Background: Mitral valve prolapse is a relatively common valvular abnormality in most communities and joint hypermobility (JHM) is also seen in many healthy people as well as in certain clinical disorders, such as Marfan syndrome. The present study was designed to investigate the association between joint hypermobility and mitral valve prolapse (MVP) in an Iranian population sample.

Methods: Fifty-seven patients with nonrheumatic and isolated mitral anterior leaflet prolapse (24 men and 33 women, mean age 23.5 +/-2.3) and 51 healthy subjects (20 men and 31 women, mean age 22.9+/-2.3) were studied. The presence of JHM was evaluated according to the Carter-Wilkinson & Beighton criteria. Echocardiographic examination was performed in all subjects and the correlation between the echocardiographic features of the mitral valve and the hypermobility score were investigated.

Results: The frequency of JHM in patients with MVP was found to be significantly higher than that of controls (26.3% vs. 7.8%), with mean JHM scores of 3.1+/-2.2 and 1.9+/-1.7, respectively. The patients in the MVP group had significantly increased the anterior mitral leaflet thickness (AMLT, 3.4+/-0.4 mm vs. 3.0+/-0.3 mm; p<0.0005) and maximal leaflet displacement (MLD, 2.4+/-0.3 mm vs. 1.5+/-0.2 mm; p<0.0005) compared to the controls.

Conclusions: We detect a statistically significant relationship between isolated MVP and joint hypermobility as well as between the severity of JHM and echocardiographic features of the mitral leaflets. These results suggest a common etiology for MVP and JHM, which should be investigated in future well-conducted studies.