how common is noonan syndrome
Noonan syndrome (NS) is a relatively common autosomal dominant congenital disorder that affects both males and females.It is referred to as the male version of Turner's syndrome (and is still sometimes described in this way); however, the genetic causes of Noonan syndrome and Turner syndrome are distinct.t is believed that between approximately 1 in 1,000 and 1 in 2,500 children worldwide are born with NS. It is one of the most common genetic syndromes associated with congenital heart disease, similar in frequency to Down syndrome. However, the range and severity of features can vary greatly in patients with NS.