Table 7.

Treatment of Manifestations in Individuals with Noonan Syndrome

Manifestation/
Concern
TreatmentConsiderations/Other
Short stature GH therapy may be considered.
  • No standard dose has been established.
  • No apparent correlation between dosage used & final height, though earlier age at initiation of GH therapy is assoc w/↑ final adult height.
  • Short stature due to NS is an FDA-approved indication for GH treatment.
  • No evidence supports ↑ prevalence of neoplasm, cardiac, or other comorbidities in those treated w/GH. 1
Feeding
difficulties
Consideration of nasogastric tube feedings in infants w/poor growth, esp if they have a congenital heart defect or cardiomyopathyInvasive intervention (i.e., placement of gastrostomy tube) may be needed, though feeding issues are often self-limited.
DD/ID See Developmental Delay / Intellectual Disability Management Issues.
Psychiatric/
Behavioral
Standard treatment for ADHD & any neuropsychiatric features &/or behavioral problemsReferral to a neurodevelopmental specialist or psychiatrist, depending on age, may be considered.
Congenital heart defects Standard treatment per cardiologistPulmonary valve stenosis treated w/percutaneous balloon pulmonary valvuloplasty has a higher reintervention rate vs pulmonary valve stenosis w/o NS but is still considered 1st-line treatment. 2
HCM Standard treatment per cardiologistHCM is assoc w/substantial early mortality; infants presenting before age 6 mos in congestive heart failure have worst prognosis (2-yr survival of 30%). 3
Cryptorchidism Standard treatment per urologist
Renal anomalies /
Hydronephrosis
Standard treatment per urologist &/or nephrologist
Bleeding
diathesis
Standard treatment per hematologist
  • Specific treatment for serious bleeding may be guided by knowledge of a factor deficiency or platelet aggregation anomaly.
  • Factor VIIa has also been used in an infant w/NS who had normal platelet count & prothrombin & partial thromboplastin times to control severe postoperative blood loss due to gastritis. 4
Abnormal
vision &/or
strabismus
Standard treatment(s) as recommended by ophthalmologistCommunity vision services through early intervention or school district
Hearing Hearing aids may be helpful; as per otolaryngologist.Community hearing services through early intervention or school district
Chiari
malformation
Standard treatment per neurosurgeon
Juvenile
myelomonocytic
leukemia & other
malignancies
Standard treatment per oncologist
Family/
Community
  • Ensure appropriate social work involvement to connect families w/local resources, respite, & support.
  • Coordinate care to manage multiple subspecialty appointments, equipment, medications, & supplies.
  • Ongoing assessment of need for palliative care involvement &/or home nursing
  • Consider involvement in adaptive sports or Special Olympics.

ADHD = attention-deficit/hyperactivity disorder; DD/ID = developmental delay / intellectual disability; GH = growth hormone; HCM = hypertrophic cardiomyopathy; NS = Noonan syndrome

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2.
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From: Noonan Syndrome

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