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Nursing Guide to Noonan Syndrome: Nursing Diagnosis, Interventions, & Care Plans

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Updated On 9 Minute Read

As a genetic disorder, Noonan syndrome affects many systems of the body. It is characterized by distinct facial features, short stature, congenital heart defects, developmental delays, and skeletal abnormalities. This condition is part of a group of related disorders called RASopathies, which are caused by mutations affecting the RAS-MAPK signaling pathway involved in cell growth and development. 

Noonan syndrome can be inherited in an autosomal dominant pattern or occur as a de novo mutation. Nurses help identify clinical features, coordinate care with genetic and medical specialists, support patients and families by providing education through developmental and psychosocial challenges.

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Etiology and epidemiology 

Noonan syndrome is caused by mutations in one of several genes that regulate the RAS-MAPK signaling pathway, a key mechanism that controls cell division, differentiation, and apoptosis. The most affected gene is PTPN11, accounting for approximately 50% of cases. Other implicated genes include SOS1, RAF1, KRAS, NRAS, BRAF, and LZTR1.  

These mutations result in gain-of-function alterations that lead to excessive or inappropriate activation of the pathway, disrupting normal tissue and organ development. Each gene mutation is associated with varying phenotypic features and severity, and identifying the causative gene can assist in early diagnosis and management planning. 

Inheritance 

In most cases, Noonan syndrome follows an autosomal dominant inheritance pattern, which means that only one copy of the mutated gene can produce the disorder. Many cases arise from de novo mutations, where there is no previous family history, especially in families with one affected child and unaffected parents. 

An individual with Noonan syndrome has a 50% chance of passing the mutation to their children, regardless of sex. Genetic counseling can help families understand inheritance risks, recurrence probability, and options for prenatal diagnosis. 

Epidemiology 

  • Estimated prevalence is approximately 1 in 1,000 to 2,500 live births globally. 
  • Noonan syndrome affects both male and female patients and occurs across all racial and ethnic groups. 
  • There is marked variability in clinical presentation, even among affected members of the same family. Some individuals may be diagnosed in infancy due to congenital heart disease, while others are diagnosed later in childhood due to subtle dysmorphic features or growth concerns. 

Clinical features 

  • Distinctive craniofacial features, including hypertelorism (wide-set eyes), epicanthal folds, ptosis, low-set posteriorly rotated ears, and down-slanting palpebral fissures, and facial characteristics may become less pronounced with age. 
  • Short stature, typically below the third percentile for age, is often evident by early childhood despite normal birth weight and length. 
  • Webbed neck, low posterior hairline, and a broad or shield-like chest. 
  • Deformities to the chest, such as pectus excavatum (sunken chest) or pectus carinatum (protruding chest). 
  • Congenital heart defects are present in up to 80% of cases, with pulmonary valve stenosis being the most common, and others may have atrial septal defects, hypertrophic cardiomyopathy, or other structural abnormalities. 
  • Developmental delays are present, ranging from mild to moderate, and may include delayed milestones, learning disabilities, and speech-language delays. 
  • Coagulopathy or bleeding diathesis due to factor deficiencies, platelet function abnormalities, or von Willebrand disease manifests as easy bruising, prolonged bleeding, or postoperative hemorrhage. 
  • Cryptorchidism (undescended testes) presents in males, which contributes to potential fertility concerns later in life. 
  • Lymphatic abnormalities, such as peripheral lymphedema or chylothorax, are especially evident in infancy or during illness. 

Diagnostic evaluation 

  • Include comprehensive physical examination to assess phenotypic characteristics and growth trends, and reviewing three-generations of family history 
  • Cardiac evaluation including echocardiogram and electrocardiogram (EKG) to assess for structural and electrical heart anomalies 
  • Growth monitoring with syndrome-specific growth charts and bone age assessment via radiography to evaluate skeletal maturity 
  • Coagulation studies including PT, aPTT, platelet function tests, and factor assays to identify bleeding risks 
  • Genetic testing via chromosomal microarray analysis or next-generation sequencing panels targeting known RASopathy-associated genes, particularly PTPN11, SOS1, and RAF1 
  • Developmental screening tools such as the Ages and Stages Questionnaire (ASQ) or Denver II, followed by neuropsychological testing if concerns are identified, to assess cognitive, speech, and motor skills, and lead to individualized therapy planning 

ICD-10 code 

  • Q87.1 — Congenital malformation syndromes are predominantly associated with short stature (includes Noonan syndrome)

Management 

Management is multidisciplinary and tailored to the individual's clinical presentation, with the primary aim of addressing medical complications, supporting development, and optimizing long-term quality of life. 

Medical management 

  • Cardiology: Frequent monitoring of congenital heart defects with echocardiograms and EKGs; management may include beta-blockers, valve repair, or other cardiac interventions depending on the severity. Throughout life ongoing cardiology follow-up is essential. 
  • Endocrinology: Monitor growth parameters and assess for growth hormone deficiency. Growth hormone therapy can be considered in children with significantly short stature, following bone age assessment and evaluation of contraindications. 
  • Hematology: Evaluate for coagulation disorders, such as factor XI deficiency or von Willebrand disease. Avoid medications that impair platelet function, such as NSAIDs. Preoperative planning should include hematologic assessment to reduce bleeding risk. 
  • Gastroenterology: Manage feeding difficulties and gastroesophageal reflux in infancy using nutritional support, positioning strategies, or pharmacologic treatment. Monitor for failure to thrive. 
  • Ophthalmology and audiology: Schedule regular screening for refractive errors, strabismus, and sensorineural or conductive hearing loss. Early identification of sensory deficits supports better developmental outcomes. 

Supportive therapies 

  • Physical therapy: This is recommended for infants and children with hypotonia and gross motor delays. Therapy focuses on improving strength, posture, and coordination to support ambulation and independence. 
  • Occupational therapy: This aids in developing fine motor skills, sensory processing, and adaptive behaviors essential for self-care and academic participation. 
  • Speech and language therapy: This is essential for managing speech delays, articulation issues, and social communication difficulties. May also address feeding and swallowing concerns. 
  • Educational support: Implement individualized education plans (IEPs) with accommodations for learning and attention difficulties. Early intervention services should be initiated in preschool years to maximize developmental potential. 
  • Genetic counseling: This offers families detailed information about the condition, recurrence risk, and reproductive options. Counselors also assist in interpreting genetic test results and providing psychosocial support. 

Monitoring and follow-up 

  • Growth and development: Do regular tracking using Noonan syndrome-specific growth charts, with monitoring of puberty onset and skeletal maturation. 
  • Cardiac evaluations: Complete annual or biennial assessments depending on cardiac findings, or more frequently if symptoms progress. 
  • Neurodevelopmental monitoring: Use ongoing assessments to identify cognitive, emotional, and behavioral needs. Coordinate with psychology or neurodevelopmental specialists to support social-emotional development and adaptive functioning in home and school environments. 

Nursing care plan 

Nursing care for individuals with Noonan syndrome requires a holistic and proactive approach tailored to the complex and multisystemic nature of the condition. Nurses serve as coordinators of care, educators, and advocates, addressing not only the physical aspects, such as cardiac monitoring and growth assessment, but also the developmental, emotional, and educational needs of the child and family. Early recognition of potential complications and close collaboration with interdisciplinary teams promotes optimal outcomes and quality of life. 

Nursing considerations 

  • Promote growth and development through regular surveillance, age-appropriate sensory and motor activities, and early referrals to developmental services. 
  • Educate families on the genetic basis of Noonan syndrome, including inheritance patterns, testing options for relatives, and family planning considerations. 
  • Monitor for complications such as heart murmurs, signs of congestive heart failure, excessive bruising, prolonged bleeding, respiratory distress, or feeding intolerance, particularly in infancy. 
  • Advocate for early intervention services, speech and occupational therapy access, and development of individualized education plans (IEPs) in collaboration with school staff and therapists. 

Assessment 

  • Measure height, weight, and head circumference, comparing to Noonan-specific growth curves. Monitor for growth velocity and pubertal delay. 
  • Observe for characteristic physical traits such as ptosis, hypertelorism, and chest wall abnormalities, along with tone, gait, and coordination. 
  • Evaluate cardiac function (heart sounds, rhythm, oxygen saturation) and respiratory effort (work of breathing, breath sounds). 
  • Screen for bruising, petechiae, prolonged bleeding, or delayed wound healing, especially post-procedure. 

Nursing diagnosis/risk for 

  • Risk for delayed growth and development related to congenital abnormalities, feeding difficulties, and hypotonia 
  • Risk for impaired cardiac output related to congenital heart defects such as pulmonary stenosis or hypertrophic cardiomyopathy 
  • Risk for impaired family coping due to chronic care demands and psychosocial stressors associated with managing a rare genetic disorder 
  • Risk for injury related to bleeding disorders and poor coordination during physical activity. 

Interventions: 

  • Facilitate multidisciplinary referrals and ensure care continuity among cardiology, endocrinology, hematology, and developmental specialists. 
  • Provide anticipatory guidance to families on how to recognize early signs of cardiac decompensation (e.g., fatigue with feeding, cyanosis) or coagulopathy (e.g., excessive bleeding after minor trauma). 
  • Coordinate with educators, school nurses, and support staff to ensure that learning challenges, fatigue, or therapy needs are addressed in the classroom. 
  • Promote structured, safe play and exercise routines that foster development while minimizing injury risk, especially in children with joint laxity or poor balance. 

Expected outcomes 

  • The patient maintains or improves developmental trajectory in accordance with individualized goals. 
  • The family articulates understanding of Noonan syndrome, including routine care requirements and emergency precautions. 
  • Potential complications are promptly recognized, reported, and managed to prevent escalation. 
  • The patient and family demonstrate increased confidence and self-efficacy in daily management of the syndrome. 

Individual/caregiver education 

  • Understand that Noonan syndrome varies in expression. Children with the same diagnosis may have very different needs. 
  • Emphasize adherence to follow-up care, especially cardiac assessments, growth monitoring, and developmental evaluations. 
  • Educate families on subtle signs of health concerns, such as feeding refusal, fatigue, unexplained bruising, or academic changes that may reflect underlying issues. 
  • Provide resources and strategies for navigating the special education system, including advocacy for services and accommodations under IDEA or Section 504. 
  • Reinforce messages of inclusion, promoting age-appropriate independence, peer interaction, and positive self-image in children with visible or functional differences. 

FAQs

Resources 

References 

Jennifer Oh, BSN, RN

Jennifer Oh, BSN, RN

Jennifer Oh, BSN, RN, has worked in med-surg telemetry and case management in Temple, Texas. She enjoys the opportunity to help the patients and families and wants to share her insights and experience with other nurses to help them on their journey toward success in the field.