How is Noonan syndrome 9 inherited?

Noonan syndrome 9 follows an autosomal dominant inheritance pattern. This means inheriting just one copy of the altered gene from either parent can cause the condition.

How is Noonan syndrome 9 diagnosed?

Information about diagnosis is currently limited for this condition.

Are there treatments for Noonan syndrome 9?

Information about treatment is currently limited for this condition.

What complications can arise from Noonan syndrome 9?

Information about specific complications related to Noonan syndrome 9 is currently limited. However, since it is a type of Noonan syndrome, individuals may experience a range of health issues. It's important to work closely with healthcare providers to monitor any potential complications that may develop.

How does Noonan syndrome 9 affect daily life?

Details about how Noonan syndrome 9 impacts daily life are not fully known. Each person may experience different challenges based on their symptoms. Families may need to adapt daily routines and seek support to help manage any difficulties that arise.

What is the life expectancy for someone with Noonan syndrome 9?

Currently, there is limited information about the life expectancy of individuals with Noonan syndrome 9. Since this condition is part of a group of similar syndromes, life expectancy may vary based on individual health factors. Regular check-ups with healthcare providers can help monitor overall health.

Are there any specialists recommended for managing Noonan syndrome 9?

Information about specific specialists for Noonan syndrome 9 is currently limited. However, individuals may benefit from seeing a team of healthcare providers, including geneticists and specialists familiar with Noonan syndrome. This team can help address the unique needs of each person with the condition.

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Noonan syndrome 9 (NS9) - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

Noonan syndrome 9

MONDO:0014691

Also known as:NS9Noonan syndrome caused by mutation in SOS2Noonan syndrome type 9

Overview

Any Noonan syndrome in which the cause of the disease is a mutation in the SOS2 gene.

GeneticsAutosomal dominant · SOS2 (chr 14)

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

Features include always present findings: Short neck, Prolonged prothrombin time, Webbed neck, and Cryptorchidism; and very common findings: Curly hair and Sparse eyebrow. 17 total HPO annotations.

Organ System	Phenotype Count	Example Features
Eyes	2	Prominent corneal nerve fibers, Ptosis

Genetic Landscape

Assembled from HGNC gene records, ClinGen gene-disease validity evidence, and ClinVar pathogenic variant data. Validity classifications reflect the strength of published evidence linking each gene to this disease.

SOS2 function has not been fully characterized.

Noonan syndrome 9 is associated with mutations in the SOS2 gene on chromosome 14.

GeneReviews

Clinical Guidance

No clinically relevant genotype-phenotype correlations for BRAF, KRAS, LZTR1, MAP2K1, MRAS, NRAS, RAF1, RASA2, RIT1, RRAS2, SOS1, or SOS2 have been identified.

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

No consensus clinical diagnostic criteria for Noonan syndrome have been published. Diagnostic scoring systems, most recently published in and embedded in the management guidelines developed by DYSCERNE in the United Kingdom , have been proposed but have not been used extensively in North America.

Suggestive Findings

Noonan syndrome (NS) should be suspected in individuals with the following clinical, laboratory, and family history findings.

Clinical findings

Source:

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for Noonan syndrome 9. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

Management guidelines have been developed by DYSCERNE, a European consortium (full text); a separate set has been published by the American Academy of Pediatrics working with the Noonan Syndrome Support Group and in the Lancet . Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with Noonan syndrome, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 6. Noonan Syndrome: Recommended Evaluations Following Initial Diagnosis

Prognosis

Based on GeneReviews surveillance recommendations, HPO phenotype frequency and severity annotations, and published prevalence estimates from Orphanet and OMIM.

GeneReviews

Surveillance Guidelines

Table 8. Noonan Syndrome: Recommended Surveillance

System/Concern

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

No clinical trials have been registered for Noonan syndrome 9.

62 publications have been identified in PubMed for Noonan syndrome 9. Research spans Epidemiology / Natural History (40%), Case Report / Case Series (19%), and Basic Science / Preclinical (19%).

Research Type	Count	% of Total
Disease patterns and progression	25	40%

Data assembled from 6 of 12 sources · Last updated Sep 17, 2026, 10:47 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

OMIM

Online Mendelian Inheritance in Man

OMIM:616559

GARD

Genetic and Rare Diseases Info Center

GARD:16137

Questions for Your Care Team

→Should I pursue genetic testing for SOS2, and what would the results mean for my family?
→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

FAQ

Frequently Asked Questions

Common questions about Noonan syndrome 9

Noonan syndrome 9 is a specific type of Noonan syndrome caused by a mutation in the SOS2 gene. It is one form of a group of conditions that share some similar features, though the exact signs and symptoms may vary among individuals. This condition is recognized by its genetic origin, and it is one of several types of Noonan syndrome. The information provided here is based on limited details about the presentation of this specific type of Noonan syndrome.

Information about symptoms is currently limited for this condition.

Noonan syndrome 9 is caused by a mutation in the SOS2 gene. This change in the gene affects how cells function, and it is the underlying reason that people with this condition show the features associated with Noonan syndrome. Genetic changes like this are the primary known cause, though other risk factors have not been detailed in published sources. Associated genes include SOS2.

← Back to All Diseases

GeneReviews

Clinical Guidance

To date, including those with a clinical and a molecular genetic diagnosis and with an estimated incidence of 1:1000-1:2500, several thousand individuals have been identified with Noonan syndrome (NS) . The following description of the phenotypic features associated with this condition is based on these reports. Table 2. Noonan Syndrome: Frequency of Select Features

Feature	% of Personsw/Feature	Comment
Eye anomalies	95%	—
Short stature	50%-70%	For age, sex, family background
Hypotonia	Majority	Can contribute to feeding problems, speech articulation issues, delayed attainment of gross motor milestones
Joint hyperextensibility	Majority	—
Pectus anomaly	Majority	Characteristic pectus deformity of the chest: pectus carinatum superiorly pectus excavatum inferiorly
Cryptorchidism in males	60%-80%	—
Congenital heart disease	50%-80%	25%-71% of affected persons have pulmonary valve stenosis, often w/pulmonary valve dysplasia.
Hearing loss	40%	May be sensorineural, conductive, or mixed
Hypertrophic cardiomyopathy	10%-29%	Half of those w/hypertrophic cardiomyopathy are diagnosed by age 6 mos.
Learning disability	25%	~10%-15% of those w/NS require special education.
Intellectual disability1	6%-23% Renal anomalies	11%
Abnormal bleeding or bruising	Bleeding: 6%-10%; bruising: majority	1. Defined as IQ 70 Prenatal features. Advanced paternal age has been observed in cohorts with simplex NS.

Source: GeneReviews — "Noonan Syndrome"

System/Concern	Evaluation	Comment
Constitutional	Measurements of growth parameters	On NS-specific growth charts; To identify those w/failure to thrive /or short stature
Endocrine	Bone age, growth hormone thyroid function studies1	In children w/short stature (height 2 SD below standard growth curve or crossing 2 major height %iles) Gastrointestinal/
Feeding	Gastroenterology / nutrition / feeding team eval	In infants w/poor weight gain, dysphagia; Eval for malrotation if persistent unexplained vomiting
Development	Developmental assessment	To incl:; Motor, adaptive, cognitive, speech-language eval; Eval for early intervention/ special education Psychiatric/
Behavioral	Neuropsychiatric eval may be considered.	For those age 12 mos: screen for behavior concerns, autism, depression, ADHD, anxiety (some symptoms may not be present until adulthood).
Cardiovascular	Echocardiogram EKG	To identify congenital heart defects, cardiomyopathy, /or cardiac conduction abnormalities
Genitourinary	Kidney ultrasound	To assess for renal anomalies; if present, referral to urologist Assessment for cryptorchidism in males
Musculoskeletal	PT/OT eval	To incl:; Assessment of gross motor fine motor skills Consider radiographs of the spine if asymmetry or scoliosis is present on physical exam.
Lymphatic	In consultation w/hematologist: bleeding history, CBC w/differential, PT/aPTT, factor XI, XII, IX, VIII, vWf, platelet aggregation testing	If initial screening was performed before age 12 mos, repeat after age 12 mos.2
Eyes	Ophthalmologic eval	To assess for amblyopia, refractive error, nystagmus, strabismus, clinically significant ptosis
Hearing	Audiologic eval	Assess for hearing loss middle ear effusion.
Integument	Full skin exam	Consider referral to dermatologist in those w/multiple lentigines requiring monitoring or significant xeroderma.3
Neurologic	Neurologic eval	To incl brain spine MRI if signs or symptoms consistent w/possible Chiari malformation Genetic
counseling	By genetics professionals4	To obtain a pedigree inform affected persons their families re nature, MOI, implications of NS to facilitate medical personal decision making Family support resources
Noonan Syndrome: Treatment of Manifestations Manifestation/Concern	Treatment	Considerations/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.
difficulties	Consideration of nasogastric tube feedings in infants w/poor growth, esp if they have a congenital heart defect or cardiomyopathy	Invasive intervention (i.e., placement of gastrostomy tube) may be needed, though feeding issues are often self-limited. DD/ID

Kisho

Noonan syndrome 9

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

OMIM

GARD

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

Clinical Guidance

Explore clinical features

Differential Diagnosis

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Recent Publications

Noonan syndrome 9

Overview

Clinical Presentation

Genetic Landscape

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

OMIM

GARD

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

What is Noonan syndrome 9?

What are the symptoms of Noonan syndrome 9?

What causes Noonan syndrome 9?

How is Noonan syndrome 9 inherited?

How is Noonan syndrome 9 diagnosed?

Are there treatments for Noonan syndrome 9?

What complications can arise from Noonan syndrome 9?

How does Noonan syndrome 9 affect daily life?

What is the life expectancy for someone with Noonan syndrome 9?

Are there any specialists recommended for managing Noonan syndrome 9?

Clinical Guidance

Explore clinical features

Differential Diagnosis

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Recent Publications