Abnormal features of<unk>  at the age of 3 months: Note the eyebrow slant and left-side eyelid dropping. Abnormal features of<unk>  at the age of 3 months: Note the low-set, posteriorly rotated, and abnormally formed ear. The most common signs leading to the diagnosis of<unk>  are unique facial characteristics and musculoskeletal features. The facial characteristics are most prominent in infancy, becoming less apparent with age in many people with<unk> . Head Some of the characteristic features of<unk>  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<unk> . 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<unk> 's 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<unk> . This can result in deeply grooved philtrum (top lip line) (over 90%), micrognathia (undersized lower jaw), high arched palate, articulation difficulties (teeth don't line up) which can lead to dental problems. Similar to the muscular manifestations above, in the mouth, poor tongue control may be observed. Skin Skin signs and symptoms in<unk>  include lymphedema (lymph swelling of the extremities), keloid formation, excessive scar formation, hyperkeratosis (overdevelopment of outer skin layer), pigmented nevi (darkly pigmented skin spots), and connective tissue disease. Musculoskeletal Abnormalities in the limbs and extremities may occur in<unk> . This may manifest as bluntly ended fingers, extra padding on fingers and toes, edema of the back of hands and tops of feet, and cubitus valgus (wide carrying angle of the elbows). For short stature, growth hormone is sometimes combined with IGF-1 (or as an alternative, IGF-1 as a stand-alone) can be used to achieve an increased height/final height quicker. The final adult height of individuals with<unk>  is about 161–167 cm in males and 150–155 cm in females, which approaches the lower limit of normal. Spinal abnormalities may be present up to 30% of the time and this may require surgery to correct in over 60% of these cases. Other musculoskeletal manifestations in<unk>  are associated with undifferentiated connective-tissue disorders which can be associated with joint contractures (tightness) or joint hypermobility (looseness). Additional factors may present in the form of winging of the scapula, scoliosis, breast bone prominence (pectus carinatum), breast bone depression (pectus excavatum). Muscle abnormalities may present as hypotonia (low muscle tone), which may lead to lordosis (increased hollow in the back) due to poor abdominal muscle tone. Heart<unk>  is the second most common syndromic cause of congenital heart disease. This includes pulmonary valvular stenosis (50–60%), atrial septal defects (10–25%), ventricular septal defects (5–20%) and hypertrophic cardiomyopathy (12–35%). Lungs Restrictive lung function has been reported in some people. Gastrointestinal A number of diverse gastrointestinal (GI) symptoms have been associated with<unk> . These include swallowing difficulties, low gut motility, gastroparesis (delayed gastric emptying), intestinal malrotation, and frequent or forceful vomiting. These digestive issues may lead to decreased appetite, failure to thrive from infancy to puberty (75%), and occasionally the need for a feeding tube. Genitourinary system In some males with<unk> , testicles do not descend (cryptorchidism). Circulation Lymphatic anomalies including Posterior cervical hygroma (webbed neck) and Lymphedema may present in people with<unk> . A number of bleeding disorders have been associated with<unk> , these include platelet dysfunction, Blood clotting disorders, partial deficiency of factor VIII:C, partial deficiency of factor XI:C, partial deficiency of factor XII:C, and an imbalance of plasminogen activator inhibitor type-1 (PAI-1) and tissue plasminogen activator (t-PA) activity. It has been associated with Von Willebrand disease, Amegakaryocytic thrombocytopenia (low platelet count), prolonged activated partial thromboplastin time, combined coagulation defects. When present, these<unk>  accompanying disorders can be associated with a predisposition to bruise easily, or hemorrhage. Neurological Occasionally, Chiari malformation (type 1),may occur, which can lead to hydrocephalus. Seizures have also been reported.
Noonan syndrome
Growth hormone deficiency
Avellis syndrome
Williams syndrome
Muenke syndrome
Christianson syndrome
GRACILE syndrome
Sugarman syndrome