Characteristics/Symptoms

Characteristic facial features:

  • Rosy coloring over face and nose
  • High prominent forehead with receding hairline
  • Down slanting eyelid openings (palpebral fissures)
  • Long narrow face
  • Prominent jaw with narrow chin and a high, narrow palate

Learning difficulties: 

  • Developmental delay
    • About 15-20% have normal intelligence
    • Ranges from mild to severe
    • IQ is in normal range (>70) in most individuals
  • Motor skill delays due to:
    • Large size
    • Hypotonia
    • Poor coordination
      • Some children will have feeding difficulties as newborns
  • Expressive language delay

Overgrowth:

  • Over 90% of children have a height and/or head circumference 2 + SD above the normal
  • Height may normalize in adulthood, but head size remains large
  • Disproportionately large hands and feet

  • Advanced bone age
  • Poor fine motor control
  • Cranial MRI/CT abnormalities
  • Joint laxity
  • Dental abnormalities
    • Soft enamel
    • Premature tooth eruption
  • Frequent upper respiratory issues
  • Behavior problems
    • Anxiety
    • Depression
    • Phobias
    • Sleep disturbances
    • Tantrums
    • Irritability
    • Stereotypies
    • Inappropriate speech
    • Withdrawal
    • Hyperactivity

  • Feeding difficulties
  • Reflux
  • Dislocated hips/club feet
  • Autonomic dysfunction
    • Flushing
    • Excessive sweating
    • Poor temp control
  • Congenital cardiac anomalies – about 20%
  • Renal anomalies
  • Scoliosis – about 40%
  • Seizures – about 30%
  • Constipation
  • Eye problems
    • Astigmatism
    • Cataracts
    • Myopia
    • Nystagmus
    • Strabismus
  • Conductive hearing loss
  • Thyroid disorders
  • Glucose intolerance
  • Hemihypertrophy (uneven limb length or body mass on one side)
  • Neoplasms and cancers (rare)