Noonan syndrome: structural abnormalities of the mitral valve causing subaortic obstruction

Area of Science:

• Cardiology
• Genetics
• Pediatrics

Background:

• Noonan syndrome is a genetic disorder associated with various congenital anomalies.
• Cardiac defects are common in Noonan syndrome, affecting a significant proportion of affected children.
• Mitral valve anomalies can contribute to significant cardiovascular complications.

Purpose of the Study:

• To investigate the prevalence and types of mitral valve anomalies in children with Noonan syndrome.
• To assess the role of echocardiography in diagnosing cardiac defects, specifically left ventricular outflow tract obstruction, in this population.
• To explore the potential link between extracellular matrix anomalies and cardiac defects in Noonan syndrome.

Main Methods:

• Retrospective analysis of echocardiographic data from 41 children with classic Noonan syndrome.
• Detailed examination of mitral valve morphology and function.
• Assessment for left ventricular outflow tract obstruction and other cardiac anomalies.

Main Results:

• 27 out of 41 children (66%) had cardiac anomalies.
• 8 patients (19.5%) presented with mitral valve congenital anomalies, including atrioventricular canal defects and anomalous mitral valve insertion.
• 5 patients (12%) exhibited significant left ventricular outflow tract obstruction due to mitral valve abnormalities.

Conclusions:

• Mitral valve anomalies are a significant feature in children with Noonan syndrome.
• Echocardiography is the primary diagnostic tool for identifying these anomalies and associated left ventricular outflow tract obstruction.
• Anatomical assessment of the mitral valve is essential for managing left ventricular outflow tract obstruction in Noonan syndrome.