AIMS: To investigate the natural history of mitral valve and aortic 
abnormalities in patients with Marfan syndrome during childhood and adolescence.
METHODS: Fifty two patients with Marfan syndrome were followed for a mean of 7.9 
years. Occurrence of adverse cardiovascular outcomes was measured clinically and 
by ultrasound examination.
RESULTS: Mitral valve prolapse (MVP) was diagnosed in 46 patients at a mean age 
of 9.7 years, more than 80% of whom presented as "silent MVP". Mitral 
regurgitation (MR) occurred in 25 patients, aortic dilatation in 43, and aortic 
regurgitation (AR) in 13. Both MVP and aortic dilatation developed at a constant 
rate during the age period 5-20 years. In 23 patients MVP was diagnosed before 
aortic dilatation, in 18 the reverse occurred, and in 11 patients the two 
abnormalities were diagnosed simultaneously. During follow up, 21 patients 
showed progression of mitral valve dysfunction; progression of aortic 
abnormalities occurred in 13. Aortic surgery was performed in 10; two died of 
subsequent complications. Mitral valve surgery was performed in six. In sporadic 
female Marfan patients the age at initial diagnosis of MVP, MR, aortic 
dilatation, and AR was lowest, the grade of MR and AR most severe, the time 
lapse between the occurrence of MVP and subsequent MR as well as between 
dilatation and subsequent AR shortest, and the risk for cardiovascular 
associated morbidity and mortality highest.
CONCLUSIONS: During childhood and adolescence in Marfan syndrome, mitral valve 
dysfunction as well as aortic abnormalities develop and progress gradually, 
often without symptoms, but may cause considerable morbidity and mortality by 
the end of the second decade, especially in female sporadic patients.