The most prevalent (common) signs are highlighted in bold with frequency listed in parentheses.
By organ system
Heart
- 2/3 of patients have one of the following heart defects:
- Pulmonary Valvular Stenosis —''(50%)''
- Septal defects: atrial —''(10%)'' or ventricular —''(less common)''
- Heart murmur
- Cardiomyopathy
Gastrointestinal System
- Failure to thrive as an infant
- Decreased appetite
- Digestive problems
- Frequent or forceful vomiting
- Swallowing difficulties
Genito-urinary system
- Cryptorchidism (undescended testicles) — ''(almost all males)''
Lymphatic system
- Posterior cervical Hygroma (webbed neck)
- Lymphedema (build-up of body fluid due to poor functioning of the lymphatic system)
Developmental
- Clumsiness
- Poor coordination
- Motor delay
- Mental retardation ''—(1/3 of patients have mild MR)''
- Learning disabilities
- Speech and language delays
Musculoskeletal
- Some patients with Noonan Syndrome suffer from severe joint pain or muscle pain often with no identifiable cause
Hematologic
- Easy bruising
- Amegakaryocytic Thrombocytopenia (low platelet count)
- Blood Clotting Disorders
- Von Willebrand disease
- Prolonged activated partial thromboplastin time
- Partial deficiency of Factor VIII:C
- Partial deficiency of Factor XI:C
- Partial deficiency of Factor XII:C
- Combined Coagulation deficiencies
Neurological
Arnold Chiari Malformation (Type 1) has been noted in some patients with Noonan Syndrome
By physical appearance
Stature/Posture
- Short stature
- Cervical (neck) spine fusion
- Scoliosis
- Prominence of breast bone (pectus carinatum)
- Depression of breast bone (pectus excavatum)
- Joint contractures or tightness
- Joint hyperextensibility or looseness
- Growth retardation
- Winging of the scapula
- Hypotonia (low muscle tone)
Head
- Excess skin on the back of the neck
- Low hairline at the nape of the neck
- High hairline at the front of the head
- Large head
- Triangular face shape
- Broad forehead
- Short neck, webbed neck, posterior cervical
- Curly hair
Eyes
- Widely set eyes (hypertelorism) —''(95%)''
- Drooping of the eyelids (ptosis)
- Epicanthal folds (extra fold of skin at the inner corner of the eye)
- Proptosis (bulging eyes)
- Refractive visual errors
- Inward or outward turning of the eyes (strabismus)
- Nystagmus - jerking movement of the eyes
Nose
Ears/hearing
- Low set ears —''(over 90%)''
- Backward rotated ears —''(over 90%)''
- Thick helix of ear (outer rim) —''(over 90%)''
- Incomplete folding of ears
- Chronic Otitis media (ear infections)
Mouth/speech
- Deeply grooved philtrum (top lip line) —''(over 90%)''
- Micrognathia (undersized lower jaw)
- High Arched palate
- Dental problems
- Articulation Difficulties
- Poor tongue control
Limbs/extremities
- Bluntly ended fingers
- Extra padding on fingers and toes
- Edema of the back of hands and tops of feet
- Cubitus valgus (elbow deformity: with abnormal turning-in)
Skin
- Lymphedema (swelling of the extremities)
- Keloids (scar hypertrophy)
- Hyperkeratosis - overdevelopment of outer skin layer
- Pigmented nevi (birthmark)
Further Reading
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"Noonan syndrome"
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