Noonan Syndrome : Causes-Symptoms-Diagnosis-Treatment

 What Is Noonan Syndrome?

Noonan syndrome is a condition that some infants are born with. It causes modifications in the face and chest, typically includes heart troubles, and slightly raises a baby's risk of blood cancer (leukemia).

Noonan syndrome is a situation that influences many regions of the body. It is characterized by using mildly uncommon facial functions, quick stature, coronary heart defects, bleeding troubles, skeletal malformations, and many other symptoms and signs and symptoms.

People with Noonan syndrome have unique facial capabilities consisting of a deep groove inside the area among the nose and mouth (philtrum), widely spaced eyes that are generally pale blue or blue-green in color, and coffee-set ears which are circled backward. Affected individuals may additionally have an excessive arch inside the roof of the mouth (high-arched palate), poor teeth alignment, and a small decreased jaw (micrognathia). Many kids with Noonan syndrome have a quick neck, and each kid and adult may additionally have excess neck skin (also referred to as webbing) and a low hairline behind the neck.

What Is Noonan Syndrome?
Noonan Syndrome

Between 50 and 70 percent of people with Noonan syndrome have a brief stature. At birth, they are typically of an ordinary length and weight, but growth slows over time. Abnormal tiers of increased hormone, a protein that is necessary for the normal increase of the frame's bones and tissues, might also contribute to the slow boom.

Individuals with Noonan syndrome often have both a sunken chest (pectus excavatum) or a sticking out chest (pectus carinatum). Some affected human beings may additionally have a bizarre aspect-to-face curvature of the spine (scoliosis).

Most humans with Noonan syndrome have some shape of vital congenital coronary heart ailment. The most common heart disorder in those individuals is a narrowing of the valve that controls blood flow from the coronary heart to the lungs (pulmonary valve stenosis). Some have hypertrophic cardiomyopathy, which enlarges and weakens the heart muscle.

A sort of bleeding issue had been associated with Noonan syndrome. Some affected individuals have excessive bruising, nosebleeds, or prolonged bleeding following harm or surgical procedure. Rarely, ladies with Noonan syndrome who've a bleeding disorder have immoderate bleeding for the duration of menstruation (menorrhagia) or childbirth.

Adolescent males with Noonan syndrome typically experience delayed puberty. They go through puberty starting at age 13 or 14 and have a discounted pubertal increase spurt that results in shortened stature. Most men with Noonan syndrome have undescended testes (cryptorchidism), which may also make contributions to infertility (inability to father a baby) later in existence. Females with Noonan syndrome can revel in not on time puberty however maximum have everyday puberty and fertility.

Noonan syndrome can motivate a variety of different symptoms and signs. Most youngsters identified with Noonan syndrome have ordinary intelligence, but some have special instructional desires, and a few have highbrow incapacity. Some affected individuals have vision or hearing problems. Affected babies may have feeding issues, which usually get better by using age 1 or 2 years. Infants with Noonan syndrome can be born with puffy palms and fat because of a buildup of fluid (lymphedema), which can leave on its own. Older people can also broaden lymphedema, commonly within the ankles and lower legs.

Some people with Noonan syndrome expand cancer, specifically the ones involving the blood-forming cells (leukemia). It has been envisioned that children with Noonan syndrome have an eightfold expanded chance of developing leukemia or other cancers over age-matched friends.

Noonan syndrome is certainly one of a collection of related situations, collectively known as RASopathies. These conditions all have similar signs and symptoms and signs and are caused by modifications within the identical mobile signaling pathway. In addition to Noonan syndrome, the RASopathies encompass cardiofaciocutaneous syndrome, Costello syndrome, neurofibromatosis kind 1, Legius syndrome, and Noonan syndrome with more than one lentigine.

  1. Medical And Anatomical Concept Of The Human Body

Medical terms

  • Noonan syndrome is a genetic disorder that affects the development of many parts of the body It causes developmental delays and a wide range of medical problems including hearing and vision loss heart defects learning disabilities and delays in growth People with Noonan syndrome may have a variety of physical features such as low-set ears widely spaced eyes or a small jaw Many people with Noonan syndrome also have heart defects Because it's caused by a mutation in one particular gene Noonan syndrome can often be diagnosed by testing a sample of the patient's blood or saliva for characteristic genetic changes There is no cure for Noonan syndrome although some symptoms can be treated with medications and surgery to correct heart abnormalities In addition speech.
  • Noonan syndrome is a genetic disease that forestalls regular improvement in various parts of the frame. A character can be tormented by Noonan syndrome in an extensive form of approaches. These include unusual facial characteristics, quick stature, heart defects, other bodily issues and viable developmental delays.
  • Noonan syndrome is because of a genetic mutation and is acquired whilst a child inherits a replica of an affected gene from a parent (dominant inheritance). It also can arise as a spontaneous mutation, that means there are no family records to worry about.
  • Management of Noonan syndrome focuses on controlling the ailment's signs and complications. Growth hormone may be used to deal with quick stature in some humans with Noonan syndrome.
  • Noonan syndrome is a genetic sickness that is typically glaring at beginning (congenital). The disorder is characterized by a wide spectrum of symptoms and physical features that adjust significantly in variety and severity. In many affected people, related abnormalities include a distinct facial look; a vast or webbed neck; a low posterior hairline; a typical chest deformity and short stature. Characteristic functions of the pinnacle and facial (craniofacial) place may consist of extensively set eyes (ocular hypertelorism); skin folds which could cowl the eyes’ inner corners (epicanthal folds); drooping of the upper eyelids (ptosis); a small jaw (micrognathia); a depressed nasal root; a short nostril with large base; and occasional-set, posteriorly turned around ears (pinnae). Distinctive skeletal malformations are also generally present, along with abnormalities of the breastbone (sternum), curvature of the spine (kyphosis and/or scoliosis), and outward deviation of the elbows (cubitus valgus). Many babies with Noonan syndrome additionally have coronary heart (cardiac) defects, which include obstruction of proper blood drift from the decrease right chamber of the heart to the lungs (pulmonary valvular stenosis) and thickening of the ventricular coronary heart muscle (hypertrophic cardiomyopathy). Additional abnormalities may include malformations of positive blood and lymph vessels, blood clotting and platelet deficiencies, getting to know problems or mild highbrow incapacity, failure of the testes to descend into the scrotum (cryptorchidism) via the primary yr of life in affected men, and/or different signs and symptoms and findings.

In most people , Noonan syndrome is an autosomal dominant genetic disorder caused by abnormalities (mutations) in more than eight genes. The five most commonly concerned genes are: PTPN11 (50%), SOS1 (10-13%), RAF1 (5%), RIT1 (five%), and KRAS (much less than five%). Fewer people have a mutation in NRAS, BRAF, MEK2, RRAS, RASA2, A2ML1, and SOS2. Noonan-like disorders are found in affiliation with mutations in SHOC2 and CBL. Noonan syndrome due to pathogenic variations in LZTR1 can be inherited in both an autosomal dominant or an autosomal recessive way.

Noonan syndrome is a genetic disorder characterized by short stature webbing of the neck low-set ears heart defects and abnormal development of the fingers and toes It occurs in one out of 1,000 births and affects both males and females equally The most common features include learning disabilities behavioral problems and heart defects In addition to these features Noonan syndrome also causes short stature low-set ears webbed necks and underdeveloped fingernails or toenails.

Symptoms Noonan syndrome

Noonan syndrome causes a variety of symptoms and problems, relying on which body structures.Signs and signs of Noonan syndrome vary significantly among individuals and can be mild to severe. Characteristics may be associated with the specific gene containing the mutation.

Facial features

Facial look is one of the key clinical functions that results in a diagnosis of Noonan syndrome. These functions may be greater pronounced in babies and young kids, however, exchange with age. In maturity, these awesome functions turn out to be greater diffused.

Features may additionally encompass the subsequent:

  • Eyes are wide-set and down-slanting with droopy lids. Irises are pale blue or green.

  • Ears are low-set and rotated backward.

  • Nose is depressed at the top, with a wide base and bulbous tip.

  • Mouth Has a deep groove among the nose and the mouth and huge peaks within the top lip. The crease that runs from the threshold of the nostril to the corner of the mouth becomes deeply grooved with age. Teeth may be crooked, the interior roof of the mouth (palate) can be highly arched and the decreased jaw can be small.

  • Facial features May appear coarse, however appear sharper with age. The face may additionally seem droopy and expressionless.

  • Head May additionally seem large with a prominent forehead and a low hairline at the return of the top.

  • Skin may appear thin and transparent with age.

Heart disease

Many people with Noonan syndrome are born with a few shapes of coronary heart defects (congenital coronary heart disease), accounting for some of the key signs and symptoms of the ailment. Some heart problems can arise later in existence. Some forms of congenital coronary heart ailment associated with this sickness consist of:

  • Valve disorders. Pulmonary valve stenosis is a narrowing of the pulmonary valve, the flap of tissue that separates the decreased right chamber (ventricle) of the coronary heart from the artery that supplies blood to the lungs (pulmonary artery). It's the maximum not unusual coronary heart problem seen with Noonan syndrome, and it can arise by myself or with different coronary heart defects.

  • Thickening of the heart muscle (hypertrophic cardiomyopathy). This is odd growth or thickening of the coronary heart muscle that influences a few human beings with Noonan syndrome.

  • Other structural defects of the heart. The defects can involve a hollow in the wall that separates the 2 lower chambers of the coronary heart (ventricular septal defect), narrowing of the artery that includes blood to the lungs for oxygen (pulmonary artery stenosis), or narrowing of the essential blood vessel (aorta) that consists of blood from the heart to the frame (aortic coarctation).

  • Irregular heart rhythm. This can arise without or with structural heart abnormalities. Irregular coronary heart rhythm takes place in the majority of human beings with Noonan syndrome.

Growth issues

Noonan syndrome can affect normal increase. Many youngsters with Noonan syndrome don't grow at an everyday price. Issues may also include the subsequent:

  • Birth weight will likely be normal, but growth slows over time.

  • Eating difficulties may result in inadequate nutrition and poor weight gain.

  • Growth hormone levels may be insufficient.

  • The growth spurt that's usually seen during the teenage years may be delayed. But because this disorder causes bone maturity to be delayed, growth sometimes continues into the late teens.

  • By adulthood, some human beings with Noonan syndrome can also have ordinary height, but quick stature is more common.

Musculoskeletal issues

Some common issues can include:

  • An unusually shaped chest often with a sunken sternum (pectus excavatum) or raised sternum (pectus carinatum)

  • Wide-set nipples

  • Short neck, often with extra folds of skin (webbed neck) or prominent neck muscles (trapezius)

  • Deformities of the spine

Learning disabilities

Intelligence isn't affected for the general public with Noonan syndrome. However, individuals may additionally have:

  • An increased risk of learning disabilities and mild intellectual disability

  • A wide range of mental, emotional and behavioral issues that are usually mild

  • Hearing and vision deficits that may complicate learning

Eye conditions

A common signal of Noonan syndrome is abnormalities of the eyes and eyelids. These may additionally consist of:

  • Problems with the eye muscles, such as cross-eye (strabismus)

  • Refractive problems, such as astigmatism, nearsightedness (myopia) or farsightedness (hyperopia)

  • Rapid movement of the eyeballs (nystagmus)

  • Cataracts

Hearing problems

Noonan syndrome can cause hearing deficits because of nerve troubles or to structural abnormalities within the internal ear bones.


Noonan syndrome can cause excessive bleeding and bruising because of clotting defects or having too few platelets.

Lymphatic conditions

Noonan syndrome can cause problems with the lymphatic device, which drains excess fluid from the body and helps fight infection. These issues:

  • May show up before or after birth or develop in the teenage years or adulthood

  • Can be focused in a particular area of the body or widespread

  • Most commonly cause excess fluid (lymphedema) on the back of the hands or top of the feet

Genital and kidney conditions

Many people, in particular adult males, with Noonan syndrome may have issues with the genitals and kidneys.

  • Testicles. Undescended testicles (cryptorchidism) are common in males.

  • Puberty. Puberty may be delayed in both boys and girls.

  • Fertility. Most ladies broaden regular fertility. In males, however, fertility may not expand typically, often because of undescended testicles.

  • Kidneys. Kidney problems are normally slight and arise in a fairly small variety of people with Noonan syndrome.

Skin conditions

People with Noonan syndrome may additionally have pores and skin conditions, which maximum normally are:

  • Various problems that affect the color and texture of the skin

  • Curly, coarse hair or sparse hair

When to see a doctor

The symptoms and signs of Noonan syndrome may be diffused. If you think you or your infant may additionally have the disease, see your primary care medical doctor or your toddler's pediatrician. You or your infant can be referred to a geneticist or a cardiologist.

If your unborn child is at risk because of a family history of Noonan syndrome, prenatal checks can be available.

Causes Noonan syndrome

Noonan syndrome is due to a fault in certainly one of several genes. At least eight distinctive faulty genes have been related to the condition so far.

In some cases, the faulty gene related to Noonan syndrome is inherited from one of the baby's parents. The determined with the faulty gene may additionally or won't have apparent features of the circumstance themselves. Only one determined person wishes to carry the fault to bypass it and every child they've has a 50% risk of being born with the situation.

In different instances, the circumstance is caused by a brand new genetic fault that isn't always inherited from either. In those cases, the danger of the dad and mom having every other infant with Noonan syndrome could be very small. 

Read approximately the reasons for Noonan syndrome.

Noonan syndrome is caused by a genetic mutation. These mutations can occur in multiple genes. Defects in those genes motivate the manufacturing of proteins which might be continually energetic. Because those genes play a position in the formation of many tissues during the frame, this steady activation of proteins disrupts the ordinary system of cell boom and department.

The mutations that reason Noonan syndrome can be:

  • Inherited. Children who've one parent with Noonan syndrome who contains the defective gene (autosomal dominant) have a 50 percent threat of growing the disease.

  • Random. Noonan syndrome can broaden because of a brand new mutation in youngsters who don't have a genetic predisposition for the ailment (de novo).

Risk factors Noonan syndrome

A discern with Noonan syndrome has a 50 percent danger (one danger in two) of passing the defective gene on to his or her toddler. The infant who inherits the faulty gene can also have fewer or greater symptoms than the affected figure.

Complications Noonan Syndrome

Complications can arise that can require unique interest, which include:

  • Developmental delays. If your baby is affected developmentally, she or he may also have difficulty with employer and spatial experience. Sometimes the developmental demanding situations are substantial enough to require a unique plan to address your toddler's learning and academic wishes.

  • Bleeding and bruising. Sometimes the immoderate bleeding, not unusual in Noonan syndrome, isn't determined until someone has dental work or surgical procedure and stories of excessive bleeding.

  • Lymphatic complications. These generally contain excess fluid that is stored in numerous places within the frame. Sometimes fluid can acquire within the area across the coronary heart and lungs.

  • Urinary tract complications. Structural abnormalities in the kidneys may also increase the risk of urinary tract infections.

  • Fertility issues. Males may additionally have a low sperm count and other fertility troubles due to undescended testicles or testicles that do not characterize nicely.

  • Increased risk of cancer. There can be a multiplied risk of developing sure types of cancer, inclusive of leukemia or positive kinds of tumors.

Prevention Noonan Syndrome

Because a few cases of Noonan syndrome occur spontaneously, there may be no acknowledged manner to save you. However, when you have a family record of this syndrome, communicate to your doctor about the benefits of genetic counseling earlier than when you have children. Noonan syndrome can be detected with molecular genetic checking out.

If Noonan syndrome is detected early, it is feasible that ongoing and complete care can also lessen a number of its complications, together with coronary heart disorder.

There isn't any way to save you Noonan syndrome. Genetic mutations, either inherited from dad and mom or happening spontaneously, motive Noonan syndrome.

A diagnosis of Noonan syndrome is usually made after a doctor observes some key signs, but this can be difficult because some features are subtle and hard to identify. Sometimes, Noonan syndrome isn't diagnosed until adulthood, only after a person has a child who is more obviously affected by the condition. Molecular genetic testing can help confirm a diagnosis.

If there's evidence of heart problems, a doctor who specializes in heart conditions (cardiologist) can assess the type and severity.

How long can you live with Noonan syndrome?

  • Noonan syndrome is a genetic disorder that affects the growth development and function of many parts of the body It can affect one or more family members though it tends to run in families Some people with Noonan syndrome live well into adulthood while others have shortened life spans Though there are no known treatments for Noonan syndrome there are ways to manage its symptoms.
  • Treatment for Noonan syndrome is aimed at managing symptoms and preventing complications This is often accomplished with medications counseling and physical therapy In severe cases of this disorder heart surgery may be required to treat the heart defects that accompany it Children with Noonan syndrome typically require lifelong monitoring by a cardiologist.

Can Noonan syndrome be prevented?

Yes Many of the conditions that cause Noonan syndrome are genetic and therefore can be inherited from a parent However this does not mean that every child born to a parent with Noonan syndrome will have the disorder The risk is highest for siblings who have the same changes in genes as the affected child but parents with one child with Noonan syndrome can typically have other children without passing on the condition.

Does Noonan syndrome affect the brain?

Noonan syndrome is a genetic disorder that affects the heart and other parts of the body It is caused by a defect in one of the genes responsible for coding proteins which are used to make up body tissues such as muscle and bone While Noonan syndrome causes some physical abnormalities it does not affect a person's brain function or personality.

Can you detect Noonan syndrome before birth?

The doctors used two different genetic tests to see if the couple's baby had a genetic disorder Noonan syndrome First they tested for a deletion on chromosome 16 that causes the Noonan syndrome They also looked for an extra piece of chromosome 13 in the baby’s cells If both of these tests were negative then it was highly unlikely that their child had Noonan syndrome.

At what age is Noonan syndrome diagnosed?

Noonan syndrome is a genetic disorder that can affect growth eyes heart and blood vessels Most cases of Noonan syndrome are diagnosed in infancy or early childhood In some cases the disorder is not diagnosed until adulthood Symptoms of Noonan syndrome include short stature learning disabilities heart defects abnormal facial features and a webbed neck.

Diagnosis Noonan syndrome

A doctor can diagnose Noonan syndrome with a physical examination and an assessment of the symptoms. In a few newborn infants, Noonan syndrome is often suspected by using the baby’s look.

The doctor may additionally order checks to discover genetic mutations or to search for coronary heart defects.

A prognosis of Noonan syndrome is commonly made after a health practitioner observes a few key signs and symptoms, however this could be difficult due to the fact a few functions are diffused and hard to discover. Sometimes, Noonan syndrome is not diagnosed till adulthood, handiest after someone has a baby who's more manifestly affected by the condition. Molecular genetic testing can assist confirm a diagnosis.

If there is proof of heart problems, a medical doctor who specializes in coronary heart situations (cardiologist) can investigate the kind and severity.

The doctor will:

  • ask about the family history of genetic conditions

  • do an exam

  • consider other genetic disorders with similar symptoms

Treatment Noonan syndrome

Doctors deal with patients consistent with their particular symptoms and their reasons. For instance, many human beings living with Noonan syndrome get hold of medications, surgery and supportive cures like compression garments for lymphedema. Treatment may also involve healthcare providers from several specialties operating together to manage the signs.

Although there's no way to restore the gene changes that cause Noonan syndrome, treatments can help minimize its consequences. In advance an analysis is made and treatment is begun, the extra the advantages.

Treatment of the signs and complications that arise with Noonan syndrome depends on type and severity. Many of the health and physical troubles associated with this syndrome are treated as they would be for everybody with a similar health trouble. Taken together, though, the many issues of this disorder require a coordinated team technique.

Recommended tactics may additionally encompass:

  • Heart treatment. Certain drugs may be powerful in treating some styles of coronary heart problems. If there's trouble with the heart's valves, surgical operation may be important. The health practitioner also can also endorse that heart characteristics be evaluated periodically.

  • Treating low growth rate. Height must be measured three instances a year until 3 years of age and then once each year till maturity to ensure she or he is growing. To compare vitamins, the health practitioner will in all likelihood request blood assessments. If your toddler's increased hormone levels are inadequate, growth hormone therapy can be a treatment option.

  • Addressing learning disabilities. For early adolescence developmental delays, ask the medical doctor about toddler stimulation packages. Physical and speech therapies may be beneficial for addressing a variety of possible troubles. In some instances unique schooling or individualized teaching strategies can be suitable.

  • Vision and hearing treatments. Eye exams are endorsed at the least each two years. Most eye troubles may be treated with glasses on my own. Surgery may be wanted for a few conditions, consisting of cataracts. Hearing screenings are advocated yearly for the duration of formative years.

  • Treatment for bleeding and bruising. If there is a record of easy bruising or immoderate bleeding, avoid aspirin and aspirin-containing products. In some cases, docs may also prescribe tablets that help the blood to clot. Notify your doctor before any approaches.

  • Treatment for lymphatic problems. Lymphatic problems can arise in many ways and might not require treatment. If they do require treatment, your doctor can recommend appropriate measures.

  • Treatment for genital problems. If one or both testicles have not moved into proper position within the first few months of existence (undescended testicle), surgical procedure may be wished.

Other reviews and everyday follow-up care can be endorsed depending on precise problems, for instance, everyday dental care. Children, young adults and adults ought to maintain ongoing, periodic reviews by way of their fitness care expert.

Coping and support

A variety of help groups are available for humans with Noonan syndrome and their households. Talk to your doctor about locating a guide organization to your area. Also ask approximately honest assets on the internet which could direct you to nearby guide groups and assets of information about Noonan syndrome.

  1. Child medical and psychological care

Preparing for your appointment

If it is suspected that you or your child has Noonan syndrome, you're in all likelihood to start by means of seeing your number one care doctor or your toddler's pediatrician. However, depending on the signs and symptoms and symptoms, you or your toddler can be noted as a consultant — for example, a heart specialist or a geneticist.

Here's some data that will help you get equipped on your appointment. If viable, convey a family member or friend with you. A depended on associate allows you to not forget information and provide emotional guidance.

What you can do

Before the appointment, make a list of:

  • Signs or symptoms that concern you

  • Any medications, Which include nutrients, herbs, over-the-counter medicines or different dietary supplements, and the doses

  • Questions to ask the doctor to make the most of your appointment

Some questions to ask might include:

  • Do the symptoms indicate Noonan syndrome?

  • What tests are needed to confirm the diagnosis?

  • Are there other possible causes?

  • What other problems might occur because of Noonan syndrome?

  • What's the best course of action for treating and managing these problems?

  • What are the alternatives to the primary approach that you're suggesting?

  • Do you recommend seeing a specialist?

  • Are there brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions during the appointment.

What to expect from your doctor

Your doctor may ask questions such as:

  • When did you first notice that something may be wrong?

  • What signs and symptoms have you noticed?

  • Do you have any family history of Noonan syndrome?

  • Do you have any family members who've had congenital heart disease, bleeding problems or short stature?

General summary

  1. Noonan syndrome is an autosomal dominant genetic disorder that causes physical and developmental abnormalities The most common feature associated with this condition is a short neck which may appear to be absent of collarbones Other signs and symptoms can include dysmorphic facial features heart defects blood vessel problems cognitive impairment and learning disabilities Although there is no cure for Noonan syndrome it can often be managed through prescription medications surgical interventions and lifestyle changes Treatments are targeted to the specific symptoms and complications that affect the individual patient.

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