Which of the following statements about Marfan syndrome is incorrect?

The INCORRECT Statement is C: Coarctation of the aorta and mitral stenosis

Statement C is incorrect because coarctation of the aorta and mitral stenosis are NOT typical cardiovascular manifestations of Marfan syndrome. The characteristic cardiovascular finding in Marfan syndrome is aortic root dilation, not coarctation, and mitral valve prolapse with regurgitation, not mitral stenosis 1, 2.

Analysis of Each Statement:

A) Tall stature with chest deformities - CORRECT

• Marfan syndrome characteristically presents with skeletal manifestations including tall stature and chest wall deformities
• The scoring system for systemic features includes pectus carinatum (2 points) and pectus excavatum or chest asymmetry (1 point) 1
• These skeletal features are part of the diagnostic criteria for the condition

B) Ectopia lentis and myopia - CORRECT

• Ectopia lentis (lens dislocation) is a cardinal ocular feature of Marfan syndrome
• It is specifically included in the diagnostic criteria: a dilated aortic root AND ectopia lentis can establish the diagnosis even without family history 1
• Myopia is commonly associated with the ocular manifestations 2, 3

C) Coarctation of the aorta and mitral stenosis - INCORRECT

• This is the wrong answer because these are NOT typical Marfan features
• The actual cardiovascular manifestations of Marfan syndrome are:
  • Aortic root dilation (the most critical finding) 1, 2
  • Mitral valve prolapse (MVP), not mitral stenosis 1
  • Progressive aortic regurgitation 1
• Coarctation of the aorta is actually mentioned in the guidelines as part of the Bicuspid Aortic Valve Sequence, which is a different condition that can be confused with Marfan syndrome 1
• Mitral stenosis is a valvular narrowing typically caused by rheumatic heart disease, not a connective tissue disorder

D) Mutations in the fibrillin gene (FBN1) with autosomal dominant inheritance - CORRECT

• "There is no case of classic, bona fide MFS due to mutations in a gene other than FBN1" 1
• The condition shows autosomal dominant inheritance 1, 2
• Mutations in FBN1 (encoding fibrillin-1) are the definitive genetic cause 2, 3
• About 25% of cases represent de novo mutations 2

E) Prenatal diagnosis is possible - CORRECT

• Given that FBN1 mutations can be identified in 90-95% of unequivocal cases 1
• Genetic testing for known familial mutations allows for prenatal diagnosis
• This is standard practice for autosomal dominant conditions with identified pathogenic variants

Key Clinical Pitfall:

The confusion likely arises because coarctation of the aorta can occur in families with left-sided flow defects and bicuspid aortic valve, which may have overlapping skeletal features with Marfan syndrome 1. However, these are distinct conditions. The hallmark cardiovascular finding in Marfan syndrome is progressive aortic root dilation leading to dissection risk, not coarctation or stenotic valve lesions.