Congenital heart disease is seen in 50% and 80% of individuals with Noonan syndrome.
Pulmonary valve stenosis is the most common heart defect in Noonan syndrome, found in 20%-50% of individuals. This finding may be isolated or associated with other heart defects.
Hypertrophic cardiomyopathy is found in 20% to 30% of individuals with Noonan syndrome. The median age at diagnosis is five months and more than 50% of individuals with Noonan syndrome and hypertrophic cardiomyopathy are diagnosed by age six months.
Other structural defects frequently observed include atrial and ventricular septal defects, branch pulmonary artery stenosis, tetralogy of Fallot, and coarctation of the aorta.
An electrocardiographic (EKG or ECG) abnormality is documented in approximately 90% of individuals with Noonan syndrome and may be present without structural heart defects.
Speak to a genetic counselor or a medical geneticist to learn more about heart defects in Noonan syndrome.
