How specific are the physical features of Noonan syndrome?
• The clinical features of Noonan syndrome can overlap with a number of other syndromes. In girls suspected of having Noonan syndrome, a chromosomal analysis will often be performed to rule out Turner Syndrome. Heart in Noonan syndrome patients • Heart problems occur in about two-thirds of Noonan syndrome patients, with the most common problem being an abnormal narrowing and often thickening of the pulmonary valve. • Other relatively common heart defects are atrial septal defect (ASDs), ventricular septal defect (VSDs), patent ductus arteriosus (PDA), and abnormal thickening of the heart muscle itself (hypertrophic cardiomyopathy). Problems with the pulmonary valve can be minor, requiring no intervention. • If the narrowing is significant it may require a procedure such as cardiac catheterization to dilate the narrowed area with a balloon. • Unfortunately, children with Noonan’s and pulmonary stenosis often have multiple levels of narrowing which cannot be dilated and will require hear
