Signs and symptoms
The most common signs leading to the diagnosis of Noonan syndrome are unique facial characteristics and musculoskeletal features. The facial characteristics are most prominent in infancy, becoming less apparent with age in many people with Noonan syndrome. Head
Some of the characteristic features of Noonan syndrome include a large head with excess skin on the back of the neck, low hairline at the nape of the neck, high hairline at the front of the head, triangular face shape, broad forehead, and a short, webbed neck. In the eyes, hypertelorism (widely set eyes) is a defining characteristic, present in 95% of people with Noonan syndrome. This may be accompanied by epicanthal folds (extra fold of skin at the inner corner of the eye), ptosis (drooping of the eyelids), proptosis (bulging eyes), strabismus (inward or outward turning of the eyes), nystagmus (jerking movement of the eyes) and refractive visual errors. The nose may be small, wide, and upturned. The development of the ears and auditory system may be affected in people with Noonans syndrome. This can result in low-set ears (in over 90%), backward-rotated ears (over 90%), thick helix (outer rim) of ear (over 90%), incomplete folding of ears, chronic otitis media (ear infections), and hearing loss. Development of the mouth may also be affected in Noonan syndrome. This can result in deeply grooved philtrum (top lip line) (over 90%), micrognathia (undersized lower jaw), high arched palate, articulation difficulties (teeth dont line up) which can lead to dental problems.
Prognosis is therefore largely dependent on the presence or absence of cardiac disease, as well as the type and severity of the disease (if disease is present). Most notably, Noonan syndrome with hypertrophic cardiomyopathy is associated with increased mortality. History
Jacqueline Noonan was practicing as a pediatric cardiologist at the University of Iowa when she noticed that children with a rare type of heart defect, valvular pulmonary stenosis, often had a characteristic physical appearance, with short stature, webbed neck, wide spaced eyes, and low-set ears. Both boys and girls were affected. These characteristics were sometimes seen running in families but were not associated with gross chromosomal abnormalities. She studied 833 people with Noonan syndrome at the congenital heart disease clinic, looking for other congenital abnormalities, and, in 1963, presented a paper: "Associated non-cardiac malformations in children with congenital heart disease". This described 9 children who in addition to congenital heart disease had characteristic facial features, chest deformities and short stature. Dr. John Opitz, a former student of Dr. Noonans, first began to call the condition "Noonan syndrome" when he saw children who looked like those whom Dr. Noonan had described. Dr. Noonan produced a paper titled "Hypertelorism with Turner Phenotype" in 1968 where she studied 19 patients who displayed symptoms indicative of Noonans Syndrome. In 1971, at the Symposium of Cardiovascular defects, the name Noonan syndrome became officially recognized. References


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