What congenital disorder is mitral valve prolapse frequently identified in?

Mitral Valve Prolapse is Most Frequently Identified in Marfan Syndrome

Mitral valve prolapse is most frequently identified in Marfan syndrome, a connective tissue disorder caused by mutations in the FBN1 gene. 1, 2 This association represents a significant cardiovascular manifestation that requires monitoring due to its potential impact on morbidity and mortality.

Prevalence and Significance

Mitral valve prolapse (MVP) is extremely common in patients with Marfan syndrome:

• Approximately 67-68% of patients with Marfan syndrome have echocardiographic evidence of mitral valve dysfunction, primarily manifesting as mitral valve prolapse 3, 4
• MVP is more common in women with Marfan syndrome (73.3%) compared to men (59.9%) 4
• The prevalence of MVP in Marfan syndrome is significantly higher than in the general population, making it a distinguishing feature of this disorder

Pathophysiology

The high prevalence of MVP in Marfan syndrome is directly related to the underlying genetic defect:

• Marfan syndrome results from mutations in the FBN1 gene, which encodes fibrillin-1, an essential component of extracellular matrix microfibrils 1, 5
• These mutations lead to weakened connective tissue throughout the body, including the mitral valve apparatus
• The defective fibrillin-1 causes myxomatous degeneration of the mitral valve leaflets, leading to redundancy and prolapse 3

Clinical Implications

The presence of MVP in Marfan syndrome has important clinical implications:

• Serious mitral regurgitation develops in approximately one in eight patients with Marfan syndrome by the third decade of life 3
• Patients with MVP who require mitral valve surgery are more likely to also need aortic root replacement (73.2% vs 42.6%) and have a higher risk of type B aortic dissection (25.0% vs 11.8%) 4
• Women with Marfan syndrome and MVP tend to require mitral valve surgery at a younger age than men (35.4 vs 43.0 years) 4

Diagnostic Considerations

When evaluating patients with MVP, consider Marfan syndrome if the following features are present:

• Tall stature with disproportionately long limbs (arachnodactyly)
• Pectus excavatum or other chest wall deformities 2
• Scoliosis
• Ectopia lentis (dislocated lens)
• Aortic root dilation
• Family history of Marfan syndrome or sudden cardiac death

Management Approach

For patients with Marfan syndrome and MVP:

1. Regular echocardiographic monitoring to assess:

   • Progression of mitral regurgitation
   • Development of left atrial enlargement
   • Aortic root dimensions

2. Antibiotic prophylaxis for endocarditis prevention in appropriate cases

3. Consider surgical intervention when:

   • Severe mitral regurgitation develops
   • Left ventricular function begins to deteriorate
   • Symptoms of heart failure appear

4. Coordinate timing of mitral valve surgery with potential aortic root surgery, as these conditions often progress in parallel 4

Important Distinctions

The natural history of MVP in Marfan syndrome differs from idiopathic or familial MVP:

• MVP in Marfan syndrome is more likely to progress to severe regurgitation requiring surgical intervention 3
• The risk of complications is higher, including the need for valve replacement and association with aortic pathology 4
• The condition should be viewed as part of a systemic disorder rather than an isolated cardiac finding 6

By recognizing the strong association between MVP and Marfan syndrome, clinicians can provide appropriate screening, monitoring, and intervention to reduce morbidity and mortality in this patient population.