Is Mitral Valve Prolapse a Congenital Condition?
Mitral valve prolapse is not typically a congenital (born with) disease, but rather a condition that develops later in life, most commonly becoming clinically manifest in the third and fourth decades of life, though it can have genetic/familial predisposition. 1
Timing of Disease Manifestation
- MVP is predominantly considered a heritable disorder with clinical manifestations not present at birth, but appearing later in life. 2
- The condition most commonly becomes clinically apparent between ages 20-40 years, with severe manifestations typically occurring after age 50. 1, 3
- In patients who eventually develop severe mitral regurgitation from MVP, the pre-existing heart murmur is first detected at an average age of 34 years, and patients remain asymptomatic for an average of 25 years before symptoms develop. 3
Etiology and Pathophysiology
MVP is mostly associated with myxomatous degeneration of the valve, which represents an acquired degenerative process rather than a congenital malformation. 4, 5
- The condition preferentially occurs in patients of tall stature and shows familial clustering, indicating genetic predisposition rather than congenital structural abnormality. 4
- Though variant genes may initiate the development of MVP, the precise phenotypic expression is related to multiple molecular, genetic, and epigenetic factors that modify disease expression over time. 2
- MVP can be familial or sporadic, isolated (non-syndromic) or part of well-defined syndromes of heritable connective tissue disorders. 2
Distinction from True Congenital Mitral Valve Abnormalities
Isolated congenital mitral valve abnormalities are relatively uncommon and are distinct entities from MVP. 4
True congenital mitral valve lesions include:
- Cleft mitral valve 4
- Double-orifice mitral valve 4
- Parachute mitral valve variants 4
- Congenital mitral valve stenosis with annular hypoplasia 4
- Supravalvular or intravalvular mitral ring 4
Key Distinguishing Features
The mitral valve prolapse seen in rheumatic fever patients differs fundamentally from the redundant, myxomatous mitral valve and prolapse seen with Barlow syndrome (classic MVP). 4
- In rheumatic valvulitis, only the coapting portion of the anterior mitral valve leaflet tip prolapses without billowing of the medial portion or body of the leaflet. 4
- In contrast, myxomatous MVP (Barlow disease) involves excessive leaflet tissue with redundant, floppy valves showing extensive myxomatous changes with collagen dissolution. 3
Clinical Implications
- MVP affects 2-3% of the general population and occurs in a heterogeneous group of patients with varying and age-dependent expressions. 2
- The condition has a wide range of phenotypic expression from asymptomatic to severe complications including mitral regurgitation requiring surgery, heart failure, arrhythmias, and sudden cardiac death. 2
- Most patients with MVP have minimal symptoms and a benign course, with the majority requiring no treatment other than reassurance. 1