Table of ContentsView AllTable of ContentsWhat Is Noonan Syndrome?TraitsSymptomsDiagnosisPrognosisTreatment
Table of ContentsView All
View All
Table of Contents
What Is Noonan Syndrome?
Traits
Symptoms
Diagnosis
Prognosis
Treatment
Noonan syndrome is a condition that produces characteristic physical traits (eye shape, for example) and contributes to the risk of conditions likeheart disease,bleeding disorders, and other health challenges.It affects approximately one out of 1,000 to 2,500 people.
Noonan syndrome is agenetic disorder, but not all cases are inherited. It is not associated with any particular ethnic group.While life expectancy with Noonan syndrome is typical and the condition is not life-threatening, the associated health problems are expected later in life.
This article discusses Noonan syndrome symptoms and its causes. It explains how Noonan syndrome is diagnosed and treated, and why careful health monitoring can help to limit the worst impacts.
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Noonan syndrome is anautosomal dominant genetic disease, which means that if one parent has the disease, then the child will also have the disease. There are instances of sporadic Noonan syndrome, which means that the genetic abnormality behind it can arise in a child who did not inherit the condition from their parents, too.
The genetic change alters a protein that is involved in modifying the rate at which the body grows. It functions in what’s called the RAS-MAPK (mitogen-activated protein kinase) signal transduction pathway, which is a key part of cell division. This is significant because the human body grows through the process of cell division, especially during childhood.
Cell division continues throughout life as the body repairs, regenerates, and renews. This means that problems with cell division (as with Noonan syndrome) can affect many organs throughout the body, with varying degrees of symptom severity or obviously visible changes in features. The next step after identifying signs of the condition is to find out if you or your child has Noonan syndrome.
Noonan Syndrome and GeneticsThere are four differentgene abnormalitiesthat can cause Noonan syndrome, affecting the PTPN11 gene (about 50% of cases), the SOS1 gene, the RAF1 gene, and the RIT1 gene. If a person inherits or develops any of these mutations, Noonan Syndrome is expected to occur.But it can occur in people with no known hereditary factors.
Noonan Syndrome and Genetics
There are four differentgene abnormalitiesthat can cause Noonan syndrome, affecting the PTPN11 gene (about 50% of cases), the SOS1 gene, the RAF1 gene, and the RIT1 gene. If a person inherits or develops any of these mutations, Noonan Syndrome is expected to occur.But it can occur in people with no known hereditary factors.
Noonan Syndrome Traits
While Noonan syndrome is usually associated with certain facial features and body type, there can be a wide range of how these features appear. Facial and body appearance cannot reliably determine whether someone definitely has Noonan syndrome or not.
Noonan Syndrome vs. Turner SyndromeNoonan syndrome and Turner syndrome have similarities, including their underlying genetic causes and features like short stature or a webbed neck.They occur about as often in the population, with the same potential to cause heart problems. Turner syndrome, though, only affects females and can also disrupt reproduction and fertility.
Noonan Syndrome vs. Turner Syndrome
Noonan syndrome and Turner syndrome have similarities, including their underlying genetic causes and features like short stature or a webbed neck.They occur about as often in the population, with the same potential to cause heart problems. Turner syndrome, though, only affects females and can also disrupt reproduction and fertility.
Symptoms of Turner Syndrome and How It Is Treated
Noonan Syndrome Symptoms
There are several symptoms of this condition, and they may or may not affect everyone who has Noonan Syndrome.
Diagnosing Noonan Syndrome
Noonan Syndrome Life Expectancy
Life expectancy with Noonan syndrome is generally normal, but there may be health problems that need to be addressed with medical or surgical attention.
How Is Noonan Syndrome Treated?
The treatment of Noonan syndrome is focused on several aspects of the disease.
Summary
Noonan syndrome is a fairly common genetic disorder that is typically hereditary but can occur in people whose parents do not carry the gene. Typical traits include short stature, angular head and eyes, and a thick neck.
Life expectancy is typical in people diagnosed with Noonan syndrome but they can experience life-long challenges with weak bones, heart trouble, blood clotting disorders, and more. Genetic testing, blood tests, and heart function tests contribute to an accurate diagnosis and appropriate care.
Some people who have rare diseases such as Noonan syndrome find it helpful to connect with advocacy groups and support groups. You can ask your healthcare provider about the latest experimental trials so that you can keep up to date on new treatments and research.
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Noonan syndrome.Jeong I, Kang E, Cho JH, et al.Long-term efficacy of recombinant human growth hormone therapy in short-statured patients with Noonan syndrome.Ann Pediatr Endocrinol Metab. 2016;21(1):26-30. doi:10.6065/apem.2016.21.1.26Hilal N, Chen Z, Chen MH, Choudhury S.RASopathies and cardiac manifestations.Front Cardiovasc Med. 2023 Jul 17;10:1176828. doi:10.3389/fcvm.2023.1176828.Tafazoli A, Eshraghi P, Koleti ZK, Abbaszadegan M.Noonan syndrome - a new survey.Arch Med Sci.2017;13(1):215-222. doi:10.5114/aoms.2017.64720MedlinePlus.Noonan Syndrome.Cui X, Cui Y, Shi L, Luan J, Zhou X, Han J.A basic understanding of Turner syndrome: Incidence, complications, diagnosis, and treatment.Intractable Rare Dis Res. 2018;7(4):223‐228. doi:10.5582/irdr.2017.01056
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Noonan syndrome.Jeong I, Kang E, Cho JH, et al.Long-term efficacy of recombinant human growth hormone therapy in short-statured patients with Noonan syndrome.Ann Pediatr Endocrinol Metab. 2016;21(1):26-30. doi:10.6065/apem.2016.21.1.26Hilal N, Chen Z, Chen MH, Choudhury S.RASopathies and cardiac manifestations.Front Cardiovasc Med. 2023 Jul 17;10:1176828. doi:10.3389/fcvm.2023.1176828.Tafazoli A, Eshraghi P, Koleti ZK, Abbaszadegan M.Noonan syndrome - a new survey.Arch Med Sci.2017;13(1):215-222. doi:10.5114/aoms.2017.64720MedlinePlus.Noonan Syndrome.Cui X, Cui Y, Shi L, Luan J, Zhou X, Han J.A basic understanding of Turner syndrome: Incidence, complications, diagnosis, and treatment.Intractable Rare Dis Res. 2018;7(4):223‐228. doi:10.5582/irdr.2017.01056
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Noonan syndrome.Jeong I, Kang E, Cho JH, et al.Long-term efficacy of recombinant human growth hormone therapy in short-statured patients with Noonan syndrome.Ann Pediatr Endocrinol Metab. 2016;21(1):26-30. doi:10.6065/apem.2016.21.1.26Hilal N, Chen Z, Chen MH, Choudhury S.RASopathies and cardiac manifestations.Front Cardiovasc Med. 2023 Jul 17;10:1176828. doi:10.3389/fcvm.2023.1176828.Tafazoli A, Eshraghi P, Koleti ZK, Abbaszadegan M.Noonan syndrome - a new survey.Arch Med Sci.2017;13(1):215-222. doi:10.5114/aoms.2017.64720MedlinePlus.Noonan Syndrome.Cui X, Cui Y, Shi L, Luan J, Zhou X, Han J.A basic understanding of Turner syndrome: Incidence, complications, diagnosis, and treatment.Intractable Rare Dis Res. 2018;7(4):223‐228. doi:10.5582/irdr.2017.01056
MedlinePlus.Noonan syndrome.
Jeong I, Kang E, Cho JH, et al.Long-term efficacy of recombinant human growth hormone therapy in short-statured patients with Noonan syndrome.Ann Pediatr Endocrinol Metab. 2016;21(1):26-30. doi:10.6065/apem.2016.21.1.26
Hilal N, Chen Z, Chen MH, Choudhury S.RASopathies and cardiac manifestations.Front Cardiovasc Med. 2023 Jul 17;10:1176828. doi:10.3389/fcvm.2023.1176828.
Tafazoli A, Eshraghi P, Koleti ZK, Abbaszadegan M.Noonan syndrome - a new survey.Arch Med Sci.2017;13(1):215-222. doi:10.5114/aoms.2017.64720
MedlinePlus.Noonan Syndrome.
Cui X, Cui Y, Shi L, Luan J, Zhou X, Han J.A basic understanding of Turner syndrome: Incidence, complications, diagnosis, and treatment.Intractable Rare Dis Res. 2018;7(4):223‐228. doi:10.5582/irdr.2017.01056
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