FAQ - noonan syndrome
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Noonan syndrome?

I just found out today that our 16 month old son has noonan syndrome. It started when he was born with pulmonic Stenosis and then he had about 7 large birth marks on his body called café-au-lait spots. I dont know how to handle all of this he is my only son. I hope someone can relate to me or give me advice and support

I'm so sorry. I know that it's difficult to know how to deal with your child getting a diagnosis. My daughter was born with a congenital heart defect. I've heard of Noonan's but don't really know much about it other than it's associated with heart defects. This website might help you connect with other families dealing with Noonan Syndrome:

The Noonan Syndrome Support Group
http://www.noonansyndrome.org/  (+ info)

What is happening wrong inside a person who has Noonan syndrome?

Noonan Syndrome is named after Dr. Jacqueline Noonan. It is a genetic anomaly that affects somewhere between 1 in 1,000 and 1 in 2,500 births.
The main features of the syndrome include: learning problems, heart malformations, short stature, impaired clotting and indentation of the chest. Also present are a certain formation of facial features.
While it is possible to test for certain genetic markers, the syndrome is still most often diagnosed my presentation of clinical features rather than this testing.
Included is a link to the homepage for the group in support of parents/people with noonan syndrome.  (+ info)

Can anyone explain to me what noonan syndrome is, and what the symptoms are?

Background: Noonan syndrome was first recognized as a unique entity in 1963 when Noonan and Ehmke described a series of patients with unusual facies and multiple malformations, including congenital heart disease. These patients were previously thought to have a form of Turner syndrome, with which Noonan syndrome shares a number of clinical features. The observation that patients with Noonan syndrome have normal karyotypes was important in allowing the distinction to be made between the Turner and Noonan syndromes. The cardinal features of Noonan syndrome are unusual facies (ie, hypertelorism, down-slanting eyes, webbed neck), congenital heart disease (in 50%), short stature, and chest deformity. Approximately 25% of individuals with Noonan syndrome have mental retardation. Bleeding diathesis is present in as many as half of all patients with Noonan syndrome. Skeletal, neurologic, genitourinary, lymphatic, eye, and skin findings may be present to varying degrees.

Pathophysiology: The pathophysiology of Noonan syndrome is not fully understood. A disease-causing gene, PTPN11, has been identified. The gene product, SHP2, plays an important role in cardiac semilunar valve development.


In the US: The incidence of Noonan syndrome is estimated at 1 in 1000 to 1 in 2500 live births.
Internationally: The incidence of Noonan syndrome appears to be consistent worldwide.
Mortality/Morbidity: The primary source of morbidity and mortality in these patients depends on the presence and type of congenital heart disease.

Race: Noonan syndrome is panethnic.

Sex: Noonan syndrome occurs in either a sporadic or autosomal dominant fashion. In either case, males and females are affected equally.

Age: The disorder is present from birth, but age impacts upon the facial phenotype. Infants with Noonan syndrome can be difficult to recognize by facial appearance alone. The phenotype becomes more striking in early childhood, but with advancing age, it may again become quite subtle. Careful examination of an affected child's parents may in fact reveal that they are affected mildly.

CLINICAL Section 3 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

History: The prenatal history typically is unremarkable; however, some cases are complicated by polyhydramnios, fetal edema, or cystic hygroma.

A careful family history should be obtained, paying particular attention to the presence of congenital heart disease, mental retardation, short stature, or unusual facies among the parents or siblings of an affected child.
A child with mild expression of the facial phenotype might only present with developmental delay and history of congenital heart disease. A history of abnormal bleeding is present in as many as 50% of patients.

Growth parameters
Size at birth is usually within the reference range.
Short stature is present in up to 80% of patients. Average adult height for males is 5'5" and for females is 5'.
Facial features

Triangular-shaped face


Down-slanting eyes


Strabismus (48%)

Amblyopia (33%)

Refractive errors (61%)

Low-set ears with thickened helices

High nasal bridge

Short webbed neck
Chest/back features
Pectus carinatum/excavatum
Cardiac features: The characteristic lesion is dysplastic/stenotic pulmonic valve, but virtually all types of congenital heart defects have been described in patients with Noonan syndrome. Hypertrophic cardiomyopathy (obstructive and nonobstructive types) is present in up to 30% of patients.
Abdominal features: Hepatosplenomegaly unrelated to cardiac status is present in approximately 25% of patients.
Genitourinary features
Renal anomalies are present in 10% of patients but are not clinically significant.
More than half of male patients have undescended testes.
Skeletal features
Joint laxity is present in more than half of patients.
Talipes equinovarus, radioulnar synostosis, cervical spine fusion, and joint contractures are less common findings.
Skin findings


Prominent pads of fingers and toes (67%)

Follicular keratosis of face and extensor surfaces (14%)

Multiple lentigines (3%)
Neurologic findings
Seizure disorder (13%)
Unexplained peripheral neuropathy (infrequent)
Causes: Both sporadic and autosomal dominant cases have been identified. At least one disease-causing gene, PTPN11, has been found. Mutations in PTPN11 are found in approximately 59% of familial cases and in 37% of sporadic cases. DIFFERENTIALS Section 4 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Fetal Alcohol Syndrome

Other Problems to be Considered:

Fetal hydantoin syndrome
LEOPARD (multiple lentigines syndrome)
Cardio-facial-cutaneous syndrome
XO/XY mosaicism
Turner syndrome

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Fetal Alcohol Syndrome

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Patient Education
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WORKUP Section 5 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Lab Studies:

Bleeding diatheses are common among patients with Noonan syndrome. The most frequent abnormality is factor XI deficiency, but various disorders have been reported in patients with Noonan syndrome. All patients should have a CBC count with platelet count, coagulation profile, and measurement of factor XI level at the minimum.
If full phenotypic expression is not apparent, karyotyping may be necessary.
Mutation analysis may confirm the diagnosis. However, the failure to identify a germline PTPN11 mutation does not rule out Noonan syndrome. This entity remains a clinical diagnosis.
Other Tests:

Any child suspected of having Noonan syndrome requires a detailed cardiac workup. This includes ECG, echocardiogram (ECHO), and consultation with a pediatric cardiologist.
Assessment of development is necessary to identify any delays and allow for intervention. Full-scale IQ ranges from 48-130, with a mean of 86.1 (approximately 1 standard deviation [SD] below the general population mean). Approximately 25% of patients with Noonan syndrome have mental retardation.
Audiologic evaluation: The incidence of progressive high-frequency sensorineural hearing loss may be as high as 50%.
TREATMENT Section 6 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Medical Care: Growth hormone has been used to accelerate growth in some patients with Noonan syndrome. To date, no effect on final adult height has been documented.

Surgical Care: Certain types of congenital heart lesions are amenable to surgical correction.


Diet: No special dietary restrictions apply.

Activity: Activity may be limited by cardiac status and the presence of hematologic abnormalities.
MEDICATION Section 7 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

No specific pharmacologic therapy is available.

FOLLOW-UP Section 8 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Further Outpatient Care:

All patients require ongoing developmental, audiologic, and ophthalmologic follow-up. Direct other follow-up at specific findings (eg, hematology follow-up for patients with bleeding disorders).

If a causative mutation is found in the affected individual, parental studies should be offered in order to distinguish familial cases from sporadic cases. If an individual carries a germline mutation, prenatal diagnosis can be offered in future pregnancies. The presentation varies widely in families, and clear genotype-phenotype correlations have not yet been identified.
Patient Education:

Once the pattern of inheritance has been identified, parents need to be counseled regarding recurrence risk with each pregnancy. Sporadic cases present minimal recurrence risk to the siblings of the affected child; the exception is parental gonadal mosaicism. Offspring of an affected individual have a 50% chance of developing Noonan syndrome.
Patients with bleeding disorders must be advised against the use of aspirin and aspirin-containing products or other medications that may interfere with coagulation or platelet function.
MISCELLANEOUS Section 9 of 10
Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Medical/Legal Pitfalls:

Recurrence risk for parents who do not appear to be affected or who have only some facial features of Noonan Syndrome is 5%. Gonadal mosaicism may account for this increase over population risk. Affected individuals have a 50% chance of passing on the disorder with each pregnancy.
Special Concerns:

Before any patient with Noonan syndrome can undergo a surgical procedure, a full hematologic workup must be performed.
Female patients have normal pubertal development and fertility. Fertility in males with undescended testes may be decreased. For this reason, the mother is more frequently the transmitting parent in familial cases.  (+ info)

My 1st child suffers from noonan syndrome that caused her to be retarded, can this affect my 2nd child?

It could as "Recurrence in siblings and apparent transmission from parent to child has long suggested a genetic defect with autosomal dominant inheritance and variable expression." http://en.wikipedia.org/wiki/Noonan_syndrome  (+ info)

does anybody know anything about noonan syndrome?

my 7 year old son has this but i am looking for info on how to deal and cope with the behaviour problems that come with it.i hope someone can help me

Very sorry to hear that.

Try this link, and keep smiling:

http://www.noonansyndrome.org/  (+ info)

Is Noonan syndrome fatil?

I dont believe it is fatal but since it does include heart malformations the possibility is there.

Here is a web support group with many answered questions that might help you.
http://www.noonansyndrome.org/home.html  (+ info)

What is the name of the syndrome that the person may appear to have facial characteristics of down's syndrome?

I previously watched a documentary about sufferers of a syndrome whose facial features appeared to be down's syndrome but it wasn't down's syndrome. The grow to be quite large adults and have special needs. Does anyone know the name of this condition?

Klinefelter syndrome  (+ info)

Are there different types of Down syndrome and what areas of the body does Down syndrome affect? ?

Also, are there any significant statistics related to Down syndrome? Has Down syndrome received any recent attention from the media? Are there any famous people that have Down syndrome.
Answer as many of the above questions as possible.

There are three types of Down syndrome, garden variety Trisomy 21, mosaicism and translocation.

Read more at:

Welcoming Babies with Down Syndrome (English, Spanish, French)

There is a slide show that also incorporates videos of the featured 'More Alike than Different' cast at the National Down Syndrome Congress website:


And great information at the National Down Syndrome Society website:
Down Syndrome Fact Sheet

You might also enjoy

Margaret's Guide to Down Syndrome

For bios of actors with Down syndrome, see:

Down Syndrome and the Acting Gene


DS in Arts and Media


Michael Johnson


Sujeet Desai

Down Syndrome Links at the Family Village website

Check out this recent New York Times article:

The DNA Age: Prenatal Test Puts Down Syndrome in Hard Focus

Have fun with your research!
  (+ info)

What is so bad about having down syndrome?

I think people are a lot colder than they want you to believe. Too many pregnancies prediagnosed with down syndrome are terminated! Doctors tell people that their kid will be like some animal and people believe them. I've met my share of people with down syndrome, and they all seem pretty human to me. On top of that, they were all decent folks, which is a lot more than I can say for the general population. And how does knowing that unborn children are purged because of down syndrome affect those who were born and have down syndrome?

WOW!! I'm so glad that there are other people who's lives have been touched as mine has. See when I was 28 I gave birth to twin girls and one of them was born with Mosaic down syndrome. Of course, I didn't know much about it til now....and yes I was shocked. They are 14 months old now, and such a blessing as well as my two boys. My daughter is about 4 months behind in her milestones, but she is always so happy! Out of all my kids she is the easiest to handle.

It's always nice to have other people, who see that they are more alike, then different from the rest of us.  (+ info)

What is the syndrome called when you cannot feel physical pain?

I remember watching a show a long time ago, and this one little girl was born with a syndrome where she could never feel pain. If she fell on the floor and cut her knee, she wouldn't cry, whereas most children would.

What is this called? Is it a syndrome? Is it a medical condition? I just want to know what it's called, and I can do the research on it.

It is for a story I am writing but I don't entirely know what it is.

It's called "congenital insensitivity to pain"  (+ info)

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