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.

General Prevention

Prenatal diagnosis in families with a known mutation

Commonly Associated Conditions

  • High prevalence of obstructive sleep apnea in MFS; may be a risk factor for aortic root dilatation
  • Increased prevalence of migraine in MFS

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