Characteristics/Symptoms

Not all people with Noonan syndrome will have all of these features.

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  • May have had surgery and/or be on medications
  • Most common deficit is pulmonary valve stenosis
  • Hypertrophic cardiomyopathy occurs in 20%
  • Lifetime cardiac follow-up is important for all

  • Final adult height approaches lower limit of normal

    • Increase in learning disabilities
    • Increase in brain differences
      • Wide array of neurologic problems
      • Seizures possible
    • Speech articulation difficulties in 72%

    • Broad neck or extra tissue at back of neck
    • Unusual shape to the chest
      • prominence at the top of the breast bone and sunken area at the bottom
      • Nipples wide spaced and low set
      • Rounded shoulders
    • Spinal abnormalities
      • Scoliosis (10-15%)
      • Less common spinal differences such as kyphoscoliosis (hunchback), spina bifida, and changes in vertebrae and ribs
    • Clubfoot 10-15%
    • Ability to hyperextend at the elbow
      • Abnormal forearm angles found in >1/2 males and females.
      • may have leg pain

    • Low set ears
    • Pale blue or blue green irises
      • Iris’ typically lighter in color
    • Wide spaced eyes with epicanthal folds (extra fold at the inner part of the eye lid) and thick or droopy eyelids
    • Lack of affect or expression

    • Problems affecting color and texture of the skin
      • Lotions or short courses of topical steroids help dry skin
      • Avoid long hot baths, perfumed soaps, and dry atmosphere
    • May have curly, coarse, or sparse hair

    • Specific testing will identify the problem and treatment if necessary.
    • May include bruising or nose bleeds, bleeding with surgery
    • Avoid aspirin unless documented that they don’t have coagulation defects

    • Poor bite in 50-66%

    • May be in one area or widespread
    • May be before or after birth
    • Overall incidence in all age groups is 20%
    • Lymphedema in the arms or legs is the most common
      • Typically resolves in first few years of life
      • Adolescents and adults can also develop peripheral lymphedema

    • Strabismus/crossed eyes
    • Refractive errors
    • Amblyopia (lazy eye)
    • Nystagmus (rhythmic movement of the eyes from side to side)

    • Present in  about 11% and are generally minor
    • Kidney swelling is most common

    • Male puberty and fertility may be normal, delayed (about age 13.5-14.5), or inadequate
    • Female puberty may be delayed
      • Mean age of first period is 13-14 years
      • Normal fertility typically